Surgical Outcomes between Routes of Hysterectomy in Patients with a Previous Cesarean Section.

STUDY OBJECTIVE: To determine the difference in surgical complications for patients with a previous cesarean section (CS) undergoing abdominal, vaginal, or laparoscopic hysterectomy. DESIGN: A population-based retrospective cohort study. SETTING: Province of Ontario, Canada. PATIENTS: 10 300 patients with at least 1 CS between July 1, 1991, and February 17, 2018. INTERVENTIONS: Benign, nongravid hysterectomy between Apr 1, 2002, and March 31, 2018. MEASUREMENTS AND MAIN RESULTS: The primary outcome was a composite of all surgical complications within 30 days of surgery. Secondary outcomes were rate of genitourinary complications, readmission to hospital, and emergency department visit occurring within 30 days of surgery. Of 10 300 patients who had at least one previous CS, who underwent subsequent hysterectomy for a benign indication, 7370 underwent an abdominal hysterectomy (71.55%), 813 (7.9%) had a vaginal hysterectomy, and 2117 (20.55%) underwent a laparoscopic hysterectomy. The adjusted odds of any surgical complication from hysterectomy was significantly lower when performed by the vaginal approach than the laparoscopic approach (odds ratio, 0.32; 95% confidence interval, 0.20-0.51; p <.0001). There was no difference in the odds of surgical complication between abdominal and laparoscopic approaches (odds ratio, 1.09; 95% confidence interval, 0.87-1.37; p = .45). CONCLUSION: Our retrospective population-based study demonstrates that, after previous CS, patients selected to undergo vaginal hysterectomy experienced lower risk than either abdominal or laparoscopic approaches. This suggests that CS alone should not be a contraindication to vaginal hysterectomy.

Population-based assessment of re-treatment and healthcare utilisation after photoselective vaporisation of the prostate or electrosurgical transurethral resection of the prostate.

OBJECTIVE: To compare the healthcare utilisation and repeat surgical treatment rate amongst older men undergoing an electrosurgical-transurethral resection of the prostate (TURP) vs photoselective vaporisation of the prostate (PVP), as the real-world implementation and outcomes of laser-based treatment have not been well studied. PATIENTS AND METHODS: We used administrative data from the province of Ontario, Canada, to identify all men aged >66 years who underwent their first electrosurgical-TURP/PVP between 2003 and 2016. Our primary exposure was type of procedure (PVP or electrosurgical-TURP). Our primary outcome was need for repeat surgical treatment. The primary analysis was an adjusted marginal Cox model approach, which accounted for clustering of patients within surgeons; adjusted hazard ratios (aHRs) or odds ratios (aORs) and 95% confidence intervals (CIs) are reported. RESULTS: We identified 52 748 men: 6838 (13%) underwent PVP, and 45 910 (87%) underwent electrosurgical-TURP. The median age was similar, and PVP became more common with time. Compared to the PVP group, more patients in the electrosurgical-TURP group had prior gross haematuria or urinary retention, and fewer had used anticoagulants, α-blockers, or 5α-reductase inhibitors. The need for repeat surgical treatment was significantly higher amongst men who had PVP (aHR 1.57, 95% CI 1.38-1.78; absolute risk difference +2.3%). PVP was also associated with a slightly higher risk of return to the emergency room within 30 days (aOR 1.11, 95% CI 1.01-1.22) and a significantly lower risk of blood transfusion (aOR 0.24, CI 0.16-0.37); the majority of PVP cases were done with a <24 h stay (73%) vs electrosurgical-TURP (7%). CONCLUSIONS: While some of the expected benefits of PVP (such as reduced transfusion risk and shorter length of stay) were observed, the significantly higher rate of repeat surgical treatment compared to electrosurgical-TURP may represent an important difference in implementation of this technology outside of clinical trials.

Is extracorporeal shockwave lithotripsy a risk factor for the development of diabetes mellitus? A population-based study.

