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Purpose of review Artificial intelligence (AI) is the ability of a machine, or computer, to simulate intelligent behavior. In medicine, the use of large datasets enables a computer to learn how to perform cognitive tasks, thereby facilitating medical decision-making. This review aims to describe advancements in AI in stone disease to improve diagnostic accuracy in determining stone composition, to predict outcomes of surgical procedures or watchful waiting and ultimately to optimize treatment choices for patients. Recent findings AI algorithms show high accuracy in different realms including stone detection and in the prediction of surgical outcomes. There are machine learning algorithms for outcomes after percutaneous nephrolithotomy, extracorporeal shockwave lithotripsy, and for ureteral stone passage. Some of these algorithms show better predictive capabilities compared to existing scoring systems and nomograms. Summary The use of AI can facilitate the development of diagnostic and treatment algorithms in patients with stone disease. Although the generalizability and external validity of these algorithms remain uncertain, the development of highly accurate AI-based tools may enable the urologist to provide more customized patient care and superior outcomes.

Objectives : To define urology applicant attitudes and usage trends of social media (SM) during the 2021 urology match cycle. Methods : We emailed an anonymous, de-identified 22-question, multiple choice survey to all applicants to our institution for the 2021 Urology Residency Match. We asked participants about use of SM and which aspects they found useful in the application process. Univariate descriptive analyses were conducted based on survey responses. Chi-square analyses were performed to define significant differences in use of social media and resultant match outcomes. Results : Of the 528 students who registered for the 2021 AUA Match, 398 received our survey (75%), and 144 responded (27% of applicants nationwide). Of survey participants, 49% made a new account on Twitter while 30% had a preexisting account. Most participants (71%) had a preexisting Instagram account, while only 3% made a new account. Most participants agreed Twitter was used as a source to gather information about programs (84%) and learn about events (89%). Participants found SM most helpful for announcing event dates (71%) and highlighting resident social life (59%). Applicants did not match more highly on their rank lists if they used Twitter (p=0.427) or Instagram (p=0.166) and were not more likely to get more interviews if they used Twitter (p=0.246) or Instagram (p=0.114) Conclusions : Applicants found Twitter to be an important source of information through the virtual interview process. Despite the use of SM by most applicants, published content did not impact rank list decisions nor did SM engagement predict match outcomes.

Robotic-assisted simple prostatectomy (RASP) has proven to be an effective minimally invasive option for benign prostatic enlargement (BPE) in recent years. Single-site surgery is theorized to reduce post-operative pain beyond traditional minimally invasive approaches. We sought to assess whether use of a single-port robotic platform decreases post-operative opioid use in patients undergoing robotic-assisted simple prostatectomy (RASP). A retrospective review was performed of all patients undergoing RASP our institution from November 2017 to July 2019. Demographic, intraoperative, and post-operative data, including morphine equivalent (ME) use, were collected. Patients were stratified by robotic platform utilized. Propensity score matching using nearest neighbor method was performed using prostate volume, Charlson comorbidity index (CCI), and post-op ketorolac use in 4:1 fashion. Chi-squared analysis and Kruskal-Wallis analyses were utilized. Two-hundred-and-seven men underwent RASP. After matching, 80 patients (64 multi-port, 16 single-port) were included in the analysis. Groups were comparable for age, body mass index, CCI, prostate volume, prior opioid use, and use of scheduled ketorolac post op. The single-port approach was associated with a reduction in MEs once admitted to the floor (5 vs. 11 mg, p = 0.025) and an increase in the proportion of patients who did not require any narcotics post-operatively (44 vs. 19%, p = 0.036). In a propensity matched cohort of patients undergoing RASP at a single institution, use of the single-port robotic system conferred a significant decrease in post-operative narcotic use by approximately 50%.

