A Rocky Road: Bladder Stones in the Augmented Exstrophy-Epispadias Complex Patient.

OBJECTIVES: To determine the rate of stone formation amongst patients of the exstrophy-epispadias complex with augmentation cystoplasty. We hypothesize that bowel segment choice influences the rate of stone formation after bladder augmentation and the rate of complications from bladder stone surgery. METHODS: An IRB approved institutional database of 1512 exstrophy-epispadias patients was reviewed retrospectively. Patients that had a history of bladder augmentation and were seen at our institution between 2003 and 2023 were included. RESULTS: Out of 259 patients, bladder stones developed in 21.6% (56), of which the bowel segment used was colon in 147 patients and ileum in 100. Stones formed in 19% of colon augments compared to 29% ileal augments, however this was not statistically significant (p=0.07). The most common primary stone component was dahllite, followed by struvite for all augments. The median time to stone treatment after augmentation was 4.14 years (0.75-31). 74% of patients had a recurrence that required a second surgery. The median time from first to second surgery and second to third surgery was 1.4 years and 2.22 years, respectively. Bladder stone surgery complications occurred in 14% of patients, vesicocutaneous fistula being the most common, and complications did not differ by augment type. Median follow up after first stone intervention was 6.07 years (0-19.5). CONCLUSION: The treatment of bladder stones in the exstrophy-epispadias complex remains challenging. Interventions to prevent recurrence are crucial as the majority of patients will require two or more stone surgeries in their lifetime.

Infarction of Paratesticular Inflammatory Myofibroblastic Tumor Mimicking Testicular Torsion.

This report describes a 14-year-old male with a rare paratesticular inflammatory myofibroblastic tumor that presented atypically with acute unilateral scrotal pain and swelling. This presentation, which raised suspicion for testicular torsion, contrasts with the typical presentation of a slow-growing scrotal mass. Scrotal exploration revealed an infarcted right testis, demonstrating this locally aggressive tumor can undergo vascular invasion and occlude testicular blood supply. Thus, inflammatory myofibroblastic tumor should be considered in the differential diagnosis when evaluating patients with acute scrotal pain suspicious for testicular infarction.

Inter-rater reliability of retrograde urethrograms.

PURPOSE: Reliability of pre-operative testing is important for adequate surgical planning. For urethral stricture disease, preoperative planning frequently includes retrograde urethrogram (RUG). The radiographic interpretation of RUGs is often done by urologists themselves. We aimed to evaluate the reliability of RUG interpretation by urologists at our institution. METHODS: We examined the RUGs of 193 patients. These were deidentified and interpreted by three urologists, two general urologists and one reconstructive urologist. These interpretations were compared in 2 ways. Each of the general urologists was compared to the "gold standard" reconstructive urologist interpretation, and the general urologists were additionally compared to each other. We used intraclass correlation coefficient (ICC) for numerical variables and Fleiss' Kappa or Cohen's Kappa statistic (κ) for categorical variables to rate inter-interpreter reliability and agreement among interpretations with regards to the quantitative variables of stricture length and caliber. RESULTS: Level of agreement ranged from poor to moderate across all variables interpreted. Comparing general urologists to the gold standard yielded no better than moderate agreement, with the majority being poor to fair. Similarly, agreement amongst the general urologists did not reach above moderate, with the majority being poor to slight. CONCLUSION: To our knowledge, this is the first analysis of inter-rater reliability of RUGs among practicing urologists. Our analysis showed clinically unacceptable reliability with regards to stricture length, location, caliber, and indicated procedures. This study suggests a need for standardized interpretation of RUGs and poses an opportunity for actionable improvement in management of strictures.

Identifying urethral strictures using machine learning: a proof-of-concept evaluation of convolutional neural network model.

INTRODUCTION: To evaluate urethral strictures and to determine appropriate surgical reconstructive options, retrograde urethrograms (RUG) are used. Herein, we develop a convolutional neural network (CNN)-based machine learning algorithm to characterize RUG images between those with urethral strictures and those without urethral strictures. METHODS: Following approval from institutional REB from participating institutions (The Hospital for Sick Children [Toronto, Canada], St. Luke's Medical Centre [Quezon City, Philippines], East Virginia Medical School [Norfolk, United States of America]), retrograde urethrogram images were collected and anonymized. Additional RUG images were downloaded online using web scraping method through Selenium and Python 3.8.2. A CNN with three convolutional layers and three pooling layers were built (Fig. 1). Data augmentation was applied with zoom, contrast, horizontal flip, and translation. The data were split into 90% training and 10% testing set. The model was trained with one hundred epochs. RESULTS: A total of 242 RUG images were identified. 196 were identified as strictures and 46 as normal. Following training, our model achieved accuracy of up to 92.2% with its training data set in characterizing RUG images to stricture and normal images. The validation accuracy using our testing set images showed that it was able to characterize 88.5% of the images correctly. CONCLUSION: It is feasible to use a machine learning algorithm to accurately differentiate between a stricture and normal RUG. Further development of the model with additional RUGs may allow characterization of stricture location and length to suggest optimal operative approach for repair.