OBJECTIVE: To determine if patients treated with extracorporeal shockwave lithotripsy (ESWL) are at a greater risk of developing diabetes mellitus (DM) than those treated with ureteroscopy (URS). PATIENTS AND METHODS: A retrospective population-based cohort study was performed of all ESWL and URS stone treatments done in Ontario between January 1994 and March 2014, utilising linked encoded healthcare databases. The primary outcome was the development of DM >90 days after treatment. The Kaplan-Meier method was used for unadjusted survival analysis and multivariable analysis with Cox proportional hazards regression was used to assess the risk of DM between the ESWL and URS groups whilst controlling for age, gender, region of residence, income quintile, year of treatment, and comorbidity index. A sensitivity analysis with a subset of ESWL patients treated for left renal or proximal ureteric stones was completed. RESULTS: We identified 106 963 patients who underwent ESWL or URS over the study period with a median follow-up of 6.6 years (ESWL 8.5 years, URS 5.6 years). Unadjusted survival analysis showed an increased risk of developing DM in the ESWL group compared to the URS group (P < 0.001); however, multivariable analysis showed no increased risk of DM in the ESWL cohort (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.91-1.02; P = 0.25). Similarly, sensitivity analysis showed no increased risk of DM in the left renal/proximal ureteric stone ESWL cohort compared to the URS cohort (HR 1.04, 95% CI 0.96-1.13; P = 0.35). CONCLUSIONS: Our population-based cohort study demonstrated no increased risk of DM in patients undergoing ESWL compared to URS.

Risk of rhabdomyolysis from 5-α reductase inhibitors.

PURPOSE: A recent regulatory warning and case reports have described the development of muscle complications with the use of 5-α reductase inhibitors (5ARIs). We wished to determine if there was a link between rhabdomyolysis and 5ARI usage. METHODS: We used a matched cohort design and linked administrative data from the province of Ontario, Canada, to investigate the risk of rhabdomyolysis in men using either finasteride or dutasteride. A total of 99 covariates were measured. We identified 93 197 men ≥66 years of age who initiated a new prescription for a 5ARI, and they were matched using a propensity score to an equal number of men not prescribed a 5ARI. RESULTS: New initiation of 5ARIs was not associated with a significantly increased risk of rhabdomyolysis (hazard ratio [HR] 1.21, 95% confidence interval [CI], 1.00-1.48, P = .06). When we examined the risk of rhabdomyolysis in the year prior to the initiation of a 5ARI, we found that men who would go on to use a 5ARI in the future had an elevated risk of rhabdomyolysis even prior to starting the medication (HR 1.31, 95% CI, 1.05-1.64, P = .01). Our secondary outcome of myositis and myopathy was significantly higher among 5ARI users (HR 1.63, 95% CI, 1.48-1.80, P < .01), and this risk was not present prior to 5ARI usage. CONCLUSION: 5-α reductase inhibitors do not appear to be associated with the development of rhabdomyolysis; however, they may be associated with an increased risk of myopathy and myositis.

Robotic Autotransplantation and Management of Post-transplant Anastomotic Strictures: the Future Is Here.

PURPOSE OF REVIEW: We set out to review the current published experience with robotic autotransplantation. Although the experience to date is limited, this surgery appears to be safe and technically feasible. We also examined the use of the robotic surgical platform for the management of post-transplant uretero-vesical anastomotic strictures. RECENT FINDINGS: To date, only four reported cases of robotic autotransplantation have been described with two being performed completely intra-corporeally. An intra-corporeal approach is feasible for benign conditions, while malignant masses should be inspected and dissected extra-corporeally. Ureteric strictures after renal transplantation are common. To date, the experience with robotic surgical management is limited but has also been shown to be safe and feasible. While robotic autotransplantation is still in its infancy, it is feasible and appears to be safe. Renal allograft function and surgical outcomes are favorable and provide patients the option to have a historically more morbid surgery performed with a minimally invasive approach.

