American Urological Association, Inc.® Nephrolithiasis Clinical Guidelines Panel: Report on the Management of Staghorn Calculi

Archived Document— For Reference Only

Clinical Practice Guidelines Nephrolithiasis Clinical Guidelines Panel Members and Consultants

Joseph W. Segura, M.D., Chairman Glenn M. Preminger, M.D., Facilitator The Carl Rosen Professor of Urology Professor, Department of Urology Department of Urology Duke University Medical Center The Mayo Clinic Durham, North Carolina Rochester, Minnesota Dean G. Assimos, M.D. Joseph N. Macaluso, Jr., M.D. Assoc. Professor of Surgical Sciences Medical Dir.; Dir. of Grants & Research Department of Urology Urologic Institute of New Orleans The Bowman Gray School of Medicine Assoc. Professor & Dir. of Endourology, Wake Forest University Lithotripsy & Stone Disease Winston-Salem, North Carolina Louisiana State Univ. Medical Center Stephen P. Dretler, M.D. School of Medicine Director, Kidney Stone Center New Orleans, Louisiana Massachusetts General Hospital David L. McCullough, M.D. Boston, Massachusetts William H. Boyce Professor Robert I. Kahn, M.D. Chairman, Department of Urology Chief of Endourology The Bowman Gray School of Medicine California Pacific Medical Center Wake Forest University San Francisco,Archived California Document—Winston-Salem, North Carolina James E. Lingeman, M.D. Claus G. Roehrborn, M.D. Director of Research Facilitator Coordinator Methodist HospitalFor ReferenceHanan Bell, Ph.D. Only Institute for Kidney Stone Disease Methodology and Statistical Consultant Associate Clinical Instructor in Urology Curtis Colby Indiana University School of Medicine Editor Indianapolis, Indiana Patrick Florer Computer Database Design Consultant

The Nephrolithiasis Clinical Guidelines Panel consists of board-certified urologists who are experts in stone disease. This Report on the Management of Staghorn Calculi was extensively reviewed by over 50 urolo- gists throughout the country in the Fall of 1993. The Panel finalized its recommendations to AUA’s Practice Parameters, Guidelines and Standards Committee, Chaired by Winston K. Mebust, MD, in December 1993. The AUA Board of Directors approved these practice guidelines at its meeting in January 1994. The Summary Report also underwent independent scrutiny by the Editorial Board of the Journal of Urology, was accepted for publication in March 1994, and appeared in its June issue. A guide to assist patients diagnosed with this condition has also been developed. The Technical Supplement to this Report is available upon request. The American Urological Association expresses its gratitude for the dedication and leadership demonstrat- ed by the members of the Nephrolithiasis Clinical Guidelines Panel in producing the AUA’s first explicit guide- line using the Eddy methodology. Introduction

Urologists and patients can choose from many alternatives today for management of renal and ureteral calculi. The improve- ments in urologic equipment, radiologic technology, and interven- tional radiologic techniques have dramatically increased the means available for stone removal. As a consequence, however, questions have arisen regarding applications of particular modalities to treat the various types of stone disease. To help clarify treatment issues, the American Urological Association, Inc., convened the Nephrolithiasis Clinical Guidelines Panel in 1990 and charged it with the task of producing practice recommendations based on outcomes evidence from the treatmentArchived literature. Document— The recommendations in this Report on the Management of Staghorn ForCalculi areReference to assist physicians in the Only treatment specifical- ly of struvite staghorn calculi. Although relatively uncommon, these kidney stones present serious problems because they occur in the presence of urinary tract infections and because the stones themselves are infected. Treatment must remove stones completely to eradicate all infected stone material. The choice of treatment can be a source of controversy – given the range of modalities and techniques now available, each with advantages and disadvantages. This makes struvite staghorn calculi an especially appropriate subject for evidence-based recommenda- tions. A Patient’s Guide and more detailed technical appendices are available upon request. Contents

Executive Summary: Treatment of staghorn calculi ...... 1 Methodology for development of treatment recommendations ...... 1 Background: Staghorn calculi ...... 1 Treatment outcomes and alternative modalities ...... 2 Treatment recommendations ...... 2 Limitations in the treatment literature ...... 4

Chapter 1: Methodology ...... 5 Literature search ...... 5 Article selection and data extraction ...... 6 Evidence combination ...... 6

Chapter 2: Staghorn calculi and their management ...... 9 Background ...... 9 Treatment Methods ...... 9

Chapter 3: Outcomes analysis for staghorn treatment alternatives ...... 12 Direct and indirect outcomes ...... 12 Combining outcome evidence ...... 12 The balance sheet ...... 13 Analysis of the balance sheet outcomes ...... 13

Chapter 4: StaghornArchived treatment recommendations . . .Document— ...... 19 Treatment outcomes and treatment recommendations ...... 19 The patient ...... 19 Recommendations: StandardsFor . . .Reference ...... Only ...... 20 Recommendations: Guidelines ...... 20 Recommendations: Options ...... 21 Recommendation limitations ...... 21 Basic research needs ...... 21

References ...... 22

Appendix A: Data presentation ...... A.1

Appendix B: Data abstraction worksheet ...... B.1

Appendix C: Description of available techniques for management of renal and ureteral calculi ...... C.1 Shock-wave lithotripsy ...... C.1 Percutaneous nephrolithotomy ...... C.3 Ureteroscopy ...... C.4 Open lithotomy ...... C.5

Index ...... I.1

Production and layout by

Lisa Emmons Tracy Kiely Betty Roberts

Copyright © 1994 American Urological Association, Inc. Executive Summary: Treatment of staghorn calculi

METHODOLOGY FOR DEVELOPMENT OF These stones are also called “infected stones” or TREATMENT RECOMMENDATIONS “infection stones” because they occur only in the presence of urinary tract infection and only when In developing recommendations for managing the infection is secondary to organisms that elabo- staghorn calculi, the AUA Nephrolithiasis Clinical rate the enzyme urease, which splits urea [Bruce Guidelines Panel reviewed the available literature and Griffith, 1981]. Cultures of pieces of struvite on treatment of struvite staghorn calculi. Relevant stones, taken both from the surface and from in- articles were selected for data extraction, and the side, have demonstrated that bacteria reside inside panel devised a comprehensive data-extraction the stones and that the stones themselves are in- form to capture as much pertinent information as fected – in contrast to stones made of cystine, cal- possible. Data analysis was conducted using the cium oxalate monohydrate, or other substances confidence profile method developed by Eddy and [Nemoy and Stamey, 1971]. Hasselblad [Eddy, 1989; Eddy, Hasselblad, and Shachter, 1990]. Chapter 1, “Methodology,” pro- An untreated struvite staghorn calculus will in vides a full description of the process. time destroy the kidney, and the stone has a signifi- cant chance of causing the death of the affected BACKGROUND:STAGHORN CALCULI patient [Rous and Turner, 1977; Koga, Arakai, Matsuoka, et al., 1991]. Moreover, struvite stones Staghorn calculiArchived are stones that fill the major Document—must be removed in their entirety to be certain of part of the collecting system. Typically, such eradicating all of the infected stone material. If all stones will occupy theFor renal pelvis, Reference and branches of the infected Only material is not removed, the patient of the stone will extend into the majority of the will continue to have recurrent urinary tract infec- calices. The term “partial staghorn” is often used tions and the stone will eventually regrow. It may when a lesser portion of the collecting system is be possible to sterilize small amounts of struvite, occupied by stone. There is, unfortunately, no but how much of the stone can be sterilized is un- agreement on how these terms should be defined, certain and unpredictable [Pode, Lenkovsky, Sha- and the term “staghorn” is often used irrespective piro, et al., 1988; Michaels and Fowler, 1991]. of the percentage of the collecting system occu- pied. The panel found four modalities reported in the There is also no widely accepted way to express literature to be potential alternatives, on the the size of a staghorn calculus. As a result, stones strength of the evidence, for treating patients with of widely different volumes are all referred to as struvite staghorn calculi: staghorns. Staghorn calculi are usually made of • Open surgery – referring to any method of struvite (magnesium ammonium phosphate) with open surgical exposure of the kidney and re- variable amounts of calcium, but stones made of moval of stones from the collecting system; cystine, calcium oxalate monohydrate, and uric • Percutaneous nephrolithotomy (PNL); acid can all fill the collecting system. Such stones • Extracorporeal shock-wave lithotripsy are frequently found intermixed with struvite cal- culi in many series reported in the literature. (SWL); and The majority of staghorn stones are composed • Combinations of PNL and SWL. of struvite. These stones tend to be soft, and their Because the panel was unable to conduct direct radiologic appearance varies from relatively faint assessments of patient preferences, panel members to moderately radiopaque. It is generally possible themselves acted as patient surrogates judging to predict on the basis of a plain x-ray film that a treatment choices on the basis of probable out- staghorn stone is composed of struvite. comes.

1 TREATMENT OUTCOMES AND patient’s hospital stay. Therefore, an analysis com- ALTERNATIVE MODALITIES bining secondary, unplanned procedures and the complications associated with the primary treat- After reviewing the literature and analyzing the ment modalities chosen may accurately reflect the data, the panel concluded that the following out- patient’s viewpoint regarding desirability or unde- come probabilities are the most significant in set- sirability of a given intervention. ting forth recommendations for treatment of stru- Of all four treatment modalities, shock-wave vite staghorn calculi: lithotripsy monotherapy has the highest combined • The probability of being stone free following complication and secondary, unplanned interven- treatment; tion rate. However, the complications associated • The probability of undergoing secondary, un- with shock-wave lithotripsy tend to be less severe planned procedures; and than those associated with percutaneous nephrolith- • The probability of having complications asso- otomy, combination therapy, or open surgery. ciated with the chosen primary treatment The peer-reviewed literature does not stratify modality. outcomes appropriately by either size or composi- The four modalities of open surgery, PNL, SWL, tion of staghorn calculi or the anatomy of the col- and combination PNL and SWL are all reasonable lecting system. Nevertheless, the panel believes treatment alternatives for patients with struvite that these factors impact the outcomes of alterna- staghorn calculi. However, outcome probabilities tive treatment procedures. differ markedly among the four. The following Also, when choosing a treatment alternative, statements are based on both statistical analysis of special circumstances such as the patient’s overall abstracted data from the treatment literature and health, body habitus, and other medical problems expert opinion. They form the basis of the panel’s need to be taken into consideration by the treating recommendations. physician. The risk of havingArchived residual fragments following Document— initial treatment is clearly higher after shock-wave TREATMENT RECOMMENDATIONS lithotripsy monotherapy than after percutaneous The AUA Nephrolithiasis Clinical Guidelines nephrolithotomy, combinationFor therapy, Reference or open sur- Panel considered, Only in its recommendations, a total of gery. five methods for managing struvite staghorn calculi It is the expert opinion of the panel that residual – including watchful waiting or observation, as fragments of infected calculi left in the renal col- well as the four active modalities: (1) open sur- lecting system may be associated with recurrent gery, (2) percutaneous nephrolithotomy (PNL), infections and eventual regrowth of these fragments (3) extracorporeal shock-wave lithotripsy (SWL), into significant stones leading to additional morbid- and (4) combinations of PNL and SWL. ity, although literature to support this opinion is scarce. Levels of flexibility Shock-wave lithotripsy monotherapy carries a The panel graded recommendations for treat- high probability of unplanned secondary proce- ment by three levels of flexibility, based primarily dures. on the strength of the scientific evidence for esti- Percutaneous nephrolithotomy, combination mating outcomes of interventions. A “standard” is therapy, and open surgery are more likely to re- defined as the least flexible of the three; a “guide- quire general or regional anesthesia. line,” more flexible; and an “option,” the most flex- The chance that a blood transfusion will be ible. These three levels of flexibility [Eddy, 1992] required is greater for percutaneous nephrolithoto- for treatment recommendations are defined on page my, combination therapy, and open surgery than for 5. shock-wave lithotripsy monotherapy. The patient Rates of complications following the four treat- ment modalities differ significantly for each modal- Panel recommendations for the treatment of ity. From the patient’s viewpoint, a complication staghorn calculi apply to standard and nonstandard may have the same importance as a secondary, un- patients whose stones are presumed to be com- planned procedure, inasmuch as it may require a posed of struvite (magnesium ammonium phos- second anesthetic procedure or prolong the phate).

2 RECOMMENDATIONS

Standards 1. As a standard, a newly diagnosed struvite staghorn calculus represents an indication for active treatment intervention. Although this recommendation was not formally subjected to data abstracting and statistical methods, the panel strongly believes based on expert opinion that a policy of watchful waiting and observation is not in the best interest of the standard patient with struvite staghorn calculi. 2. As a standard, a patient with a newly diagnosed struvite staghorn calculus must be informed about the four accepted active treatment modalities, including the relative benefits and risks associated with each of these treatments.

Guidelines 1. As a guideline, percutaneous stone removal, followed by shock-wave lithotripsy and/or repeatArchived percutaneous procedures Document— as warranted, should be utilized for most standard patients with struvite staghorn calculi, with percutaneous lithotripsy being the first part Forof the combination Reference therapy. Only 2. As a guideline, shock-wave lithotripsy monotherapy should not be used for most standard patients as a first-line treatment choice. 3. As a guideline, open surgery (nephrolithotomy by any method) should not be used for most standard patients as a first-line treatment choice.

Options 1. As options, shock-wave lithotripsy monotherapy and percutaneous lithotripsy monotherapy are equally effective treatment choices for small-volume struvite staghorn calculi in collecting systems which are of normal or near normal anatomy. 2. As an option, open surgery is an appropriate treatment alternative in unusual situations where a staghorn calculus is not expected to be removable by a reasonable number of percutaneous lithotripsy and/or shock-wave lithotripsy procedures. 3. As an option for a patient with a poorly functioning, stone-bearing kidney, nephrectomy is a reasonable treatment alternative.

3 A “standard patient” is defined as an adult standard method of describing the collecting sys- patient who has two functioning kidneys (function tem, and no widely accepted system of reporting of both kidneys relatively equal) or a solitary kid- the size of staghorn calculi. ney with substantially normal function, and whose Few prospective, randomized, controlled studies overall medical condition, body habitus, and anato- have been conducted concerning the treatment of my permit performance of any of the four accepted struvite staghorn calculi. In addition, there is no active treatment modalities including use of anes- uniform system in the literature for reporting out- thesia. comes following treatment for struvite staghorn A “nonstandard patient” is defined as one with a calculi. struvite staghorn stone who does not fulfill the Further uncertainty stems from differences in above criteria. For this patient, the choice of avail- health care delivery systems in various countries as able treatment options may be limited to three or they impact the outcomes reported in the literature. even fewer of the four accepted active treatment Variability in the data leads to uncertainty in out- modalities, depending on individual circumstances. come estimates, which leads to flexibility in rec- The recommended standards and guidelines on ommendations. This limitation applies to a variety page 3 apply to the treatment of standard patients, of outcomes. followed by options for nonstandard patients. Notwithstanding these limitations, the panel believes that the standards, guidelines, and options LIMITATIONS IN THE presented are well supported by the data reviewed. TREATMENT LITERATURE Recommendations are founded primarily on the data and partially on the expert opinion of panel Limitations to the process of developing treat- members. Outcomes for which there is consider- ment recommendations became apparent during the able uncertainty are clearly identified as such in the panel’s review of the literature. Most obviously, document. Whenever the panel’s expert opinion for the purpose of thisArchived document, there is no uni- Document—prevailed over the limited amount of available data, form system of categorizing staghorn calculi, no this is specified in the document as well. For Reference Only

4 Chapter 1: Methodology

The recommendations in this Report on the 1. Standard: A treatment policy is considered a Management of Staghorn Calculi were developed standard if the health and economic outcomes of following an explicit approach to the development the alternative interventions are sufficiently of practice policies [Eddy, 1992], as opposed to an well-known to permit meaningful decisions and implicit approach relying solely on expert opinion there is virtual unanimity about which interven- without any open description of the evidence con- tion is preferred. sidered. 2. Guideline: A policy is considered a guideline if The explicit approach attempts to provide mech- the health and economic outcomes of the inter- anisms for arriving at recommendations that take ventions are sufficiently well-known to permit into account the relevant factors for making selec- meaningful decisions, and an appreciable but tions between alternative interventions. Such fac- not unanimous majority agree on which inter- tors include estimation of the outcomes from the vention is preferred. interventions, consideration of patient preferences, and assessing when possible the relative priority of 3. Option: A policy is considered an option if the interventions for a share of limited health care (1) the health and economic outcomes of the resources. Emphasis is placed on the use of scien- interventions are not sufficiently well-known to tific evidence in estimating the outcomes of the permit meaningful decisions, (2) preferences interventions. among the outcomes are not known, (3) pa- In developing the recommendations in this tients’ preferences are divided among the alter- report, an extensiveArchived effort was made to review theDocument—native interventions, and/or (4) patients are literature on staghorn stones and to estimate the indifferent about the alternative interventions. outcomes of the alternative treatment modalities as A standard has the least flexibility as a treat- accurately as possible.For The Nephrolithiasis Reference Clin- ment policy. Only A guideline has significantly more ical Guidelines Panel members themselves served flexibility, and options are even more flexible. As as proxies for patients in considering preferences noted in the definitions, options can exist because with regard to health and economic outcomes. of insufficient evidence or because patient prefer- The review of the evidence began with a litera- ences are divided. In the latter case particularly, ture search and extraction of data as described the panel considered it important to take into ac- below. The data available in the literature were count likely preferences of individual patients displayed in evidence tables. From these tables, when selecting from among alternative interven- the panel developed estimates of the outcomes tions. from the various interventions (shock-wave litho- tripsy, percutaneous nephrolithotomy, combination LITERATURE SEARCH shock-wave lithotripsy percutaneous stone removal and open removal). The panel used the FAST* A literature search was performed utilizing PRO meta-analysis package as described below to MEDLINE. Articles retrieved from MEDLINE combine the evidence from the various studies. included all manuscripts related to renal calculi These estimates of outcomes are arrayed on the published from 1966-1992. Articles prior to 1966 balance sheet on page 13. were identified by hand searching bibliographies The panel generated recommendations based on and reference lists from other articles. Complete- the outcomes shown in the balance sheet. These ness of the search was confirmed by cross-check- recommendations were graded according to three ing indices of important journals. Journals deemed levels of flexibility, based on the strength of the important, but not listed on MEDLINE (such as evidence and on amount of variation in patient The Journal of Endourology), were also searched. preferences. The three levels of flexibility for The total yield was 1,250 articles. The specifics of treatment recommendations [Eddy, 1992] are de- the MEDLINE search criteria are included in the fined as follows: Technical Supplement.

