One- vs 4-week stent placement after laparoscopic and robot-assisted pyeloplasty: results of a prospective randomised single-centre study.

Objectives To determine whether 1-week stenting of the pelvi-ureteric anastomosis of laparoscopic or robot-assisted pyeloplasty is as effective as 4-week stenting, based on their respective success rates. Patients and Methods A total of 100 patients with pelvi-ureteric junction obstruction were treated by Anderson-Hynes pyeloplasty and the anastomosis was stented using a 6-F JJ catheter for either 1 week (1W series) or 4 weeks (4W series), based on a randomisation protocol. Postoperative follow-up was performed at 3 months using intravenous urography (IVU), at 6 months using diuretic renography and at 1, 3 and 5 years using ultrasonography. Statistical analysis was performed using a one-sided Z-test, Pearsons's chi-squared test and a Wilcoxon rank sum test. Results The primary outcome measure, success rate, which was defined as no obstruction on IVU and diuretic renography, was 100% in the 1W series and not inferior to the success rate of 98% in the 4W series (P = 0.006). The following secondary outcome measures were not significantly different between the 1W and the 4W series with regard to residual symptoms (10 vs 6%; P = 0.48), rate of complications (4 vs 6%; P = 0.65), need for synchronous robot-assisted pyelolithotomy (4 vs 8%; P = 0.47), improvement in split renal function (1 vs 0%; P = 0.59) and duration of surgery (200 vs 192 min; P = 0.87). Only length of hospital stay was significantly different; this was shorter in the 1W series (5 vs 6 days; P = 0.01). Conclusions Stenting of the pelvi-ureteric anastomosis after laparoscopic or robot-assisted pyeloplasty for 1 week is as effective as stenting for 4 weeks. Both procedures, laparoscopic or robot-assisted pyeloplasty have an excellent success rate.