Vishnu Ganesan

Accuracy of ultrasonography for renal stone detection and size determination: is it good enough for management decisions?

To determine the sensitivity and specificity of ultrasonography (US) for detecting renal calculi and to assess the accuracy of US for determining the size of calculi and how this can affect counselling decisions.

Intermediate-Term Outcomes for Men with Very Low/Low and Intermediate/High Risk Prostate Cancer Managed by Active Surveillance

Purpose: We compare intermediate term clinical outcomes among men with favorable risk and intermediate/high risk prostate cancer managed by active surveillance. Materials and Methods: A total of 635 men with localized prostate cancer have been on active surveillance since 2002 at a high volume academic hospital in the United States. Median followup is 50.5 months (IQR 31.1–80.3). Time to event analysis was performed for our clinical end points. Results: Of the cohort 117 men (18.4%) had intermediate/high risk disease. Overall 5 and 10‐year all cause survival was 98% and 94%, respectively. Cumulative metastasis‐free survival at 5 and 10 years was 99% and 98%, respectively. To date no cancer specific deaths had been observed. Overall freedom from intervention was 61% and 49% at 5 and 10 years, respectively. Overall cumulative freedom from failure of active surveillance, defined as metastasis or biochemical failure after local therapy with curative intent, was 97% and 91% at 5 and 10 years, respectively. Of the men 21 (9.9%) experienced biochemical failure after deferred treatment and the 5‐year progression‐free probability was 92%. Compared to men with favorable risk disease those with intermediate/high risk cancer experienced no difference in metastases, surveillance failure or curative intervention. However, patients at higher risk were at significantly increased risk for all cause mortality, likely reflecting patient selection factors. These conclusions may be limited by the small number of events and the duration of our study. Conclusions: Patients with localized prostate cancer who are on active surveillance demonstrated a low rate of active surveillance failure, prostate cancer specific mortality and metastases regardless of baseline risk.

Stone formation and management after bariatric surgery.

Obesity is a significant health concern and is associated with an increased risk of nephrolithiasis, particularly in women. The underlying pathophysiology of stone formation in obese patients is thought to be related to insulin resistance, dietary factors, and a lithogenic urinary profile. Uric acid stones and calcium oxalate stones are common in these patients. Use of surgical procedures for obesity (bariatric surgery) has risen over the past two decades. Although such procedures effectively manage obesity-dependent comorbidities, several large, controlled studies have revealed that modern bariatric surgeries increase the risk of nephrolithiasis by approximately twofold. In patients who have undergone bariatric surgery, fat malabsorption leads to hyperabsorption of oxalate, which is exacerbated by an increased permeability of the gut to oxalate. Patients who have undergone bariatric surgery show characteristic 24 h urine parameters including low urine volume, low urinary pH, hypocitraturia, hyperoxaluria and hyperuricosuria. Prevention of stones with dietary limitation of oxalate and sodium and a high intake of fluids is critical, and calcium supplementation with calcium citrate is typically required. Potassium citrate is valuable for treating the common metabolic derangements as it raises urinary pH, enhances the activity of stone inhibitors, reduces the supersaturation of calcium oxalate, and corrects hypokalaemia. Both pyridoxine and probiotics have been shown in small studies to reduce hyperoxaluria, but further study is necessary to clarify their effects on stone morbidity in the bariatric surgery population.

Clinical Predictors of 30-Day Emergency Department Revisits for Patients with Ureteral Stones

PURPOSE Patients with ureteral stones frequently present to the emergency department for an initial evaluation with pain and/or nausea. However, a subset of these patients subsequently return to the emergency department for additional visits. We sought to identify clinical predictors of emergency department revisits. MATERIALS AND METHODS We reviewed emergency department visits at our institution with an ICD-9 diagnosis of urolithiasis and an associated computerized tomography scan between 2010 and 2013. Computerized tomography studies were independently reviewed to confirm stone size and location, and degree of hydronephrosis. The primary outcome was a second emergency department visit within 30 days of the initial visit for reasons related to the stone. Patient characteristics and stone parameters at presentation were recorded. Univariable and multivariable analyses were done to identify factors associated with emergency department revisits. RESULTS We reviewed the records of 1,510 patients 18 years old or older who presented to the emergency department with a diagnosis of ureteral stones confirmed by computerized tomography. Of the patients 164 (11%) revisited the emergency department within 30 days. On multivariable analysis the presence of a proximal ureteral stone, age less than 30 years and the need for intravenous narcotics in the emergency department remained independently associated with an emergency department revisit. CONCLUSIONS Younger patients, those with proximal stones and those requiring intravenous narcotics for pain control are more likely to return to the emergency department. Consideration should be given for early followup or intervention for these patients to prevent costly emergency department returns.