5 All of the citations were imported into a Papy- committee of the panel to ensure accuracy. Figure rus Bibliography System (Research Software A-1, on page A.1 in Appendix A, represents the Design, Portland, OR) and assigned specific key- number of articles reviewed by the panel by year. words. Once keywords had been associated with Figure A-2 demonstrates the source of articles each article, the articles could be sorted according from the English-language literature. The majority to the mode of therapy (for example, medical or of articles came from The Journal of Urology, surgical), the stone location (renal or ureteral), and Urology, The Journal of Endourology, and The the primary mode of stone removal (for example, British Journal of Urology. Figure A-3 on page SWL vs. PNL vs. COMBO vs. OPEN). For rea- A.2 shows the breakdown of articles selected for sons of practicality and validity, the panel decided review and Figures A-4 and A-5, the breakdown of that only articles from peer-reviewed journals in selected articles stratified by staghorn calculi and English-language literature would be utilized in the by treatment modalities, respectively. analysis. Prior to initiating abstraction of the articles, fur- ther searching of MEDLINE was performed with EVIDENCE COMBINATION particular emphasis on the most recent articles on In order to generate a balance sheet, estimates staghorn calculi. All pertinent stone articles as of of the probabilities and/or magnitudes of the out- January 1993 were included in the analysis. Search comes are required for each alternative interven- criteria from the Papyrus program to select appro- tion. Ideally, these come from a synthesis of the priate articles for review were: keywords = CAL- evidence. This synthesis or combination of the CULI; KIDNEY; SURGICAL; RENAL; and evidence can be performed in a variety of ways STAGHORN. depending on the nature and quality of the evi- Further review by the entire panel of the 479 dence. For example, if there is one good random- articles that met the initial search criteria yielded ized controlled trial, the results of that one trial 110 articles with 136 differentiated groups of alone may be used in the balance sheet. Other patients. These wereArchived articles containing viable Document—studies of significantly lesser quality would be data not duplicated in another manuscript. The ignored. articles are listed in Table A-1 and are the basis for If there are no studies of satisfactory quality for the panel’s analysis of staghornFor calculi. Referencecertain balance Onlysheet cells or the studies found are not commensurable, then expert opinion is used to ARTICLE SELECTION AND fill in those cells. DATA EXTRACTION If a number of studies have some degree of rele- After identifying articles from the MEDLINE vance to a particular cell or cells, then meta-ana- database and entering them into the Papyrus pro- lytic mathematical methods may be used. gram, the panel reviewed the abstracts and selected Different specific methods are available depending the relevant citations for data extraction. A com- on the nature of the evidence. For this Report on prehensive data-extraction form was devised by the the Management of Staghorn Calculi, the AUA panel to capture as much pertinent information as elected to use the confidence profile method possible from each article. A sample of the form is [Eddy, 1989; Eddy, Hasselblad, and Shachter, in Appendix B. The selected articles were divided 1990], which provides methods for analyzing data among the panel members who then reviewed the from studies that are not randomized controlled tri- articles and transcribed the data onto the form. als. The FAST*PRO computer package [Eddy and Panel members reported that there is little consis- Hasselblad, 1992] was used in the analysis. tency in the kidney stone literature in reporting Because there are few randomized controlled outcomes data. trials for staghorn stones, the package was used to All articles used to complete the report were combine the single arms from various clinical reviewed by at least two panel members for accu- series to estimate the outcome for each interven- racy. All articles excluded were by decision of the tion. The series that were combined frequently panel as a group. The forms from both reviews showed very different results – implying site-to- were forwarded to the panel facilitator, and any site variations that may be caused by differences in discrepancies in the data were resolved. All data patient populations, in how the intervention was were then entered into a PARADOX database. All performed, or in the skill of those performing the computer entries were reviewed again by a sub- intervention. Because of the differences, a ran-

6 dom-effects, or hierarchical, model was used to Note that both curves in the graph center on 75 combine the studies. percent, but the curve for the first study is much A random-effects model assumes that for each flatter. There is a much larger uncertainty about site there is an underlying true rate for the out- the true value with 20 patients studied than with a comes being assessed. It further assumes that this sample of 1,000. Figure 2 adds a third study of underlying rate varies from site to site. This site- 600 patients with 400 (66.7 percent) having the to-site variation in the true rate is assumed to be outcome. This study centers over a different point normally distributed. The method of meta-analysis and is intermediate in height between the first two used in analyzing the staghorn data attempts to studies. determine this underlying distribution. The results of the confidence-profile method are probability distributions. They can be described using a mean or median probability with a confi- dence interval. In this case, the 95-percent confi- dence interval is such that the probability (Bayes- ian) of the true value being outside the interval is 5 percent. The probability distribution can be displayed graphically (as a density function). This graph indicates the probability of any interval as the area under the graph on that interval. Thus, if a curve Probability on a graph is very sharply peaked, the area under Figure 2. Confidence profiles for studies 1 (15 of 20 pts.), 2 the curve is narrow indicating a narrow confidence (750 of 1000 pts.), and 3 (400 of 600 pts.) interval. If a curve is relatively flat, this indicates If these studies are combined using the method a wide confidence interval. The total area under described above, the result is a combined profile the graph is always equal to 1. Archived Document—(Curve 4 in Figure 3). This profile is very narrow The three graphs that follow illustrate a simple indicating that there is little difference among stud- example of the use of the FAST*PRO software. ies. Since two of the studies have the same result Two studies looked at Fora certain outcome Reference after a and the other Only is close, it is not surprising that there treatment for a given disease. In each study, 75 would be minimal site-to-site variation suggested percent of the patients had the outcome. The first by these studies. study had a total of 20 patients, and the second had a total of 1,000. If the software is used to update the probabilities for each site, the resultant (poste- rior) probability distributions of the true probabili- ty of the outcome can be graphed for each study.

Probability

Figure 3. Confidence profiles for studies 1, 2, and 3 and combined profile 4 (hierarchical Bayes’) The method of computation is Bayesian in nature. This implies the assumption of a “prior” Probability distribution that reflects knowledge about the prob-

Figure 1. Confidence profiles for studies 1 (15 of 20 pts.) and ability of the outcome before the results of any 2 (750 of 1000 pts.) experiments are known. The prior distributions

7 selected for this analysis are among a class of modality are also presented as an estimate of the “noninformative” prior distributions, which means difference between the modalities. that they correspond to little or no preknowledge. With regard to certain outcomes, more data have The existence of such a prior can cause small chan- been reported for one or another treatment modali- ges in results, particularly for small studies. In the ty. This results in a sharper and narrower peak in foregoing example, for instance, the mean of the the graph reflecting the available data. However, distribution for the sample of size 20 is 0.74 rather the probability for certain outcomes can vary wide- than 0.75. The effect of the prior distribution is to ly from study to study within one treatment modal- slightly discount the value of the experiment. This ity. Such variability will result in a wide, flat com- effect will not be pronounced except in very small bined distribution, which reflects considerable un- studies, and the combination of multiple studies certainty about the outcome or considerable differ- will reduce this tendency further. ences between sites and practitioners. For the statistically sophisticated reader, the prior distribution for all probability parameters is Jefferey’s prior (beta distribution with both parame- Study Median 95% CI ters set to 0.5). The prior for the variance for the underlying normal distribution is gamma distrib- 1 .746 .536 - .898 uted with both parameters set to 0.5. 2 .750 .722 - .776 In addition to graphical presentations, 95-per- cent confidence intervals are used to present re- 3 .667 .628 - .703 sults. The medians and 95-percent confidence intervals for the results of the three foregoing sam- Combination .716 .687 - .743 ple studies and the combination are as follows: Outcomes considered important to patients As mentioned previously, there are few random- receiving treatment for nephrolithiasis were ana- ized controlled trials for staghorn stones. Thus, the lyzed in such fashion.Archived In some cases, surrogates Document—differences seen by comparing studies as done here for patient outcomes were analyzed – for example, may be biased to some degree. For example, dif- stone-free rate as a surrogate for symptom im- ferences in patient selection may have had more provement. Evidence fromFor all studies Reference meeting weight in yielding Only the results shown than the dif- inclusion criteria that reported a certain outcome fering effects of the treatment modalities. How- were combined within each treatment modality. ever, these results reflect the best outcome esti- Graphs showing the combined results for each mates known at the present time.

8 Chapter 2: Staghorn calculi and their management

BACKGROUND eradicating all of the infected stone material. If all of the infected material is not removed, the patient Staghorn calculi are stones that fill the major will continue to have recurrent urinary tract infec- part of the collecting system. Typically, such tions and the stone will eventually regrow. It may stones will occupy the renal pelvis, and branches be possible to sterilize small amounts of struvite, of the stone will extend into the majority of the but how much of the stone can be sterilized is calices. The term “partial staghorn” is often used uncertain and unpredictable [Pode, Lenkovsky, when a lesser portion of the collecting system is Shapiro, et al., 1988; Michaels and Fowler, 1991]. occupied by stone. There is, unfortunately, no agreement on how these terms should be defined, TREATMENT METHODS and the term “staghorn” is often used irrespective of the percentage of the collecting system occu- Four modalities reported in the literature are pied. acceptable as potential alternatives for treating There is also no widely accepted way to express patients with struvite staghorn calculi: the size of a staghorn calculus. As a result, stones • Open surgery – referring to any method of of widely different volumes are all referred to as open surgical exposure of the kidney and staghorns. Staghorn calculi are usually made of removal of stones from the collecting system; struvite (magnesium ammonium phosphate) with • Percutaneous nephrolithotomy (PNL); variable amounts of calcium, but stones made of cystine, calcium oxalateArchived monohydrate, and uric Document—• Extracorporeal shock-wave lithotripsy acid can all fill the collecting system. Such stones (SWL); and are frequently found intermixed with struvite cal- • Combinations of PNL and SWL. culi in many series reportedFor in the Referenceliterature. Only The majority of staghorn stones are composed Open surgery of struvite. These stones tend to be soft, and their Open surgical removal of the stone has been the radiologic appearance varies from relatively faint so-called “gold-standard,” to which all other forms to moderately radiopaque. It is generally possible of stone removal have been compared. A variety to predict on the basis of a plain x-ray film that a of specific operations on the kidney may be per- staghorn stone is composed of struvite. formed in order to remove a staghorn calculus. These stones are also called “infected stones” or Depending on anatomy, a pelviolithotomy, extend- “infection stones” because they occur only in the ed pyelotomy, nephrotomy, partial nephrectomy, or presence of urinary tract infection and only when even nephrectomy may all play a role in specific the infection is secondary to organisms that elabo- cases. The most common operation performed rate the enzyme urease, which splits urea [Bruce today is anatrophic nephrolithotomy, and this is and Griffith, 1981]. Cultures of pieces of struvite reflected in the literature over the past 20 years stones, taken both from the surface and from [Assimos, Boyce, Harrison, et al., 1989]. inside, have demonstrated that bacteria reside Anatrophic nephrolithotomy is usually per- inside the stones and that the stones themselves are formed with the patient in the flank position. A infected – in contrast to stones made of cystine, standard flank incision is made and frequently a calcium oxalate monohydrate, or other substances [Nemoy and Stamey, 1971]. rib is resected. After surgical exposure of the kid- ney, an incision is made lengthwise, bivalving the An untreated struvite staghorn calculus will in time destroy the kidney, and the stone has a signifi- kidney and exposing the stone. Direct inspection cant chance of causing the death of the affected and the use of intraoperative x-rays demonstrate patient [Rous and Turner, 1977; Koga, Arakai, that the kidney is stone free. The time allowed for Matsuoka, et al., 1991]. Moreover, struvite stones removal of the stone is short, unless the kidney is must be removed in their entirety to be certain of cooled. The principles of the operation are well

9 established, with usual operating times of 3-7 The procedure may be divided into two parts, hours. If the patient has had previous renal access and stone removal. To achieve percutaneous surgery, the operation may be more difficult access, the urologist or radiologist places a small [Stubbs, Resnick, and Boyce, 1978]. flexible guide wire, under fluoroscopic control, through the patient’s flank into the kidney and Hospitalizations of 7-14 days are the rule. In down the ureter. Care is taken to optimize the addition to the usual morbidity associated with any approach to the kidney so that the best approach to operation, flank incisions are painful and probably the stone is obtained. Once access is achieved, the more painful than midline abdominal incisions. tract is dilated to 24-30 F. and the nephroscope Many patients complain of numbness, paresthesia, introduced. Under direct vision, the stone is bro- and weakness of the abdominal wall resulting in ken up (usually with an ultrasonic probe) and the bulging, which may be unsightly. The average pieces removed. One of the characteristics of stru- postoperative disability is six weeks. This is based vite is that the stone is usually soft, and fragmenta- on the fact that a typical incision has regained tion with removal of the pieces is often quick. about 80 percent of its preoperative strength by then, but recent work suggests that months may PNL has unquestioned advantages: (1) If the pass before many patients feel completely normal stone can be seen, it can almost always be des- [Assimos, Wrenn, Harrison, et al., 1991]. troyed. (2) The collecting system may be directly inspected so that small fragments may be identified Occasionally, the stone has caused enough dam- and removed. (3) Because the tract can be kept age to a kidney that nephrectomy is indicated. open indefinitely, repeated inspections are possible. Such kidneys reveal the effects of years of chronic (4) The process is rapid, with success or lack of it infection, episodes of acute pyelonephritis, and being obvious immediately. hydronephrosis [Assimos, Boyce, Harrison, et al., 1989]. Archived Document—Hospitalizations are usually from 4-10 days with most patients returning to light activity after 1-2 The development of anatrophic nephrolithotomy weeks. Transfusion rates for PNL in treating and the demonstration thatFor patients withReference infected staghorn calculi Only vary from 5 to 50 percent. Re- stones could be stone free made an excellent case treatment rates – that is, the rate at which the in- for this surgical approach, which became the stan- strument must be reinserted through the tract to dard throughout the 1960’s and 1970’s. In 1994, remove residual stones – vary from 10 percent in the incidence of open surgery for the treatment of simple situations to 40-50 percent for more compli- all stones is about 1-2 percent. Staghorn calculi cated problems. Stone-free rates of 75-90 percent comprise most of the indications. are regularly achievable using PNL. The decision in favor of nephrectomy is usually One disadvantage is that the expertise required made when the contralateral kidney is normal or for this operation is not as widely available as it nearly so, and when there is poor function in the once was, because a greater number of urology affected kidney. training programs are focusing less on PNL and more on shock-wave lithotripsy for stone manage- Percutaneous stone removal ment. Percutaneous nephrolithotomy (PNL), which became popular as a primary technique for stone Extracorporeal shock-wave removal in the early 1980s (Appendix C, page lithotripsy C.3), can theoretically be used for all stones. In Shock-wave lithotripsy (SWL) has become the practice, extracorporeal shock-wave lithotripsy standard method for management of many calculi (SWL) is used in the majority of situations where in the urinary tract (Appendix C, page C.1). SWL PNL was once employed. Struvite staghorn cal- is based on the principle that a high-pressure shock culi, however, are often best managed by PNL wave will release energy when passing through either as a single technique or in combination with areas of different acoustic impedance. Shock SWL. waves generated outside the body can be focused

