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, 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) 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, age 41-65, and undergo URS.

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.

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.

A Population-Based Analysis of the Impact of the COVID-19 Pandemic on Solid Organ Transplantation in Ontario, Canada: Policy Response and Changes in Volume and 90-Day Outcomes.

Objectives: To evaluate the impact of the COVID-19 pandemic on solid organ transplantation. Background: COVID-19 caused unprecedented disruption to solid organ transplantation (kidney, liver, heart, lung). Concerns about safety and decreases in deceased donors due to pandemic lockdowns have been described as potential causes. Methods: We report population-based rates of transplantation during the first 3 waves of COVID-19 in Ontario, Canada (March 1, 2020-July 3, 2021) versus a pre-COVID-19 baseline period (January 1, 2017-February 29, 2020). Poisson models were used to predict transplantation rates during COVID-19, based on pre-COVID-19 rates, and generate observed to expected rate ratios (RRs). Ninety-day transplant outcomes (mortality, retransplantation, transplant nephrectomy) were captured. Results: A 34.4% decrease (RR, 0.656; 95% confidence interval [CI], 0.586-0.734) in transplant rates was observed, coinciding with wave 1 and the deployment of a provincial transplant triaging system. Transplants decreased by 14.6% in wave 2 (RR, 0.854; 95% CI, 0.770-0.947) and 23.1% in wave 3 (RR, 0.769; 95% CI, 0.690-0.857) despite the triaging system not being activated. Overall, there was a 24.3% decrease (RR, 0.757; 95% CI, 0.679-0.844) in transplant rates, equivalent to 409 fewer transplants. No sustained changes were observed in heart or liver but sustained and large decreases were seen for lung (RR, 0.664; 95% CI, 0.482-0.915) and kidney (RR, 0.721; 95% CI, 0.602-0.863) transplantation. A low prevalence (1.7%) of COVID-19 infection within 90 days of transplantation was seen. No differences were observed in other 90-day outcomes. Conclusions: Early safety concerns limited transplantation to immediate life-saving procedures; however, the reductions in kidney and lung transplants continued for the rest of the pandemic, where no restrictions were in place.

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.

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.

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.

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.

Infection complications after transrectal ultrasound-guided prostate biopsy: A radiology department's experience and strategy for improvement.

INTRODUCTION: Transrectal ultrasound (TRUS)-guided prostate biopsy is a common procedure performed to diagnose prostate cancer. The risk of infection complications is well-described in the literature, and strategies to avoid such complications continue to evolve over time. We performed a retrospective review of our infection complications and propose a strategy for improvement. METHODS: We reviewed clinical outcomes from patients undergoing TRUS-guided prostate biopsy at our institution from November 2018 to November 2020. We reported the antimicrobial prophylaxis received, whether the biopsy was systematic or targeted, and we examined the rate of clinically significant infection complications and hospitalization. RESULTS: Among 312 men who underwent TRUS-guided prostate biopsy during the study period, seven (2.2%) had an infection. Four patient groups with distinct antimicrobial regimen were identified; the largest of these patient groups received a three-day course of cefixime and a single dose of fosfomycin (59%). The proportion of patients with infection complications across these groups did not demonstrate a statistically significant difference (p=0.803). There was no significant difference in proportion of infection between systematic and targeted biopsy groups (3.0% vs. 0%, p=0.204). The proportion of patients hospitalized was 1.3%, with a mean length of stay of four days. CONCLUSIONS: We report a rate of clinically significant infection following TRUS-guided prostate biopsy of 2.2%. Due to our referral pathway, we have an inconsistent approach to antimicrobial prophylaxis, although there was no statistically significant difference in infection rate between the groups. We propose a standardized approach that may lead to improved patient outcomes.

A high-fidelity, virtual-reality, transurethral resection of bladder tumor simulator: Validation as a tool for training.