Objective To evaluate urology applicants’ opinions about the interview process during the COVID-19 pandemic. Material and Methods An anonymous survey was emailed to applicants to our institution from the 2019 and 2020 urology matches prior to issuance of professional organization guidelines. The survey inquired about attitudes toward the residency interview process in the era of COVID-19 and which interview elements could be replicated virtually. Descriptive statistics were utilized. Results Eighty percent of urology applicants from the 2019 and 2020 matches received our survey. One hundred fifty-six people (24% of recipients) responded. Thirty-four percent preferred virtual interviews, while 41% in-person interviews at each program, and 25% regional/centralized interviews. Sixty-four percent said that interactions with residents (pre/postinterview social and informal time) were the most important interview day component and 81% said it could not be replicated virtually. Conversely, 81% believed faculty interviews could be replicated virtually. Eighty-seven percent believed that city visits could not be accomplished virtually. A plurality felt that away rotations and second-looks should be allowed (both 45%). Comment Applicants feel that faculty interviews can be replicated virtually, while resident interactions cannot. Steps such as a low-stakes second looks after programs submit rank lists (potentially extending this window) and small virtual encounters with residents could ease applicant concerns. Conclusion Applicants have concerns about changes to the match processes. Programs can adopt virtual best practices to address these issues.

To determine the effect of partial nephrectomy (PN) in the solitary kidney on systolic and diastolic blood pressures (SBP and DBP, respectively), and use of antihypertensive medications. We performed a retrospective cohort study of solitary kidney patients who underwent PN for kidney cancer from 1999–2015. Primary outcomes evaluated were blood pressure (BP) and antihypertensive medication changes from baseline up to 5 years postoperatively. Using a multivariable mixed-effects model to account for repeated measurements, we evaluated the effect of PN on the outcome measurements while controlling for baseline patient, pathologic, and perioperative characteristics. 292 patients who underwent PN on solitary kidneys met inclusion criteria (median [range] age, 63 [24–84] years; 179 men [61%]). SBP decreased immediately postoperatively (− 1.7 mmHg [− 2.6, − 0.7], p

The aim of the study was to test the hypothesis that high levels of preoperative C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are associated with an increased risk of systemic inflammatory response syndrome (SIRS) following percutaneous nephrolithotomy (PCNL).This is a retrospective study of patients who underwent PCNL at our institution between October 2012 and October 2013 when ESR and CRP levels were part of our standard preoperative order set. The primary endpoint was development of SIRS. Receiver operating characteristic curves were used to evaluate the discriminative ability of the test.Among the 107 PCNLs performed during the study period, 35 (33%) patients had evidence of SIRS during the postoperative stay. Patients who experienced SIRS had a longer operative time (99 min vs. 85 min, p = 0.016), were more likely to have been transferred to the intensive care unit (ICU) (15% vs. 0%, p = 0.002), and experienced a longer length of stay (2 days vs. 1 day, p 0.001). On multivariable analysis controlling for operative time and positive urine culture, ESR (odds ratio [OR] 1.32, 95% confidence interval [CI]: 1.01-1.72, p = 0.04) and CRP (OR 1.59; 95% CI: 1.07-2.37, p = 0.02) were associated with development of SIRS. Among patients without a positive urine culture, an ESR6.5 mm/hr (AUC 0.62; 95% CI: 0.52-0.78) had sensitivity, specificity, and negative predictive value (NPV) of 70.4%, 61.5%, and 80.0%, respectively, for development of SIRS. Among all patients, a CRP0.65 mg/dL (AUC 0.63; 95% CI: 0.51-0.74) had sensitivity, specificity, and NPV of 51.4%, 69.4%, and 74.6%.A preoperative blood test for ESR and CRP was predictive for the development of SIRS after PCNL. This knowledge could be used to risk stratify patients and guide duration of antibiotic prophylaxis before PCNL, particularly among those without a positive urine culture.

Urolithiasis is among the top 10 causes of Emergency Department (ED) visits in the United States. Approximately 50% of these patients undergo abdominopelvic CT scan, many more than once. We hypothesized that chronic pain conditions may contribute to frequent CT scans in patients who are evaluated in ED for urolithiasis.A retrospective review of patients presenting to our tertiary care and the associated satellite EDs for urolithiasis, during the period 12/2012-05/2013, was performed. Patients with multiple ED visits and two or more abdominopelvic CT scans in any 6-month period were labeled as the frequent CT group. Control group consisted of similar patients who had no more than one CT scan in any 6-month period. Background information, number of CT scans for urolithiasis and other reasons, and the presence of chronic pain (established pain clinic visits, chronic pain medication, known chronic pain syndromes) were captured from charts. Wilcoxon rank-sum test and Fisher's exact test were used to compare variables. Multivariable logistic regression was performed to identify predictors associated with frequent CT scans.We identified 185 patients with frequent CTs and 139 patients in the control arm. Frequent CT scans were independently associated with chronic pain (odds ratio [OR]: 2.67, confidence interval [95% CI]: 1.55, 4.50), age (OR: 0.73, 95% CI: 0.60, 0.89), history of prior urolithiasis (OR: 2.15, 95% CI: 1.11, 4.15), and Medicaid insurance status (OR: 3.94, 95% CI: 1.66, 9.35).Chronic pain is a significant contributing factor to frequent CT scans among patients presenting to ED with urolithiasis, leading to increased radiation exposure and healthcare costs.