Impact of Resident Overnight Duty Hour Changes on Obstetrical Outcomes: A Population-Based Cohort Study.

OBJECTIVE: To determine whether obstetrical patient outcomes have changed following the introduction of restricted resident work hours. METHODS: A population-based retrospective cohort study of the effects of restricted duty hours for residents in July 2013 at three academic hospitals in Toronto, ON using linked health care databases. The study included 6763 deliveries in the 2 years pre-exposure and 5548 deliveries in the 2 years post-exposure. RESULTS: The primary outcome, planned prior to data collection, was a composite index of 29 maternal/fetal outcomes including maternal transfusion/postpartum hemorrhage, maternal infection, fetal mortality, NICU admissions, and surgical/obstetrical complications. There were seven secondary outcomes analysed: NICU admissions; neonatal death; maternal transfusion or postpartum hemorrhage; maternal infection; and three composite measures. A generalized estimating equation model, clustered by institution, was utilized to assess for differences post-intervention. We found no significant differences in baseline demographics between groups. After the implementation of duty hour restrictions, no significant difference was seen in the primary outcome. However, an increased incidence of composite maternal surgical/obstetrical outcomes (OR 1.191; 95% CI 1.037-1.367, P = 0.013) and transfusion/postpartum hemorrhage (OR 1.232; 95% CI 1.074-1.413, P = 0.003) was found. There were no significant differences in other secondary outcomes. CONCLUSION: Since the implementation of resident duty hour restrictions, there was no overall change in patient outcomes. However, there was an increase in surgical/obstetrical complications and transfusion/postpartum hemorrhage. This suggests that duty hour restrictions may not be beneficial to patient outcomes. It highlights the need to further investigate the clinical impact of a change in resident duty hours.

Low expression of miR-126 is a prognostic marker for metastatic clear cell renal cell carcinoma.

Clear cell renal cell carcinoma (ccRCC) is an aggressive tumor with unpredictable behavior. Clinical parameters are not always accurate for predicting prognosis. miR-126 is differentially expressed in many cancers, including RCC, and is down-regulated in metastatic versus primary ccRCC. We assessed the prognostic significance of miR-126 in 264 primary ccRCCs. We also compared its expression in normal kidney, primary and metastatic ccRCC, and RCC subtypes. We validated our results on an independent set of 481 ccRCCs. miR-126 was down-regulated in metastatic versus primary tumors and in tumors of higher stage (P = 0.005) or higher grade (P = 0.002). miR-126 up-regulation was associated with significantly prolonged disease-free survival (P < 0.001) and overall survival (P = 0.015). For larger tumors (>4 cm), patients with higher miR-126 expression had significantly longer survival. Restoration of miR-126 expression decreased cellular migration and proliferation in RCC cell lines. The ccRCCs exhibited the highest miR-126 expression, and papillary RCCs exhibited the lowest expression. We identified a number of miR-126 targets and pathways that are involved in carcinogenesis, including the apoptosis signaling pathway. miR-126 is a promising prognostic marker in ccRCC that can distinguish between clear cell and papillary subtypes. In addition, miR-126 has potential therapeutic applications.

Development and evaluation of a retroperitoneal dialysis porcine model.

