The use of a novel reverse thermosensitive polymer to prevent ureteral stone retropulsion during intracorporeal lithotripsy: a randomized, controlled trial.

PURPOSE: We present the first randomized clinical study using BackStop, a novel reverse thermosensitive water-soluble polymer that is dispensed above the stone(s) and temporarily occludes the ureter to prevent retropulsion of stone fragments during ureteroscopic lithotripsy. After fragmentation is completed and concretions are extracted, conventional irrigation with saline dissolves the polymer, which is then flushed out. MATERIALS AND METHODS: A total of 68 subjects with a single stone in the proximal ureter and an indication for ureteroscopic lithotripsy were enrolled in this prospective, randomized, single-blind, controlled, multisite clinical study. Each subject was randomly assigned to the BackStop group (34) or the control group (34 with no antiretropulsion device). For subjects in the experimental group BackStop was dispensed into the ureter above the stone using a 3Fr or 5Fr catheter. Ureteroscopic lithotripsy was performed in all subjects using pneumatic or laser energy. Measured end points included the retropulsion rate, the need for subsequent procedures, the stone-free rate at followup, the occurrence of adverse events and ureteral occlusion, if any, and post-stone fragmentation and extraction. RESULTS: Subjects randomized to the BackStop group experienced a statistically significant (p = 0.0002) lower rate of retropulsion (8.8%, 3 of 34) vs the control group (52.9%, 18/34). There were no adverse events in the BackStop group and BackStop was successfully dissolved in every subject, resulting in a patent ureter. CONCLUSIONS: BackStop appears to be a novel, safe and effective means of preventing stone fragment retropulsion during ureteroscopic lithotripsy for the management of ureteral stones.

Objective Assessment and Standard Setting for Basic Flexible Ureterorenoscopy Skills Among Urology Trainees Using Simulation-Based Methods.

Objective: To objectively assess the performance of graduating urology residents performing flexible ureterorenoscopy (fURS) using a simulation-based model and to set an entrustability standard or benchmark for use across the educational spectrum. Methods: Chief urology residents and attending endourologists performed a standardized fURS task (ureterorenoscopy and repositioning of stones) using a Boston Scientific© Lithovue ureteroscope on a Cook Medical© URS model. All performances were video-recorded and blindly scored by both endourology experts and crowd-workers (C-SATS) using the Ureteroscopic Global Rating Scale, plus an overall entrustability score. Validity evidence supporting the scores was collected and categorized. The Borderline Group (BG) method was used to set absolute performance standards for the expert and crowdsourced ratings. Results: A total of 44 participants (40 chief residents, 4 faculties) completed testing. Eighty-three percent of participants had performed >50 fURS cases at the time of the study. Only 47.7% (mean score 12.6/20) and 61.4% (mean score 12.4/20) of participants were deemed "entrustable" by experts and crowd-workers, respectively. The BG method produced entrustability benchmarks of 11.8/20 for experts and 11.4/20 for crowd-worker ratings, resulting in pass rates of 56.9% and 61.4%. Conclusion: Using absolute standard setting methods, benchmark scores were set to identify trainees who could safely carry out fURS in the simulated setting. Only 60% of residents in our cohort were rated as entrustable. These findings support the use of benchmarks to earlier identify trainees requiring remediation.

Peritoneal dialysis catheter removal at the time of renal transplantation: Choosing the optimal candidate.

INTRODUCTION: Concurrent peritoneal dialysis (PD) catheter removal during renal transplantation is controversial, with limited evidence supporting this practice. Our objective was to determine the rate of delayed graft function (DGF) in patients on preoperative PD. Additionally, we sought to identify which patients can safely have their PD catheter removed during transplantation due to a low risk of DGF. METHODS: We conducted a retrospective observational study between June 2011 and December 2015. The primary outcome was the diagnosis of DGF, defined as the need for dialysis within the first week of transplantation. Clinical and transplant factors, including graft type and donor criteria, were assessed for association with the primary outcome. Catheter-related complication rates were also compared between post-transplant PD and hemodialysis (HD). RESULTS: Of our cohort of 567 patients, 145 patients (25.6%) developed DGF. Obesity (odds ratio [OR] 1.06; 95% confidence interval [CI] 1.00-1.11; p=0.04) and increased perioperative blood loss (OR 1.002; 95% CI 1.000-1.003; p=0.03) were predictors of DGF. Protective factors included living donor (LD) grafts (OR 0.15; 95% CI 0.05-0.49; p=0.002) and intraoperative graft urine production (OR 0.39; 95% CI 0.23-0.65; p<0.001). In our PD cohort, only LD grafts demonstrated lower DGF rates (0 LD vs. 20.8% deceased donor; p=0.003). In terms of post-transplant renal replacement therapy, patients on PD and HD had similar duration of temporary dialysis (one day PD vs. two days HD; p=0.48) and catheter-related complication rates (4.5% PD vs. 2.6% HD; p=0.30). CONCLUSIONS: Carefully selected patients, such as those receiving LD grafts, may benefit from concurrent PD catheter removal.