10 onto a stone using a variety of geometric tech- Combination PNL and SWL niques. The shock wave passes through the body Some stones can be best managed by using both without trauma and releases its energy as it passes PNL and SWL on the same stone. This combines into the stone. Hundreds, or sometimes thousands, the main advantage of percutaneous ultrasonic of such shock waves are required to break up the lithotripsy, that of removing rapidly large volumes average small stone, with the goal being to reduce of easily accessible stone, with the advantage of the size of the stone to particles small enough to SWL in easily treating small volumes of stone that pass without significant pain. are difficult or dangerous to access using PNL. There are many different shock-wave machines The surgeon first utilizes PNL, making every available today. Although they are based on the effort to remove as much stone as possible, before same general principle, there are significant differ- using SWL. Experience has demonstrated that fol- ences that relate to the use of these machines for lowing SWL, the passage of fragments cannot be treatment of large stones such as staghorn calculi. predicted. Therefore, depending upon the extent The original machine, the Dornier HM-3, proba- and location of residual stones, repeat SWL and/or bly the most common machine throughout the repeat PNL may be necessary to remove residual world, has the largest focal point and, in its unmod- fragments. ified version, the highest power of all current devices. In an effort to reduce the anesthesia Ancillary procedures requirement, newer machines often have less power Percutaneous nephrostomy tube placement and smaller focal points. This means that stones (PNTP) may be necessary at any point in the man- treated with such machines will often require more agement of staghorn stones. It is a routine part of procedures to achieve the same result produced PNL, of course, and is frequently used after SWL with fewer procedures by other devices. Archived Document—for drainage of an infected stone and for pain relief Obviously, for very large stones, multiple treat- ments may be required. when obstruction is present. Preliminary stent in- For Referencesertion prior Onlyto SWL for staghorn calculi is so Shock-wave lithotripsy has few short-term com- common as to be part of the procedure. Frequently plications, its noninvasive nature has much appeal, a double-pigtail stent is placed and left indwelling and the technique is widely available. SWL has for days or weeks to maintain drainage while frag- disadvantages, however, particularly in regard to ments pass. the management of staghorns. The panel found, as stated on pages 14 and 19, a relatively higher risk Irrigations of the collecting system with solu- of residual fragments following initial treatment tions such as Renacidin to dissolve remaining frag- and a high probability of unplanned secondary pro- ments of infected stones, particularly after PNL, cedures. have been advocated by some. This is not a com- mon procedure, probably because it often means Because multiple treatments may be needed, use added hospitalization. The panel did not find suffi- of SWL may not be practical to provide the cient evidence in the literature to support the use of required frequency of service if only mobile SWL Renacidin as a primary procedure for treating in- is available and ancillary procedures directed fected stones. toward the management of fragments are necessary. In addition, although many factors bear on the cost Ureteroscopy may be needed to remove frag- of any medical procedure, at the present time SWL ments too large to pass spontaneously. General or is often more expensive than endourology or open regional anesthesia is necessary, but success rates surgery for the same condition [Hatziandreu, are very high (95 percent or greater). Most often, Carlson, Mulley, et al., 1990]. ureteroscopy is an outpatient procedure.

11 Chapter 3: Outcomes analysis for staghorn treatment alternatives

DIRECT AND INDIRECT OUTCOMES incidence of infection may serve as a proxy for the degree of symptom improvement after treatment, Any therapeutic medical intervention has a cer- and stone-free rate is used as a proxy for stone tain set of outcomes, some of which are desirable recurrence and symptom recurrence because these (benefits) and some of which are not (harms) data are not available in the current literature. [Eddy, 1990]. Direct health outcomes are those felt directly by the patient and have an impact on COMBINING OUTCOME EVIDENCE the quantity or quality of life. Indirect biologic outcomes are physiologic end points such as ab- The panel conducted a comprehensive review of sence of infection or incidence of stone recurrence. the English-language literature and combined all These may be of great importance to the clinical outcome evidence for given treatment options, uti- researcher. Also, physicians, in general, believe lizing the confidence profile method as described that outcomes such as absence of residual stones, on pages 6-8 of Chapter 1. The results of the com- prevention of stone recurrence, and limitation of bined review are presented in the balance sheet residual stone growth are of the greatest impor- table on page 13. tance when assessing treatment options for Outcomes with a wide confidence interval in- staghorn calculi, although patients may not view dicate considerable uncertainty in the medical these outcomes per se as important end points. knowledge base. This uncertainty is due either to An example of the difference between the two a limited number of studies reported for a given types of outcomes is Archivedillustrated by the patient with Document—intervention (as is the case for combination thera- a recent myocardial infarction. Although the level py) or to a wide variation in outcome probability of the CPK enzyme is an important parameter for reported in different studies (as is the case for the physician (indirect biologicFor outcome), Reference it cannot shock-wave lithotripsy Only therapy). The short dura- be felt by the patient in any way. Meanwhile, the tion of many studies introduces uncertainty as chest pain or death associated with the infarction well. has an immediate impact on the patient’s quality or The combined analysis is also weakened by the quantity of life (direct health outcome). quality of the individual studies. As noted previ- Similarly, in treatment of staghorn calculi, the ously, there are currently few randomized, pro- patient may not be interested in the stone-free rate, spective controlled studies of staghorn calculi ther- the chance of developing recurrent stones, or the apy in the literature. Therefore, most of the data incidence of growth of residual calculi following analyzed by the panel come from clinical series. stone removal, despite the critical importance of The limitations of including these types of studies these parameters to the physician – unless the im- are obvious. Nevertheless, if clinical series were plications of the parameters are explained to the not included, nothing could be said about the bene- patient. fits and harms of various types of surgical removal However, the patient will very likely be interest- of staghorn calculi. ed in direct outcomes such as the degree of symp- Further limitations arise from differences in tom improvement after treatment, the complica- study populations. In many cases, it is likely that tions or side effects of treatment, mortality, and the patients who are entered into trials of alternative cost and duration of hospital stay. For patients to therapies have less severe disease states than those participate in a shared decision-making process undergoing surgery. Moreover, the definition of regarding treatment, they must be fully aware not staghorn calculi may differ significantly among only of the magnitude of the direct outcomes relat- various investigators, and some of the reports re- ed to treatment alternatives, but also of the range garding the management of staghorn calculi do not of uncertainty associated with these outcomes. specify the size of the stones or portion of the col- Indirect biologic outcomes can occasionally lecting system occupied. Thus, not all studies may serve as proxies for direct health outcomes. The be comparing treatment outcomes of stones of sim-

12 ilar size, composition, or location within the kid- the median of an array of individual study results. ney. In these cases, the panel attempted to extrap- In some cases, combined analysis could not be per- olate from existing information to equate the treat- formed because of the way outcomes were report- ment outcomes. ed in the literature. Despite such limitations, the panel is reasonably certain that the confidence intervals contain the ANALYSIS OF THE “true” probability of a given outcome for most BALANCE SHEET OUTCOMES sites. Better estimates, narrower confidence inter- The following sections discuss in detail the vals, and greater certainty about treatment differ- analysis used to generate the data on the balance ences can be obtained through large, well-con- sheet. The information is organized in relation to trolled studies that test the different therapies in the outcomes listed on the left side of the balance same patient population. However, until these sheet, beginning with stone-free rate. Tables in types of outcome studies are completed, guidance addition to those from Appendix A (A-1 - A-21), can still be given to the physicians and patients referenced in this chapter, are contained in the who are forced to make decisions at the present Technical Supplement available upon request. time. These additional tables include FAST*PRO analy- sis tables. THE BALANCE SHEET The balance sheet table details the results of an Stone-free rate exhaustive combined analysis of the staghorn cal- To assess “successful” outcomes following vari- culi treatment literature. In most cases, a 95-per- ous modalities of stone removal, one can deter- cent confidence interval is reported along with the mine the resolution of symptoms, absence of infec- median probability. This median – both as given tion, or inhibition of recurrent stone formation or in the balance sheet and as referred to in the out- stone growth. However, most urologists would come analysis discussionArchived that follows – is the Document—agree that the stone-free rate following stone re- median of the probability distribution resulting moval is the most quantifiable and meaningful from the meta-analysis of outcome data. It is not determinant of successful treatment.

ForBalance sheet:Reference outcomes of treatments for staghorn kidney Only stones

Combined SWL and Percutaneous Percutaneous Outcomes SWL Nephrolithotomy Nephrolithotomy Open Surgery Stone-free rate: Median 0.500 0.733 0.808 0.816 95% confidence interval 0.256-0.744 0.547-0.874 0.678-0.905 0.566-0.957 Acute complications: Overall significant complications:* Median 0.308 0.074 0.244 0.119 95% confidence interval 0.022-0.816 0.003-0.322 0.039-0.611 0.006-0.465 Transfusion: Median 0.009 0.108 0.120 0.089 95% confidence interval 0.002-0.022 0.003-0.478 0.052-0.222 0.078-0.101 Death: Median 0.0007 0.001 0.002 0.006 95% confidence interval 0.00006-0.003 0.0001-0.005 0.0001-0.006 0.004-0.009 Procedures/pt.: Primary 2.122 1.486 2.768 1.026 Secondary 0.424 0.047 0.034 0.002 Long-term complications: Stone recurrence: Median 0.058 0.068 No data 0.120 95% confidence interval 0.016-0.161 0.015-0.176 0.036-0.269 Stone growth: Median No data 0.070 No data 0.083 95% confidence interval 0.026-0.142 0.030-0.171 Renal impairment: Median No data No data No data 0.063 95% confidence interval 0.021-0.138 Loss of kidney: Median No data 0.016 No data 0.037 95% confidence interval 0.001-0.061 0.011-0.086 No. hospital days 8.72 10.09 12.73 10.99 * Hydrothorax, pneumothorax, perirenal hematoma, vascular injury, urinoma, secondary unplanned interventions, sepsis, loss of kidney.

13 Much of the literature regarding stone-free rate (Table A-5). It should be noted that the open surgi- has been clouded in the age of shock-wave litho- cal procedures included simple pyelolithotomy, tripsy by studies that include patients with small extended pyelolithotomy, combination pyelolithoto- residual fragments (so-called “clinically insignifi- my with radial nephrotomies, as well as a formal cant” residual fragments) together with patients anatrophic nephrolithotomy. Analysis of these who are truly stone free. Also, the method of studies revealed a median stone-free rate of 0.816 assessing the stone-free state has a significant (95% CI 0.566 - 0.957) using FAST*PRO. impact on the number of patients who are free of Comparative analysis using the FAST*PRO pro- stones following surgery. gram for the four different surgical modes of stone Several studies evaluating different methods of removal is represented in Figure 4. The findings assessing stone-free status conclude that a plain demonstrate, not surprisingly, that stone-free rates abdominal radiograph (KUB) may significantly increase as the “invasiveness” of the surgical proce- underestimate the incidence of residual fragments, dure increases. If, indeed, stone-free figures are as compared to plain renal tomograms or ultrason- used to ultimately decide the most appropriate ography [Denstedt, Clayman, and Picus, 1991; mode of stone removal, open surgery should pro- Jewett, Bombardier, Caron, et al., 1992]. Direct vide the “best” results. Moreover, this comparative vision nephroscopy has the highest sensitivity rate analysis should demonstrate to the patient that al- for assessing stone-free status, but it is the most though shock-wave lithotripsy monotherapy might invasive method of residual stone determination. be the least morbid of the surgical modalities, it The majority of the studies included in the present definitely provides the lowest stone-free rates of analysis utilized only a plain abdominal radiograph the available treatment options. to assess residual fragments. Therefore, the stone- free figures are probably overestimated. A total of 26 studies utilizing SWL monotherapy to manage staghorn calculi were analyzed, repre- senting a total of 1,669Archived patients or renal units. TheDocument— median stone-free rate for this group was 0.50 (95% CI 0.256 - 0.744). The studies included in the analysis are listed Forin Table A-2, Reference Appendix A. Only The type of SWL machine may impact the stone-free rates for staghorn calculi. The higher- powered lithotripters (the electrohydraulic Dornier HM-3 and the electromagnetic Siemens Lithostar) impart significantly more energy to fragment the stones than do the piezoelectric devices (Wolf 2300 Probability and EDAP). Although only data from two piezo- electric machines are included in this analysis, their Figure 4. Staghorn stone-free rates stone-free rates appear to be significantly lower than those reported for the other lithotripsy devices Acute complications (Table A-2). The data abstraction sheet (Appendix B) lists a The stone-free data for PNL monotherapy are number of acute complications. They include per- listed in Table A-3 and represent a total of 14 stud- foration of the renal pelvis, hydrothorax/pneumo- ies in 511 renal units. The FAST*PRO analysis thorax, perirenal hematoma, significant blood loss, calculated the median stone-free rate at 0.733 (95% vascular injury, transfusion, urinoma, sepsis, stent CI 0.547 - 0.874). migration, renal impairment, wound infection, loss The stone-free rates for combination percuta- of kidney, and death. Secondary, unplanned inter- neous stone removal and shock-wave lithotripsy ventions were also considered by the panel to be treatment of staghorn calculi are listed in Table acute complications. A-4. This group represents five studies reporting In reviewing all studies for which there were on 796 patients. The stone-free rate for the group data regarding acute complications, it became ob- was 0.808 (95% CI 0.678 - 0.905) using vious to the panel that three major acute complica- FAST*PRO analysis. tions would most concern the patient as well as the Thirty-one studies reported stone-free rates in physician: (1) the need for secondary, unplanned 2,487 patients using open surgical techniques interventions, (2) the need for transfusion, and

14 (3) death. Data for these three major complica- planned interventions for this percutaneous group tions are listed separately in Appendix A (Tables significantly less than for SWL monotherapy. The A-6, A-7, A-8, and A-9). Secondary, unplanned median transfusion rate for PNL, however, was interventions were not analyzed by FAST*PRO 0.108 (95% CI 0.003 - 0.478), significantly higher separately, but were combined with other acute than for SWL. The median mortality rate for PNL complications for inclusion in the balance sheet was also much higher at .0011 (95% CI .0001 - under “Overall Significant Complications.” .0045). Transfusion and death were analyzed by The data suggest that the more invasive percuta- FAST*PRO separately, and median probabilities neous procedure results in higher transfusion and and 95-percent confidence intervals for these two death rates than SWL monotherapy does. The outcomes appear separately on the balance sheet. number of secondary, unplanned interventions, Table A-6 gives the acute-complications data for however, was significantly higher in the SWL shock-wave lithotripsy monotherapy used to treat group, which suggests problems with incomplete staghorn calculi. The FAST*PRO analysis shows, stone removal secondary to SWL. for overall significant complications in patients un- The panel analyzed five studies that utilized dergoing SWL monotherapy for staghorn calculi, a combination percutaneous and shock-wave litho- relatively high median rate of 0.308 (95% CI 0.022 tripsy treatment for staghorn calculi. For the 781 - 0.816). A major contributor to this high overall patients represented, where data for acute compli- rate was the high percentage of secondary, un- cations were available, the percentage of overall planned interventions shown in Table A-6. The significant complications was 23.94 percent (Table median transfusion rate for SWL monotherapy was A-8). This included a secondary, unplanned inter- 0.009 (95% CI 0.002 - 0.022). vention rate of 1.62 percent. The percentage of deaths following SWL mono- FAST*PRO analysis of data from the combina- therapy, when initially assessed, was found to be tion PNL-SWL group yielded the following bal- 0.13 percent. This mortality rate was based on one ance-sheet estimates: for overall significant com- reported death in a populationArchived of 771 patients for Document—plications, a median rate of 0.244 (95% CI 0.039 - whom acute complications were reported (Table 0.611); for transfusion, a median rate of 0.120 A-6). The panel believed that the resulting per- (95% CI 0.052 - 0.222); for mortality, a median centage was clinically tooFor high and thatReference the reason rate of 0.002 (95% Only CI 0.0001 - 0.006). may have been that many studies of SWL mono- Acute complications were reported in 27 studies therapy for staghorn stones did not report acute of open surgery for staghorn calculi, representing complications, thereby lowering the denominator 2,314 patients. Of these 2,314 patients, 27.53 per- used in the calculation. cent experienced overall significant complications The mortality rate was recalculated using a (Table A-9), of which 0.30 percent represented sec- patient denominator of all patients undergoing ondary, unplanned interventions. The FAST*PRO SWL monotherapy for staghorn calculi (1,681 pa- analysis yielded a median rate of 0.119 (95% CI tients), rather than only those for whom acute com- 0.006 - 0.465) for overall significant complications plications were reported. (The panel assumed that following open surgery for staghorns. The median if a patient had died during any clinical study of transfusion rate was 0.089 (95% CI 0.078 - 0.101), SWL monotherapy to treat staghorn calculi, the and the median rate for mortality was 0.006 (95% death would surely have been reported.) The recal- CI 0.004 - 0.009). culation dropped the mortality rate to 0.06 percent, Acute-complications data overall for the four which is more consistent with the panel’s percep- modalities of stone removal show the more invasive tion of mortality from SWL monotherapy. FAST* modalities, such as open surgery and percutaneous PRO analysis of mortality for the balance sheet stone removal, with higher rates of transfusion and produced a median of 0.0007 (95% CI 0.00006 - death than the rates for the less invasive therapy of 0.003). shock-wave lithotripsy. However, as noted previ- For PNL monotherapy of staghorn calculi (11 ously, shock-wave lithotripsy monotherapy of studies, 921 patients), the median rate for overall staghorn calculi was followed by many more sec- significant complications was 0.074 (95% CI 0.003 ondary, unplanned interventions. The panel - 0.322). Listings in Appendix A are in Table A-7. believes that this is a significant finding since these There were seven secondary, unplanned inter- secondary, unplanned interventions resulted in ventions in the total of 921 PNL patients (Table increased patient morbidity as well as increased A-7), making the percentage of secondary, un- cost for stone removal. Figures 5-7 display

