Haim Herzberg

Background: Preoperative identification of the bowel on imaging is essential in planning renal access during percutaneous nephrolithotomy (PCNL) and avoiding colonic injury. We aimed this study to assess which noncontrast computed tomography (NCCT) window setting provides the optimal colonic identification for PCNL preoperative planning. Methods: Ten urologic surgeons (four seniors, six residents) reviewed 22 images of NCCT scans in both abdomen and lung window settings in a randomized blinded order. Colonic area delineation in each image was performed using a dedicated, commercially available area calculator software. A comparison of the marked colonic area between the abdomen and lung window settings was performed. Results: Overall, the mean marked colonic area was greater in the lung window compared with the abdomen window (8.82 cm ² vs 7.4 cm ² , respectively, p < 0.001). Switching the CT window from abdomen to lung increased the identified colonic area in 50 cases (50%). Intraclass correlation showed good agreement between the senior readers and among all readers (0.92 and 0.87, respectively). Similar measurements of the colonic area in both abdomen and lung windows were observed in 26/44 (60%) of the seniors cases and in 7/66 (10%) of the resident cases ( p = 0.002). Conclusion: Lung window solely or in combination with abdomen window appears to provide the most accurate colonic identification for preoperative planning of PCNL access and potentially reduce the risk of colonic injury. This pattern is more evident among young urologists, and we propose to introduce it as a standard sequence in PCNL preplanning.

We aimed to validate a formula for improving the estimation of prostatic volume by abdominal ultrasound (AUS) prior to transurethral laser enucleation. A total of 293 patients treated for benign prostate hyperplasia (BPH) by laser enucleation from 2019–2022 were included. The preoperative AUS volume was adjusted by the formula 1.082 × Age + 0.523 × AUS − 53.845, which was based on specimens retrieved by suprapubic prostatectomy. The results were compared to the weight of the tissue removed by laser enucleation as determined by the intraclass correlation coefficient test (ICC). The potential impact of preoperative planning on operating time was calculated. The ICC between the adjusted volumes and the enucleated tissue weights was 0.86 (p < 0.001). The adjusted volume was more accurate than the AUS volume (weight-to-volume ratio of 0.84 vs. 0.7, p < 0.001) and even more precise for prostates weighing >80 g. The median operating time was 90 min. The adjusted volume estimation resulted in an overall shorter expected preoperative operating time by a median of 21 min (24%) and by a median of 40 min in prostates weighing >80 g. The adjustment formula accurately predicts prostate volume before laser enucleation procedures and may significantly improve preoperative planning, the matching of a surgeon’s level of expertise, and the management of patients’ expectations.

The aim of this study was to examine ureteral stricture rate after the use of UAS in an unstented ureter and compare complications of smaller vs. larger-caliber UAS. We conducted a retrospective analysis of consecutive RIRS for renal stones, with the use of UAS in unstented ureters. We excluded cases with previous ureteroscopies, who carried ureteral stent or nephrostomy, had impacted stones, underwent radiation treatment, or had urinary tract malignancies. The primary outcome was formation of ureteral strictures diagnosed by hydronephrosis in ultrasound test and late secretion in dynamic renal scan. Secondary outcome was stone-free-rate (SFR) and complications. In addition, we compared safety and efficacy of smaller (9.5/11.5Fr) vs. larger-caliber (12/14Fr) UAS. The cohort included 165 patients with a median follow-up time of 115 days. There was no case of ureteral stricture formation after the use us UAS, despite using a larger-caliber UAS in nearly half the cases. Larger-caliber UAS was not associated with more complications compared to the smaller-caliber one (p = 0.780). SFR was non-significantly higher in the larger-caliber UAS group (p = 0.056), despite having a larger stone burden, and only stone number was associated with SFR (p = 0.003). These data suggest that the use of UAS during RIRS in an unstented ureter is safe and does not involve ureteral stricture formation after one procedure. Furthermore, the use of wider sheaths was not found to be associated with higher complications rate.