Flexible ureteroscopy in conjunction with in situ lithotripsy for lower pole calculi.

OBJECTIVES: To demonstrate the efficacy and safety of ureteroscopy as a compromise in treating small and intermediate-size lower pole calculi. The optimal management of lower pole calculi remains controversial. Shock wave lithotripsy is associated with minimal morbidity but with suboptimal stone clearance rates. Conversely, percutaneous nephrostolithotomy has greater morbidity but stone-free rates greater than 90% regardless of size. METHODS: Seventy-two patients underwent ureteroscopy for lower pole calculi 2 cm or less (mean 8.7 mm) during a 3-year period. To minimize confounding, 11 patients with additional calculi at other ipsilateral renal sites and 1 patient with large (2.4 cm each) bilateral calculi were excluded. Two patients with bilateral lower pole calculi and four who required a second procedure were included in the analysis. Thus, the final cohort consisted of 60 patients who underwent 66 procedures. RESULTS: Of patients with follow-up longer than 1 month, 79% were stone free after a single procedure, and this improved to 88% after a second procedure in 4 patients. All 7 patients with follow-up less than 1 month had a reduction in stone burden after successful fragmentation. Overall, 8 patients required an auxiliary procedure. No intraoperative complications, and 7 (11%) postoperative complications occurred. CONCLUSIONS: Ureteroscopy for lower pole calculi is associated with minimal morbidity and stone-free rates comparable to shock wave lithotripsy for smaller stones. The greatest utility of ureteroscopy is in the management of intermediate-size calculi, for which it has substantially higher stone-free rates and lower repeated treatment rates than does shock wave lithotripsy.

Revision rate after artificial urinary sphincter implantation for incontinence after radical prostatectomy: actuarial analysis.

PURPOSE: We determined the actuarial revision rate for artificial urinary sphincters implanted in patients who were incontinent after radical prostatectomy. MATERIALS AND METHODS: We reviewed the records of 70 consecutive patients who were incontinent after radical prostatectomy and who underwent primary artificial urinary sphincter implantation at the University of Michigan between 1984 and 1999. Questionnaires were mailed to all patients with an indwelling device, and telephone calls were placed to those who did not respond to the mailing. Information about surgical revision and current continence status was obtained from chart review and questionnaire response. The Kaplan-Meier curves for actuarial freedom from operative revision were constructed. RESULTS: Of the 66 patients with available postoperative data 24 (36%) required reoperation at a mean followup of 41 months. The 5-year actuarial rate for freedom from any operative revision was 50%, and the corresponding rate for cuff revision was 60%. A single operative revision did not predispose the patient to further revision. Questionnaire data indicated a continence rate of 80% (range 0 to 2 pads). CONCLUSIONS: Approximately half of the patients who were incontinent after radical prostatectomy may expect to undergo operative revision within 5 years after artificial urinary sphincter implantation. Despite this high reoperation rate, an excellent level of continence is maintained.

Comparison of outcomes of ureteroscopy for ureteral calculi located above and below the pelvic brim.

OBJECTIVES: To compare the safety and efficacy of ureteroscopy performed for proximal and distal ureteral calculi in a contemporary cohort. Ureteroscopy has been used most often for distal ureteral calculi. However, advances in endoscopic equipment have facilitated access to the proximal urinary tract and have broadened the indications for ureteroscopy. METHODS: One hundred ninety-one patients underwent rigid and/or flexible ureteroscopy for ureteral calculi at the University of Michigan between January 1, 1997 and September 30, 1999. Only 7 patients with either bilateral calculi or steinstrasse were excluded. The final cohort consisted of 184 patients who underwent ureteroscopy for distal stones (n = 103) or middle/upper ureteral stones (n = 81). RESULTS: Bivariate analyses of pretreatment and perioperative characteristics were used to assess the sample population. The initial success rate for the distal and proximal ureteral calculi was 96% and 78%, respectively (P = 0.0008). After a "second-look" procedure in 4 and 7 patients with distal and proximal calculi, respectively, the success rate improved to 99% and 88%, respectively (P = 0.004). No differences were noted between groups regarding the intraoperative (P = 0.51) or postoperative (P = 0.85) complication rates. Multivariate logistic regression analysis confirmed that larger stone size (odds ratio 1.2, P = 0.0006) and proximal ureteral location (odds ratio 4.8, P = 0.01) are independent predictors of treatment failure. CONCLUSIONS: Ureteroscopic management of proximal and distal ureteral calculi is highly successful, and the difference in success rates has narrowed substantially. Currently, no greater risk is conferred to the patient for endoscopy of more proximal ureteral calculi.