15 FAST*PRO graphical analyses comparing the four Procedures per patient modalities with regard to overall significant com- (primary and secondary) plications, transfusions, and death. An important outcome on the balance sheet, in comparing the various surgical modes of staghorn stone removal, analyzes the number of procedures performed per patient to achieve a successful re- sult. Before 1979, when open surgery was the only modality available to treat struvite staghorn calculi, it was unusual to perform more than one procedure per patient to remove all stone material. However, in an age of less invasive techniques for stone re- moval, the need for repeat primary and, in some cases, secondary procedures has significantly in- creased in order to attempt complete removal of the stone material. Probability A total of 16 studies using SWL monotherapy were available for analysis, representing 835 pa- Figure 5. Overall significant complications: Comparison of modalities tients. These individuals underwent 1,772 primary SWL procedures, 2.12 per patient (Table A-10). In total, the 835 SWL patients underwent 2,126 pro- cedures, which represented an additional 0.42 sec- ondary procedures per patient (Table A-10). Thus, the advantage of reduced invasiveness for SWL therapy for staghorn calculi resulted in a total of 2.55 procedures per patient – including both prima- Archived Document—ry and secondary SWL procedures – as well as additional procedures which included percutaneous nephrostomy tube placement, ureteroscopy, and in For Referencesome cases openOnly surgery. Twenty-three studies that reported SWL monotherapy of staghorn stones were not included in this analysis of procedures per patient because they reported on less than five pa-

Probability tients or did not contain specific information on numbers of procedures per patient. Figure 6. Transfusions: Comparison of modalities In the PNL group, 10 studies met entrance crite- ria. They represent a total of 854 patients. These patients underwent 1,269 primary percutaneous stone removal procedures, for a primary procedure rate of 1.49 per patient. The 854 patients under- went a total of 1,309 procedures, including an addi- tional 0.05 secondary procedures per patient (Table A-11). The total procedures-per-patient rate of 1.53 was significantly less than the total proce- dures-per-patient rate of 2.55 seen with the SWL monotherapy group. Ten additional PNL studies were not included in this analysis because no spe- cific data were presented regarding the number of procedures per patient or because the study sample was less than five patients. In the combination therapy group, six studies

Probability met entrance criteria, representing 168 patients (Table A-12). These patients underwent a total of 222 percutaneous procedures and 243 SWL proce- Figure 7. Death: Comparison of modalities dures, representing a 2.77 primary procedures-per-

16 patient rate. By definition, in the combination ther- recurrence rate, 0.120 (95% CI 0.036 - 0.269), than apy group, which includes management of the the median rates for the SWL and PNL groups. A staghorn stone by both percutaneous and shock- small number of patients in the open group were wave lithotripsy, the minimum procedures-per- found to have growth of their residual stones, patient rate would be 2.0. An additional 0.03 pro- yielding a median stone growth rate of 0.083 (95% cedures per patient were performed in the combina- CI 0.030 - 0.171). Renal impairment during long- tion group, yielding a total procedures-per-patient term follow-up was a median 0.063 (95% CI 0.021 rate of 2.80 (Table A-12). - 0.138), and 21 of the 1,549 patients eventually As one would expect, the number of procedures lost a kidney (Table A-16). per patient in the open surgery group was the low- No data on long-term complications were report- est of all four modalities for stone removal. Table ed for the combination PNL-SWL group. It should A-13 presents the 27 studies. They represent 1,672 be noted that renal impairment or loss of kidney procedures on 1,630 patients for a primary proce- may not necessarily be due directly to stone remov- dure rate of 1.03 per patient. With secondary pro- al, but may be secondary to other factors. cedures, a total of 1,676 procedures were per- formed in this group of patients. The total proce- dures-per-patient rate remained at 1.03 (rounded off), as the number of additional procedures per patient was only 0.002. Most series of open surgery were reported before 1980, prior to the availability of percuta- neous surgery and shock-wave lithotripsy. This explains the low secondary procedure rate, reflect- ing reluctance of the surgeon and the patient to repeat open surgical procedures. Twenty-five stud- ies were excluded Archivedfrom the analysis of procedures Document— per patient in the open group because there were Probability fewer than five patients or because of not providing specific data regardingFor the numbers Reference of procedures Figure 8. Stone Only recurrence: All modalities combined per patient. It appears that the open surgery group had the Long-term complications highest rate of stone recurrence, but in comparison with very scanty data presented for the SWL and The long-term complications reported for the PNL series. The discrepancy is probably due to the four modes of stone removal included stone recur- fact that a larger number of open studies have rence, stone growth, renal impairment, and loss of investigated the long-term results of this form of kidney following surgery. Unfortunately, only a stone removal. SWL and PNL studies, for the small amount of data was available from the stud- most part, have only reported short-term follow-up. ies analyzed regarding these long-term complica- The panel anticipates that, if followed long enough, tions. Only one SWL monotherapy study reported the PNL, SWL, and combination groups will show stone recurrence in 3 of their 54 patients (Table rates of stone recurrence and growth similar to A-14), yielding a FAST*PRO median recurrent stone rate of 0.058 (95% CI 0.016 - 0.161). Analysis of the percutaneous monotherapy group of studies (Table A-15), also with a limited number of patients (93), yielded a median rate of stone recurrence of 0.068 (95% CI 0.015 - 0.l76) as well as a median rate of stone growth of 0.070 (95% CI 0.026 - 0.142). One of the 93 patients in the PNL group had a long-term complication of renal loss. A significant amount of information was re- ported in the studies of open surgery, with data on 1,549 patients for whom long-term complications were noted (Table A-16). FAST*PRO analysis of Probability the open group yielded a higher median stone Figure 9. Stone growth: All modalities combined

17 senting 305 patients and 2,660 hospital days, met appropriate criteria and were included for analysis (Table A-17). An additional 30 studies were excluded because they did not meet appropriate criteria for analysis. They either did not report hospital days or reported less than five patients. Six studies, representing 247 patients who had undergone percutaneous monotherapy for staghorn stones, and representing 2,493 days, met analysis criteria and are listed in Table A-18. Fourteen studies of percutaneous monotherapy were exclud- ed from analysis due either to low numbers of pa- Probability tients or to nonreporting of hospitalization.

Figure 10. Loss of kidney: All modalities combined Table A-19 defines the five studies utilizing combination shock-wave lithotripsy and percuta- those in the open series. One would not expect neous stone removal for the management of stag- the mode of stone removal to have any effect on a horn stones in 775 patients, for a total of 9,869 patient’s propensity for recurrent stone formation hospital days. One combination study was ex- or growth of residual stone fragments. Median cluded from analysis due to nonreporting of hospi- rates for long-term complications are graphed in talization. Figures 8-10. Of the patients with staghorn calculi treated Hospital days with open surgery, nine studies met entrance crite- ria for analysis, representing 1,354 patients and Any form of surgical stone removal for staghorn 14,886 patient days (Table A-20). In 42 studies calculi, including theArchived least invasive option of Document—where patients had undergone open therapy for shock-wave lithotripsy, may require patient hospi- staghorn calculi, hospitalization data were not pre- talization. The data on hospital days was directly sented and could not be analyzed. extracted from the literature and included in the balance sheet. In the caseFor of SWL Reference and of combi- Hospitalization Only was highest for the combination nation therapy, the total hospitalization may not therapy groups (12.73 hospital days), probably due represent continuous stay within the hospital. For to the increased number of procedures performed example, the patient might have been hospitalized on each patient. Although the hospitalization data for 1-3 days the first time, discharged, and then for the shock-wave lithotripsy monotherapy group readmitted for a second or third treatment. The seem somewhat high at 8.72 hospital days, it hospital days represent a cumulative total of the should be noted that these were complex staghorn reported hospital stay for each modality. calculi being treated with shock-wave monothera- Hospitalization practices vary from country to py with an average of approximately 2.5 proce- country and change over time. No attempt was dures per patient. made to correct for varying practices of this type. Moreover, five of the seven studies included in All of the hospital data are somewhat exaggerated the SWL monotherapy group were performed out- by current standards. side the U. S. (Table A-21), where there is less in- For patients with staghorn calculi undergoing centive to minimize hospitalization than in the SWL monotherapy, a total of seven studies, repre- U. S. health care system.

18 Chapter 4: Staghorn treatment recommendations

There are five methods of managing staghorn Shock-wave lithotripsy monotherapy carries a calculi. One is by watchful waiting (observation). high probability of unplanned secondary proce- The other four are the active treatment modalities dures. described in Chapter 2 and in greater detail in Percutaneous nephrolithotomy, combination Appendix C. They are (1) open surgery, (2) percu- therapy, and open surgery are more likely to taneous nephrolithotomy (PNL), (3) extracorporeal require general or regional anesthesia. shock-wave lithotripsy (SWL), and (4) combina- The chance that a blood transfusion will be tions of PNL and SWL. required is greater for percutaneous nephrolithoto- The panel’s recommendations regarding use of my, combination therapy, and open surgery than for these modalities to treat struvite staghorn calculi shock-wave lithotripsy monotherapy. are based on the outcomes analysis presented in Rates of complications following the four treat- detail in Chapter 3. ment modalities differ significantly for each modal- ity. From the patient’s viewpoint, a complication TREATMENT OUTCOMES AND may have the same importance as a secondary, TREATMENT RECOMMENDATIONS unplanned procedure, inasmuch as it may require a The panel concluded, from reviewing the litera- second anesthetic procedure or prolong the ture and analyzing the data, that the following out- patient’s hospital stay. Therefore, an analysis com- come probabilities are the most significant in set- bining secondary, unplanned procedures and the ting forth recommendations for treatment of stru- complications associated with the primary treat- vite staghorn calculi: ment modalities chosen may accurately reflect the Archived Document—patient’s viewpoint regarding desirability or unde- • The probability of being stone free following sirability of a given intervention. treatment; Of all four treatment modalities, shock-wave • The probability of undergoingFor secondary,Referencelithotripsy monotherapy Only has the highest combined unplanned procedures; and complication and secondary, unplanned interven- tion rate. However, the complications associated • The probability of having complications associ- ated with the chosen primary treatment modality. with shock-wave lithotripsy monotherapy tend to be less severe than those associated with percuta- The four modalities of open surgery, PNL, SWL, neous nephrolithotomy, combination therapy, or and combination PNL and SWL are all reasonable open surgery. treatment alternatives for patients with struvite The peer-reviewed literature does not stratify staghorn calculi. However, outcome probabilities outcomes appropriately by either size or composi- differ markedly among the four. The following tion of staghorn calculi or the anatomy of the col- statements are based on both statistical analysis of lecting system. Nevertheless, the panel believes abstracted data from the treatment literature and that these factors impact the outcomes of alterna- expert opinion. They form the basis of the panel’s tive treatment procedures. recommendations: Also, when choosing a treatment alternative, The risk of having residual fragments following special circumstances such as the patient’s overall initial treatment is clearly higher after shock-wave lithotripsy monotherapy than after percutaneous health, body habitus, and other medical problems nephrolithotomy, combination therapy, or open need to be taken into consideration by the treating surgery. physician. It is the expert opinion of the panel that residual THE PATIENT fragments of infected calculi left in the renal col- lecting system may be associated with recurrent Panel recommendations for the treatment of infections and eventual regrowth of these fragments staghorn calculi apply to standard and nonstandard into significant stones leading to additional morbid- patients whose stones are presumed to be com- ity, although literature to support this opinion is posed of struvite (magnesium ammonium phos- scarce. phate).

19 A “standard patient” is defined as an adult those treated with observation alone compared to patient who has two functioning kidneys (function 81 percent for those who underwent nephrolithoto- of both kidneys relatively equal) or a solitary kid- my. ney with substantially normal function, and whose Another study [Blandy and Singh, 1976] overall medical condition, body habitus, and anato- reviewed a group of 185 patients with staghorn cal- my permit performance of any of the four accepted culi. Sixty of these patients were treated with ob- active treatment modalities including use of anes- servation alone, and 125 had surgical removal of thesia. their stones. The operated group had a 7.2-percent A “nonstandard patient” is defined as one with mortality rate over a 10-year period, but 28 percent a struvite staghorn stone who does not fulfill the of those in the observation-only group died over above criteria. For this patient, the choice of avail- that period. Significant hydronephrosis was noted able treatment options may be limited to three or in another 15 percent. even fewer of the four accepted active treatment In a recent study of 167 patients, 61 of whom modalities, depending on individual circumstances. were followed for an average of nearly eight years, The standards and guidelines recommended by one-third had chronic renal failure secondary to the panel apply to the treatment of standard pa- bilateral staghorn stones and seven died of uremia tients, followed by options for nonstandard pa- [Koga, Arakaki, Matsuoka, et al., 1991]. Twenty- tients. five percent had nephrectomy revealing changes of The terms standards, guidelines, and options, as hydronephrosis, abscess, and pyelonephritis. used in the panel’s recommendations, refer to the It is clear that left untreated, a struvite staghorn three levels of flexibility for treatment policies. A will eventually destroy the kidney. Patients will standard is the least flexible of the three, a guide- usually have recurrent urinary tract infections, line more flexible, and an option the most flexible. episodes of sepsis, and pain. Also, the stone has a significant chance of causing death in the affected RECOMMENDATIONS:STANDARDS patients. Nonsurgical treatment, that is, manage- Archived Document—ment with antibiotics and supportive measures 1. As a standard, a newly diagnosed struvite only, is not considered a viable option except in staghorn calculus represents an indication for those patients otherwise too ill to tolerate stone active treatment intervention.For Although Reference this rec- removal. Only ommendation was not formally subjected to data 2. As a standard, a patient with a newly diagnosed abstracting and statistical methods, the panel struvite staghorn calculus must be informed strongly believes based on expert opinion that a about the four accepted active treatment modali- policy of watchful waiting and observation is not ties, including the relative benefits and risks in the best interest of the standard patient with associated with each of these treatments. struvite staghorn calculi. Although, as a practical matter, it is evident that In previous years, some physicians thought that the availability of equipment and the expertise of patients with staghorn stones were better left an individual practitioner may impact the choice of untreated, without efforts to remove the stone a treatment intervention, it is unacceptable to with- [Libertino, Newman, Lytton, et al., 1971]. This hold certain treatments from the patient and not idea was based on the concept that staghorn calculi offer them as alternatives because of personal inex- were likely to be asymptomatic except for bacteri- perience or unfamiliarity with one of the accepted uria and that if symptoms were few, it was hard to treatment modalities, or because of the local justify the aggressive surgical procedures necessary unavailability of equipment or expertise. to render the patient stone free. Review of the lit- erature, however, reveals that few patients do well RECOMMENDATIONS:GUIDELINES without the removal of their stones [Rous and Turner, 1977]. 1. As a guideline, percutaneous stone removal, fol- At the Mayo Clinic, the histories of 382 patients lowed by shock-wave lithotripsy and/or repeat with staghorn calculi were reviewed [Priestly and percutaneous procedures as warranted, should be Dunn, 1949]. Two hundred and thirty-four patients utilized for most standard patients with struvite had only a unilateral staghorn calculus. In these staghorn calculi, with percutaneous lithotripsy patients, the survival rate was only 41 percent for being the first part of the combination therapy.

