Chronological Changes In Uroflowmetry After Hypospadias Repair: An Observational Study

Urinary flow after urethroplasty is of paramount importance. The aim of this study is to evaluate the progression of uroflowmetry (UF) parameters after different distal and proximal hypospadias repair techniques.

In this cohort study, cases that underwent primary hypospadias repair at our institution between March 2010 and December 2018 were included when uncomplicated, asymptomatic and toilet-trained. UF findings and post void residual were described after each specific technique.

In all, 88 patients were eligible. Time to last UF ranged from 35 to 138 months postoperatively. Significant increase started 36 months after distal tubularized incised plate urethroplasty (TIP) and afterwards than Mathieu technique. While was noticed 24 and 36 months after Onlay technique and proximal TIP, respectively; however, TIP showed steady significant increase atall time intervals. Duckett repair exhibited insignificant change in maximum flow rate (Qmax) values, buccal mucosal graft (BMG) and inner preputial graft (IPG), significant increase in the Qmax values after 6 and 24 months, respectively, then remained steady high. Transposed preputial flap (TPF) showed significant increase at 6-12 months only, then remained steady lower than the other two techniques. Obstructed flow was 37% after distal TIP, 30% after Mathieu, 25% after proximal TIP, 66.7% after Duckett repair, and 33.3% after TPF. There were no obstructed cases after BMG and IPG.

Improvement by time varied between techniques. After repair most cases are below the 50th percentile, implying that the reconstructed urethra is not functioning as a normal urethra. Staged repair for proximal hypospadias is preferable to a heroic one-stage procedure.

Choice of the surgical technique for hypospadias repair had impact on the improvement of Qmax values. TIP improved 36 months postoperatively. However, for proximal cases staged graft repair had earlier improvement and higher Qmax values than proximal TIP and Onlay techniques.