Robot-Assisted Pyeloureterostomy for Lower Pole Ureteropelvic Junction Obstruction in an Incomplete Duplicated System

Abstract

Introduction: Ureteropelvic junction obstruction (UPJO) and duplicated collecting systems, complete or incomplete, are relatively common congenital urologic anomalies, but rarely occur together. UPJO in incomplete duplicated systems usually involves the lower pole moiety1,2 and patients can present with obstruction-related problems, including flank pain and upper urinary tract infection.3 We present a video-enhanced description of a robot-assisted pyeloureterostomy for a symptomatic right lower pole UPJO in an incomplete duplex system. The video outlines the initial presentation, provides all related radiologic investigations, details the surgical technique, and provides initial outcome data. Methods: A healthy 54-year-old woman presented with a 3-year history of intermittent right flank pain. All preoperative imaging studies confirmed the diagnosis of a right lower pole UPJO in an incomplete duplicated system. Renal scintigraphy revealed 53% right differential function and a furosemide clearance half-time of 145 minutes for the lower pole moiety. One week preoperatively, the patient's right upper pole (UP) moiety was stented to facilitate identification of the collecting system. After appropriate preparation of the patient, pneumoperitoneum was obtained using a Veress needle technique. The da Vinci© robot was docked after placement of all ports: a 12-mm camera, two 8-mm robotic and one 8-mm assistant ports. First, the right colon was mobilized to expose the retroperitoneum. To aid exposure, the overlying perinephric tissue was tacked laterally to the abdominal sidewall using Hem-o-Lok® clips. The bladder was filled with methylene blue-infused normal saline (methyleneNS), which easily refluxed into the UP, but did so very slowly into the lower pole moiety. This permitted easier identification of the dilated lower pole moiety with a narrowed entry point at the level of the bifurcation. We continued dissection to identify, but not devascularize, the common ureter and its bifurcation into the upper and lower pole moieties. Rather than excise the stenotic UPJ and perform an end-to-side anastomosis, a decision was made to perform a side-to-side anastomosis in an effort to minimize scarring of the common ureter. An incision was made on the cephalad aspect of the lower pole pelvis and the caudal aspect of the dilated UP moiety ureter. Using a 3-0 PDS suture, a side-to-side anastomosis was performed in a running fashion. The posterior layer of the pyeloureterostomy was closed first, from lateral to medial, followed by the anterior layer in a similar manner. Before completing the anastomosis, a 6F ureteric stent was inserted antegradely over a hydrophilic-tipped guidewire, next to the existing preoperative UP moiety stent. The anastomosis was then tested using retrograde infusion of methyleneNS. At the end of the procedure, a Jackson-Pratt drain was placed through the lower robotic port. Results: The surgical time was 127 minutes, estimated blood loss was 50 cc, and the patient was discharged on POD 2 with no postoperative complications. Both ureteric stents were removed 4 weeks postoperatively and 6 weeks later, renal scintigraphy demonstrated no evidence of obstruction with a significantly improved furosemide clearance half-time of 6 minutes. The patient remains pain free for 9 months postoperatively. Conclusion: Robot-assisted pyeloureterostomy for lower pole UPJO in an incomplete duplicated system is a safe and feasible option. No competing financial interests exist. Runtime of video: 6 mins 7 secs