20 2. As a guideline, shock-wave lithotripsy mono- for shock-wave lithotripsy. Future studies in which therapy should not be used for most standard other machines are used, as monotherapy or in patients as a first-line treatment choice. combination with other modalities, could change the results of treatment requirements. 3. As a guideline, open surgery (nephrolithotomy by any method) should not be used for most Notwithstanding these limitations, the panel standard patients as a first-line treatment choice. believes that the standards, guidelines, and options presented are well supported by the data reviewed. Recommendations are founded primarily on the ECOMMENDATIONS PTIONS R :O data and partially on the expert opinion of panel 1. As options, shock-wave lithotripsy monotherapy members. Outcomes for which there is consider- and percutaneous lithotripsy monotherapy are able uncertainty are clearly identified as such in the equally effective treatment choices for small- document. Whenever the panel’s expert opinion volume struvite staghorn calculi in collecting prevailed over the limited amount of available data, systems which are of normal or near normal this is specified in the document as well. anatomy. Panel recommendations are made with the knowledge that they have not undergone review by 2. As an option, open surgery is an appropriate the public. Further, the panel acknowledges that treatment alternative in unusual situations where although issues of expense may have a bearing on a staghorn calculus is not expected to be remov- treatment choices, the panel is unable to address able by a reasonable number of percutaneous this aspect of the problem at the present time. lithotripsy and/or shock-wave lithotripsy proce- Moreover, to date, no patient preference analysis dures. has been performed to validate the recommenda- 3. As an option for a patient with a poorly func- tions of the panel. Rather, the panel acted as tioning, stone-bearing kidney, nephrectomy is a patient advocate and recommended treatment reasonable treatment alternative. choices based on the balance sheet while acting as Archived Document—a “proxy patient.” The panel realizes that this RECOMMENDATION LIMITATIONS method is less than ideal and may not reflect the thinking of actual patients, but it is currently the Limitations to the processFor of developing Reference treat- method most Only available to formulate treatment rec- ment recommendations became apparent during the ommendations. panel’s review of the literature. Most obviously, for the purpose of this document, there is no uni- BASIC RESEARCH NEEDS form system of categorizing staghorn calculi, no standard method of describing the collecting sys- Four basic improvements are needed to build a tem, and no widely accepted system of reporting more solid foundation for future research on the size of staghorn calculi. staghorn calculi: Few prospective, randomized, controlled studies 1. A consistent method of classifying staghorn cal- have been conducted concerning the treatment of culi needs to be devised, including an accepted struvite staghorn calculi. In addition, there is no system for reporting size. uniform system in the literature for reporting out- 2. A consistent method of describing the collecting comes following treatment for struvite staghorn system also needs to be devised. calculi. Further uncertainty stems from differences in 3. Uniform methods of reporting outcomes are health care delivery systems in various countries as needed. For example, in reporting stone-free they impact the outcomes reported in the literature. rates, distinctions need to be made between Variability in the data leads to uncertainty in out- stone free and stone free with “insignificant” come estimates, which leads to flexibility in rec- residual fragments. ommendations. This limitation applies to a variety 4. Parameters need to be established for stratifying of outcomes. study results in terms of demographic data – for Also, in most of the papers reviewed for this example, in terms of a study population’s size document, the unmodified Dornier HM-3 was used and composition.

21 References*

1. * Alken P, Thüroff, JW, Hammer, C. The use of operative ultra- 19. Bruce RR, Griffith DP. Retrospective follow-up of patients with sonography for the localization of renal calculi. World Journal of struvite calculi. In: Smith LH, Robertson WGL, Finlayson, B, Surgery 1987;11:586-92. editors. Urolithiasis Clinical and Basic Research. New York: 2. Alken, P. Percutaneous ultrasonic destruction of renal calculi. Plenum Press; 1981, p. 191. Urol Clin North Am 1982;9:145-51. 20. * Bueschen AJ, Zahm MJ, Lloyd, LK. Adjuvant surgical tech- 3. * Androulakakis PA, Michael V, Polychronopoulou S, niques in the removal of staghorn calculi. J Urol 1980;123:342-4. Aghioutantis C. Evaluation of open surgery for staghorn calculi 21. * Buttarazzi PJ, Devine PC, Devine CJ Jr, Poutasse EF. The in children. Child Nephrol Urol 1990;10:139-42. indications, complications and results of partial nephrectomy. J 4. * Aso Y, Ohta N, Nakano M, Ohtawara Y, Tajima A, Kawabe K. Urol 1968;99:376-8. Treatment of staghorn calculi by fiberoptic transurethral 22. * Cato AR, Tulloch AGS. Hypermagnesemia in a uremic patient nephrolithotripsy. J Urol 1990;144:17-19. during renal pelvis irrigation with Renacidin. J Urol 5. * Assimos DG, Wrenn JJ, Harrison LH, McCullough DL, Boyce 1974;111:313-14. WH, Taylor CL, Zagoria RJ, Dyer RB. A comparison of anat- 23. Chaussy C, Schmiedt E, Jocham D, Brendel W, Forssmann B, rophic nephrolithotomy and percutaneous nephrolithotomy with Walther V. First clinical experience with extracorporeally and without extracorporeal shock wave lithotripsy for manage- induced destruction of kidney stones by shock waves. J Urol ment of patients with staghorn calculi. J Urol 1991;145:710-14. 1982;127:417-20. 6. Assimos DG, Boyce WH, Harrison LH, McCullough DL, 24. * Chen J, Hsu TC. Staged ESWL monotherapy of complete Kroovand RL, Sweat KR. The role of open stone surgery since renal staghorn calculi. J Formosan Med Assoc 1991;90:48-52. extracorporeal shock wave lithotripsy. J Urol 1989;142:263-7. 25. Clayman RV, McClennan BL, Garvin TJ, Denstedt JD, Andriole 7. * Beck EM, Riehle RA Jr. The fate of residual fragments after GL. Lithostar: an electromagnetic acoustic shock wave unit for extracorporeal shock wave lithotripsy monotherapy of infection stones. J Urol 1991;145:6-10. extracorporeal lithotripsy. J Endourol 1989;3:307-13. 8. Beck EM, Vaughan ED Jr, Sosa RE. The pulsed dye laser in the 26. * Clayman RV, Surya V, Miller RP, Castaneda-Zuniga WR, treatment of ureteral calculi [Review]. Semin Urol 1989;7:25-9. Amplatz K, Lange PH. Percutaneous nephrolithotomy. An Archived Document—approach to branched and staghorn renal calculi. JAMA 9. * Begun FP, Jacobs SC, Lawson RK. Small-bowel perforation 1983;250:73-5. during percutaneous nephrolithotomy. J Endourol 1989;3:81-4. 27. * Constantinides C, Recker F, Jaeger P, Hauri D. Extracorporeal 10. Begun FP, Jacobs SC, LawsonFor RK. Use of a prototypeReference 3F elec- shock wave lithotripsy Only as monotherapy of staghorn renal calculi: trohydraulic electrode with ureteroscopy for treatment of ureteral 3 years of experience. J Urol 1989;142:1415-18. calculous disease. J Urol 1988;139:1188- 91. 28. * Constantinople NL, Waters WB, Yalla SV. Operative versus 11. * Belis JA, Morabito RA, Kandzari SJ, Lai JCW, Gabriele OF. non-operative management of patients with staghorn calculi and Anatrophic nephrolithotomy: preservation of renal function neurogenic bladder. J Urol 1979;121:716-18. demonstrated by differential quantitative radionuclide renal scans. J Urol 1981;125:761-4. 29. Coptcoat MJ, Ison KT, Watson G, Wickham JEA. Lasertripsy for ureteral stones: 100 clinical cases. J Endourol 1987;1:119-22. 12. * Blandy JP, Singh M. The case for a more aggressive approach to staghorn stones. J Urol 1976;115:505-6. 30. Denstedt JD, Clayman, RV. Electrohydraulic lithotripsy of renal 13. * Blandy JP, Tresidder GC. Extended pyelolithotomy for renal and ureteral calculi. J Urol 1990;143:13-17. calculi. Br J Urol 1967;39:121-30. 31. Denstedt JD, Clayman RV, Picus DD. Comparison of endoscopic 14. * Bloom LS, Nieh PT. Retrograde nephrostolithotomy in man- and radiological residual fragment rate following percutaneous agement of complex renal calculi. J Urol 1991;145:706-9. nephrolithotripsy. J Urol 1991;145:703- 5. 15. * Böhle A, Knipper A, Thomas S. Extracorporeal shock wave 32. * Di Silverio F, Gallucci M, Alpi G. Staghorn calculi of the kid- lithotripsy in paediatric patients. Scand J Urol Nephrol ney: classification and therapy. Br J Urol 1990;65:449-452. 1989;23:137-40. 33. * Drach GW, Dretler S, Fair W, Finlayson B, Gillenwater J, 16. * Boyce WH. Surgery of urinary calculi in perspective. Urol Griffith D, Lingeman J, Newman D. Report of the United States Clin North Am 1983;10:585-94. cooperative study of extracorporeal shock wave lithotripsy. J Urol 1986;135:1127-33. 17. * Boyce WH, Elkins IB. Reconstructive renal surgery following anatrophic nephrolithotomy: followup of 100 consecutive cases. 34. Dretler SP. Laser photofragmentation of ureteral calculi: analysis J Urol 1974;111:307-12. of 75 cases. J Endourol 1987;1:9-14. 18. Brown RD, Preminger, GM. Changing surgical aspects of uri- 35. Dretler SP, Bhatta KM. Clinical experience with high power (140 nary stone disease [Review]. Surg Clin North Am 1988;68:1085- mj), large fiber (320 micron) pulsed dye laser lithotripsy. J Urol 1104. 1991;146:1228-31.

*Articles that were selected for review, abstracted, included in evidence tables, and stratified by staghorn calculi, for meta-analysis of outcome data, are preceded by an asterisk (*). These articles, 110 in total, are also listed in Table A- 1 in Appendix A.

22 36. Dretler SP, Watson G, Parrish JA, Murray S. Pulsed dye laser 58. * James R, Novick AC, Straffon RA, Stewart BH. Anatrophic fragmentation of ureteral calculi: initial clinical experience. J nephrolithotomy for removal of staghorn or branched renal cal- Urol 1987;137:386-9. culi. Urology 1980;15:108-11. 37. Eddy DM. The confidence profile method: a Bayesian method 59. Jewett MAS, Bombardier C, Caron D, Ryan MR, Gray RR, St. for assessing health technologies. Oper Res 1989;37(2):210-28. Louis EL, Witchell SJ, Kumra S, Psihramis KE. Potential for inter-observer and intra-observer variability in x-ray review to 38. Eddy DM. Clinical decision making: from theory to practice. establish stone-free rates after lithotripsy. J Urol 1992;147:559- Comparing benefits and harms: the balance sheet. JAMA 62. 1990;263:2493-2505. 60. * Kahnoski RJ, Lingeman JE, Coury TA, Steele RE, Mosbaugh 39. Eddy, DM. A manual for assessing health practices & designing PG. Combined percutaneous and extracorporeal shock wave practice policies: the explicit approach. Philadelphia (PA): lithotripsy for staghorn calculi: an alternative to anatrophic American College of Physicians; 1992. 126 p. nephrolithotomy. J Urol 1986;135:679-81. 40. Eddy DM, Hasselblad V. FAST*PRO. Software for meta-analysis 61. * Katz G, Meretyk S, Verstandig A, Sharpiro A. Persistence of by the confidence profile method. San Diego: Academic Press, matrix material in urinary collecting system after extracorporeal Inc. Harcourt Brace Jovanovich; 1992. 196 p. shock wave lithotripsy. J Endourol 1990;4:235-9. 41. Eddy DM, Hasselblad, V, Shachter, R. A Bayesian method for 62. * Kawamura J, Itoh H, Okada Y, Higashi Y,Yoshida O, Fujita T, synthesizing evidence: the confidence profile method. Int J Torizuka K. Preoperative and postoperative cortical function of Technol Assess Health Care 1990;6:31-55. the kidney with staghorn calculi assessed by 99 mtechnetium- 42. * Eshghi AM, Roth JS, Smith AD. Percutaneous transperitoneal dimercaptosuccinic acid renal scintigraphy. J Urol 1983;130:430- approach to a pelvic kidney for endourological removal of 3. staghorn calculus. J Urol 1985;134:525-7. 63. * Kerlan RK Jr, Kahn RK, Laberge JM, Pogany AC, Ring EJ. 43. * Eshghi M, Smith AD. Endourologic approach to transplant Percutaneous removal of renal staghorn calculi. Am J Roentgenol kidney. Urology 1986;28:504-7. 1985;145:797-801. 44. * Farcon EM, Morales P, Al-Askari S. In vivo hypothermic per- 64. * Koga S, Arakaki Y, Matsuoka M, Ohyama C. Staghorn calculi fusion during renal surgery. Urology 1974;3:414-20. long-term results of management. Br J Urol 1991;68:122-4. 45. Feagins BA, Wilson WT, Preminger GM. Intracorporeal electro- 65. * Korth K, Bernius U. Percutaneous litholapaxy. Urol Int hydraulic lithotripsy with flexible ureterorenoscopy. J Endourol 1986;41:375-84. 1990;4:347-51. 66. * Lalude AO, Martin DC. Renal arteriovenous fistula: a compli- 46. * Fiorentini L, Minervini R, Palla R, Bianchi C. The effect of cation of anatrophic nephrolithotomy. J Urol 1983;130:754-6. bivalve nephrotomy on renal function in patients with staghorn Archived Document—67. * Lam HS, Lingeman JE, Barron M, Newman DM, Mosbaugh calculi. J Nucl Med Allied Sci 1980;24:159-61. PG, Steele RE, Knapp PM, Scott JW, Nyhuis A, Woods JR. 47. * Fuchs AM, Wolfson BA, Fuchs GJ. Staghorn stone treatment Staghorn calculi: analysis of treatment results between initial per- with extracorporeal shock wave lithotripsy monotherapy: long- cutaneous nephrostolithotomy and extracorporeal shock wave term results. J Endourol 1991;5:45-8.For Referencelithotripsy monotherapyOnly with reference to surface area. J Urol 48. * Giuliani L, Martorana G, Giberti C, Pescatore D. Bivalve 1992;147:1219-25. nephrolithotomy in kidneys with ileal ureter. J Urol 68. * Lam HS, Lingeman JE, Mosbaugh PG, Steele RE, Knapp PM, 1979;122:815-16. Scott JW, Newman DM. Evolution of the technique of combina- 49. * Gleeson M, Lerner SP, Griffith DP. Treatment of staghorn cal- tion therapy for staghorn calculi: a decreasing role for extracorpo- culi with extracorporeal shock-wave lithotripsy and percutaneous real shock wave lithotripsy. J Urol 1992;148:1058-62. nephrolithotomy. Urology 1991;38:145-51. 69. * Lazare JN, Saltzman B, Sotolongo J. Extracorporeal shock 50. Green DF, Lytton B. Early experience with direct vision electro- wave lithotripsy treatment of spinal cord injury patients. J Urol hydraulic lithotripsy of ureteral calculi. J Urol 1985;133:767-70. 1988;140:266-9. 51. * Harada M, Ko ZR, Kamidono S. Experience with extracorpo- 70. * Lee WJ, Snyder JA, Smith AD. Staghorn calculi: endourologic real shock wave lithotripsy for cystine calculi in 20 renal units. J management in 120 patients. Radiology 1987;165:85-8. Endourol 1992;6:213-15. 71. * Libertino JA, Newman HR, Lytton B, Weiss RM. Staghorn 52. Hatziandreu EE, Carlson K, Mulley AG Jr, Weinstein MC. Cost- calculi in solitary kidneys. J Urol 1971;105:753-7. effectiveness study of the extracorporeal shock-wave lithotriptor. 72. * Liston TG, Montgomery BSI, Bultitude MI, Tiptaft RC. Int J Technol Assess Health Care 1990;6:623-32. Extracorporeal shock wave lithotripsy with the Storz Modulith 53. Higashihara E, Horie S, Takeuchi T, Kameyama S, Asakage Y, SL20: the first 500 patients. Br J Urol 1992;69:465-9. Hosaka Y, Honma Y, Minowada S, Aso Y. Laser ureterolithotrip- 73. * Mahmood P, Morales PA. Extended pyelolithotomy (Gil sy with combined rigid and flexible ureterorenoscopy. J Urol Vernet’s pyelotomy). J Urol 1973;109:772-4. 1990;143:273-4. 74. * Marshall VF, Lavengood RW Jr, Kelly D. Complete longitudi- 54. Hofmann R, Hartung R. Use of pulsed Nd:YAG laser in the nal nephrolithotomy and the Shorr regimen in the management of ureter. Urol Clin North Am 1988;15:369-75. staghorn calculi. Ann Surg 1965;162:366-73. 55. * Hofmann R, Stoller ML. Endoscopic and open stone surgery 75. * Martin X, Salas M, Labeeuw M, Pozet N, Gelet A, Dubernard in morbidly obese patients. J Urol 1992;148:1108-11. JM. Cystine stones: the impact of new treatment. Br J Urol 56. Huffman JL. Early experience with the 8.5 F compact uretero- 1991;68:234-9. scope. Sur Endosc 1989;3:164-6. 76. * Matsuoka K, Ueda S, Eto K. A clinical study of percutaneous 57. * Hutchison AG. Cystine stones treated by surgery and D-peni- nephroureterolithotripsy. Kurume Med J 1990;37:247-51. cillamine. Proc R Soc Med 1968;61:1144-6.

