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