Impact of the type of ureteroileal anastomosis on renal function measured by diuretic scintigraphy: long-term results of a prospective randomized study

Objective To determine the long-term effects of the direct refluxing-type ureteroileal anastomosis technique with those of an antireflux technique on individual renal units, using diuretic scintigraphy in a prospectively randomized study. Patients and Methods Between 2002 and 2006, a prospective randomized study was conducted on 102 patients undergoing radical cystectomy and urinary diversion. In every patient, both ureters were randomized to be implanted using a direct refluxing technique or an antireflux, serous-lined extramural tunnel (SLET) technique. Renal function (RF) was evaluated using 99mTc-MAG-3 diuretic scintigraphy. The serial changes in corrected glomerular filtration rate (cGFR) for each technique and for each side were compared. Results Over a median follow-up of 6 years, the patients in both the direct refluxing and the SLET technique groups were found to have a significant reduction in mean (sd) cGFR between baseline and last follow-up: cGFR decreased from 59.4 (12.4) to 45.6 (15.3) mL/min (P < 0.001) and from 54.3 (11.2) to 46.3 (12.8) mL/min (P = 0.002), respectively. Five patients (4.9%) in the SLET group developed obstruction (four left-sided and one right-sided) compared with one (0.9%) in the direct refluxing group (right-sided). The onset of obstruction was noted 1–7 months after radical cystectomy. There was no significant difference between the groups in reductions in cGFR across the timepoints. Comparison of the two techniques according to the side of ureter implantation showed that the direct refluxing technique trended towards better functional outcomes on the left side. Conclusions There was no observed difference in the RF of individual renal units between the SLET and the direct refluxing groups in the long term. The need to incorporate an antireflux technique should be questioned and tailored according to the surgeon's experience and confidence.