OBJECTIVES: We attempted to create a surgical model to evaluate the retroperitoneal space for the ability to transfer solutes through the retroperitoneal membrane. Our dual objectives were to develop a technique to assess the feasibility of retroperitoneal dialysis (RPD) in a porcine model. METHODS: We incorporated two 35-kg Yorkshire pigs for this pilot study. In the first animal, we clamped renal vessels laparoscopically. In the second animal, we embolized renal arteries. In both animals, we dilated the retroperitoneal space bilaterally and deployed dialysis catheters. We measured serum creatinine (Cr), urea, and electrolytes at baseline 6 hours before the dialysis and every 4 hours after. RESULTS: We successfully created retroperitoneal spaces bilaterally and deployed dialysis catheters in both animals. In the first animal, dialysate and plasma Cr ratio (D/P) on the left and right side were 0.43 and 0.3, respectively. Cr clearance by 40 minutes of dialysis treatment was 6.3 mL/min. The ratio of dialysate glucose at 4 hours dwell time to dialysate glucose at 0 dwell time (D/D0) for left/rights sides were 0.02 and 0.02, respectively. kt/Vurea was 0.43. In the second animal, D/P Cr for left/right sides were 0.34 and 0.33, respectively. kt/Vurea was 0.17. We euthanized the pigs due to fluid collection in the peritoneal space and rapid increase of serum Cr, urea, and electrolytes. CONCLUSIONS: We demonstrated the feasibility of creation of a functionally anephric porcine model with successful development of retroperitoneal spaces using balloon inflation. Notwithstanding minimal clearance and limited diffusion capacity in this experiment, additional studies are needed to examine potential use of retroperitoneal space for peritoneal dialysis.

Repeated Diagnostic Imaging Studies in Ontario and the Impact of Health Information Exchange Systems.

Health information exchange systems can link the results of diagnostic imaging tests across hospitals and geographic areas. One of the potential benefits of these systems is a reduction in imaging studies ordered by physicians who do not know about or have access to the previous imaging results. We used administrative data from Ontario, Canada (from the year 2013), to measure how frequently the same cross-sectional imaging study is repeated in a patient. Overall, 12.8% of the specified imaging tests were repeated within 90 days. An area of Southwestern Ontario with a health information exchange system for diagnostic imaging tests had a 13% lower rate of repeat cross-sectional imaging compared with the rest of the province (11.2 vs 12.8%, p < 0.01). The use of linked radiology systems may be able to reduce the number of repeated imaging tests and improve patient safety and hospital efficiency.

A population based study of the changing demographics of patients undergoing definitive treatment for kidney stone disease.

PURPOSE: We examined temporal changes in the demographics of patients undergoing definitive treatment for kidney stones during a 20-year period in Ontario, Canada. MATERIALS AND METHODS: Using the Ontario Health Insurance Plan physician claims database and the Canadian Institute for Health Information Discharge Abstract Database we performed a population based cross-sectional time series analysis by identifying all kidney stone treatments done between July 1, 1991 and December 31, 2010. The demographics assessed were patient gender, age and socioeconomic status. The rate and/or proportion of kidney stone treatments per strata of these demographics were calculated for each 1-year block of the study period. We used time series analysis with exponential smoothing and autoregressive integrated moving average models to assess for trends with time. RESULTS: We identified 116,115 patients who underwent treatment for kidney stones during the study period. The rate of stone procedures performed per year increased steadily from 85/100,000 to 126/100,000 population. With time the rate of females who were treated increased significantly from 40/100,000 to 53/100,000 (p <0.0001). In contrast, the rate of males who were treated remained stable, increasing from 82/100,000 to 83/100,000 (p = 0.11). In regard to age the rate of patients older than 64 years increased significantly with time from 67/100,000 to 89/100,000 (p <0.0001). In regard to socioeconomic status approximately 20% of the patients were in each of the 5 income quintiles during the entire study period. CONCLUSIONS: Our population based study shows an increased rate of females and of patients older than 64 years undergoing definitive treatment for kidney stones with time.

The surgical management of kidney stone disease: a population based time series analysis.

