SEMINARS IN INTERVENTIONAL RADIOLOGY VOLUME 17, NUMBER 4 2000 Percutaneous Nephrostomy Michael M. Maher, M.D., Timothy Fotheringham, M.D., and Michael J. Lee, M.D. ABSTRACT Percutaneous nephrostomy (PCN) is now established as a safe and effective early treatment for patients with urinary tract obstruction. In experienced hands, PCN is usually successful and is associated with low complication rates. This article discusses all aspects of PCN, including the indications and contraindications to PCN, patient preparation, the techniques employed for gaining access to the urinary tract, and placement of the PCN tube. In addition, we discuss the complications of PCN and possible ways of avoiding them, as well as the care of patients following PCN. Keywords: Percutaneous nephrostomy, renal failure, pyonephrosis Urinary tract obstruction invariably requires eral anesthesia is avoided and surrounding organs treatment, and indications for immediate or urgent can be imaged and avoided during PCN. In expert intervention include clinical and laboratory signs of hands, PCN is associated with a major complication underlying sepsis and clinical or radiological signs rate of 4 to 5%4 and a minor complication rate of of pyonephrosis. Urgent intervention is also manda- approximately 15%.1 PCN is usually faster, less ex- tory for the treatment of life-threatening biochemi- pensive, and less likely to be associated with compli- cal abnormalities associated with the rapid onset of cations than is surgery.5 In the current era, PCN renal failure. also allows access to the urinary tract for more In the past decade, image-guided PCN has re- definitive treatment of underlying pathologies such placed the conventional surgical approach for the as percutaneous nephrolithotomy (PCNL) for temporary drainage of urinary tract obstruction. treating urinary tract calculi and the placement of PCN is now established as a safe and effective initial ureteric stents for treating malignant urinary tract treatment for patients with urinary tract obstruc- obstruction. The type of image guidance used dur- tion.1–3 The percutaneous approach has many ad- ing PCN frequently varies depending on imaging fa- Downloaded by: University of Florida. Copyrighted material. vantages over surgery, including the fact that gen- cilities available at the institution and, more impor- Objectives Upon completion of this article, the reader will understand how to perform percutaneous nephrostomy safely and avoid complications. Accreditation Tufts University School of Medicine is accredited by the Accreditation Council for Continuing Medical Education to sponsor continuing medical education for physicians. TUSM takes full responsibility for the content, quality, and scientific integrity of this continuing education activity. Credit The Tufts University School of Medicine designates this educational activity for a maximum of 1.0 hours credit toward the AMA Physicans Recognition Award in category one. Each physician should claim only those hours that he/she actually spent in the educational activity. Department of Radiology, Beaumont Hospital and the Royal College of Surgeons Medical School, Dublin, Ireland Reprint requests: Michael J. Lee, Department of Radiology, Beaumont Hospital and the Royal College of Surgeons Medical School, Beaumont Hospital, Dublin 9, Ireland. Copyright © 2000 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001, USA. Tel.: +1(212) 584-4662. 0739-9529,p;2000,17,04,329,340,ftx,en; sir00085x. 329 SEMINARS IN INTERVENTIONAL RADIOLOGY VOLUME 17, NUMBER 4 2000 tantly, the preference of the operator. Modern quently aid in deciding the optimal timing of the nephrostomy is usually performed in the fluo- procedure and can optimize the patient’s biochemi- roscopy suite using a combination of ultrasound cal and other parameters prior to the procedure. It and fluoroscopic guidance. However, in recent is important that the urologist is available should times both computed tomography (CT)6,7 and mag- any complications occur that might require urgent netic resonance imaging (MRI)8 have been added surgical intervention. to the list of imaging modalities used to facilitate Prothrombin time and activated partial throm- PCN. boplastin time estimations should be performed prior to PCN, and, if abnormal, attempts should be made to optimize coagulation and other hemato- INDICATIONS logic parameters prior to the procedure.9–11 The procedure should be explained to the patient and The most common indications for PCN in- his or her relatives prior to the procedure, and po- clude benign obstruction resulting from ureteric tential complications such as hemorrhage, urinary stones and malignant obstruction resulting from leakage, septicaemia, and death should be men- carcinoma