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.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.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.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.

The purpose of this study was to describe technical considerations and first outcomes from a single-port robotic-assisted sacrocolpopexy (RSC) using the da Vinci SP platform (Intuitive Surgical, Sunnyvale, CA) and the Levita™ Magnetic Surgical System (San Mateo, CA, USA), a novel magnetic retraction system. Three females with pelvic organ prolapse elected to undergo RSC using the da Vinci SP platform. The supraumbilical incision length was 25 mm through which SP trocar was placed. A 12-mm assistant port was placed in the right upper quadrant. The external magnet was attached to the left side of the bed and used for bowel and bladder retraction. We then proceeded by duplicating the steps of our approach for a RSC performed using a multi-port robotic platform with necessary modifications given the SP approach. Intra-operative outcomes and peri-operative outcomes were collected and reported. The patients were women of 64, 66 and 73 years of age with BMI of 22, 25, and 34, respectively, and POP-Q stage III and IV prolapse. The RSC was performed between 198 and 247 min, estimated blood loss was 10–50 cc, and there were no complications. All patients were discharged home on post-operative day 1. All patients were doing well 1 month out with resolution of bulge symptoms. To our knowledge, this represents the first case series of robotic, magnetic-assisted sacrocolpopexies using the da Vinci SP platform and the Levita™ Magnetic Surgical System. It appears to be a safe and feasible approach, but long-term comparative studies will be necessary to assess functional outcomes.

This study aims to assess the effect of statin therapy on outcomes among men managed with active surveillance.This is a retrospective cohort study evaluating 635 men managed with active surveillance from 2005 to 2015 at a large, academic medical center. The primary endpoints of analyses are disease reclassification (i.e., change in volume or grade of cancer on subsequent biopsies after diagnosis), progression to definitive therapy with curative intent (i.e., surgery or radiotherapy), and surveillance failure-defined as the development of either biochemical failure after definitive therapy, metastases, or prostate cancer-specific mortality-among statin and non-statin users. Secondary analyses were performed to assess the effect of statin use on outcomes among men who progressed to definitive treatment.Three hundred fifty-six (56.1%) patients in the cohort were on statin therapy at the initiation of surveillance. The median age was 66.7 and 63.3 years among statin and non-statin users, respectively. On univariate analysis, there were no differences in the rates of disease reclassification, progression to definitive treatment, and surveillance failure between the statin and non-statin users in the cohort (all p 0.05). There was no difference in the rate of biochemical failure among men who progressed to definitive therapy when stratified by statin use (p = 0.89). Pathologic data were available for 105 men who progressed to radical prostatectomy while on surveillance at our institution. Duration of statin use (months) was inversely correlated with adverse pathology for radical prostatectomy on both univariate (OR: 0.99; 95% CI 0.98, 0.99; p = 0.03) and multivariate analysis (OR: 0.98; 95% CI 0.97, 0.99; p = 0.02).Statin use was not associated with any clinical benefit with regard to disease reclassification, progression to definitive treatment, or surveillance failure among men selecting active surveillance at our institution. There was a 2% decrease in the odds of adverse pathology for each month of statin use among the men who progressed to radical prostatectomy while on active surveillance, but it is unclear at this time if this association has any durable impact on surveillance outcomes among men with favorable risk prostate cancer.

OBJECTIVE To identify which active surveillance candidates benefit most from confirmatory biopsies to exclude grade underclassification. MATERIALS AND METHODS This observational study includes 556 men diagnosed between 2002 and 2015 with Gleason 3 + 3 (GG1) disease on initial diagnostic biopsy, of whom 406 received a confirmatory biopsy within 12 months for active surveillance. Multivariable logistic regression analysis was performed to determine clinicopathologic features associated with Gleason 7 or higher (GG2+) on a confirmatory biopsy. Regression tree analysis was employed to stratify patients into select risk groups. RESULTS Eighty-five of 406 patients (20.9%) with initially GG1 disease were reclassified to GG2+ on a confirmatory biopsy. On multivariable analysis, increasing age (per year odds ratio 1.07; 95% confidence interval 1.02-1.12; P

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.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.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, p0.001). Kurtosis was significantly higher in each axis for calcium oxalate stones (each p0.001). 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.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.