PURPOSE: We evaluate population based trends in the use of extracorporeal shock wave lithotripsy, ureteroscopy and percutaneous nephrolithotomy during the last 20 years, as well as assess the re-treatment rate and morbidity from treatment over time. MATERIALS AND METHODS: Using administrative databases in the province of Ontario, Canada, a population based cross-sectional time series analysis was performed between July 1, 1991 and December 31, 2010. All extracorporeal shock wave lithotripsy, ureteroscopy and percutaneous nephrolithotomy procedures were identified, along with all hospital readmissions and emergency department visits within 7 days of treatment. The primary outcome was treatment use, and secondary outcomes were the need for ancillary treatment and hospital readmission or emergency department visit after treatment. Exponential smoothing and autoregressive integrated moving average (ARIMA) models were used to assess trends over time. RESULTS: We identified 194,781 kidney stone treatments performed during the study period. Time series modeling revealed a significant increase in the use of ureteroscopy over time (25% to 59% of all procedures, p <0.0001) and a reciprocal decrease in the use of extracorporeal shock wave lithotripsy (69% to 34% of all procedures, p <0.0001). A corresponding significant decrease in the need for ancillary treatment over time (23% to 15%, p <0.0001) and increase in the need for hospital readmission (7% to 11%, p <0.0001) or emergency department visit (7% to 11%, p=0.0024) after treatment were also demonstrated. CONCLUSIONS: Our population based study demonstrates a shift in the treatment paradigm with increased use of ureteroscopy over time and a reciprocal decrease in the use of extracorporeal shock wave lithotripsy. We also observed a corresponding decrease in ancillary treatment and increase in posttreatment morbidity over time.

The role of prophylactic versus selective ureteric stenting in kidney transplant patients: a retrospective review.

OBJECTIVE: To evaluate the role of prophylactic versus selective ureteric stenting in the development of postoperative ureterovesical complications in kidney transplant recipients. METHODS: Records of 614 transplant patients seen from January 2006 to May 2011 were retrospectively reviewed. The primary outcome was the rate of ureterovesical complications, defined as the development of ureteric obstruction or a ureterovesical anastomotic leak. The secondary outcomes were the rate of urinary tract infections and forgotten stents. Using a χ2 test, we compared the primary and secondary outcomes across the selective and prophylactic cohorts. Logistic regression was used to compare the 2 cohorts while adjusting for potential confounders. RESULTS: The selective and prophylactic cohorts consisted of 258 and 330 patients, respectively. Unadjusted analysis showed that the prophylactic group had a significantly lower rate of ureterovesical complications than did the selective group (2.12% vs 6.20%; odds ratio, 0.33; P= .01). After adjustment for differences in sex and donor type, the prophylactic group still had a lower risk for ureterovesical complications (odds ratio, 0.30; P= .009). Rates of urinary tract infections and forgotten stents did not differ significantly between the 2 groups. CONCLUSIONS: Prophylactic stenting is associated with a significantly lower rate of ureterovesical complications than is selective stenting.

Robotic-assisted laparoscopic pyeloplasty for ureteropelvic junction obstruction A retrospective review of a high-volume Canadian center.

INTRODUCTION: At present, there is no literature on the outcomes of robotic-assisted laparoscopic pyeloplasty (RALPyelo) in a Canadian context. Our objective was to perform a retrospective review of RALPyelo cases at a high-volume Canadian center. METHODS: We performed a retrospective review of patients who underwent RALPyelo at St. Michael's Hospital, between January 2012 and May 2019. Demographics, operative details, and pre- and postoperative imaging results (ultrasounds, computed tomography [CT] scans, and diuretic renal scan [DRS ]) were recorded. Patients were excluded if at least one-year followup data was unavailable. Our primary outcome was clinical and radiologic improvement defined as 1) symptom improvement; 2) stable/improved split renal function on DRS ; and 3) either improvement in the degree of hydronephrosis on ultrasound or CT, or improved drainage time on DRS. Secondary outcomes included postoperative complications, need for diagnostic intervention, and reintervention for recurrent UPJO. RESULTS: A total of 156 patients underwent RALPyelo after exclusions. The median age was 42 and 66% were female. Mean followup was 2.5 years. For our primary outcome, 87% had clinical and radiologic improvement. Diagnostic investigation for possible recurrent/persistent obstruction, based on symptoms and/or imaging results, was required in 17% of cases, but only 3% required reintervention for recurrent UPJO. Accordingly, the overall treatment success was 97%. The most common postoperative complication was urinary tract infection (18%), and urine leak was seen in only 2% of patients. CONCLUSIONS: The results of our study compare favorably with currently reported outcomes in the literature and demonstrate the safety and high level of success of RALPyelo at a high-volume Canadian center.