Complications of ureteroscopy: analysis of predictive factors.

PURPOSE: Although overall and major complication rates of 10% to 20% and 0% to 6%, respectively, have been observed in large series of ureteroscopy, to our knowledge no systemic analysis to determine factors predictive of these complications has been reported. MATERIALS AND METHODS: We retrospectively reviewed all ureteroscopies performed at our institution for calculous disease from January 1997 through September 1999. A total of 322 procedures were performed by 5 attending surgeons. Intraoperative and immediate postoperative complications were identified. Bivariate and multivariate analysis was performed to identify associated factors with ureteral perforation and postoperative complications as the dependent variables. RESULTS: Bivariate analysis showed a significant association of ureteral perforation with increased operative time (p = 0.0001). In addition, we noted a significant association of postoperative complications with stones in the kidney (p = 0.0004), operative time (p = 0.05) and decreased surgeon experience (p = 0.0035) as well as a trend toward significance for the type of ureteroscope used (p = 0.0609). In multivariate logistic regression models ureteral perforation remained highly associated with operative time (p = 0.0005) when controlling for the other factors. Similarly decreased surgeon experience and a stone in the kidney were predictive of postoperative complications when controlling for the other factors (p = 0.004). CONCLUSIONS: Longer duration of the ureteroscopic procedure is strongly associated with ureteral perforation. The likelihood of immediate postoperative complications is greater when renal calculi are treated and less when the surgeon is more experienced.

Use of bipolar electrocautery during laparoscopic donor nephrectomy.

PURPOSE: We describe a technique enabling easier placement of the endoscopic linear stapling device on the renal vein during laparoscopic nephrectomy. MATERIALS AND METHODS: Bipolar electrocautery rather than a clip applier was used in 20 laparoscopic donor nephrectomy cases to coagulate the renal vein branches before transection. Warm ischemia time of the specimens and the number of surgical clip applier devices used were compared with those in the 20 immediate preceding cases in which bipolar electrocautery was not used. RESULTS: Using bipolar electrocautery no clips were placed on the specimen side of the renal vein before stapling. Average warm ischemia time for the 20 kidneys in which bipolar electrocautery was performed was 2 minutes 13 seconds compared with 3 minutes 1 second for the previous 20 (p = 0.157). Significantly fewer clip applying devices were used in the 20 bipolar electrocautery cases (p = 0.005). CONCLUSIONS: Bipolar electrocautery of the renal vein branches enables easier placement of the endoscopic linear stapling device on the renal vein and the use of fewer surgical clip appliers during laparoscopic surgery. Because the bipolar electrocautery device is reusable, it decreases operative costs.

Routine placement of ureteral stents is unnecessary after ureteroscopy for urinary calculi.

OBJECTIVES: To report a matched comparison of patients with and without stenting after ureteroscopy for calculi, including middle or proximal ureteral and renal calculi. The elimination of routine stenting after ureteroscopy would prevent stent pain, minimize the need for re-instrumentation, and reduce costs-as long as efficacy and safety are not diminished. METHODS: Of 318 patients who underwent ureteroscopy, 81 (25%) did not have a ureteral stent placed. Of those, 51 were suitable for analysis and included patients with distal ureteral (n = 22), middle or proximal ureteral (n = 11), and renal calculi (n = 18). This cohort was matched to a stented group by stone size and location. RESULTS: The preoperative characteristics of the groups were similar. A stone-free rate of 86% and 94% was achieved in the stented and nonstented groups, respectively (P = 0.32). Complications in the nonstented group were less frequent (flank pain in 3 and postoperative nausea in 1) than in the stented group (hospital visits for flank pain in 12, persistent nausea and vomiting in 1, sepsis in 1, perinephric hematoma in 1, and urinary retention in 1) (total of 4 versus 16, P = 0.025). CONCLUSIONS: Ureteroscopy for distal ureteral stones without ureteral stent placement has been previously described. Our experience expands to include the elimination of stent placement after ureteroscopy for middle or proximal ureteral (22%) and renal (35%) calculi. Our data suggest that after ureteroscopies with short operative times and minimal ureteral trauma, ureteral stents may not be necessary, even if proximal ureteral or renal ureteroscopy has been performed.