INTRODUCTION: Simulation-based training is used to help trainees learn surgical procedures in a safe environment. The objective of our study was to test the face, content, and construct validity of the transurethral resection of bladder tumor (TURBT) module built on the Simbionix TURP Mentor simulator. METHODS: Participants performed five standardized cases on the simulator. Domains of the simulator were evaluated on a five-point Likert scale to establish face and content validity. Construct validity was assessed through the simulator's built-in scoring metrics, as well as video recordings of the simulator screen and an anonymized view of participants' hands and feet, which were evaluated using an objective structured assessment of technical skills (OSATS) tool. RESULTS: Ten experienced operators and 15 novices participated. Face validity was somewhat acceptable (mean realism 3.8/5±1.03 standard deviation [SD]; mean appearance 4.1/5±0.57), as was content validity, represented by simulation of key steps (mean 3.9±0.57). The simulator failed to achieve construct validity. There was no difference in mean simulator scores or OSATS scoring between experienced operators and novices. Novices significantly improved their mean simulator scores (305.9 vs. 332.4, p=0.006) and OSATS scoring (15.8 vs. 18.1, p=0.001), while 87% felt their confidence to perform TURBT improved. Overall, 92% of participants agreed that the simulator should be incorporated into residency training. CONCLUSIONS: Our study suggests a role for the TURBT module of the Simbionix TURP Mentor simulator as an introduction to TURBT for urology trainees. Strong support was found from both experienced operators and novices for its formal inclusion in resident education.

Systematic Review of the Prevalence of Kidney Stones in Cystic Fibrosis.

Purpose: To investigate the prevalence of urolithiasis in cystic fibrosis (CF) and to summarize the available clinical features within this unique population. Methods: Studies reporting the prevalence of urolithiasis in CF patients were identified by a systematic search of the literature from inception to July 31, 2020 on three databases: Ovid Medline, Ovid Embase, and Web of Science. Data were extracted on a predetermined standardized form by two independent authors. Results: A total of 596 publications were retrieved and screened, 15 of which met the eligibility criteria. The publications were published between 1993 and 2019 and were all observational in design. There was a total of 2982 patients with CF included in this review. The overall prevalence of stone formation in the CF population was 4.6% (137/2982). The mean age of diagnosis was 25.1 ± 9.6 and ranged from 0.25 to 47. Ultrasound was the most common imaging modality for kidney stone diagnosis. There was no apparent sex difference, with a female to male ratio of 1:1. Surgical intervention was required in 37.8% (34/90) of cases. Stone recurrence was reported in 42.9% (33/77) of stone formers. Conclusions: This review provides the most recent update for the prevalence of urolithiasis in CF patients and summarizes the available clinical data. Our findings suggest that patients with CF could be at risk for developing stones at a younger age and require interventional management strategies at higher rates compared with the general population. Given the heterogeneity of the literature for urolithiasis in CF, larger population-based studies reporting the epidemiology, clinical features, and management strategies are required to further our understanding of urolithiasis in CF.

Clips Can be Safely Used for Vascular Control of the Renal Vessels During Laparoscopic Donor Nephrectomy.

OBJECTIVE: To review our experience using clips to control the renal vessels during laparoscopic donor nephrectomy (LDN) and determine the safety of this practice. METHODS: We performed a retrospective review of patients who underwent LDN at our centre January 1, 2007-September 17, 2019. The primary outcome was the rate of complication associated with vascular control of the renal vessels, which included (1) conversion to open to manage bleeding, (2) additional procedures for bleeding, and (3) major bleeding requiring blood transfusion. Secondary outcomes included the rate of renal artery/vein clip dislodgement or crossing, change in hemoglobin, warm ischemia time and the incidence of intra-operative complications and postoperative in-hospital complications. RESULTS: We included 503 patients who underwent LDN, of which 497 were left sided. The main renal artery was controlled with 3 titanium clips in 489 (97%) cases. The main renal vein was controlled with 2 polymer-locking clips in 478 (95%) cases. For our primary outcome, there were no conversions to open to manage bleeding, no secondary procedures due to bleeding and no major bleeding requiring blood transfusion. Additionally, there were no donor deaths. Regarding our secondary outcomes, there were 5 intraoperative events related to the titanium clips being placed on the renal artery and 1 intraoperative event related to the polymer-locking clips on the renal vein, none of which resulted in any morbidity. CONCLUSION: Using 3 titanium clips on the renal artery and 2 polymer-locking clips on the renal vein during left LDN is safe and provides excellent vascular control.