Incidence and trends in the treatment of kidney stones in Canada A population-based cohort study.

INTRODUCTION: Our objective was to assess the incidence of kidney stones requiring acute care, trends in the surgical treatment of stones, and the demographics of stone formers in Canada. METHODS: We conducted a population-based, retrospective cohort study using administrative data from the Canadian Institute for Health Information. We included Canadian residents age >18 years, outside of Quebec, who presented between January 1, 2013, and December 31, 2018, with a kidney stone episode. This was defined as a kidney stone resulting in hospital admission, emergency department visit, or stone intervention, specifically shockwave lithotripsy (SWL), ureteroscopy (URS), or percutaneous nephrolithotomy (PCNL). RESULTS: There were 471 824 kidney stone episodes, including 184 373 interventions. The number of kidney stone episode increased from 277/100 000 in 2013 to 290/100 000 in 2018. The median age was 53 (interquartile range 41-65) years and 59.9% were male. The crude rate for stone intervention was 877/100 000. The age- and gender-standardized rate for interventions was highest in Nova Scotia and Newfoundland and Labrador, and lowest in Prince Edward Island. The most common intervention in Canada was URS (73.5%), followed by SWL (19.8%) and PCNL (6.7%). The percent utilization of SWL was highest in Manitoba, whereas for URS, it was highest in Prince Edward Island and Alberta. CONCLUSIONS: Our study provides the first population-based data on the demographics of stone formers and treatment trends across Canada. There has been a 4.7% increase in kidney stone episodes over the study period. Those presenting to hospital or requiring intervention for a kidney stone are more likely to be male, aged 41-65, and undergo URS.

A prospective study examining the incidence of bacteriuria and urinary tract infection after shock wave lithotripsy with targeted antibiotic prophylaxis.

PURPOSE: Controversy exists regarding antibiotic prophylaxis before shock wave lithotripsy. The AUA (American Urological Association) guideline recommends universal antibiotic prophylaxis, whereas the EAU (European Association of Urology) guideline recommends prophylaxis only for select patients. We evaluated the use of targeted antibiotic prophylaxis in preventing urinary tract infections in patients undergoing shock wave lithotripsy. MATERIALS AND METHODS: A prospective single cohort study was performed during 6 months with patients undergoing shock wave lithotripsy. All patients underwent urine dipstick and culture before shock wave lithotripsy. Targeted antibiotic prophylaxis was provided at the discretion of the treating urologist. All patients had a urine culture performed after shock wave lithotripsy and completed a survey documenting fevers or urinary symptoms. The primary outcome was the incidence of urinary tract infections, urosepsis and asymptomatic bacteriuria after shock wave lithotripsy. The secondary outcome was the sensitivity and specificity of urinary dipstick leukocytes and nitrites. RESULTS: A total of 526 patients were enrolled in the study. Of the 389 patients included in the determination of the primary outcome, urinary tract infection developed in only 1 (0.3%), urosepsis did not develop in any patients and asymptomatic bacteriuria developed in 11 (2.8%). Eight (2.1%) patients were administered antibiotic prophylaxis. The specificity of urine dipstick nitrites was high (95%) while the sensitivity was poor (9.7%). CONCLUSIONS: In our cohort study using targeted antibiotic prophylaxis the rates of urinary tract infection after shock wave lithotripsy and rates of asymptomatic bacteriuria were extremely low, with no development of urosepsis. This finding questions the need for universal antibiotic prophylaxis before shock wave lithotripsy.

The Incidence and Risk Factors for Emergency Department Imaging in Acute Renal Colic.