Prospective randomized trial comparing shock wave lithotripsy and ureteroscopy for lower pole caliceal calculi 1 cm or less.

PURPOSE: The optimal management of lower pole renal calculi is controversial. We compared shock wave lithotripsy (SWL) and ureteroscopy (URS) for the treatment of patients with small lower pole stones in a prospective, randomized, multicenter trial. MATERIALS AND METHODS: A total of 78 patients with 1 cm or less isolated lower pole stones were randomized to SWL or URS. The primary outcome measure was stone-free rate on noncontrast computerized tomography at 3 months. Secondary outcome parameters were length of stay, complication rates, need for secondary procedures and patient derived quality of life measures. RESULTS: A total of 67 patients randomized to SWL (32) or URS (35) completed treatment. The 2 groups were comparable with respect to age, sex, body mass index, side treated and stone surface area. Operative time was significantly shorter for SWL than URS (66 vs 90 minutes). At 3 months of followup 26 and 32 patients who underwent SWL and URS had radiographic followup that demonstrated a stone-free rate of 35% and 50%, respectively (p not significant). Intraoperative complications occurred in 1 SWL case (unable to target stone) and in 7 URS cases (failed access in 5 and perforation in 2), while postoperative complications occurred in 7 SWL and 7 URS cases. Patient derived quality of life measures favored SWL. CONCLUSIONS: This study failed to demonstrate a statistically significant difference in stone-free rates between SWL and URS for the treatment of small lower pole renal calculi. However, SWL was associated with greater patient acceptance and shorter convalescence.

Rectal gastrointestinal stromal tumor mimicking a primary prostatic lesion.

The interstitial cells of Cajal have been identified in locations beyond the gastrointestinal tract, including the prostate, uterus and bladder. Indeed, there are reports of primary gastrointestinal stromal tumor (GIST) arising from each of these sites. We report the case of a 72-year old male who presented with benign prostatic hypertrophy and was diagnosed on retropubic prostatectomy as having a GIST. While the initial clinical and radiologic impression was that of a primary prostatic GIST, subsequent imaging ultimately revealed a small rectal extension as the source of the lesion. The purpose of our report is to highlight the need to assiduously rule-out gastrointestinal sources of GIST prior to making the diagnosis of primary prostatic GIST.

Dual usage of a stone basket: Stone capture and retropulsion prevention.

INTRODUCTION: Stone migration during ureteroscopy (URS) for proximal ureteric calculi is a constant challenge. Several retropulsion prevention devices have been developed to optimize URS outcomes. Our technique involves capturing the stone within a four-wire Nitinol stone basket and then performing laser lithotripsy to dust the stone while it is engaged in the basket. The dusted fragments wash out with the irrigation fluid and once small enough, the remaining stone is removed intact. METHODS: A retrospective chart review was performed of all proximal semi-rigid URS procedures for a solitary calculus (2000-2016). We compared our new technique introduced in 2010 to URS control procedures that did not use retropulsion prevention techniques or devices. RESULTS: One hundred and forty patients underwent URS for proximal ureteric calculi. Mean stone diameter was 9.3±3.4 mm, with similar impaction rate between both groups (44.1% vs. 43.1% control; p=n/s). The mean surgical procedure time was 53.3±17.9 minutes for the new technique and 65.2±29.2 minutes for the control group (p=0.005). Compared to the new technique, the control group had a higher rate of retropulsion (33.3% vs. 14.7%; p=0.01) and required flexible URS more often to exclude or remove residual fragments (24.1% vs. 59.1%; p=0.001). Using the new technique, stone-free rates were higher (79.1% vs. 69.4%; p=n/s) and there was a lower likelihood of leaving residual fragments both <3 mm and ≥3 mm (p=0.001). CONCLUSIONS: Our novel technique results in shorter operative times, lower retropulsion rates, and decreases postoperative residual stone fragments.

Malignant pheochromocytoma of the urinary bladder.

