Hand-assisted laparoscopy confers equal efficacy in simple and radical nephrectomy.

BACKGROUND AND OBJECTIVES: To evaluate outcomes for simple hand-assisted laparoscopic nephrectomy (HALSN). METHODS: A retrospective chart review was performed at our institution for all patients who had undergone HALSN from January 2002 to January 2009. Thirty-three patients underwent HALSN during this time period and were matched with 33 patients who underwent radical handassisted laparoscopic nephrectomy (HALRN). RESULTS: Operative times were similar between both groups (301 vs 286 min for HALSN vs HALRN; P=.54). There were no intraoperative or postoperative transfusions in either group. There was one conversion to open nephrectomy in the HALSN group in a patient with xanthogranulomatous pyelonephritis and no conversions in the HALRN group. The mean opioid equivalence requirement was not statistically different between both groups (110 vs 120 for HALSN vs HALRN, P=.70). Mean hospital stay was similar for patients undergoing HALSN and HALRN (5.0±3.8 days vs 4.0±1.2 days, P=.63). There was 1 major complication in the HALSN group (pulmonary embolus) and no major complications in the HALRN group. Rates of minor complications were comparable between the 2 groups (18% vs 24% for HALSN vs HALRN). CONCLUSIONS: HALSN may be associated with similar operative times and length of postoperative hospital stay as well as comparable complication rates compared to HALRN.

Patients with and without prior urolithiasis have hypocitraturia and incident kidney stones while on topiramate.

OBJECTIVES: To determine the effect of topiramate (TPM) on 24-hour urinary parameters in stone formers. TPM is frequently prescribed for epilepsy, migraine headaches, and eating disorders. METHODS: Twelve stone-forming patients who were prescribed TPM between 2003 and 2008 were identified from our stone clinic. Of these, 9 patients (M:F, 4:5; 47 ± 7.1 y SEM) underwent a full metabolic workup (UroRisk Diagnostic Profile, Mission Pharmacal Reference Laboratory, San Antonio, TX) and were included for review. Parameters examined include duration and dose of the drug, 24-hour urine calcium, oxalate, citrate, volume, and pH. If available, urine parameters before taking TPM and after either stopping it or receiving potassium citrate therapy were recorded. RESULTS: Mean duration taking TPM was 17 ± 5.2 months (range, 3-43) months and median dose was 100 mg (range, 25-300) daily. Mean urinary citrate excretion was 136 ± 29 mg/d (range, 30-280) in all patients taking the drug. Three patients were either taken off the drug or placed on potassium citrate, resulting in a mean increase in urinary citrate of 374 mg/d (65%). TPM dosage correlated inversely with urinary citrate excretion (Pearson correlation coefficient = -0.73). CONCLUSIONS: TPM therapy is associated with a profound, dose-dependent decrease in urinary citrate, leading to increased lithogenic risk. This hypocitraturia persists even after long periods of taking the drug. Urologists should be aware of the stone-forming risk of this medication. Strategies to maintain therapeutic urinary citrate concentrations in patients on TPM are needed.

A technique for the management of a large median lobe in robot-assisted laparoscopic radical prostatectomy.

An enlarged median lobe is encountered 8% to 18% of the time during robot-assisted laparoscopic prostatectomy. A large intravesical lobe can obscure the anatomy of the bladder neck and generate a large bladder neck, necessitating reconstruction. In addition, it may increase the likelihood of ureteral injury, positive surgical margin, and residual prostate tissue. When encountering this anatomic variant, a clear surgical plan is required. We describe our approach to the large median lobe and highlight a specific technique that may be beneficial in managing this anatomic variant.

Hydroxyproline-induced hyperoxaluria using acidified and traditional diets in the porcine model.

INTRODUCTION: Swine models have proven useful for many different disease processes, especially for urologic research. In this study, we sought to create a model of hyperoxaluria in the adult sow by feeding hydroxyproline (HP). The development of an adult porcine model for calcium oxalate stone disease would represent a significant contribution to stone research as previous animal models have been developed only for rats and baby pigs. METHODS: The experiment included a total of 12 multiparous, gestating sows (Large White x Landrace). Sows were randomly allotted to one of the two treatment groups. Treatments involved basal diets that were either control diet (CD) or acidogenic diet (AD). Urine was collected for 6 consecutive days. On days 1 and 2, each sow was fed 2 kg of the assigned basal diet (CD or AD). On days 3, 4, and 5, 200 g of L-hydroxyproline (Wilshire Technologies, Princeton, NJ) was added to each basal diet for all the 12 sows. The HP was evenly mixed with the basal diets before feeding. On day 6, each sow was fed the basal diet originally assigned without HP ( Fig. 1 ). Urine was collected for each entire 24-hour period to control for differences in the diurnal and postprandial variations in the renal handling of oxalate and glycolate. RESULTS: The addition of HP to the diet increased urinary oxalate excretion. Overall, there was a 192% (CD) and 187% (AD) increase in urinary oxalate between days 1 and 3. The increase peaked on day 3 and gradually returned to baseline by day 6. Student's paired t-test was performed and it confirmed that oxalate on days 3 and 5 was significantly different than baseline (p = 0.009 and p = 0.03, respectively). Urinary glycolate also increased as a result of adding HP to the diet. Overall, there was a 12,340% (CD) and 14,400% (AD) increase in urinary glycolate between days 1 and 3. The increase peaked on day 3 and then declined, although remained more than 10 x greater than baseline at day 6. Student's paired t-test confirmed that glycolate levels on days 3, 5, and 6 were significantly different than baseline (p < 0.001, p = 0.01, and p = 0.03, respectively). CONCLUSION: The role of oxalate in the formation of kidney stones cannot be understated. Medical prevention and management of calcium oxalate nephrolithiasis will require a comprehensive understanding of oxalate metabolism in humans. A model for human hyperoxaluria can be reliably created in the adult sow. Such a model is necessary to further our understanding of oxalate metabolism and ultimately aid in the prevention of calcium oxalate calculi.

