99mTc-DMSA Renal Scan after Anti-reflux Surgery in Children with Primary Vesicoureteral Reflux / 대한비뇨기과학회지

ABSTRACT

PURPOSE: 99mTc-dimercaptosuccinic acid(DMSA) renal scintigraphy is recognized as the most effective imaging modality for demonstrating renal scarring In children with vesicoureteral reflux. We determined if significant numbers of new scar develop and progression of scarring occur after antireflux surgery. MATERIALS AND METHODS: Retrospective study was undertaken In a series of 102 reflux renal units out of 60 children(male 35, female 25) with vesicoureteral reflux as documented by voiding cystourethrography, whose age was 28(median, range1-150) months. We carefully examined DMSA renal scans taken in 2(median, range0.3-58) months before operation and 18(median, range3-62) months after operation in each patients. Twenty two children(37 renal units) were further followed up by additional scans up to 50(median, range25-120) months postoperatively. Each scan was blindly reviewed twice in terms of the size, number and zonal location of the cortical defects based on morphology. The Interval changes were categorized into 3 patterns(improved, no change, progressed) based on the review findings RESULTS: There were no patients with postoperative pyelonephritis but asymptomatic bacteriuria were found in 19 patients(31.5%). Most(57 patients, 109 renal units) of the antireflux operation were done by Cohen method and refluxes were still found in 8 renal units(7.8%) in immediately postoperative periods and were ultimately disappeared. No postoperative urethral obstruction was found on intravenous pyelogram. On follow-up renal scintigraphy most of renal units(89, 87.3%) showed no change while 11(10.7%) showed improvement and progression was observed In 2(2.0%). No correlation was established between scintigraphic change and several clinical factors such as sex, age of first pyelonephritis presentation, presence or frequency of pyelonephritis before initial renal scan , nor postoperative episodes of urinary tract infection. CONCLUSIONS: Our results show that on the contrary to the most of the previous reports, no further development of renal scar was found after successful surgery. There was no significant morphologic change in the postoperative follow-up renal scan in most of reflux and if any, most were disappearance or diminution of renal scars.