Reducing Costs for Robotic Radical Prostatectomy: Three-instrument Technique

OBJECTIVE To describe our technique for performing robotic-assisted laparoscopic prostatectomy (RALP) and pelvic lymph node dissection using only 3 robotic instruments to reduce disposable costs associated with the robotic surgical platform. METHODS The financial impact of robotic surgery is real. Whereas the initial capital investment of the robotic platform (including the cost of the device itself and the maintenance contract) is largely fixed, the cost of disposable instrumentation can vary depending on utilization. Herein we describe our technique for 3-instrument robotic radical prostatectomy that may decrease costs by limiting the use of disposable instruments. RESULTS Exclusion of the high-cost energy instruments may reduce operative costs by up to 40%. In addition, using 1 robotic needle driver vs 2 may decrease overall costs by another 12%. At our institution, we have adopted these techniques in cost-efficiency and have gone further by only using 3 instruments during robotic radical prostatectomy. The only 3 instruments necessary to perform a successful RALP are a robotic needle driver, Prograsp forceps, and monopolar scissors. CONCLUSION To improve the value of care while utilizing robotic technology, we must be cognizant of keeping operative costs to a minimum while maintaining positive patient outcomes. We demonstrate here a method to decrease disposable operating room costs while preserving the ability to successfully perform a RALP.

Prognostic Significance of a Negative Confirmatory Biopsy on Reclassification Among Men on Active Surveillance

OBJECTIVE To examine the association between absence of disease on confirmatory biopsy and risk of pathologic reclassification in men on active surveillance (AS). MATERIALS AND METHODS Men with grade groups 1 and 2 disease on AS between 2002 and 2015 were identified who received a confirmatory biopsy within 1 year of diagnosis and ≥3 biopsies overall. The primary outcomes were pathologic reclassification by grade (any increase in primary Gleason pattern or Gleason score) or volume (>33% of sampled cores involved or increase in the number of cores with >50% involvement). The effect of a negative confirmatory biopsy survival was evaluated using Kaplan-Meier analysis and a Cox proportional hazards modeling. RESULTS Out of 635 men, 224 met inclusion criteria (median follow-up: 55.8 months). A total of 111 men (49.6%) had a negative confirmatory biopsy. Decreased grade reclassification (69.7% vs 83.9%; P = .01) and volume reclassification (66.3% vs 87.4%; P = .004) was seen at 5 years for men with a negative confirmatory biopsy compared with those with a positive biopsy. On adjusted analysis, a negative confirmatory biopsy was associated with a decreased risk of grade reclassification (hazard ratio, 0.51; 95% confidence interval, 0.28-0.94; P = .03) and volume reclassification (hazard ratio, 0.32; 95% confidence interval, 0.17-0.61; P = .0006) at a median of 4.7 years. CONCLUSION Absence of cancer on the confirmatory biopsy is associated with a significant decrease in rate of grade and volume reclassification among men on AS. This information may be used to better counsel men on AS.

Robotic-assisted Laparoscopic Bilateral Nerve Sparing and Apex Preserving Cystoprostatectomy in Young Men With Bladder Cancer

OBJECTIVE To describe our technique and outcomes of robotic-assisted nerve-sparing cystoprostatectomy with prostatic apex preservation and orthotopic ileal conduit urinary diversion in young men undergoing robotic-assisted radical cystectomy (RARC) for the management of urothelial carcinoma. MATERIALS AND METHODS Young men (<40 years old) with the diagnosis of urothelial carcinoma undergoing RARC with orthotopic neobaldder formation were eligible for our technique of nerve-sparing cystoprostatectomy with prostatic apex preservation at the time of orthotopic ileal conduit urinary diversion. During the apical prostatic dissection step of the RARC, the plane of dissection is directed under the dorsal vein complex and through anterior prostatic fibromuscular stroma. This plane is further carried through the prostatic urethra, transecting the most caudal aspect of prostatic peripheral zone posteriorly, to create a long urethra and a posterior urethral plate formed by peripheral zone of the prostate, which serves as a robust, long stump for the subsequent vesicourethral anastomosis. RESULTS From January 2013 to January 2014, 3 men were treated with RARC and intracorporeal neobladder urinary diversion based on the described technique. There were no intraoperative complications. Two patients experienced grade II complications postoperatively. Pathologic assessment demonstrated negative surgical margins in all 3 cases. With mean follow-up time of 28.2 months, 2 out of 3 patients are free from disease recurrence. All patients report daytime urinary continence with no pad usage and potency without the need for phosphodiesterase-5 inhibitors. CONCLUSION RARC with bilateral nerve and apical preservation can be performed safely in appropriately selected young patients with excellent functional and acceptable short-term oncologic results.