Medical management of acute urolithiasis in one American academic emergency room.

STUDY TYPE: Therapy (case series). LEVEL OF EVIDENCE: 4. OBJECTIVE: To determine the implementation of medical expulsive therapy (MET) for ureterolithiasis in one tertiary-care emergency room (ER); referral patterns in the surgical and metabolic follow-up of ureterolithiasis were also assessed. PATIENTS AND METHODS: In this retrospective review we identified 556 patients with ureterolithiasis in the ER at our centre between 2005 and 2007. Of these, 131 patients met inclusion criteria, including first-time stone formers and no urological visit within the previous 5 years. ER records were reviewed and telephone interviews conducted to determine if MET was used, if the patient was referred to a urologist, if surgery was ultimately required, and if there was ultimately a metabolic evaluation. RESULTS: The mean (range) stone size was 4.2 (2-10) mm. Ten patients were admitted directly from the ER and 121 were discharged home. Of the 121 discharged patients, 48 (40%) were prescribed MET. In all, 46 patients received tamsulosin 0.4 mg and two received doxazosin 2 mg; no patient was prescribed steroids. The mean size of passed stones was statistically significantly lower than that of stones that did not pass (P < 0.05). Patients prescribed MET had a 23% chance of needing surgery, vs 32% in those not prescribed MET (P < 0.05). Seventy-one (61%) patients were followed up by a urologist, 27 (23%) by a primary-care physician, and eight (7%) had no further follow-up. Ultimately, 31 (23%) patients had a metabolic evaluation and it was abnormal in 29 (95%). CONCLUSIONS: In this single-institution ER experience, 40% of patients with symptomatic ureterolithiasis were treated with MET on discharge from the ER. Our data also show that only patients referred to a urologist received a metabolic evaluation. This is notable given that the vast majority of those evaluated were found to have a correctable abnormality.

Gastric band placement for obesity is not associated with increased urinary risk of urolithiasis compared to bypass.

PURPOSE: Obesity is associated with multiple health risks. Bariatric surgery is a treatment for clinically severe obesity and is known to increase urolithiasis risk. However, trends in risk over time are not well characterized. Moreover little attention has been devoted to laparoscopic gastric band placement. A comparison of urinary risk of urolithiasis after the Roux-en-Y and gastric banding procedures was performed. MATERIALS AND METHODS: We evaluated 24-hour urine collections from 39 subjects (11 male and 28 female, mean age 51 years) after bariatric surgery. Of these subjects 27 underwent Roux-en-Y gastric bypass and 12 had gastric banding procedures. Mean time since surgery was 3.4 and 2.1 years for the Roux-en-Y gastric bypass and gastric banding groups, respectively. RESULTS: Urine volume was low in both groups (less than 1.5 l daily). Urinary calcium excretion was lower (p = 0.001) in the Roux-en-Y gastric bypass (100 mg daily) vs the gastric banding group (191 mg daily). After Roux-en-Y gastric bypass surgery 48% had a urinary oxalate of 45 mg daily or more compared to 25% after gastric banding. Urinary citrate was less than 370 mg daily for 14 subjects in the Roux-en-Y gastric bypass and 1 in the gastric banding group. All patients were taking calcium supplements. Dietary intake of high oxalate foods did not correlate with urinary oxalate excretion or with hyperoxaluria. CONCLUSIONS: Our study confirms the risk of urinary stones following the Roux-en-Y gastric bypass procedure as a result of hyperoxaluria, low urine volume and hypocitraturia. Those with gastric banding placement had low urine volumes. Future studies should elucidate the effect of nutrition and/or pharmacological therapy on stone risk of both surgeries as their incidence increases.

Renal parenchyma thickness: a rapid estimation of renal function on computed tomography.