Objective: To determine the incidence of and risk factors for imaging in patients presenting to the emergency department (ED) with renal colic. Subject/Patients and Methods: We conducted a population-based cohort study in the province of Ontario, utilizing linked administrative health data. Patients who presented to an ED with renal colic between April 1, 2010, and June 30, 2020, were included. The rate of initial imaging (CT scans and ultrasound [U/S]) and repeat imaging within 30 days was determined. Generalized linear models were utilized to evaluate patient and institutional-level characteristics associated with imaging, and specifically CT vs U/S. Results: There were 397,491 index renal colic events, of which 67% underwent imaging (CT 68%, U/S 27%, and CT+U/S same day 5%). Repeat imaging was performed in 21% of events (U/S in 12.5%, CT in 8.4%) at a median of 10 days. Of those with an initial U/S, 28% had repeat imaging compared with 18.5% for those with an initial CT. Undergoing an initial CT was associated with being male, urban residence, later year of cohort entry, history of diabetes mellitus and inflammatory bowel disease, and presentation to nonacademic hospitals of larger size, or with a higher volume of ED visits. Conclusion: Two-thirds of renal colic patients underwent imaging, and CT was the most utilized modality. Patients undergoing an initial CT had a lower likelihood of repeat imaging within 30 days. The utilization of CT increased over time and was more common in males and those presenting to nonacademic hospitals of larger size, or with higher ED volumes. Our study highlights the patient- and institution-level factors that need to be targeted with prevention strategies to reduce the utilization of CT scans, when possible, for cost reduction and to minimize patient exposure to ionizing radiation.

5α-reductase inhibitors and the risk of bladder cancer in a large, population-based cohort.

PURPOSE: The ability of 5α-reductase inhibitors (5ARI) to reduce the risk of new onset bladder cancer (BC) has been studied with variable results. Our objective was to conduct a retrospective cohort population-based study to evaluate the association between 5ARI use, BC diagnosis, and BC mortality. PATIENTS AND METHODS: We used routinely collected health care data from Ontario, Canada. Men ≥66 years of age with a prescription for a 5ARI were matched to non-5ARI users. Matching was done using a propensity score of selected covariates to make 96 different covariates comparable. We measured 5 additional baseline variables which may have impacted the risk of future BC diagnosis: prior cystoscopy, urine cytology, urinalysis, gross hematuria episodes, and transurethral resection of a bladder lesion. Only the first period of continuous usage of 5ARIs was considered. The prespecified at-risk period for outcomes started 1 year after initiating therapy and ended at the last date of 5ARI exposure + 1 year. RESULTS: We identified 93,197 men who initiated 5ARI therapy (52% dutasteride, and 48% finasteride) between 2003 and 2013 and matched them 1:1 to men who did not start a 5ARI. The median at-risk period for the 5ARI group was 1.68 years (interquartile range 1.00, 4.27). With adjustment for the variables related to prior BC investigations there was no significant difference in BC diagnosis (hazard ratio [HR] 1.05, 95% confidence interval [CI] 0.82-1.32) during the period of 0 to <2 years of 5ARI use; however, after ≥2 years of 5ARI use, the risk of BC diagnosis was significantly lower among the 5ARI group (HR 0.82, 95% CI 0.79-0.94). In a similarly adjusted model, BC mortality was lower among 5ARI users, but no longer statistically significant (HR 0.82, 95% CI 0.65, 1.02). When stratified by type of 5ARI, finasteride significantly reduced the risk of BC diagnosis after ≥2 years of continuous use (HR 0.86, 95% CI 0.76, 0.96); however, dutasteride did not (HR 0.92, 95% CI 0.83, 1.03). CONCLUSIONS: In a large cohort of men, the use of a 5ARI was associated with a significantly decreased the risk of BC diagnosis after more than 2 years of continuous therapy.

Determination of optimal stent length: a survey of urologic surgeons.

