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.

A Novel Ureteroscopy Training Platform That Utilizes CT Urograms to Replicate Complex Renal Collecting System Anatomies.

Introduction: Flexible ureteroscopy (fURS) is a one-person surgical technique, limiting trainees' ability to practice intraoperatively. Although well suited for simulation training, few existing fURS simulators can accurately reproduce complex renal collecting system anatomies. We developed an anatomically accurate fURS simulator using three-dimensional (3D) reconstruction of CT urograms and 3D printing technology to address this need. Materials and Methods: Patient-specific CT urograms were used to create 3D reconstruction of the renal collecting system using Slicer™. 3D models were modified using Blender™. Hollow, elastomer kidney models were created using an Objet 3D™ printer. To test and evaluate the new fURS simulator, 25 volunteers were recruited (5 novices, 13 residents, and 7 urologists). Participants were asked to explore the model with fURS and were evaluated on their ability to deduce its 3D anatomy, their ability to navigate to prespecified calices, and their time to task completion. Furthermore, participants were asked to compare the anatomical model with existing fURS benchtop models (Cook Medical™ and Limbs & Things™) on several criteria, including internal visualization, tactile feedback, and overall functional and teaching fidelity, in a survey. Results: We were able to create a fURS simulator that accurately replicates anatomically complex renal collecting systems. In exploring the model, we noted that unlike staff urologists, novices and residents often completely missed lower pole calices. A survey comparison between our simulator and comparable benchtop simulators revealed consistently better ratings of our simulator on all criteria (p < 0.05). Conclusions: We were able to create an anatomically accurate fURS simulator that provides a more realistic scoping experience. Preliminary testing revealed that trainees will benefit from this simulator, particularly with respect to learning how to navigate challenging collecting systems.

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.

Ureteral Obstruction Secondary to an Appendiceal Mucocele: A Case Report and Literature Review.

Background: Ureteral obstruction is rarely caused by extrinsic compression from the appendix. In addition, mucinous neoplasms of the appendix are rare, found incidentally in 0.2%-0.7% of appendectomy specimens. Case Presentation: We present an unusual case of ureteral obstruction caused by a large appendiceal mucocele. An asymptomatic 53-year-old caucasian male patient, known for recurrent nephrolithiasis, was referred for management of bilateral nephrolithiasis. A noncontrast CT scan found an atrophic kidney with an obstructive 1.8 cm right midureteral stone above a 9 × 4.3 cm appendiceal mucocele compressing the right midureter. Although the impacted ureteral stone was extracted with retrograde ureteroscopy and holmium laser lithotripsy, the appendiceal mucocele was resected by laparoscopic appendectomy. Final pathology analysis revealed an unperforated low-grade appendiceal mucinous neoplasm of 13 cm without lymphovascular invasion. Since the whole mucocele was completely excised, it did not require any further follow-up. Postoperative CT scan demonstrated stone-free status on the right side with residual mild right hydroureteronephrosis. A diuretic renal scintigraphy showed a nonobstructed right kidney with a chronically dilated pelvicaliceal system and a 34% differential function in the right kidney. Follow-up for up to 2 years postoperatively demonstrated that his diuretic renal scan did not show deterioration of the differential renal function, indicating that there was no significant obstruction. Conclusion: This is the fourth reported case of appendiceal mucocele causing extrinsic ureteral obstruction, and the secondary urinary stasis contributed to formation of a large midureteral stone and cortical renal atrophy. This case demonstrates the importance of the work-up and management of obstructive ureteral stones before definitive management of appendiceal mucoceles.

Lumbar Artery Pseudoaneurysm: A Complication of Percutaneous Nephrostomy.

A 21 year-old male underwent nephrostomy tube insertion for hydronephrosis due to a large para-aortic adenopathy of a testicular tumor. In order to reduce infections during chemotherapy, a ureteral stent was placed. While removing the nephrostomy tube, a pulsatile bleeding was found and a renal angiography was done. A pseudoaneurysm of his first left lumbar (L1) artery communicating with the nephrostomy's access site was found. An embolization was performed with coils in the left L1 artery and one of its subdivisions. Post-embolization controls revealed no bleeding. On the follow-up CT, there were no suspicious retroperitoneal mass.