of the bladder, prostate, and cervix. tioned prior to the examination. Good peripheral Ureteric obstruction can also result from extrinsic intravenous access should be ensured prior to the compression of the ureters by metastatic deposits procedure. Many authors initially recommended from carcinoma of the uterus, colon, cervix, breast, the use of antibiotics before PCN in instances in and abdominal lymphoma. Another common indi- which the patient was at high risk of sepsis, in other cation for PCN is iatrogenic damage to the ureter, words, suspected pyonephrosis.4,5 More recently, an- which most commonly occurs following abdominal tibiotics have been recommended for all patients re- hysterectomy or right or left hemicolectomy or fol- gardless of preprocedure risk profile, with antibiotic lowing instrumentation of the ureter during endo- dosage depending on the perceived risk of sepsis.4 scopic treatment of ureteric stones. Other less com- Our practice is to prescribe preprocedure antibi- mon indications for PCN include the relief of otics to the patients with leukocytosis or fever. We do terminal vesicovaginal fistula and ureteral fistulae. not routinely give antibiotics for noninfected pa- The most common indication for emergency tients. A broad-spectrum cephalosporin is suitable nephrostomy is acute sepsis is an obstructed urinary for administration prior to the procedure. When tract secondary to pyonephrosis. The other most fungal infection is suspected, this should also be cov- common reason for emergency nephrostomy is ered by the antibiotic regimen administered prior to acute renal failure secondary to acute obstructive the procedure. For sedation and pain relief, we use uropathy. The most worrying biochemical abnor- midazolam and fentanyl in incremental amounts of mality associated with renal failure, which can lead 1 mg and 50 to 100 ␮g, respectively. Patients are to a life-threatening cardiac arrhythmia, is severe monitored using blood pressure and pulse oximetry hyperkalaemia. If there is no evidence of either apparatus throughout the procedure. acute sepsis or acute hyperkalaemia, PCN can be A nurse trained in the monitoring of critically Downloaded by: University of Florida. Copyrighted material. performed on the next elective interventional list. ill patients should be available during the proce- dure to monitor blood pressure and pulse oximeter readings. PATIENT SELECTION AND PREPARATION In most cases of acute urinary tract obstruc- ANTEGRADE PYELOGRAPHY tion, PCN is used as a temporizing measure until definitive medical or operative correction of the Antegrade pyelography involves the insertion cause of obstruction can be carried out. The aim of of a needle into the pelvicalyceal system and the PCN is immediate treatment of acute pyonephrosis opacification of the collecting system with contrast or acute hyperkalemia, allowing stabilization of the material to clearly delineate the pelvicalyceal sys- critically ill patient prior to definitive investigation tem and ureter.12 The routine performance of ante- of the cause of ureteric obstruction. The placement grade pyelography has two main advantages. Firstly of a PCN catheter allows the kidneys to regain func- the pelvicalyceal system can be opacified and dis- tion and relieves pyonephrosis, septicemia, and as- tended, which greatly aids access to the pelvi- sociated biochemical abnormalities. calyceal system. Secondly the presence of the ante- The treatment of acute urinary tract obstruc- grade needle in the pelvis during the procedure tion requires a multidisciplinary approach, and allows the pelvicalyceal system to be reopacified prior consultation with the urologist and or and distended should decompression occur at any nephrologist is advisable. The nephrologist can fre- time. 330 PERCUTANEOUS NEPHROSTOMY—Maher et al. The anatomy at the renal hilum is fundamental ployed. Alternatively, if there is marked hydro- to the performance of antegrade pyelography. It nephrosis, ultrasound can be performed prior to must be remembered that the renal vein, artery, puncture and the site can be marked. The needle and ureter run anterior to posterior in this order at can then be inserted without the necessity for real- the renal hilum. In addition, the colon can occa- time ultrasound guidance. In the case of a mildly or sionally be found posterior to the kidney, which can moderately obstructed kidney, real-time ultrasound result in colonic injury during PCN. Ultrasound ex- guidance is necessary. amination prior to needle puncture is helpful in de- Most centers use either a 20- or 22-gauge nee- termining whether the colon is posterior to the kid- dle. Our preference, however, is for the 20-gauge ney. CT has been advocated either prior to PCN or