Introduction: Ureteral double-J stent length is an important factor affecting stent-related symptoms. Multiple techniques exist to determine ideal stent length for a given patient, however, little is known about what techniques urologists rely on. Our objective was to identify how urologists determine optimal stent length. Material and methods: An online survey was e-mailed in 2019 to all members of the Endourology Society. The survey sought to assess what methods are commonly used to determine choice of stent length, along with frequency of stent placement post ureteroscopy, duration of stenting, availability of different stent lengths and the use of stent tether. Results: 301 urologists (15.1%) responded to our survey. Following ureteroscopy, 84.5% of respondents would stent at least 50% of the time. Following uncomplicated ureteroscopy, most respondents (52.0%) would leave a stent for 2-7 days. Patient height was most commonly ranked first as the method of choice in determining stent length (47.0%), followed by estimation based on experience only (20.6%) and intra-operative direct measurement of ureteric length (19.1%). Most respondents utilized multiple methods in determination of optimal stent length. Most respondents (66.5%) were interested in a simple intra-operative technique utilizing a special ureteral catheter that would help choose the most appropriate stent length. Conclusions: Post-ureteroscopy stent insertion is common and patient height is the most common method of choice used in determining optimal stent length. Most respondents were interested in using a simple, novel ureteral catheter device that would allow them to more accurately select optimal stent length.

An Updated Systematic Review and Meta-Analysis on the Technical, Oncologic, and Safety Outcomes of Microwave Ablation in Patients with Renal Cell Carcinoma.

Introduction: Percutaneous microwave ablation (MWA) has emerged as a new energy modality for percutaneous renal tumor ablation with potential advantages over radiofrequency and cryoablation. The goal of our study was to determine MWA outcomes for suspicious renal masses, with a subset analysis for biopsy-proven renal cell carcinoma (RCC) and larger (T1b) tumors. Methods: Studies reporting outcomes of MWA for RCC were identified. Random-effects models with inverse-variance weighting were used to pool outcomes, including technical success rate (TSR), technical efficacy rate (TER), local recurrence rate (LRR), cancer-specific survival rate (CSSR), overall survival rate (OSR), and complications. Results: Among 914 studies captured, 27 studies with 1584 patients (1683 malignant renal tumors) were included. The pooled TSR and TER were 99.6% (95% confidence interval [CI], 98.0%-100%) and 96.2% (95% CI, 93.8%-98.2%). The pooled LRR was 3.2% (95% CI, 1.9%-4.7%). At 1, 3, and 5 years, the pooled CSSRs were 100% (95% CI, 99.4%-100%), 100% (95% CI, 98.4%-100%), and 97.7% (95% CI, 94.5%-99.7%), while pooled OSRs were 99.0% (95% CI, 97.5%-99.9%), 96.0% (95% CI, 93.1%-98.3%), and 88.1% (95% CI, 80.3%-94.2%). The pooled minor and major complication rates were 10.3% (95% CI, 7.1%-13.9%) and 1.0% (95% CI, 0.3%-2.1%). In 204 patients with 208 T1b tumors, the pooled TSR and TER were 100% (95% CI, 96.6%-100%) and 85.2% (95% CI, 71.0%-95.8%). The pooled LRR was 4.2% (95% CI, 0.9%-8.9%). At 1, 3, and 5 years, the pooled CSSRs were 98.2% (95% CI, 88.7%-100%), 97.2% (95% CI, 78.5%-100%), and 98.1% (95% CI, 72.3%-100%). At 1 and 3 years, the pooled OSRs were 94.3% (95% CI, 85.7%-99.6%) and 89.3% (95% CI, 68.7%-100%). The pooled minor and major complication rates were 14.8% (95% CI, 7.4%-23.8%) and 2.6% (95% CI, 0%-7.8%). Conclusions: MWA demonstrated favorable short- to intermediate-term oncologic outcomes with low complication rates, including in the T1b subset, with moderate quality of data and heterogeneity of assessed outcomes. This supports MWA as a safe and effective treatment for RCC and a potential viable option for larger tumors.