23 77. * Mays N. Relative costs and cost-effectiveness of extracorpore- 99. Preminger GM, Schultz S, Clayman RV, Curry T, Redman HC, al shock-wave lithotripsy versus percutaneous nephrolithotomy in Peters PC. Cephalad renal movement during percutaneous the treatment of renal and ureteric stones. Soc Sci Med nephrostolithotomy. J Urol 1987;137:623-5. 1991;32:1401-12. 100. Priestly JT, Dunn JH. Branched renal calculi. J Urol 78. * McDonald DF. Surgical management of stag-horn renal cal- 1949;61:194-203. culi. South Med J 1974;67:1067-9. 101. * Puppo P, Bottino P, Germinale F, Caviglia C, Ricciotti G, 79. Michaels EK, Fowler JE Jr. Extracorporeal shock wave lithotrip- Giuliani L. Percutaneous debulking of staghorn stones combined sy for struvite renal calculi: prospective clinical study with with extracorporeal shockwave lithotripsy: results and complica- extended follow-up. J Urol 1991;146:728-32. tions. Eur Urol 1988;15:18-25. 80. * Middleton RG, Marshall VF. Complete longitudinal 102. Raney AM. Electrohydraulic lithotripsy: experimental study and nephrolithotomy for staghorn calculi in children. J Urol case reports with the stone disintegrator. J Urol 1975;113:345-7. 1971;106:776-9. 103. Raney AM, Handler J. Electrohydraulic nephrolithotripsy. 81. Morgentaler A, Bridge SS, Dretler SP. Management of the Urology 1975;6:439-42. impacted ureteral calculus. J Urol 1990;143:263-6. 104. * Redman JF, Bissada NK. Extensive nephrolithotomy in previ- 82. Nemoy NJ, Stamey TA. Surgical, bacteriological, and biochemi- ously operated solitary kidneys. J Urol 1976;115:502-4. cal management of infection stones. JAMA 1971;215:470. 105. * Redman JF, Bissada NK, Harper DL. Anatrophic nephrolitho- 83. * Nemoy NJ, Stamey TA. Use of hemiacidrin in management of tomy: experience with a simplification of the Smith and Boyce infection stones. J Urol 1976;116:693-5. technique. J Urol 1979;122:595-7. 84. * Nesbitt JA, Drago JR, Wise HA II, Nelson JH III, Perez JF. 106. * Regan JS, Lam HS, Lingeman JE. Simultaneous bilateral per- Extracorporeal shock wave lithotripsy: first-year experience with cutaneous nephrolithotomy. J Endourol 1992;6:245-7. 1360 patients. J Endourol 1988;2:235-40. 107. * Resnick MI, Boyce WH. Bilateral staghorn calculi-patient 85. * Nijman RJM, Ackaert K, Scholtmeijer RJ, Lock TWTM, evaluation and management. J Urol 1980;123:338-41. Schröder FH. Long-term results of extracorporeal shock wave 108. Resnick MI. The craft of urologic surgery. lithotripsy in children. J Urol 1989;142:609-11. Pyelonephrolithotomy for removal of calculi from the inferior 86. Patel VJ. The coagulum pyelolithotomy. Br J Surg 1973;60:230- renal pole. Urol Clin North Am 1981;8:585-90. 6. 109. Reuter HJ, Kern E. Electronic lithotripsy of ureteral calculi. J 87. * Patterson DE, Segura JW, LeRoy AJ. Long-term follow-up of Urol 1973;110:181-3. patients treated by percutaneous ultrasonic lithotripsy for struvite 110. * Rigatti P, Francesca F, Montorsi F, Consonni P, Guazzoni G, Di staghorn calculi. J EndourolArchived 1987;1:177-80. Document—Girolamo V. Extracorporeal lithotripsy and combined surgical 88. * Peiser J, Kaneti J, Lissmer L, Klain J, Blank C, Hertzanu Y. procedures in the treatment of renoureteral stone disease: our Perinephric inflammatory process following extracorporeal shock experience with 2,955 patients. World Journal of Surgery wave lithotripsy. Int Urol NephrolFor 1991;23:107- Reference 11. 1989;13:765-75. Only 89. * Petersen HK, Moller BB, Iversen HG. Regional hypothermia 111. * Rodrigues Netto N Jr, Lemos GC, Palma PCR, Fiuza JL. in renal surgery for severe lithiasis. Scand J Urol Nephrol Staghorn calculi: percutaneous versus anatrophic nephrolithoto- 1977;11:27-34. my. Eur Urol 1988;15:9-12. 90. * Petersen SE, Olesen S, Jörgensen TM, Wolf H. Initial experi- 112. * Rous SN, Turner WR. Retrospective study of 95 patients with ence with percutaneous nephrolithotomy: results, problems and staghorn calculus disease. J Urol 1977;118:902-4. complications. Scand J Urol Nephrol Suppl 1987;104:145-50. 113. * Rovinescu I, Bélanger PM, Lapalme R. A new technique for 91. * Pettersson B, Tiselius H-G. One-year follow-up of unselected removal of staghorn calculi. The pyelo-renal flap. Urol Int group of renal stone formers treated with extracorporeal shock 1968;23:326-34. wave lithotripsy. J Endourol 1989;3:19-30. 114. * Russell JM, Harrison LH, Boyce, WH. Recurrent urolithiasis 92. * Pettersson B, Tiselius H-G, Andersson A, Eriksson I. following anatrophic nephrolithotomy. J Urol 1981;125:471-4. Evaluation of extracorporeal shock wave lithotripsy without anes- 115. * Ruys JCA, Moonen WA. Our experiences dealing with one thesia using a Dornier HM3 lithotriptor without technical modifi- hundred patients with staghorn calculi. Arch Chir Neerl cations. J Urol 1989;142:1189-92. 1968;20:7-14. 93. * Pettersson B, Tiselius H-G, Carlsson P, Rahmqvist M. What 116. * Ryan PC, Butler MR. EDAP LT01 lithotripter. J Endourol do our patients have to endure in order to get their stones 1988;2:181-7. removed? Scand J Urol Nephrol Suppl 1989;122:29-33. 117. * Schmeller NT, Kersting H, Schüller J, Chaussy C, Schmiedt E. 94. * Picus D, Weyman PJ, Clayman RV, McClennan BL. Combination of chemolysis and shock wave lithotripsy in the Intercostal-space nephrostomy for percutaneous stone removal. treatment of cystine renal calculi. J Urol 1984;131:434-8. Am J Roengenol 1986;147:393-7. 118. * Schulze H, Hertle L, Kutta A, Graff J, Senge T. Critical evalu- 95. * Pode D, Caine M, Pfau A, Shapiro A, Lencovsky Z, Katz G, ation of treatment of staghorn calculi by percutaneous Davidson JT. Shock-wave treatment for stones in the kidney and nephrolithotomy and extracorporeal shock wave lithotripsy. J ureter. The Jerusalem experience. Isr J Med Sci 1987;23:243-8. Urol 1989;141:822-5. 96. * Pode D, Lenkovsky Z, Shapiro A, Pfau A. Can extracorporeal 119. Segura JW, Patterson DE, LeRoy AJ, Williams HJ Jr, Barrett DM, shock wave lithotripsy eradicate persistent urinary infection asso- Benson RC Jr, May GR, Bender CE. Percutaneous removal of ciated with infected stones? J Urol 1988;140:257-9. kidney stones: review of 1,000 cases. J Urol 1985;134:1077-81. 97. Preminger GM. Sonographic piezoelectric lithotripsy: more bang 120. * Selli C, Carini M. Treatment of large renal calculi with extra- for your buck. J Endourol 1989;3:321-7. corporeal shock wave lithotripsy monotherapy. Eur Urol 98. Preminger GM, Roehrborn CG. Special applications of flexible 1988;15:161-5. deflectable ureterorenoscopy. Semin Urol 1989;7:16-24.

24 121. * Shioshvili TI. Results of the clinical use of a ‘dry’ kidney’s 137. * Tóth C, Holman E, Khan MA. Nephrostolithotomy monother- hypothermia. Eur Urol 1977;3:154-8. apy for staghorn calculi. J Endourol 1992;6:239-43. 122. * Silber N, Kremer I, Gaton DD, Servadio C. Severe sepsis fol- 138. * Valente R, Marini F, Signori G. Combined therapy of staghorn lowing extracorporeal shock wave lithotripsy. J Urol calculi with ureteroscopy and extracorporeal shock wave lithotrip- 1991;145:1045-6. sy. Experience with 10 cases. Eur Urol 1988;14:349-52. 123. * Singh M, Marshall V, Blandy J. The residual renal stone. Br J 139. * Vanden Bossche M, Simon J, Schulman CC. Shock wave Urol 1975;47:125-9. monotherapy of staghorn calculi. Eur Urol 1990;17:1-6. 124. * Singh M, Chapman R, Tresidder GC, Blandy J. The fate of the 140. * Vandeursen H, Baert L. Extracorporeal shock wave lithotripsy unoperated staghorn calculus. Br J Urol 1973;45:581-5. monotherapy for staghorn stones with the second generation lithotriptors. J Urol 1990;143:252-6. 125. * Singh M, Tresidder GC, Blandy J. The long-term results of removal of staghorn calculi by extended pyelolithotomy without 141. * Vandeursen H, Devos P, Baert L. Electromagnetic extracorpo- cooling or renal artery occlusion. Br J Urol 1971;43:658-64. real shock wave lithotripsy in children. J Urol 1991;145:1229-31. 126. * Smith MJV, Boyce WH. Anatrophic nephrotomy and plastic 142. * Vargas AD, Bragin SD, Mendez R. Staghorn calculus: its clin- calyrhaphy. J Urol 1968;99:521-7. ical presentation, complications and management. J Urol 1982;127:860-2. 127. * Spirnak JP, DeBaz BP, Green HY, Resnick MI. Complex stru- vite calculi treated by primary extracorporeal shock wave 143. * Virgili G, Vespasiani G, Mearini E, Di Stasi SM, Micali F. lithotripsy and chemolysis with hemiacidrin irrigation. J Urol Extracorporeal piezoelectric lithotripsy: experience in 930 1988;140:1356-9. patients. J Endourol 1992;6:309-14. 128. * Stage KH, Lewis S. Pre- and postoperative evaluation of renal 144. * Walton JK. A New Zealand experience of staghorn calculus function in patients with staghorn calculi utilizing quantitative surgery. Aust N Z J Surg 1978;48:301-3. renal scanning. Urology 1981;17:29-32. 145. Weber HM, Miller K, Rüschoff J, Gschwend J, Hautmann, RE. 129. * Stenzl A, Fuchs GJ, Fuchs AM. Extracorporeal shock wave Alexandrite laser lithotripter in experimental and first clinical lithotripsy of pelvic allograft kidney. J Endourol 1988;2:19-22. application. J Endourol 1991;5:51-5. 130. * Streem SB, Geisinger MA, Risius B, Zelch MG, Siegel SW. 146. * Wickham JEA, Mathur VK. Hypothermia in the conservative Endourologic “sandwich” therapy for extensive staghorn calculi. surgery of renal disease. Br J Urol 1971;43:648-57. J Endourol 1987;1:253-9. 147. * Winfield HN, Clayman RV, Chaussy CG, Weyman PJ, Fuchs 131. * Streem SB, Lammert G. Long-term efficacy of combination GJ, Lupu AN. Monotherapy of staghorn renal calculi: a compara- therapy for struvite staghorn calculi. J Urol 1992;147:563-6. tive study between percutaneous nephrolithotomy and extracorpo- real shock wave lithotripsy. J Urol 1988;139:895-9. 132. * Stubbs AJ, ResnickArchived MI. Struvite staghorn calculi in crossed Document— fused ectopia. J Urol 1977;118:369-71. 148. * Wirth MP, Theiss M, Frohmuller HGW. Primary extracorpore- al shock wave lithotripsy of staghorn renal calculi. Urol Int 133. Stubbs AJ, Resnick MI, Boyce WH. Anatrophic nephrolithotomy 1992;48:71-5. in the solitary kidney. J UrolFor 1978;119:457-60. Reference Only 149. * Woodhouse CRJ, Farrell CR, Paris AMI, Blandy JP. The place 134. * Thomas R, Lewis RW, Roberts JA. The renal quantitative scin- of extended pyelolithotomy (Gil-Vernet operation) in the manage- tillation camera study for determination of renal function after ment of renal staghorn calculi. Br J Urol 1981;53:520-3. anatrophic nephrolithotomy. J Urol 1981;125:287-8. 150. * Wulfsohn MA. Extended pyelolithotomy: the use of renal 135. * Thornhill JA, Moran K, Mooney EE, Sheehan S, Smith JM, artery clamping and regional hypothermia. J Urol 1981;125:467- Fitzpatrick JM. Extracorporeal shockwave lithotripsy monother- 70. apy for paediatric urinary tract calculi. Br J Urol 1990;65:638- 40. 151. * Young AT, Hulbert JC, Cardella JF, Hunter DW, Castaneda- Zuniga WR, Reddy P, Amplatz K. Percutaneous nephrostolitho- 136. * Tombolini P, Mandressi A, Ruoppolo M, Dormia G, Trinchieri tomy: application to staghorn calculi. Am J Roentgenol A, Zanetti G, Montanari E, and Pisani E. The percutaneous treat- 1985;145:1265-9. ment of the cast, branched and staghorn renal stones. Contrib Nephrol 1987;58:270-3.