Assessing the Necessity of Routine Crossmatching for Blood Transfusion in Renal Transplantation.

INTRODUCTION: Routine crossmatch of packed red blood cells (pRBCs) is completed preoperatively at many centers despite conflicting evidence on the incidence of blood transfusions with renal transplantation. In the current economic climate, resource adjudication should be judicious and medically appropriate. The objective of this study was to determine the incidence, timing, and predictors of early postoperative pRBC transfusion in patients undergoing renal transplantation. METHODS: A retrospective review of all patients undergoing renal transplantation at our institution from January 2013 to May 2016 was performed. Demographic, biochemical, and clinical parameters were recorded. The primary outcome was early postoperative transfusion, defined as an intraoperative transfusion or within 2 days of surgery. Multivariable logistic regression was performed to identify associations with early postoperative transfusion. RESULTS: We identified 428 patients during the study period (average age 55 years, 60% male, 30% obese, 67% deceased donor, and 43% preoperative antithrombotic use). Forty (9.3%) patients required early postoperative transfusion (mean: 2.8 pRBCs/transfusion) and most did not require blood urgently. Only 20 (4.7%) patients required a transfusion intraoperatively or on the same day of surgery. Lower preoperative hemoglobin (per g/L unit: odds ratio [OR]: 0.943), female gender (OR: 2.752), and preoperative antithrombotic use (OR 2.369) were associated with a need for early postoperative transfusion. CONCLUSION: Transfusion in the early postoperative period following renal transplantation was less than 10%, suggesting that routine crossmatch may not be necessary for all patients. Preoperative hemoglobin, female gender, and preoperative antithrombotic use were associated with increased risk and may be useful to risk-stratify patients who require crossmatch.

A Propensity Score-weighted Comparison of Outcomes Between Living and Standard Criteria Deceased Donor Kidney Transplant Recipients.

BACKGROUND: Consider a theoretical situation in which 2 patients with similar baseline characteristics receive a kidney transplant on the same day: 1 from a standard criteria deceased donor, the other from a living donor. Which kidney transplant will last longer? METHODS: We conducted a population-based cohort study using linked administrative healthcare databases from Ontario, Canada, from January 1, 2005, to March 31, 2014, to evaluate several posttransplant outcomes in individuals who received a kidney transplant from a standard criteria deceased donor (n = 1523) or from a living donor (n = 1373). We used PS weighting using overlap weights, a novel weighting method that emphasizes the population of recipients with the most overlap in baseline characteristics. RESULTS: Compared with recipients of a living donor, the rate of all-cause graft failure was not statistically higher for recipients of a standard criteria deceased donor (hazard ratio, 1.1; 95% confidence interval [CI], 0.8-1.6). Recipients of a standard criteria deceased donor, compared with recipients of a living donor had a higher rate of delayed graft function (23.6% versus 18.7%; odds ratio, 1.3; 95% CI, 1.0-1.6) and a longer length of stay for the kidney transplant surgery (mean difference, 1.7 d; 95% CI, 0.5-3.0). CONCLUSIONS: After accounting for many important donor and recipient factors, we failed to observe a large difference in the risk of all-cause graft failure for recipients of a standard criteria deceased versus living donor. Some estimates were imprecise, which meant we could not rule out the presence of smaller clinically important effects.