Which Patients Are at Higher Risk for Residual Valves After Posterior Urethral Valve Ablation?

PURPOSE: To find patients at high risk of obstructive remnant leaflets after valve ablation among boys with posterior urethral valve (PUV), we evaluated any possible relationship between preoperative findings in our patients and residual obstructive leaflets after valve ablation. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 55 patients with PUV that was treated by the same surgeon between 2008 and 2012. Of these, 37 patients (67.3%) had no obstructive remnant leaflets (group A) and 18 patients (32.7%) had obstructive remnant leaflets (group B) in follow-up cystoscopy. Preoperative clinical and radiological findings were evaluated and compared between the groups. RESULTS: Among all the preoperative data we examined, the analysis revealed that age at the time of surgery (median age: group A, 15 months; group B, 7 months; p=0.017), echogenicity of kidneys (p<0.05), presence of vesicoureteral reflux (p<0.05), and grade of reflux (p<0.05) were significantly different between the groups. Method of valve ablation, anterior-posterior diameters of the renal pelvis, renal cortical thickness, bladder wall thickening, and scarring on the dimercaptosuccinic acid scan showed no significant differences between the two groups. CONCLUSIONS: In our patients, younger age at surgery time, hyperechogenicity of renal parenchyma, presence of vesicoureteral reflux, and grade 4 or 5 reflux before surgery had a significant relationship with residual valves. More studies may result in enhanced management of patients at high risk of residual valves after PUV ablation, because the sooner the obstruction is resolved entirely, the better the outcome.