Ureteral strictures after kidney transplantation: risk factors

Ureteral obstruction is one of the most commonly reported urological complications after kidney transplantation often occurring within the first 3 months after surgery. Ischemia is the most frequent cause of ureteral stenosis and is the result of excessive hilar dissection and a poor anastomotic technique. Aim of this study was to identify the main risk factors for ureteral stenosis after kidney transplantation from cadaveric donors and to assess their impact on both graft survival and patient.

We retrospectively investigated 761 kidney transplants from cadaveric donors performed between 1998 to 2011. In all the patients, the ureteroneocystostomy was stented with a double J stent 4.7Ch x 12 cm held in place for an average time of 4-6 weeks post-operatively. Each patient underwent at least 3 ultrasound scans during hospital stay and subsequently during follow-up. All patients with severe hydronephrosis were followed by sequential renal scintigraphy with MAG3 and diuretic stimulus.

After a mean follow-up of 60.1 (+/- 38.5) months, severe ureteral stenosis was discovered in 21 patients (2.76%), with exclusive involvement of the vesicoureteral junction. No statistically significant correlation was found with donor age and the incidence of delayed graft function, whereas a significant correlation between ureteral obstruction and unilateral placement of both grafts in dual kidney transplantation (DKT) (p < 0.001) was found. These patients had a longer mean hospital stay than the control group, but there was no influence on survival of the organ or patient.

ureteral obstruction after renal transplantation often features subtle and late symptoms. Early ultrasound monitoring is therefore essential and in the presence of severe hydronephrosis, scintigraphic confirmation of the obstruction. In fact. early resolution of the stenosis appears to provide optimal graft and patient survival.