Efficacy of mini-endoscopic combined intrarenal surgery for pediatric kidney calculi: a single center retrospective study.

Management of large pediatric kidney calculi (PKC) is challenging. This study aimed to evaluate the efficacy and safety of miniature endoscopic combined intrarenal surgery (mini-ECIRS) for PKC. We retrospectively analyzed mini-ECIRS in 16 pediatric patients undergoing kidney stone treatment between November 2014 and October 2023 to determine its safety, efficacy, and associated outcomes. The median age was 50.50 (interquartile range: 36.75, 84.75) months, and the mean stone size was 21.63 ± 11.65 mm. The stone-free rate was 81.25%. The median decrease in hemoglobin level on the day after surgery was 1.10 (0.80, 1.55), and no patient required a blood transfusion. The median number of general anesthesia procedures was 2.00 (2.00, 2.00). Postoperative complications included fever in two patients and difficulty in removing the ureteral stent in one patient. In this cohort, five patients underwent pre-stenting under general anesthesia before mini-ECIRS. Age was significantly lower in the pre-stenting group than in the non-pre-stenting (P < 0.01); however, there were no significant differences in operative time, stone-free rate, total number of general anesthesia procedures, hemoglobin loss, or postoperative hospital stay between the groups. Mini-ECIRS was found to be a safe and efficient treatment method with a high stone removal rate in pediatric patients.

Defining a learning curve for urology trainees to achieve renal access without complications in endoscopic combined intrarenal surgery.

OBJECTIVES: There is a lack of data on the number of surgeries required for endoscopic combined intrarenal surgery (ECIRS). Accordingly, we aimed to identify the learning curve for ECIRS performed by multiple surgeons. METHODS: We included 296 patients who underwent ECIRS at our university hospital between 2016 and 2021. A learning curve for percutaneous nephrolithotomy side was calculated considering urology-resident surgeons. The learning curve was retrospectively analyzed for surgical time, renal puncture time, stone-free rate, and complications and corrected for age, body mass index, stone size, computed tomography value, cumulative number of surgeries, and stone location. RESULTS: This study included cases performed by 32 surgeons, including 30 residents and 2 attending surgeons. The median number of surgeries performed by the residents and attending surgeons prior to this study was 4.5 and 90, respectively. The median number of surgical procedures performed during the training period was seven. The surgical time of the residents decreased as the number of cases increased, reaching a median surgical time of 111 min for the attending surgeons after 16.4 cases. Renal puncture time was achieved in 20.1 cases. Complications related to renal access were observed in 13.0% (34 patients), Clavien-Dindo grade II in 1.9% (5 patients), and grade III or higher in 0.8% (2 patients). Comparing the first to fifth cases with the 21st and subsequent cases, the complication rate improved from 35% to 13%. CONCLUSION: Our study demonstrated that ECIRS training provided 16-20 cases with a learning curve to achieve acceptable surgical outcomes.

Comparison of Percutaneous Renal Access Between Robot-Assisted Fluoroscopy Guidance Using the Bi-Plane Method and Ultrasound Guidance: A Multicenter Randomized Control Benchtop Study.

Purpose: To evaluate the efficacy of supine percutaneous renal access by robot-assisted (RA) fluoroscopy and ultrasound (US) guidance in terms of procedural outcomes and surgeon workload. Methods: We conducted a multicenter, randomized, controlled benchtop study involving 32 urologists using a renal phantom model. RA puncture was performed using the developed version of automated needle targeting with X-ray (ANT-X), which determines the direction of the needle. US puncture was performed under US guidance. The primary endpoint was the single-puncture success rate, and the secondary outcomes were the procedural time for each step, time of fluoroscopic exposure, and workload assessment. Results: The single-puncture success rates were 90.6% and 56.3% for RA and US punctures, respectively (p < 0.01). In RA puncture, the median device setup time was 120 seconds longer, the median total procedural time was 100 seconds longer, the median time of fluoroscopic exposure was 40 seconds longer, the median needle puncture time was 17 seconds shorter, and the distance from the target sphere was 1 cm shorter than those in US puncture (all p < 0.01). The mental and physical task workload, effort required by the surgeons, frustration felt by the surgeons, and overall National Aeronautics and Space Administration Task Load Index scores were lower in the RA puncture group than in the US puncture group (p = 0.01, p = 0.046, p < 0.01, p = 0.021, and p ≤ 0.01, respectively). Conclusions: RA puncture using ANT-X, which can also be used for puncture in the supine position, offers advantages over renal puncture in terms of accuracy and surgical workload.