This report describes an illustrative case of malignant pheochromocytoma of the urinary bladder in a 28-year old man. A combined-modality treatment plan with partial cystectomy and post-operative radiotherapy and concurrent chemotherapy with single agent cisplatin weekly was performed. Three weeks after completing concurrent chemoradiation the first of four planned cycles of cisplatin 25 mg/m2 and etoposide 100 mg/m2 was administered daily over 3 days. Although there are no controlled series offering proof of benefit, postoperative concurrent chemoradiation followed by chemotherapy alone are reasonable options for patients with residual disease or at high risk for locoregional relapse.

Evaluating potential live-renal donors: Causes for rejection, deferral and planned procedure type, a single-centre experience.

BACKGROUND: Renal transplantation is the preferred therapy to extend life expectancy and quality of life for patients with chronic kidney disease. There are many barriers in the process of live kidney donation that prevent the timely progression from organ requirement to transplantation, including the progression of the live donor through a medical evaluation. We assess how easily patients complete the donor workup, how often the medical evaluation identifies significant incidental findings, and which surgical procedure is planned for organ retrieval. METHODS: We reviewed our donor database and the minutes from our multidisciplinary rounds from 2002 to 2008 to assess how medical, radiological and psychological findings were used to decide on the candidacy of potential donors. RESULTS: Half (50.2%) of patients did not pass the initial health screen. Of the 467 patients who progressed beyond the health screen to the computed tomographic angiogram evaluation, 48 (10.3%) were excluded as donors and 419 (89.7%) were accepted. Of those accepted, 136 (32.5%) were conditional on further medical workup. Of the patients accepted (n=419), 375 (89.5%) were planned for laparoscopic left-sided approach. CONCLUSIONS: The vast majority of patients who passed the initial health screen for kidney donation will be accepted as donors, but about one-third will require further workup. It is rare to identify life-threatening disease on screening computerized tomographic angiograph for kidney donor workup.

The Canadian StoneBreaker trial: a randomized, multicenter trial comparing the LMA StoneBreaker™ and the Swiss LithoClast® during percutaneous nephrolithotripsy.

BACKGROUND AND PURPOSE: Percutaneous nephrolithotripsy (PCNL) is the treatment of choice for patients with large renal stones. The StoneBreaker™ (SB) is a novel handheld pneumatic lithotriptor, powered by a compressed carbon dioxide cartridge. The purpose of this study was to compare the efficiency of the SB to a standard pneumatic lithotriptor, the Swiss LithoClast(®) (LC). PATIENTS AND METHODS: From January 2008 to December 2009, patients undergoing PCNL were randomized to either the SB or the Swiss LC. Primary outcomes included time to fragment the stone, retrieve the fragments, and remove debris using ultrasonic lithotripsy. Secondary end points were stone-free rate, lithotriptor setup time, ease of use, operator fatigue, endoscopic visualization, damage to mucosa, and device-related complications. RESULTS: Of the initial 115 patients recruited, 77 were enrolled and 38 were excluded. The SB had significantly faster stone fragmentation time, total lithotripsy time, and setup time than the Swiss LC (P ≤ 0.05). A significant difference was also noted in the ease of use and operator fatigue in favor of the SB. There were no device-related complications. CONCLUSION: The SB pneumatic lithotriptor is easier to set up and use, and it provides faster stone fragmentation than the Swiss LC.

Prospective, randomized trial comparing shock wave lithotripsy and ureteroscopy for lower pole caliceal calculi 1 cm or less.

PURPOSE: The optimal management of lower pole renal calculi is controversial. We compared shock wave lithotripsy (SWL) and ureteroscopy (URS) for the treatment of patients with small lower pole stones in a prospective, randomized, multicenter trial. MATERIALS AND METHODS: A total of 78 patients with 1 cm or less isolated lower pole stones were randomized to SWL or URS. The primary outcome measure was stone-free rate on noncontrast computerized tomography at 3 months. Secondary outcome parameters were length of stay, complication rates, need for secondary procedures and patient derived quality of life measures. RESULTS: A total of 67 patients randomized to SWL (32) or URS (35) completed treatment. The 2 groups were comparable with respect to age, sex, body mass index, side treated and stone surface area. Operative time was significantly shorter for SWL than URS (66 vs 90 minutes). At 3 months of followup 26 and 32 patients who underwent SWL and URS had radiographic followup that demonstrated a stone-free rate of 35% and 50%, respectively (p not significant). Intraoperative complications occurred in 1 SWL case (unable to target stone) and in 7 URS cases (failed access in 5 and perforation in 2), while postoperative complications occurred in 7 SWL and 7 URS cases. Patient derived quality of life measures favored SWL. CONCLUSIONS: This study failed to demonstrate a statistically significant difference in stone-free rates between SWL and URS for the treatment of small lower pole renal calculi. However, SWL was associated with greater patient acceptance and shorter convalescence.