We determined the effect of 5α-reductase inhibitors on disease reclassification in men with prostate cancer optimally selected for active surveillance.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.At diagnosis 371 patients met study inclusion criteria, of whom 70 (19%) were started on 5α-reductase inhibitors within 12 months. Median time on active surveillance was 53 vs 35 months in men on vs not on 5α-reductase inhibitors (p 0.01). Men on 5α-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 5α-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 5α-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).Among our cohort of men on active surveillance 5α-reductase inhibitor use was not associated with a significant difference in grade reclassification with time.

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.

Objective To compare stone composition and serum/urine biochemistries in stone formers with multiple sclerosis (MS) against stone formers without MS and to examine the association between mobility, methods of bladder emptying, and stone formation. Materials and Methods In this retrospective case-control study, we identified patients diagnosed with multiple sclerosis and kidney stone disease who were seen at our institution between 2001 and 2016. For the first part of the study, up to 2 controls (stone formers without a history of MS) were identified for each case and matched on age, body mass index (BMI), and sex. For the second part of this study, matched controls (MS patients without a history of stones) were identified in a 1:1 ratio in a similar fashion. Results of 24-hour urine biochemistry studies, stone compositions, serum labs, medications, history of stone surgeries, mobility, and method of bladder emptying were collected. Results A total of 587 patients were identified who had both multiple sclerosis and a history of stone disease. Of these, 118 patients had a stone composition available. When compared to matched controls, patients with MS were significantly more likely to have calcium phosphate stones (42% vs 15%, p < 0.001) and struvite stones (8% vs 3%, p = 0.03) and less likely to have calcium oxalate monohydrate stones (39% vs. 64%, p < 0.001). Among those patients with a composition available, those with MS were more likely to have undergone a PCNL (25% vs 12%, p = 0.005) or a cystolithopaxy (16% vs. 3%, p < 0.001) compared to their matched controls. 61 patients had a complete 24-hour urinary stone panel. There were no significant differences in urinary pH, volume, creatinine, calcium, citrate, oxalate, sodium, and uric acid as well as rates of hypocitraturia, hyperoxaluria, hypercalciuria, and hyperuricosuria among patients with MS. Use of intermittent straight catheterization (OR, 3.50 [95% CI, 1.89-6.47]; P = < 0.001) or an indwelling catheter (OR, 9.78 [95% CI, 4.81-19.88]; P =

Objectives 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. Materials and Methods We retrospectively identified all patients at our institution with a diagnosis of nephrolithiasis who underwent US followed by non-contrast computed tomography (CT) within 60 days. Data on patient characteristics, stone size (maximum axial diameter) and stone location were collected. The sensitivity, specificity and size accuracy of US was determined using CT as the standard. Results A total of 552 US and CT examinations met the inclusion criteria. Overall, the sensitivity and specificity of US was 54 and 91%, respectively. There was a significant association between sensitivity of US and stone size (P < 0.001), but not with stone location (P = 0.58). US significantly overestimated the size of stones in the 0–10 mm range (P < 0.001). Assuming patients with stones 0–4 mm in size will be selected for observation and those with stones ≥5 mm could be counselled on the alternative of intervention, we found that in 14% (54/384) of cases where CT would suggest observation, US would lead to a recommendation for intervention. By contrast, when CT results would suggest intervention as management, US would suggest observation in 39% (65/168) of cases. An average of 22% (119/552) of patients could be inappropriately counselled. Stones classified as 5–10 mm according to US had the highest probability (43% [41/96]) of having their management recommendation changed when CT was performed. The use of plain abdominal film of kidney, ureter and bladder and US increases sensitivity (78%), but 37% (13/35) of patients may still be counselled inappropriately to undergo observation. Conclusions Using US to guide clinical decision-making for residual or asymptomatic calculi is limited by low sensitivity and inability to size the stone accurately. As a result, one in five patients may be inappropriately counselled when using US alone.

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.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.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.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.

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 486min (standard deviation: 112min) 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.

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.