Efficacy of Robot-Assisted Ureteroureterostomy in Patients with Complex Ureteral Stricture after Ureteroscopic Lithotripsy.

BACKGROUND: Ureteral stricture (US) postureteroscopic lithotripsy (URSL) has emerged as a severe complication with the widespread use of laser technology. Furthermore, managing a complex US is challenging. Therefore, this study evaluated the efficacy of robot-assisted ureteroureterostomy (RAUU) in addressing US post-URSL and analyzed the pathology of transected ureteral tissues to identify the risk factors for US. METHODS: we conducted a prospective cohort study on patients who underwent RAUU for URSL-induced US from April 2021 to May 2023. RESULTS: A total of 14 patients with a mean age of 49.8 years were included in this study. The mean stricture length on radiography was 22.66 ± 7.38 mm. Nine (64.2%) patients had experienced failure with previous interventions. The overall success rate was 92.9%, both clinically and radiographically, without major complications, at a mean follow-up of 12.8 months. The pathological findings revealed microcalcifications and a loss of ureteral mucosa in 57.1% and 28.6% of patients, respectively. CONCLUSIONS: The RAUU technique shows promise as a viable option for US post-URSL in appropriately selected patients despite severe pathological changes in the ureter. Therefore, the migration of microcalcifications to the site of ureteral perforation may be a significant factor contributing to US development.

Impact of pelvicalyceal anatomical variation on surgical outcomes of endoscopic combined intrarenal surgery.

Objectives: The objective of this work is to investigate the impact of the pelvicalyceal anatomical system (PCS) on calyceal stone formation and surgical outcomes of endoscopic combined intrarenal surgery (ECIRS) for renal and/or proximal ureteral stones with a diameter >15 mm. Patients and methods: PCS was classified as Type I (single pelvis) or Type II (divided pelvis) according to the simple anatomical Takazawa classification. Using prospectively collected data from January 2016 to April 2020, 219 patients were retrospectively reviewed. After excluding patients who underwent a staged procedure, had hydronephrosis greater than grade 2, prior nephrostomy tubes, and failed to access the renal collecting system, 115 patients (Type I: 81, Type II: 34) were included, and the distribution of calyceal stones and surgical outcomes in ECIRS were compared between Types I and II PCS. Results: The median number of renal stone calyces in the Type II group was significantly more than that in the Type I group (p = 0.016). In particular, the Type II group possessed more upper stone calyces. Multivariate logistic regression analysis revealed that Type II PCS was associated with an increased odds ratio (OR) for the presence of upper stone calyces (OR: 2.93, p = 0.018). The stone-free (SF) status at 1 month after surgery, confirmed by abdominal plain radiography, was significantly higher in the Type I group compared with that in Type II (67.9% vs. 39.4%, respectively; p = 0.006). The requirement for additional surgical interventions was significantly higher in the Type II group compared with that in Type I (35.4% vs. 7.4%, respectively; p < 0.001). Multivariate analysis revealed that the number of stone calyces (OR: 4.26; p = 0.001) and Type II PCS (OR: 3.43; p = 0.009) were independent predictors of residual stones after ECIRS. Conclusion: We first revealed that the anatomic properties of PCS play a role in both upper calyceal stone formation and in the success of the ECIRS procedure. Because the SF rate in Type II PCS was significantly lower than that in Type I PCS, additional percutaneous nephrolithotomy tracts might be required, even for ECIRS.

A rare case of a clear cell carcinoma in a female urethral diverticulum.

Introduction: Urethral clear cell carcinoma is rare and often arises from a urethral diverticulum and rarely from the Müllerian duct. However, an explanation for this correlation remains unknown. Case presentation: We report the case of a 46-year-old woman who presented with hypermenorrhea. Magnetic resonance imaging revealed a papillary tumor in a cystic lesion in the dorsal urethra. We performed a robot-assisted radical cystourethrectomy and created an ileal conduit. Since pathological findings revealed microvascular and lymphovascular invasions around the urethra, adjuvant radiation therapy was administered. The patient showed no signs of recurrence or metastasis after treatment. Conclusion: We report a case of clear cell carcinoma in a female urethral diverticulum originating from a Müllerian duct cyst. While postoperative radiation therapy has been shown to produce a good outcome in carcinoma cases similar to this one, we recommend that a radical cystourethrectomy be performed.