High urinary excretion of uric acid combined with high excretion of calcium links kidney stone disease to familial hypertension.

BACKGROUND: Past studies identified an association between kidney stone disease (KSD) and hypertension. We recently reported a high occurrence of hypertension in families of patients with hyperuricosuric KSD. As hypercalciura frequently coexists with hyperuricosuria and high urinary excretion of calcium is found in patients with hypertension, we hypothesized that hyperuricosuria that is accompanied by hypercalciuria better describes the familial association between KSD and hypertension. METHODS: Four hundred and eighty-six KSD patients, aged 18-50 years, attending a lithotripsy unit collected a 24-h urine sample for metabolic analysis and provided information on family history of hypertension. The familial occurrence of hypertension was compared among four groups of patients: those who had combined elevation of both urinary calcium and uric acid excretions ("combined" abnormality, n=56), those who had hyperuricosuria without concomitant hypercalciuria ("pure" hyperuricosuria, n=67), those who had hypercalciuria without concomitant hyperuricosuira ("pure" hypercalciuria, n=52), and a control KSD patient group ("other" abnormality, n=311). The prevalence of treated hypertension in patients from the four groups was 16%, 12%, 2%, 10%, respectively. RESULTS: Thirty-four per cent of the patients with the "combined" abnormality had a positive family history of hypertension, defined as two or more first-degree relatives with treated hypertension, that was significantly higher than in patients with either "pure" hyperuricosuira (15%, P<0.02), "pure" hypercalciuria (8%, P<0.001), or patients with "other" abnormality (10%, P<0.001). The adjusted OR for positive family history of hypertension in the "combined" abnormality group compared to the control KSD patient group was 5.6 (2.39-13.30). The prevalence of hypertension in siblings of patients with the "combined" abnormality (13%) was significantly higher than in siblings of patients with either "pure" hyperuricosuria (3%, P<0.001), "pure" hypercalciuria (1%, P<0.001), or siblings of control patients with "other" abnormality (4%, P<0.001). The adjusted OR for hypertension in siblings of a patient with "combined" abnormality compared to a control KSD patient was 3.4 (1.97-5.91). Patients in the "combined" abnormality group were also characterized by significantly elevated urinary sodium, phosphorus, citrate and potassium excretions. CONCLUSIONS: Our data suggest that there is a strong, independent association between familial occurrence of hypertension and the phenotype characterized by combined elevation of both urinary uric acid and calcium excretions. The association is not present in those with "pure" hyperuricosuria or "pure" hypercalciuria. Ascertainment of patients based on this phenotype may identify more homogeneous populations for genetic analysis of hypertension.

Soy consumption and phytoestrogens: effect on serum prostate specific antigen when blood lipids and oxidized low-density lipoprotein are reduced in hyperlipidemic men.

PURPOSE: Herbal remedies high in phytoestrogens have been shown to reduce serum prostate specific antigen (PSA) and have been proposed as a treatment for prostate cancer. Soy proteins used to lower serum cholesterol are rich sources of phytoestrogens. Therefore, we assessed the effect of soy consumption on serum PSA in men who had participated in cholesterol lowering studies. MATERIALS AND METHODS: For 3 to 4 weeks 46 healthy middle-aged men with a range of starting PSA values took soy (mean 44 gm. soy protein daily, 116 mg. isoflavones daily) or control foods, and a subgroup of men took a lower level of soy supplements for 3 months. PSA was measured at the start and end of each treatment. RESULTS: Soy had no significant effect on serum total or free PSA, independent of PSA starting value or isoflavone intake. The lack of effect on PSA was seen, although soy intake was sufficient to reduce low-density lipoprotein cholesterol (5.8 +/- 2.2%, p = 0.012), the estimated coronary heart disease risk (6.1 +/- 2.8% for 10 years, p = 0.032) and the serum concentration of oxidized low-density lipoprotein measured as conjugated dienes (9.5 +/- 3.4%, p = 0.008) in the 3 to 4-week study. In addition, the lack of effect of soy on PSA persisted for the 3 months of the extended study. CONCLUSIONS: At levels of soy intake which reduce low-density lipoprotein cholesterol any potential benefits of soy consumption on prostate cancer are likely to occur for reasons other than alterations in hormone activity.