PURPOSE: To define the relationship between renal parenchyma thickness (RPT) on computed tomography and renal function on nuclear renography in chronically obstructed renal units (ORUs) and to define a minimal thickness ratio associated with adequate function. MATERIALS AND METHODS: Twenty-eight consecutive patients undergoing both nuclear renography and CT during a six-month period between 2004 and 2006 were included. All patients that had a diagnosis of unilateral obstruction were included for analysis. RPT was measured in the following manner: The parenchyma thickness at three discrete levels of each kidney was measured using calipers on a CT workstation. The mean of these three measurements was defined as RPT. The renal parenchyma thickness ratio of the ORUs and non-obstructed renal unit (NORUs) was calculated and this was compared to the observed function on Mag-3 lasix Renogram. RESULTS: A total of 28 patients were evaluated. Mean parenchyma thickness was 1.82 cm and 2.25 cm in the ORUs and NORUs, respectively. The mean relative renal function of ORUs was 39%. Linear regression analysis comparing renogram function to RPT ratio revealed a correlation coefficient of 0.48 (p < 0.001). The linear regression equation was computed as Renal Function = 0.48 + 0.80 * RPT ratio. A thickness ratio of 0.68 correlated with 20% renal function. CONCLUSION: RPT on computed tomography appears to be a powerful predictor of relative renal function in ORUs. Assessment of RPT is a useful and readily available clinical tool for surgical decision making (renal salvage therapy versus nephrectomy) in patients with ORUs.

Renal parenchyma thickness: a rapid estimation of renal function on computed tomography

Purpose: To define the relationship between renal parenchyma thickness (RPT) on computed tomography and renal function on nuclear renography in chronically obstructed renal units (ORUs) and to define a minimal thickness ratio associated with adequate function. Materials and Methods: Twenty-eight consecutive patients undergoing both nuclear renography and CT during a six-month period between 2004 and 2006 were included. All patients that had a diagnosis of unilateral obstruction were included for analysis. RPT was measured in the following manner: The parenchyma thickness at three discrete levels of each kidney was measured using calipers on a CT workstation. The mean of these three measurements was defined as RPT. The renal parenchyma thickness ratio of the ORUs and non-obstructed renal unit (NORUs) was calculated and this was compared to the observed function on Mag-3 lasix Renogram. Results: A total of 28 patients were evaluated. Mean parenchyma thickness was 1.82 cm and 2.25 cm in the ORUs and NORUs, respectively. The mean relative renal function of ORUs was 39 percent. Linear regression analysis comparing renogram function to RPT ratio revealed a correlation coefficient of 0.48 (p < 0.001). The linear regression equation was computed as Renal Function = 0.48 + 0.80 * RPT ratio. A thickness ratio of 0.68 correlated with 20 percent renal function. Conclusion: RPT on computed tomography appears to be a powerful predictor of relative renal function in ORUs. Assessment of RPT is a useful and readily available clinical tool for surgical decision making (renal salvage therapy versus nephrectomy) in patients with ORUs.

Prostatic capsular perforation with extravasation resulting in pubic osteomyelitis: a rare complication of KTP laser prostatectomy.

The use of lasers for management of benign prostatic hyperplasia has evolved greatly over the last several years. The 120-W potassium-titanyl-phosphate laser, introduced in 2006 as the GreenLight HPS, boasts a 50% improvement in power over the 80-W laser with theoretical benefit of greater vaporization ability and decreased surgery times. Because of higher energy applied to the tissue, there is also a theoretical risk of increased complications related to capsular perforation or injury to adjacent organs. We report a case involving perforation of the anterior prostatic capsule leading to extravasation and osteomyelitis of the pubic bone.

The association of urethrorrhagia and urethral stricture disease.

INTRODUCTION: Urethrorrhagia characterized by terminal hematuria and/or bloody spotting of the underwear between episodes of voiding is a common problem of childhood. We describe a series of boys with urethrorrhagia and associated clinical and endoscopic findings. METHODS AND MATERIALS: The records of boys presenting between 1990 and 2005 with urethrorrhagia were retrospectively reviewed for age, symptoms, symptom duration, physical examination, radiographic evaluation, laboratory data and endoscopic findings. RESULTS: Of 66 boys, 50 presented with classic symptoms of terminal hematuria and/or blood spotting, and 16 with atypical symptoms who underwent cystoscopy with similar findings. Endoscopic evaluation was performed in 55 (82%) patients for prolonged symptomatology or recurrent symptoms and revealed four distinct patterns: Group 1, three (5%) patients with a normal appearing urethra; Group 2, 27 (49%) patients who were found to have inflammation or hyperemia of the bulbar urethra; Group 3, 17 (31%) cases in which there was a white membranous exudate or mucosal irregularity; and Group 4, eight (14%) patients who were found to have stricture disease on cystoscopy. Stricture developed after initial cystoscopy in six cases. CONCLUSION: Consistent with previous studies, a subset of patients developed urethral stricture disease after presenting with urethrorrhagia. As eight patients had a urethral stricture on initial cystoscopy, and those with strictures are clinically indistinguishable symptomatically from those without, we feel that uroflow and selective cystoscopy are important tools for the work-up of severe and persistent cases of urethrorrhagia. Group 3 may represent a population at significant risk for the development of stricture disease warranting closer follow up and evaluation. The white membranous exudate found on cystoscopy may represent a pre-stricture lesion as evidenced by four cases that subsequently developed strictures.