Management of Challenging Urethro-ileal Anastomosis During Robotic Assisted Radical Cystectomy with Intracorporeal Neobladder Formation

BACKGROUND Robotic assisted radical cystectomy (RARC) is increasingly being adopted, but intracorporeal neobladder formation remains a challenging procedure limited to selected centers. Common challenges with intracorporeal neobladder formation relate to fashioning a tension-free urethro-ileal anastomosis. In this paper, we describe a series of maneuvers to overcome these challenges that we believe will be of great utility to surgeons performing intracorporeal neobladder. OBJECTIVE To describe maneuvers to overcome challenges during intracorporeal urethro-ileal anastomosis formation and to report postoperative outcomes for patients in whom these maneuvers were used. DESIGN, SETTING, AND PARTICIPANTS A retrospective review of medical records of patients who underwent RARC with intracorporeal neobladder performed by one surgeon (G.-P.H.) at our tertiary center from January 2012 to February 2015 in which at least one additional maneuver was required beyond preservation of urethral length, removal of the sigmoid colon from the pelvis, and careful ileal loop selection. The primary end point was 90-d complications. Follow-up ranged from 6 to 36 mo, and 16 patients had at least 1-yr follow-up. SURGICAL PROCEDURE RARC with intracorporeal neobladder formation. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSES Clinical and operative data collected from a prospectively maintained, institutional review board-approved database. Maneuvers used during intracorporeal urethro-ileal anastomosis were recorded. Descriptive statistics were used to evaluate postoperative outcomes. RESULTS AND LIMITATIONS Nineteen patients met the inclusion criteria. Mean operative time was 486 min (standard deviation: 112 min) with median hospitalization of 7 d (interquartile range: 7-9 d). Seven patients (36.8%) experienced a complication, with one (5.3%) major complication thought to be unrelated to surgery. No open conversions were required. There was no 90-d mortality. CONCLUSIONS Our stepwise approach can help overcome challenges of urethro-ileal anastomosis during intracorporeal neobladder formation. PATIENT SUMMARY When performing intracorporeal neobladder formation, challenges are often encountered in fashioning the urethro-ileal anastomosis. We describe a series of maneuvers that, when used in a stepwise manner, help overcome these challenges.

Impact of 5α-Reductase Inhibitors on Disease Reclassification among Men on Active Surveillance for Localized Prostate Cancer with Favorable Features

Purpose: We determined the effect of 5&agr;‐reductase inhibitors on disease reclassification in men with prostate cancer optimally selected for active surveillance. Materials and Methods: In this retrospective review we identified 635 patients on active surveillance between 2002 and 2015. Patients with favorable cancer features on repeat biopsy, defined as absent Gleason upgrading, were included in the cohort. Patients were stratified by those who did or did not receive finasteride or dutasteride within 1 year of diagnosis. The primary end point was grade reclassification, defined as any increase in Gleason score or predominant Gleason pattern on subsequent biopsy. This was assessed by multivariable Cox proportional hazards regression analysis. Results: At diagnosis 371 patients met study inclusion criteria, of whom 70 (19%) were started on 5&agr;‐reductase inhibitors within 12 months. Median time on active surveillance was 53 vs 35 months in men on vs not on 5&agr;‐reductase inhibitors (p <0.01). Men on 5&agr;‐reductase inhibitors received them for a median of 23 months (IQR 6–37). On actuarial analysis there was no significant difference in grade reclassification for 5&agr;‐reductase inhibitor use in patients overall or in the very low/low risk subset. The overall percent of patients who experienced grade reclassification was similar at 13% vs 14% (p = 0.75). After adjusting for baseline clinicopathological features 5&agr;‐reductase inhibitors were not significantly associated with grade reclassification (HR 0.80, 95% CI 0.31–1.80, p = 0.62). Furthermore, no difference in adverse features on radical prostatectomy specimens was observed in treated patients (p = 0.36). Conclusions: Among our cohort of men on active surveillance 5&agr;‐reductase inhibitor use was not associated with a significant difference in grade reclassification with time.

Accurately Diagnosing Uric Acid Stones from Conventional Computerized Tomography Imaging: Development and Preliminary Assessment of a Pixel Mapping Software

Purpose: Preoperative determination of uric acid stones from computerized tomography imaging would be of tremendous clinical use. We sought to design a software algorithm that could apply data from noncontrast computerized tomography to predict the presence of uric acid stones. Materials and Methods: Patients with pure uric acid and calcium oxalate stones were identified from our stone registry. Only stones greater than 4 mm which were clearly traceable from initial computerized tomography to final composition were included in analysis. A semiautomated computer algorithm was used to process image data. Average and maximum HU, eccentricity (deviation from a circle) and kurtosis (peakedness vs flatness) were automatically generated. These parameters were examined in several mathematical models to predict the presence of uric acid stones. Results: A total of 100 patients, of whom 52 had calcium oxalate and 48 had uric acid stones, were included in the final analysis. Uric acid stones were significantly larger (12.2 vs 9.0 mm, p = 0.03) but calcium oxalate stones had higher mean attenuation (457 vs 315 HU, p = 0.001) and maximum attenuation (918 vs 553 HU, p <0.001). Kurtosis was significantly higher in each axis for calcium oxalate stones (each p <0.001). A composite algorithm using attenuation distribution pattern, average attenuation and stone size had overall 89% sensitivity, 91% specificity, 91% positive predictive value and 89% negative predictive value to predict uric acid stones. Conclusions: A combination of stone size, attenuation intensity and attenuation pattern from conventional computerized tomography can distinguish uric acid stones from calcium oxalate stones with high sensitivity and specificity.