Bladder Volume Change and Post-Transplant Vesicoureteral Reflux (VUR) in Pediatric Recipients With Atrophic Bladder After Kidney Transplantation.

Abstract

Background Children with CKD have high prevalence of atrophic bladder due to disused situation and inadequate bladder-cycling after long-term dialysis and congenital urinary tract anormaly. Small capacity bladder have potential risks of ureterocystoneostomy. We retrospective reviewed our surgical outcome of ureterocystoneostomy and bladder volume change at 4 months after kidney transplantation in pediatric recipients with atrophic bladder. Methods Between 2000 and 2012, 153 pediatric renal transplant recipients were performed kidney transplantation with evaluation of bladder size using voiding cystography before and 4 months after transplantation. Patients with neurogenic bladder were excluded. Definition of atrophic bladder volume is less than 50% of estimated bladder capacity(30×(age+1)) under 10 years old and less than 150ml over 10 years old. Result Seventy-two (47.1%) pediatric recipients showed atrophic bladder (42 males and 30 females). Average age of transplants is 7.2±5.3 years old. Average height is 107.2±22.8cm and weight is 19.2±10.9kg. Mean bladder volume is 46.0±35.1ml at pre-transplant and 164±80.4ml at 4 months after transplant. The bladder capacity of pre-transplant atrophic bladder significantly increased approximately 3 times at 4 months after transplantation regardless of pre-transplant age, bladder volume and body weight. There is a significant difference of the incidence of post-transplant vesicoureteral reflux(VUR) in the graft between the atrophic baladder and the normal group(14.1%: 1.2%). Procedures of ureterocystoneostomy in the atrophic bladder group were intravesical(P-L) method (n=37), extravesical(L-G) method(n=34) and uretero-ureterostomy(n=1). There is no significant difference of prevalence of VUR in the graft kidney between P-L and L-G method(13.5%(n=5); 14.7%(n=5)). However, there is a significant difference of the incidence of VUR among pre-transplant bladder capacity(0-50ml:19.6%, 50-100ml:4.8%,100-150ml:0%). Conclusion Pediatric kidney recipients had high prevalence of atrophic bladder, and the improvement of bladder volume is excellent without special procedure of ureterocystoneostomy and pre-transplant management in pediatric recipients. However there is potential high risk of VUR in recipients with atrophic bladder.