Renal Scarring in Surgically Treated Primary Vesicoureteral Reflux

Kim, Seong Yong; Shin, Ki Yong; Woo, Young Nam

Abstract

PURPOSE: We investigated the relationship of vesicoureteral reflux (VUR) and renal scarring in children who were treated surgically due to failure of initial medical management.
MATERIALS AND METHODS
Thirty two children (51 renal units), 15 boys and 17 girls, aged 1-8 (median 3.2) years, with VUR were analyzed retrospectively. All children were initially treated with antibiotic prophylaxis for median 15.2 months (10-19 months). In 51 renal units, reflux grade at presentation was grade II in 8, III in 14, IV in 25 and V in 4. Renal scars were evaluated with dimercaptosuccinic acid (DMSA) scan and classified into three grades. We analyzed the incidence and severity of renal scar according to various clinical characteristics and discussed the optimal treatment in vesicoureteral reflux with respect to the development of renal scar.
RESULTS
DMSA scan revealed that 69% (35/51) of the renal units had renal scars. Scarring at presentation was grade I in 10, II in 20 and III in 5 renal units. The incidence of renal scar was 86% at ages less than 2 years, 72% at ages 2 to 5 and 27% at ages greater than 5, of which the difference was statistically significant. And the incidence of renal scar according to the reflux grade was 38% in II, 50% in III, 84% in IV and 100% in V, of which the differnce was also statistically significant. However, the sex and laterality did not affect the incidence of renal scar in this study. With respect to the scar grade, the grade of refux was the only statistically significant determining factor. Especially, grade IV reflux resulted in much more severe scarring than grade III reflux. Comparing the result of DMSA scan at presentation with that just before operation in 13 children (18 renal units), only two renal units with grade IV reflux showed increase in renal scar.
CONCLUSIONS
The most important factor to affect the development and severity of renal scar was the reflux grade. Considering relatively higher incidence of renal scar and more severe scarring in grade IV reflux than grade III reflux, early surgical management may be a possible option in the treatment of children with grade IV reflux.