25 Archived Document— For Reference Only

A. 1 Archived Document— For Reference Only

A. 2 Archived Document— For Reference Only

A. 3 Archived Document— For Reference Only

A. 4 Archived Document— For Reference Only

A. 5 Archived Document— For Reference Only

A. 6 Archived Document— For Reference Only

A. 7 Archived Document— For Reference Only

A. 8 Archived Document— For Reference Only

A. 9 Archived Document— For Reference Only

A. 10 Archived Document— For Reference Only

A. 11 Archived Document— For Reference Only

A. 12 Archived Document— For Reference Only

A. 13 Archived Document— For Reference Only

A. 14 Archived Document— For Reference Only

A. 15 Archived Document— For Reference Only

A. 16 Archived Document— For Reference Only

B. 1 Archived Document— For Reference Only

B. 2 Appendix C: Description of available techniques for management of renal and ureteral calculi

SHOCK-WAVE LITHOTRIPSY stone localization provided by biplanar fluoroscopy. Modifications of the four basic components of the HM-3 Since the first patient with a renal calculus was suc- lithotripter have now provided a new class of lithotrip- cessfully treated with shock-wave lithotripsy in 1980, ters of which ten machines are currently either available this form of stone therapy has rapidly gained widespread commercially or undergoing clinical trials. This section acceptance to become the treatment of choice for the on new instrumentation reviews the features and princi- majority of renal and ureteral calculi. Worldwide clini- pal differences between these lithotripters with regard to cal series have documented the efficacy of shock-wave shock-wave generation, focusing, patient coupling, and lithotripsy [Chaussy, Schmiedt, Jocham, et al., 1982; stone localization. Brown and Preminger, 1988]. Shock waves are high-energy amplitudes of pressure Shock-wave generation generated in the air or water by an abrupt release of The two basic types of energy sources for generating energy in a small space. They propagate according to shock waves are point sources and extended sources. the physical laws of acoustics and are transmitted The electrohydraulic devices (Dornier, Direx, Medstone, through media with low attenuation. When a shock Northgate, and Technomed) utilize point sources for wave encounters a boundary between substances of dif- energy generation, whereas extended sources are incor- fering acoustic impedance (density), compressive stress- porated in the piezoelectric devices (Diasonics, EDAP, es are generated that may overcome the tensile strength and Wolf) and the electromagnetic devices (Siemens). of that object. Shock waves travel through water and the soft tissues of the body with low attenuation because The electrohydraulic shock-wave generator is located these materials have similarArchived densities. Document—at the base of a water bath and produces shock waves by an electric spark-gap of 15,000 to 25,000 volts of one However, when kidney stones of any composition are microsecond duration. The high-voltage spark discharge contacted by a shock wave of sufficient energy, a com- produces rapid evaporation of water, which generates a pression wave is induced alongFor the front Referenceface of the Only shock wave by expanding the surrounding fluid at the stone. As a result, the stone surface facing the shock first focal point (F1). This electrohydraulic generator is wave begins to crumble. As a shock wave crosses the located within an ellipsoidal reflector that concentrates opposite surface of the stone, part of the energy is re- the reflected shock waves at the second focal point (F2). flected, creating tensile stress and fragmentation. Re- peated shock waves eventually reduce the stone to small Multiple, repeated electrohydraulic shock waves from fragments, ideally 2 mm or less in diameter, which may a first-generation machine produce pain at the skin level be passed spontaneously. and within the focal region, thus requiring general or Extensive clinical testing has determined that the regional anesthesia during lithotripsy. “Anesthesia-free” compression tensile wave phenomenon results in an second-generation electrohydraulic lithotripters have implosion rather than an explosion of the fragments and been developed by widening the aperture of the ellipse that the total kinetic energy of all fragments can be min- and decreasing the overall energy intensity of the shock- imized by using a large number of relatively low-energy wave generator. However, some form of analgesia, shock waves rather than fewer shocks of higher energy. sedation, or local anesthesia is usually required with the majority of second-generation electrohydraulic Although the basic principles of shock-wave lithotripters. lithotripsy remain unchanged, a myriad of technological advances and modifications in the currently available Piezoelectric shock waves are generated by the sud- lithotripters have significantly expanded the clinical den expansion of ceramic elements excited by a high- applications. frequency, high-voltage energy pulse. The motion of the piezoceramic elements generates an ultrasonic wave Lithotripter instrumentation which in turn produces a shock wave directed to the focal point. The shock wave is then propagated through All lithotripters share four main features: an energy either a water-filled bag (EDAP and Diasonics) or basin source, a focusing device, a coupling medium, and a (Wolf). The spherical focusing mechanism of the piezo- stone-localization system. The original Dornier HM-3 electric lithotripters provides a wide region of shock- design utilizes a spark plug energy generator with an wave entry at the skin’s surface and a very small focal elliptical reflector for focusing the shock waves. A region (4 x 8 mm in the Wolf lithotripter). The combi- water bath transmits the shock waves to the patient with nation of a wide aperture of the focusing sphere, a larger

C. 1 skin-entry zone, a small focal region, and lower peak contrast material to help delineate the anatomy of the pressures generated by the piezoelectric machines has collecting system. However, fluoroscopy requires more provided an anesthesia-free form of lithotripsy. space and carries the inherent risk of ionizing radiation In the electromagnetic device (Siemens), shock to both the patient and medical staff. waves are generated when an electrical impulse moves a Ultrasonography is becoming an increasingly impor- metallic membrane that is housed within a “shock tube.” tant modality for the urologist. Sonography-based litho- The resulting shock wave produced in the water-filled tripters offer the advantages of stone localization with shock tube cylinder is focused by an acoustic lens and continuous monitoring and effective identification of coupled to the body surface with a water cushion. Some radiolucent stones, without radiation exposure [Premin- form of sedation and/or local anesthesia is usually re- ger, 1989]. Additionally, ultrasound has been document- quired during treatment with this electromagnetic litho- ed to be effective in localizing stone fragments as small tripter due to the smaller aperture and moderate peak as 2-3 mm. The major disadvantages of ultrasound pressures generated. The Dornier DLC “Compact” lith- stone localization include the need for basic mastery of otripter also utilizes an electromagnetic generator and is ultrasonic techniques by the urologist and the difficulty currently undergoing clinical trials in the U.S. in localizing ureteral stones. Shock-wave focusing Instrumentation for newer lithotripters Once shock waves are generated, they must be Currently, there are a number of lithotripters in clini- focused on the target calculus. The method of focusing cal trials that attempt to incorporate many of the charac- is dictated by the type of shock-wave generation. Mach- teristics of an “ideal lithotripter.” The basic design of ines that utilize point sources, such as the electrohy- draulic lithotripters, generate shock waves that travel in the newer machines includes dual-imaging capabilities an expanding circular pattern and require ellipsoidal re- as well as variable shock-wave power. Among these flectors for focusing the shock waves at the second focal machines are the Dornier MFL 5000 (HM5), Dornier point. The array of piezoceramic elements is positioned MPL 9000X, EDAP LT-02, Siemens Lithostar Plus, on a spherical disc, which allows focusing at a very Storz, Modulith SL-20, and Wolf Piezolith 2500. small focal region, whereas the vibrating metal mem- branes of the electromechanical lithotripter produce an Dual imaging acoustical wave that Archivedrequires a lens for focusing the Document—Dual-imaging capabilities entail having both fluoro- shock wave. scopic and sonographic localization systems available in the same machine. Such a design has the advantage of Coupling ofFor the shock Reference wave utilizing fluoroscopy Only for imaging stones within the kid- The coupling media currently utilized by the different ney, as well as the ureter, while having the option to use lithotripters ranges from a 1,000-liter water bath to an sonography for the identification of radiolucent or bil- enclosed water cushion. The water bath requires unique iary tract calculi. Moreover, sonographic capabilities positioning of the patient in the tub so that the calculus allow one to initially target a stone using fluoroscopy is at the second focal point. Recent modifications in the and then switch over to ultrasound to avoid an excessive patient gantry system of the first-generation Dornier amount of ionizing radiation. Having fluoroscopy capa- HM-3 lithotripter have allowed the treatment of children bilities may also lessen the “learning curve” for many as well as distal ureteral calculi. urologists who are unfamiliar with sonographic stone- Second-generation machines have adopted designs localization procedures. for coupling that minimize the space requirements as Interestingly, whereas the Dornier, Siemens, and well as the physiological and functional disadvantages Storz machines have all added ultrasound capabilities to of a large water bath. Current models use either an provide dual imaging, none of these systems provides enclosed water cushion, a small exposed pool of water, “in-line” imaging for both the fluoroscopic or sono- or a totally contained shock tube. The water-filled cush- graphic localization devices. For example, with the ions and shock tubes contain the shock-wave source, Dornier and Siemens devices, one can utilize sonogra- conditioned water, and a coupling membrane to allow phy to target a radiolucent or biliary tract calculus; yet simplified positioning and “dry” lithotripsy. However, the patient must be moved “blindly” to the fluoroscopy the direct water-skin interface utilized by two units unit which is in-line with the shock-wave generator. (Technomed and Wolf) is believed by some to offer im- Alternatively, it is possible to utilize the fluoroscopic proved shock-wave coupling. localization system with the Storz machine, but only the ultrasound is in-line with the shock-wave generator. Stone localization Of these devices, only the Wolf Piezolith 2500 and Stone localization during lithotripsy is accomplished EDAP LT-02 at this time have both the fluoroscopy and with either fluoroscopy or ultrasonography. Fluoros- sonography in-line with the piezoelectric shock-wave copy provides the urologist with a familiar modality and generator. This design permits rapidly changing from has the added benefits of effective ureteral stone local- fluoroscopic to sonographic stone localization without ization. Moreover, fluoroscopy facilitates the use of moving the patient off the treatment dish.

C. 2 Variable power then be passed directly into the renal collecting system to perform various manipulations. All six of the aforementioned third-generation devices have variable-power shock-wave generators that Endoscopy is begun by performing rigid or flexible allow the operator to apply the appropriate amount of nephroscopy. Although specially designed nephroscopes shock-wave energy for a particular stone. One can turn with a 30-degree side-arm viewing system are available, down the generator power to provide significantly re- a traditional panendoscope of 24 F. is equally well suit- duced anesthesia/analgesia requirements with the Dorn- ed for rigid nephroscopy and allows visualization and ier, EDAP, Siemens, and Storz machines, as well as to manipulation inside the renal collecting system. Once provide totally anesthesia/analgesia-free lithotripsy with the renal pelvis and those calyces that are accessible to a the Wolf device. Moreover, the shock-wave intensity rigid nephroscope have been visualized and the surgeon can be increased with all four machines to allow ade- is familiar with the intrarenal anatomy, flexible nephros- quate fragmentation of extremely hard or large calculi. copy can be performed to inspect individual calyces However, when using these lithotripters in the “high which may not be within reach of the rigid instrument. power mode,” various forms of anesthesia/analgesia are With the help of these flexible instruments, the entire necessary. collecting system can be visualized by taking advantage of the tip deflection and rotating the instrument inside So, in fact, no one has yet developed the “ultimate the kidney. shock wave” which allows totally anesthesia-free litho- tripsy with maximum efficiency. Yet, by varying the The internal diameter of the working sheath is usual- shock-wave energy, one can administer a highly efficient ly 30 F., which equals about 1 cm. Therefore, stones up shock wave with the need for anesthesia/analgesia when to this size can be extracted intact through the sheath. high shock-wave pressures are indicated. On the other For the fragmentation of stones inside the renal collect- hand, with a small or soft stone, the shock-wave energy ing system (and the ureter) that are too large to be ex- tracted (> 1 cm), three modalities of “power lithotripsy” can be significantly decreased to provide minimal-anes- are available: ultrasonic lithotripsy (UL), electrohydraul- thesia lithotripsy. ic lithotripsy (EHL), and laser lithotripsy. Two addition- al modalities are under FDA study: electromechanical PERCUTANEOUS NEPHROLITHOTOMY impactor (EMI) and pneumatic lithotrite. Percutaneous endoscopic manipulation of stones in the renal collecting Archivedsystem, in its development, has noDocument—Modalities precedent in the history of urologic surgery. The tech- nique evolved, within a decade, from a procedure under- Ultrasonic lithotripsy taken by a few physiciansFor to a procedure Reference performed rou- Only tinely by thousands of urologists worldwide – only to Percutaneous lithotripsy to fragment kidney stones then be forced into the background by an even more rev- was first described in 1979 [Alken, 1982]. Commer- olutionary procedure for stone treatment, namely shock- cially available units consist of a power generator and an wave lithotripsy. ultrasound transducer and a probe, both forming the “sonotrode.” A piezoceramic element in the handle of Techniques in percutaneous the sonotrode is stimulated to resonate, and this converts electrical energy into ultrasound waves (with a frequen- stone manipulation cy of 23,000-27,000 Hz) which then are transmitted Initially, a percutaneous nephrostomy tract needs to along the hollow metal probe to create a vibrating action be established in order to gain access to the intrarenal at its tip. When the vibrating tip is brought in contact collecting system. The access tract should enter the kid- with the surface of a stone, the calculus can be disinte- ney through a posterior calyx, which is usually facilitat- grated. ed by positioning the patient at 30 degrees on the fluo- The probe must be rigid because sound waves cannot roscopy table. In most cases, the lower or middle pole be transmitted without energy loss along flexible probes. calyces may be accessed below the 12th rib, but occa- The probes come in sizes of 10 F. and 12 F. and are sionally a supracostal approach is necessary to optimally passed through the straight working channel of a rigid reach the targeted stone [Segura, Patterson, LeRoy, et nephroscope with an offset lens (24-F. or 26-F. nephro- al., 1985]. One should anticipate possible cephalad ren- scope diameter). Suction tubing can be connected to the al movement during nephrostomy access placement, end of the sonotrode probe, thus converting the unit into which may alter the proposed approach [Preminger, a “vacuum cleaner” for stone fragments. Normal saline Schultz, Clayman, et al., 1987]. at body temperature should be used as irrigant. The nephrostomy tract is then formed by dilating the Ultrasonic lithotripsy is generally used for fragmenta- skin, fascia, muscles, and renal tissues over the guide tion of large renal stones. However, some uric acid, cal- wire. Nephrostomy tract dilatation can be performed cium oxalate monohydrate, or cystine stones may not using graduated dilators or a balloon catheter. After the break up easily, thereby necessitating EHL. Besides the nephrostomy tract has been dilated up to a 30-F. (10-mm risk for perforation and extravasation of irrigant, UL is diameter) size, a hollow plastic sheath is placed into the associated with noise levels of around 90 dB several renal pelvis. A variety of endoscopic instruments may inches from the transducer. For lengthy UL sessions,

C. 3 ear plugs are recommended. Depending on the location however, are for intraureteral fragmentation of stones of the stones, retained fragments are seen in 3-35 per- and are discussed below in the section on ureteroscopy. cent of all cases treated with ultrasonic lithotripsy. This cannot be considered a failure in many cases because the URETEROSCOPY UL is often performed for the debulking of large stones, to be followed by shock-wave lithotripsy as part of a The advent of ureterorenoscopy has dramatically planned two-stage procedure. altered the management of symptomatic ureteral calculi. Rigid ureteroscopy has been used in conjunction with Electrohydraulic lithotripsy ultrasonic and electrohydraulic lithotripsy and pulsed- dye laser probes to successfully fragment ureteral calculi The principles of electrohydraulic lithotripsy (EHL) [Beck, Vaughan, and Sosa, 1989; Preminger and Roehr- were described and developed by a Russian engineer in born, 1989]. Improvements in fiberoptics and irrigation 1950. This technology has been used extensively for the systems have fostered the use of smaller semirigid ure- destruction of bladder stones, and in 1975 reports were teroscopes (6.9 to 8.5 F.), but it has been mainly the published on its use for the fragmentation of kidney introduction of the flexible deflectable ureteroreno- stones [Raney and Handler, 1975]. The EHL unit has a scopes that makes access to the upper ureter and intra- probe, a power generator, and a foot pedal. The probe renal collecting system a safer and less tedious proce- consists of a central metal core and two layers of insula- dure [Beck, Vaughan, and Sosa, 1989; Huffman, 1989; tion with another metal layer between them. Probes are Preminger and Roehrborn, 1989]. flexible and available in multiple sizes to be used The extremely small working channel of the semi- through rigid and flexible nephroscopes. rigid and flexible instruments, which ranges from 2.4 to Commercially available EHL units are manufactured 4.0 F., has limited the size and usefulness of instruments with power up to 120 volts. The electrical discharge is that can be passed through these ureterorenoscopes and transmitted to the probe where it generates a spark at the used for stone removal. Indeed, for larger stones in the tip. The intense heat production in the immediate area proximal ureter, the 3-F. basket or grasping forceps are surrounding the tip results in a cavitation bubble which often inadequate to accomplish successful stone extrac- produces a shock wave that radiates spherically in all tion. This limitation of available instrumentation has directions. Collapse of the bubble causes a second prompted the use of intracorporeal lithotripsy for the shock wave. These shockArchived waves, repeated at a frequen- Document—management of larger upper ureteral and intrarenal cal- cy of 50-100 per second, result in destruction of the culi. stone. Currently the two most commonly employed methods EHL will effectively fragmentFor all kindsReference of urinary for intracorporeal Only lithotripsy of ureteral stones, via the calculi including the very hard cystine, uric acid, and flexible or semirigid ureterorenoscope, are EHL and the calcium oxalate monohydrate stones. Since the probes pulsed dye laser. Ultrasonic lithotripsy is occasionally are small and flexible, they can be used through flexible used for lower ureteral calculi, but its use has been sup- nephroscopes and ureteroscopes to fragment stones in planted to a large extent by EHL and laser lithotripsy. calyces inaccessible by UL through a rigid instrument. Although the choice of intracorporeal fragmentation is The primary disadvantage of EHL is its inability to effi- frequently based on the location and composition of the ciently remove the stone fragments. All particles have stone to be treated, the experience of the clinician and to be either washed out during intraoperative irrigation availability of equipment more often dictate this deci- or grasped with forceps. It is advantageous to fragment sion. the stone into the smallest number of particles that allow extraction with grasping devices (usually < 1 cm). Electrohydraulic lithotripsy There is no virtue in transforming a large stone into hun- dreds of small particles, or even sand-like material, be- The first experience with electrohydraulic lithotripsy cause a significant amount of time is required to remove in the ureter entailed a 6-F. EHL probe which was fluo- the debris. Overall, EHL should be the second choice roscopically guided to the obstructing calculus [Reuter for routine stone fragmentation in the kidney, but may and Kern, 1973]. The most common cause of failure in be the procedure of choice in the ureter. Its main appli- this early experience was secondary to the operator’s in- ability to pass the probe to the level of the stone. Addi- cation should be for very hard stones or stones not with- tional early experience with EHL within the ureter des- in reach of the rigid nephroscope/UL probe. cribed the use of a 9-F. probe which provided excellent Laser lithotripsy fragmentation of the stone. However, 40 percent of the patients had ureteral extravasation following the litho- Laser lithotripsy is the newest modality available for tripsy procedure [Raney, 1975]. This high complication stone fragmentation. The 250-micron quartz fiber of the rate was attributed to the large probe size. The use of a pulsed dye laser is easily passed through the smallest smaller 5-F. EHL probe through the rigid ureteroscope flexible nephroscope for treatment of renal calculi. The was compromised by decreased stone visualization indications for use of laser lithotripsy on renal calculi because the probe occupied most of the working channel are similar to those for use of EHL. Most applications, of the rigid ureteroscope [Green and Lytton, 1985].

