Is routine voiding cystourethrogram necessary following double hit for primary vesicoureteral reflux?

Abstract

Current AUA guidelines recommend voiding cystourethrogram (VCUG) following endoscopic treatment of vesicoureteral reflux (VUR). We evaluated the clinical and radiographic outcomes of children undergoing Double HIT (hydrodistention implantation technique) for primary VUR to determine success rates and the necessity of postoperative VCUG. Children with a history of febrile urinary tract infection (fUTI) undergoing Double HIT for primary VUR between 2009 and 2012 were identified. Patients were prospectively classified as high or low clinical and radiographic risk. Children were categorized as high clinical risk if they had ≥ 3 fUTIs or documented bladder bowel dysfunction (BBD). High radiographic risk included those <2 years of age or with grade 4-5 VUR. Initially, all children underwent postoperative VCUG ("routine" group), while only those with an indication (high radiographic risk or clinical failure) did so during the latter portion of the study ("indicated" group). Clinical success was defined as no postoperative fUTI and radiographic success as negative postoperative VCUG. Average clinical follow-up was 34.7 ± 17.2 months. Two hundred and twenty-two children (198 girls, 24 boys) underwent Double HIT at a mean age of 4.1 ± 2.7 years. Mean maximum VUR grade was 3 ± 0.8. Sixty-eight children (30.6%) had documented BBD. Fourteen children (6.3%) experienced postoperative fUTI, for a clinical success rate of 93.7%. One hundred and fourteen patients (51.4%) underwent postoperative VCUG; 76 were "routine" and 38 were "indicated" [Figure]. Of children classified as low clinical/radiographic risk, 96.6% did not have a postoperative fUTI, compared to 91.1% for high risk patients (P = 0.771). Odds of clinical success for routine VCUG group were 9.9 times higher than for the indicated VCUG group (95% CI, 2-50). Odds of radiographic success for the routine cohort were 13 times higher than for the indicated group (95% CI, 4.2-40). Nine children (4.1%) underwent additional procedures. We found no difference in clinical success among the different risk groups; the number of children with postoperative fUTI was relatively few so there was not statistical power to discern any differences between patients who experienced clinical success versus clinical failure. However, children with an "indicated" VCUG (i.e. those less than 2 years of age, grade 4-5 VUR or those with a fUTI) were 13 times more likely to experience a radiographic failure. This cohort of 38 patients had a 50% radiographic cure rate and a 78.9% clinical cure rate, compared to the overall long-term clinical success rate of 93.7%. Our data demonstrates that we can predict failures with relatively high sensitivity, and it may therefore be prudent to selectively obtain postoperative VCUG rather than recommend it for all children undergoing dextranomer hyaluronic acid co-polymer (Dx/HA) injection. Our study has several limitations that warrant consideration. Not all children underwent a postoperative VCUG, so the true radiographic success rate is unknown. Incidence of fUTI may also be artificially low, as some radiographic failures proceeded directly to another injection or reimplantation. While we were able to demonstrate that children undergoing an "indicated" VCUG were more likely to experience radiographic failure, a larger patient cohort is necessary to determine whether age or VUR grade is more predictive of failure. Finally all patients underwent endoscopic Dx/HA injection, therefore the incidence "spontaneous resolution" is unknown. Long-term clinical success following Double HIT for the endoscopic correction of primary VUR is high, and the majority of children avoid additional procedures. Unless indicated by high-grade, young age, clinical failure, or family/surgeon preference, consideration should be given to making postoperative VCUG an option rather than a recommendation in children undergoing endoscopic treatment of primary VUR using the Double HIT method.