Thomas M.T. Turk

Incidence of urolithiasis in cystectomy patients after intestinal conduit or continent urinary diversion.

Abstract The purpose of this study was to determine the incidence of nephrolithiasis in radical cystectomy patients treated with either intestinal conduit or continent urinary diversion. The charts from 94 patients who had undergone radical cystectomy with urinary diversion at our institution from 1988 to 1998 were reviewed retrospectively for this study. Charts and radiographs from all patients were examined for renal function and evidence or urinary tract calculi. Two groups were compared: group I patients had undergone diversion with an intestinal conduit, and group II patients had received a continent diversion (primarily involving an Indiana pouch). Conduit diversions were typically done with a freely refluxing anastomosis (Bricker), whereas continent diversions were done with a nonrefluxing ureteral-intestinal anastomosis. Group I consisted of 54 patients who had undergone ileal conduit (50) or colon conduit (4) diversion with a mean follow-up of 2.5 years (range 0.6–7.0 years). Group II consisted of 40 patients who had undergone continent diversion (33 Indiana pouches, 7 orthotopic diversions) with a mean follow-up of 3.1 years (range 0.5–10.5 years). Laboratory studies of serum blood urea nitrogen, creatinine, and CO2 were similar between the two groups. Six patients in group I developed urolithiasis, all in the upper tract. Stones developed at a mean of 3.1 years after urinary diversion. Three patients required operative intervention, whereas the others were managed expectantly. One patient in group II had an upper tract stone at the time of presentation for his bladder cancer, but no patient developed new upper tract stones during the present study period. Two patients in group II developed pouch calculi at a mean of 5 years after diversion; both required surgical intervention. In our study the risk for upper tract urolithiasis seemed higher in the intestinal conduit group (group I), with 11% of the patients developing stones. In the continent diversion group, no patient developed upper tract stones, although two patients (5%) developed pouch stones. Refluxing urine may contribute to an increased risk for stone formation after urinary diversion, whereas pouch stasis may contribute to stone formation in the continent diversion group.

Durability of the Next-generation Flexible Fiberoptic Ureteroscopes: A Randomized Prospective Multi-institutional Clinical Trial

OBJECTIVES To evaluate the durability of 4 next-generation flexible ureteroscopes in a randomized, multi-institutional, prospective study. METHODS Patients at 3 institutions were randomized to 1 of 4 flexible ureteroscopes: the Wolf Viper, Olympus URF-P5, Gyrus-ACMI DUR-8 Elite (DUR-8E), and Stryker FlexVision U-500. Each center used 1 scope from each manufacturer until it needed major repair (primary endpoint). Intraoperative data included total time of use, number of scope insertions through an access sheath, working time in the lower pole, number of insertions and total time for accessory instrumentation in the working channel, number of laser insertions through the working channel, and total laser energy used. RESULTS A total of 175 patients were randomized. The DUR-8E experienced early catastrophic failure (< or = 10 cases) at all 3 sites; however, this also occurred at 1 site each for the Stryker and Wolf scopes. The DUR-8E required major repair after the fewest average number of cases (5.3), the lowest average total time of usage (108 minutes), the fewest insertions through an access sheath (20.3), the shortest duration of laser firing (31.3 minutes), and the shortest instrument in the working channel time (224.7 minutes). As such, due to variation in durability within manufacturers, no differences could be demonstrated. Visibility ratings for the Wolf iper were significantly better than the DUR-8E (P = .034) and the Flexvision (P = .038). CONCLUSIONS The Wolf Viper, Olympus URF-P5, and Stryker Flexvision U-500 flexible ureteroscopes seem comparable with regard to durability. However, larger prospective registry-based studies are needed to document significant differences between them.

Laparoscopic Living Donor Nephrectomy: A Look at Current Trends and Practice Patterns at Major Transplant Centers Across the United States

PURPOSE Laparoscopic living donor nephrectomy is now the preferred technique for living donor renal transplantation. To our knowledge we provide the first published multi-institutional consensus describing practice patterns, technical considerations and interesting controversies involved in laparoscopic living donor nephrectomy. MATERIALS AND METHODS We designed a survey with 33 multiple choice questions looking at demographics, patient selection, technical considerations, postoperative care and followup involved in laparoscopic living donor nephrectomy. Surveys were sent to the 58 fellowship training programs in the United States accredited by the American Society of Transplant Surgeons. RESULTS The 32 responding programs performed approximately 40% of laparoscopic living donor nephrectomies in the United States in 2005. We found that almost all centers used a donor committee to screen candidates, enforce a body mass index cutoff, and use right kidneys when necessary and left kidneys in women of childbearing age. Regarding laparoscopic access, pure laparoscopy was favored 2 to 1 over the hand assisted technique and most of those who use nonbladed trocars do not close the fascia. Most surgeons divide the adrenal vein in left cases, use a vascular stapler on the renal artery and vein, and keep the ureter with the gonadal vein in the specimen. At most centers heparin is given before controlling the vessels. Extraction in pure laparoscopic cases is usually performed using a preplaced entrapment bag through a modified Pfannenstiel incision. CONCLUSIONS Our survey describes how most renal transplant centers with accredited fellowship programs in the United States approach laparoscopic living donor nephrectomy. Specifically trends are revealed regarding patient selection, laparoscopic access and surgical technique.