Efficacy of ultrasound monitoring during extracorporeal shock wave lithotripsy: A multi-institutional propensity score-matched study.

OBJECTIVES: To evaluate the efficacy of ultrasound-assisted monitoring during shock wave lithotripsy for kidney and proximal ureteral calculi. METHODS: We retrospectively reviewed 535 patients who initially underwent shock wave lithotripsy for renal or proximal ureteral calculi between January 2012 and December 2021. The patients were divided into the X-ray group (n = 294) and ultrasound plus X-ray group (n = 241) based on the methods of targeting and monitoring calculi during shock wave lithotripsy. Because of differences in patient backgrounds, 1:1 propensity score-based matching was performed. The primary endpoint was the stone-free rate. RESULTS: In the final 1:1 matched cohort, 192 kidney stone cases and 162 proximal ureteral stone cases were analyzed. For patients with kidney calculi, the stone-free rate of the ultrasound plus X-ray group was significantly higher than that of the X-ray group (66.7% vs. 47.9%; P = 0.013). In the multivariate analysis, a large stone area (odds ratio 2.37), lower caliceal stones (odds ratio 3.37), and X-ray monitoring alone (odds ratio 0.49) were independently associated with shock wave lithotripsy failure. For patients with proximal ureteral stones, there was no significant difference in the stone-free rate between the ultrasound plus X-ray group and X-ray group (71.6% and 58.0%, respectively; P = 0.100). During the multivariate analysis, high computed tomography attenuation (odds ratio 2.31) and large stone area (odds ratio 2.18) were independent factors associated with residual stones after shock wave lithotripsy. CONCLUSIONS: Ultrasound-assisted monitoring may contribute to a higher stone-free rate for patients with kidney calculi, but not for those with proximal ureteral calculi.

Risk Factors for Failure of Endoscopic Management of Stone-related Ureteral Strictures.

PURPOSE: To investigate factors determining the outcomes of endoscopic management for stone-related ureteral stricture. MATERIALS AND METHODS: Data of patients who underwent endoscopic surgery for ureteral stricture due to stones from January 2016 to April 2020 were retrospectively analyzed. We compared cases successfully treated with endoscopic surgery with cases that resulted in failure. We focused on factors associated with treatment success, including cause and length of stricture, methods of stricture treatment, surgical time, and duration of hydronephrosis before the treatment. Treatment success was defined as improvement in hydronephrosis status. RESULTS: Nineteen patients were treated for stone-related ureteral stricture. Hydronephrosis was successfully improved in 12 patients (63.2%). Seven patients with failed endoscopic management had ureteroscopic lithotripsy- related stricture, whereas 3/12 (25.0%) patients with ureteroscopic lithotripsy-related stricture and 7/12 (58.3%) patients with impacted stone-related stricture were successfully treated by endoscopic management (P = .004). The prevalence of stricture length > 15 mm was significantly higher in the patients with failed management than in the patients with successful management (71.4 vs 16.6%, P = .046). Intraoperative endoscopic observation demonstrated that the mucosa of the ureteroscopic lithotripsy-related stricture had ischemic appearance with relatively long stricture length (P = 0.13) compared to the impacted stone-related stricture. No association was observed between treatment outcome and method of endoscopic management, including laser incision, balloon dilation, or both. CONCLUSION: Ureteroscopic lithotripsy as a cause and stricture length > 15 mm could affect the success rate of endoscopic management of ureteral stricture. In such cases, reconstructive management should probably be considered in the early stages.

Dual ureteral stent placement after redo laser endoureterotomy to manage persistent ureteral stricture.

INTRODUCTION: Endourological intervention is a minimally invasive approach for the management of ureteral strictures. Contraindications to this approach include active infection, strictures of sizes >2 cm, and failure of endoureterotomy. This report demonstrates a case of successful dual stent placement after redo endoureterotomy. CASE PRESENTATION: A recurring ureteral stricture in a 69-year-old woman, who had undergone ureteroscopic lithotripsy for a right ureteral calculus 60 months earlier, was successfully managed by redo endoureterotomy. The procedure involved insertion of dual ureteral stents after endoluminal incision and balloon dilation. Ureteral stents were removed 8 weeks after the operation. No significant complications or signs of stricture were observed 42 months after endoscopic repair. CONCLUSION: This minimally invasive and effective technique of dual ureteral stent placement following laser endoureterotomy successfully managed the recalcitrant ureteral stricture in a case with failed single stent placement following endoureterotomy.