Pelvic recurrences post cystectomy: current treatment strategies.

Pelvic recurrence following cystectomy is a devastating problem for both physician and patient. Patients who recur locally usually do so within the first 2 years following surgery. Stage, grade, and possibly p53 status of the tumor are prognostic indicators for local failure. Patients with extensive disease at the time of diagnosis may benefit from adjuvant or neoadjuvant treatment to attempt to decrease the rate of recurrence. Treatment of patients with local failure should use a multimodality approach that includes systemic chemotherapy with or without local radiation therapy or surgery. Although rare, long-term survival can be achieved in selected patients.

The relative amount of epithelium, muscle, connective tissue and lumen in prostatic hyperplasia as a function of the mass of tissue resected.

PURPOSE: The relative amounts of epithelium, connective tissue, muscle and gland lumen in benign prostatic hyperplasia have been reported but they have not been correlated with prostate size. We determine if the relative amount of prostatic tissue varies with prostate size. MATERIALS AND METHODS: Paraffin blocks of transurethrally resected prostate tissue were randomly chosen from the archives of 58 patients with benign prostatic hyperplasia. Two new slides per patient were made and stained with prostate specific antigen or Masson trichrome, respectively. A total of 20 images from each slide were captured using a high resolution camera, digitized and analyzed with computer software for the relative percentage of the various tissue components. RESULTS: As the amount of prostate tissue resected increased from less than 10 to greater than 70 gm. the epithelium had a 4-fold increase from 5.37 to 21.92%, the muscle component had a 42% decrease from 28.46 to 16.62%, the lumen doubled from 7.05 to 14.01% and the connective tissue remained relatively unchanged from 35.58 to 31.53%. There was a statistically significant difference in all components of prostatic tissue except for connective tissue when comparing prostates less than 30 versus greater than 30 gm., including epithelium 6.52 versus 16.10% (p <0.01), muscle 28.45 versus 20.78% (p <0.01), lumen 7.42 versus 14.58% (p <0.01) and connective tissue 35.74 versus 32.45% (p <0.06). The stroma-to-epithelium and muscle-to-epithelium ratios each had a 9-fold decline (p = 0.01). CONCLUSIONS: As the prostate increases in size, there is statistically significant more epithelium and lumen, and less muscle tissue.

Preliminary noninvasive back-pressure recordings of bladder pressure.

Obstructive voiding is best evaluated with urodynamics, including bladder pressure and urine flow rates. Until recently, the recording of bladder pressure required the use of a urethral catheter. In preliminary observations, a noninvasive back-pressure method using an external condom catheter has been introduced to determine bladder pressure. This device uses a side tube for pressure recording and an outlet tube that is clamped for short periods of time. We have investigated design criteria for back-pressure recording techniques. In the laboratory setting using a plastic model, we determined that a low compliance condom is needed. In addition, a back flow of fluid during the clamping procedure helps to obtain quick back pressures and facilitates evaluation of pressure when low flow rates are present. These modified condom devices were evaluated in four male subjects. Back pressures were not statistically different than bladder pressures recorded with a urethral catheter. The use of back pressures in the evaluation for obstructive uropathy can be enhanced by using a pressure and flow nomogram.

mnd2: a new mouse model of inherited motor neuron disease.

The autosomal recessive mutation mnd2 results in early onset motor neuron disease with rapidly progressive paralysis, severe muscle wasting, regression of thymus and spleen, and death before 40 days of age. mnd2 has been mapped to mouse chromosome 6 with the gene order: centromere-Tcrb-Ly-2-Sftp-3-D6Mit4-mnd2-D6Mit 6, D6Mit9-D6Rck132-Raf-1, D6Mit11-D6Mit12-D6Mit14, mnd2 is located within a conserved linkage group with homologs on human chromosome 2p12-p13. Spinal motor neurons of homozygous affected animals are swollen and stain weakly, and electromyography revealed spontaneous activity characteristic of muscle denervation. Myelin staining was normal throughout the neuraxis. The clinical observations are consistent with a primary abnormality of lower motor neuron function. This new animal model will be of value for identification of a genetic defect responsible for motor neuron disease and for evaluation of new therapies.