Metabolic Syndrome and Urinary Stone Composition: What Factors Matter Most?

OBJECTIVE To determine which metabolic syndrome (MetS) factors lead to differences in stone composition in a multivariate analysis. METHODS We retrospectively reviewed medical charts of patients who had a kidney stone removed over a 5-year period (2006-2011). MetS factors (obesity [body mass index {BMI} >30], diabetes mellitus [DM], hypertension [HTN], and dyslipidemia [DLD]) were tallied in each patient. For the latter 3 factors, medical treatment for the condition was used to tag a patient with the condition. Stone composition was determined by the dominant (>50%) component. Statistical analysis was designed to determine which MetS factors were independently associated with differences in stone composition. RESULTS Five hundred ninety kidney stones were included in the analysis. Patients with MetS had a higher prevalence of uric acid stones and lower prevalence of calcium phosphate stones. HTN and DM were independently associated with differences in composition, specifically uric acid stones (higher proportion), and calcium phosphate stones (lower proportion). Obesity was not associated with differences in composition, although a secondary analysis of morbidly obese patients showed a higher proportion of uric acid stones and a lower proportion of calcium oxalate stones. CONCLUSION HTN and DM are the MetS factors independently associated with differences in stone composition, specifically the uric acid and calcium phosphate components. Obesity has little effect on stone composition until a very high (>40) BMI is reached. The overall effect of MetS factors on stone type is relatively small, because most stones are calcium oxalate and MetS factors have little impact on calcium oxalate frequency.

Metallic Ureteral Stents: A Cost-Effective Method of Managing Benign Upper Tract Obstruction

INTRODUCTION The management of patients with upper urinary tract obstruction who are not candidates for definitive reconstruction often presents a challenge. We report our initial experience with the Resonance (Cook Urological, Spencer, IN) metallic ureteral stent for the management of benign ureteral obstruction and present a comparative cost analysis of metallic to standard polymer stent use. METHODS Data were retrospectively gathered on all patients undergoing metallic ureteral stent placement for benign causes from July 2007 to February 2009. Baseline demographics, previous method of drainage, pre- and postoperative creatinine levels, procedural complications, stent-related side effects, and metallic stent dwell time were recorded. The cost of stent maintenance for polymer and metallic stents for a 12-month interval was calculated for each patient. RESULTS Fifteen stents were placed in 13 patients to manage obstruction due to a variety of benign etiologies. Metallic stents provided adequate drainage in 12/13 patients, but were discontinued prematurely in 3 patients (2 for voiding symptoms, 1 for hematuria). Eight patients had their metallic stents changed after a mean time of 11.6 months, with no encrustation. The yearly cost associated with polymer and metallic stent use was

The FECal Double-J: a simplified approach in the management of encrusted and retained ureteral stents.

23,999 and

Retroperitoneal schwannoma mimicking an adrenal lesion

11,183, respectively. This amounted to a

Five-year experience with metallic stents for chronic ureteral obstruction.

10,394 annual cost reduction (43%) for each patient. CONCLUSIONS Metallic ureteral stents provide effective upper tract drainage for the majority of patients with benign upper tract obstruction, with significant cost benefit, largely because of the shorter exchange interval.

Endophytic Lesions: A Predictor of Failure in Laparoscopic Renal Cryoablation

INTRODUCTION The management of the forgotten, encrusted, calcified (FECal) Double-J ureteral stents can represent one of the most difficult and challenging surgical conditions for the practicing urologist. We present a novel and simple grading system for the FECal stent and, taking into account our own experience and literature review, propose an algorithm in the management of the encrusted stent based on this new system. MATERIALS AND METHODS A retrospective analysis of our stone database was performed from March 2000 to April 2007 revealing a total of nine patients presented with a FECal Double-J stent managed at our institution and included in our series for further analysis. Based on this population, our experience, and current surgical techniques, we designed a simplified grading system to universally define the retained indwelling FECal ureteral stents. RESULTS A total of nine patients with encrusted and retained ureteral stents were identified, graded, classified, and treated at our institution. Our population consisted of five women and four men with an average age of 54.4 years and average stent indwelling time of 11.44 months. We present our novel management algorithm based on our simplified FECal stent grading system. CONCLUSION The management of the FECal ureteral stent represents a formidable challenge due to the need for a multimodal approach with advanced endourological techniques. Our proposed grading system and management algorithm provide a simplified and directed alternative for the surgical management dilemma of the encrusted retained ureteral stent.

ACUTE AND LONG-TERM OUTCOMES OF RADIO FREQUENCY BLADDER NECK SUSPENSION

Abstract. Schwannomas are usually benign tumors that arise from the nerve supporting the Schwann cell. The majority arise at the cranial nerves or nerves of the upper extremities. Most patients with retroperitoneal schwannomas present with vague abdominal or back pain. We present a case in which a retroperitoneal mass thought to be arising from the adrenal gland on computed tomography and magnetic resonance imaging was found after excision to be a Schwannoma. The available literature on retroperitoneal schwannomas is then discussed.