Correlations Between Pretransplant Dialysis Duration, Bladder Capacity, and Prevalence of Vesicoureteral Reflux to the Graft

Background. Urinary bladder capacity is reduced in patients undergoing long-term dialysis, which may increase the risk of vesicoureteral reflux (VUR) to a transplanted kidney. This study investigated the correlations between dialysis duration, pretransplant and posttransplant bladder capacity, and prevalence of VUR to the graft. Methods. Voiding cystography was performed in 101 adult renal transplant recipients without neurogenic disorders immediately before and 1 year after transplantation to evaluate bladder capacity and VUR. Nonstented extravesical antireflux ureteroneocystostomy was performed in all patients. Results. The median dialysis duration and pretransplant bladder capacity were 32 months (range 1-426 months) and 120 mL (range 15-450 mL), and 21 patients (20.8%) underwent dialysis for more than 120 months, and 30 patients (29.7%) had a pretransplant bladder capacity of less than 80 mL. Dialysis duration was correlated with pretransplant bladder capacity (R(2)=0.466, P<0.001). Bladder capacity expanded more than 6-fold from pretransplantation to posttransplantation, and all recipients had a bladder capacity greater than 150 mL at 1 year posttransplantation. Thirty patients had VUR to the graft. Dialysis duration longer than 60 months (P=0.021) and pretransplant bladder capacity of less than 130 mL (P=0.024) were associated with VUR. VUR was associated with lower graft function. Conclusions. Although bladder capacity decreased because of long-term dialysis, it exceeded 150 mL at 1 year posttransplantation. A small bladder can be used in renal transplantation, but it may increase the risk of VUR.