C. 4 The development of a smaller 3-F. EHL probe, used for laser lithotripsy units [Weber, Miller, Rüschoff, et through a flexible ureteroscope, was reported in 1988 al., 1991]. [Begun, Jacobs, and Lawson, 1988]. Recently, a 1.9-F. EHL probe has been developed. It is quite successful in OPEN LITHOTOMY fragmenting ureteral and intrarenal stones. An addition- al benefit of these small-caliber probes is improved visu- While percutaneous nephrolithotomy, shock-wave alization through the flexible ureteroscope, as a larger lithotripsy, and ureteroscopy have become widely em- portion of the working channel is available for irrigation braced as treatments of choice for the majority of renal [Denstedt and Clayman, 1990; Feagins, Wilson, and and ureteral calculi, the indications for open lithotomy Preminger, 1990]. have decreased dramatically. Given currently available technology, only 1-5 percent of stones now require an Laser lithotripsy open procedure for removal. A recent study [Assimos, Boyce, Harrison, et al., 1989] found that, of 893 stone As noted before, laser lithotripsy also is utilized for procedures performed since the introduction of lithotrip- the management of ureteral calculi. The significant sy at their institution, 4.1 percent required open lithoto- advances in laser fibers and power-generation systems my for renal calculi. The most common indication for have propelled laser lithotripsy, in many practitioners’ open lithotomy was failure of lithotripsy or percuta- hands, the treatment of choice for ureteral stones [Dret- neous nephrolithotomy. ler, 1987]. Morbidly obese patients often require open lithotomy. The pulsed dye laser delivers short one-microsecond Their body habitus precludes fluoroscopic or sonograph- pulsations at 5-10 Hz produced from a coumarin green ic localization or effective treatment of renal calculi be- dye. A plasma is formed at the stone surface, resulting cause the shock waves become attenuated in the excess in a highly localized shock wave. The 504-nanometer tissue. Also, the large amount of adipose tissue in the wave length produced by the dye laser is selectively ab- flank may prevent placement of an Amplatz sheath into sorbed by the stone and not the surrounding ureteral the renal pelvis during percutaneous nephrostolithotomy. wall. Because the energy is delivered in short pulses, Stones in a collecting system with distal obstruction the heat generated is minimal, thus protecting the ureter may require open lithotomy with concomitant pyeloplas- [Coptcoat, Ison, Watson, et al., 1987; Dretler, 1987; ty. In addition, obstructed or scarred calyceal infundibu- Dretler, Watson, Parrish,Archived et al., 1987]. Document—la can be repaired with calyorrhaphy or calycoplasty Initial experience has yielded fragmentation rates after removal of the stone [Resnick, 1981]. Coagulum from 64 to 95 percent [Hofmann and Hartung, 1988; pyelolithotomy may be helpful in patients with many Higashihara, Horie, Taksuchi,For et al., 1990; Reference Morgentaler, small stones in multipleOnly calyces. This procedure could Bridge, and Dretler, 1990]. Failures have been related also be of benefit for clearing small residual calculi in to equipment malfunction (4 to 19 percent) or more of- patients who have undergone anatrophic nephrolithoto- ten to stone composition. Also, the use of EHL and/or my [Patel, 1973]. basketing has been necessary as an adjunctive measure For branched renal calculi, surgical procedures with the laser in some cases of successful stone removal. beyond simple open pyelolithotomy may be necessary Use of the pulsed dye laser in the ureter in all series ap- for stone removal. Anatrophic nephrolithotomy is based pears to be safe. No significant intraoperative or postop- on the blood supply to the kidney, using the relatively erative complications have been noted. avascular plane of Brodel’s line for the lateral renal par- Continued development of laser technology has enchymal incision prior to entering the collecting sys- yielded larger diameter laser fibers able to fragment hard tem. This approach permits wide exposure of the renal calculi more effectively. Newer 300- and 320-microme- pelvis enabling en bloc removal of the branched calculi ter fibers are superior to the 200-micrometer fibers in with minimal residual calculi [Blandy and Singh, 1976]. fragmentation of calcium oxalate monohydrate and cys- Patients with complex stones or evidence of parenchy- tine stones [Dretler and Bhatta, 1991]. Fragmentation mal loss may benefit from either partial or complete rates of greater than 90 percent have been obtained with nephrectomy for stone disease [Assimos, Boyce, Harri- these new fibers. As the field continues to advance, new son, et al., 1989]. materials (alexandrite) are now being tested as sources

C. 5 Index

(Entries followed by “f” indicate figures; entries followed by “t” indicate tables.)

A F Anatrophic nephrolithotomy ...... 9-10 FAST*PRO meta-analysis package ...... 5-7 Anesthesia ...... 2, 19 Fluoroscopy, stone localization ...... C.2

B G Balance sheet, outcome analysis of treatment Guideline, as treatment policy recommendation . .2-5, 20 alternatives ...... 13t Blood transfusion, comparison of modalities . . . . .16, 16f H Health care resources, share of ...... 5 C Hospitalization, all treatment modalities ...... 18 Calcium oxalate monohydrate, in staghorn calculi .1, 9 Hydronephrosis ...... 10 Calcium, in staghorn calculi ...... 1, 9 Hydrothorax ...... 14 Collecting system ...... 1, 9 Combination therapy ...... 1, 2, 3, 4, 11, 19, 20 I acute complications ...... 14-15 Infected stones ...... 1, 9 blood transfusion required ...... 2, 19 description ...... 11 hospital days ...... 18 K long-term complications ...... 17-18 Kidney, loss of ...... 14, 17, 18f management of staghorn calculi and ...... 11 outcome analysis of treatment alternatives . . . . .13t procedures per patientArchived ...... 16 Document—L residual fragments after ...... 2, 19 Laser, lithotripsy ...... C.4 stone-free rate ...... 14 Limitations in the literature ...... 4, 8, 21 treatment recommendations ...... 3, 20-21 Literature search ...... 5-6 Complications For ReferenceLithotripter instrumentation Only ...... C.1-C.32 acute ...... 14-17 dual imaging ...... C.2 combination therapy ...... 15 variable power ...... C.3 comparison of modalities ...... 16f Lithotripsy open surgery ...... 15 electrohydraulic ...... C.4 outcomes of different treatments ...... 13t laser ...... C.4 percutaneous nephrolithotomy ...... 15 shock-wave; see shock-wave lithotripsy shock-wave lithotripsy ...... 15 ultrasonic ...... C.3-C.4 treatment recommendations and ...... 17 long-term ...... 17-18 combination therapy ...... 17-18 M open surgery ...... 17-18 Magnesium ammonium phosphate; see struvite outcomes of different treatments ...... 13t MEDLINE ...... 5 percutaneous nephrolithotomy ...... 17-18 shock-wave lithotripsy ...... 17-18 treatment recommendations and ...... 17 N Confidence profile method ...... 6-7, 7f Nephrectomy ...... 3, 9, 10, 21 Cystine, in staghorn calculi ...... 1, 9 Nephrolithiasis Clinical Guidelines Panel, AUA . .1-5, A8- A10 Nephrolithotomy; see percutaneous nephrolithotomy D Nephroscopy ...... 13-14, C.3 Death, comparison of modalities ...... 15, 16f Nephrostomy tract ...... C.3 Diasonics ...... C.1 Nephrostomy tube placement ...... 16 Dornier HM-3 ...... 11, 14, C.1 Nephrotomy ...... 9 Dual imaging, stone localization ...... C.2 O E Obesity, open lithotomy and ...... C.5 EDAP ...... 14, C.1 Open surgery ...... 1-4, C.5 Electrohydraulic devices ...... C.1 acute complications ...... 14-15 Extracorporeal shock-wave lithotripsy; see blood transfusion required ...... 2, 19 shock-wave lithotripsy description ...... 9, 10, C.5 Explicit approach, development of practice hospital days ...... 18 policies ...... 5 long-term complications ...... 17-18

I. 1 management of staghorn calculi and ...... 9-10 Shock-wave lithotripsy ...... 1, 2, 3, 4, outcome analysis of treatment alternatives . . . . .13t 10-11, 19, 20-21 procedures per patient ...... 16 acute complications ...... 14-15 residual fragments after ...... 2, 19 blood transfusion required ...... 2, 19 stone-free rate ...... 14 description ...... 10, 11, treatment recommendations ...... 3, 21 C.1 Option, as treatment policy recommendation . . . . .2, 3, 4, 5, hospital days ...... 18 21 long-term complications ...... 17-18 Outcome analysis, staghorn treatment alternatives .12-18 management of staghorn calculi and ...... 10-11 Outcomes outcome analysis of treatment alternatives . . . . .13t complications with primary treatment ...... 2, 14-16, procedures per patient ...... 16 19 residual fragments after ...... 2, 19 direct and indirect ...... 12 stone-free rate ...... 14 secondary, unplanned procedures ...... 2, 19 treatment recommendations ...... 3, 20-21 stone-free rate ...... 2, 13-14, unplanned secondary procedures after ...... 2, , 19 19 Siemans Lithostar ...... 14, C.2 Sonotrode ...... C.3 Staghorn calculi P background ...... 9 Panendoscopy ...... C.3 basic research needs ...... 21-22 Papyrus Bibliography System ...... 6, A1-A3 definition ...... 1, 9 PARADOX database ...... 6 development of treatment recommendations . . . .1-4 Partial staghorn ...... 1, 9 outcome analysis of treatment alternatives . . . . .12-18 Patient circumstances, choice of treatment radiologic appearance ...... 1, 9 modality and ...... 2, 19 size ...... 1, 9 Patients, standard and nonstandard ...... 2, 4, 19- treatment modalities ...... 1-4 20 treatment recommendations ...... 3, 20-21 Pelviolithotomy ...... 9 Standard, as treatment policy recommendation . . .2, 3, 4, 5, Percutaneous nephrolithotomy ...... 1, 2, 3, 4, 20 10, 19, 20-21 Stent migration ...... 14 acute complications ...... 14-15 Stone growth ...... 17f blood transfusion required ...... 2, 19 Stone recurrence ...... 17f description ...... 10, C.3 Stone-free rate ...... 2, 19 hospital days ...... 18 outcomes of different treatments ...... 13t, 13- long-term complicationsArchived ...... 17-18 Document—14, management of staghorn calculi and ...... 10 14f outcome analysis of treatment alternatives . . . . .13t treatment recommendations and ...... 17 procedures per patient ...... 16 Struvite ...... 1, 9 residual fragments after For...... Reference ...... 2, 19 Only stone-free rate ...... 14 techniques in stone manipulation ...... C.3 T treatment recommendations ...... 3, 20-21 Tomography, renal, visualization of residual Percutaneous nephrostomy, tube placement ...... 11 fragments ...... 13-14 Piezoelectric devices ...... 14, C.1 Treatment recommendations Pneumothorax ...... 14 limitations ...... 4, 8, 21 Practice policies, development of ...... 5 outcomes and ...... 19 Primary procedures ...... 16-17 standard and nonstandard patients ...... 19-20 Pyelonephritis, acute ...... 10 standards, guidelines, and options ...... 3, 20-21 Pyelotomy, extended ...... 9 U R Ultrasonic lithotripsy ...... C.3 Radiography, visualization of residual fragments . .13-14 Ultrasonography Random-effects model ...... 6-8 lithotripsy ...... C.3 Renacidin, irrigation with ...... 11 residual fragment visualization ...... 13-14 Renal pelvis stone localization ...... C.2 perforation ...... 14 Urease ...... 1, 9 staghorn calculi in ...... 1, 9 Ureteroscopy ...... 11, C.4 Research needs ...... 21 Uric acid ...... 1, 9 Urinary tract infection, struvite staghorn calculi . .1, 9 S Urinoma ...... 14 Secondary procedures ...... 2, 16-17, 19 W unplanned ...... 2, 14, 19 Watchful waiting ...... 2, 3, 20 Sepsis ...... 14 Wolf 2300 ...... 14, C.1 Shock waves Wolf Piezolith 2500 ...... C.2 coupling ...... C.2 focusing ...... C.2 generation of ...... C.1 localization ...... C.2

I. 2 American Urological Association, Inc.

Board of Directors (1993 - 1994) Abraham T.K. Cockett, MD* Winston K. Mebust, MD* C. Eugene Carlton, Jr., MD* W. Lamar Weems, MD* H. Logan Holtgrewe, MD* Jack W. McAninch, MD* William R. Turner, Jr., MD* Harry E. Lichtwardt, MD Roy J. Correa, Jr., MD* Jay Y. Gillenwater, MD Harry C. Miller, Jr., MD* Joseph N. Corriere, Jr., MD Dennis J. Card, MD* Alan H. Bennett, MD E. Darracott Vaughan, Jr., MD* G. James Gallagher John D. Silbar, MD* Richard J. Hannigan Irwin N. Frank, MD* *Voting

Practice Parameters, Standards and Guidelines Committee (1993 - 1994) Winston K. Mebust, MD, Chair Warren W. Koontz, Jr., MD John D. McConnell, MD, Vice-Chair Richard G. Middleton, MD Anton J. Bueschen, MD Harry C. Miller, Jr., MD Abraham T. K. Cockett, MD Ian M. Thompson, Jr., MD Roy J. Correa, Jr., MD William R. Turner, Jr., MD Thomas C. Fenter, MD Hanan Bell, PhD, Consultant John B. Forrest, MD Alfred S. Buck, MD, Consultant John A. Fracchia, MD Claus G. Roehrborn, MD, Consultant Charles E. Hawtrey, MD Linda D. Shortliffe, MD, Consultant ArchivedJohn A. Heaney, MD Document—Edward S. Tank, Jr., MD, Consultant Health Policy Department Staff and Consultants 1120 N. Charles Street • Baltimore, MD 21201 ForPhone: Reference 410.727.1100 • Fax: 410.223.4375 Only Stephanie Mensh Harriet Rubinson Director Practice Quality Coordinator Kim Hagedorn Julie Bowers Assistant to Director Administrative Assistant Sheri Huff Secretary Randolph B. Fenninger Lisa Emmons Washington Liaison Health Policy Manager Justine Germann Tracy Kiely Legislative Associate Health Policy Information Assistant Betty Roberts William Glitz Administrative Assistant Public Relations Consultant Megan Cohen Government Relations Coordinator Karen Costanzo Roger Woods University of Texas, Government Relations Assistant Southwestern Medical School

This Report on the Management of Staghorn Calculi was developed by the Nephrolithiasis Clinical Guidelines Panel of the American Urological Association, Inc. This Report is intended to furnish to the skilled practitioner a consensus of clear principles and strategies for quality patient care, based on current professional literature, clinical experience, and expert opinion. It does not establish a fixed set of rules or define the legal standard of care, preempting physician judgement in individual cases. An attempt has been made to recommend a range of generally acceptable modalities of treatment, taking into account variations in resources and in patient needs and preferences. It is recommended that the practi- tioner articulate and document the basis for any significant deviation from these parameters. Finally, it is recognized that conformance with these guidelines cannot ensure a successful result. The parameters should not stifle innovation, but will, themselves, be updated and will change with both scientific knowledge and technological advances. Report on the Management of Staghorn Calculi September 1994 Only Document— Document— ® Reference For Archived , Maryland 21090 000 Corporate Boulevard 1000 Corporate Linthicum American Inc. Association, Urological