Insight into the early postoperative improvement of the functionality of the reconstructed urethra after distal hypospadias repair treated by the Snodgrass technique.

Objective: This study aimed to evaluate the functional status of the urethra using uroflowmetry before surgery, as well as three and six months postoperatively in cases of distal hypospadias.

Material and methods: Thirty-nine consecutive patients who underwent surgery for distal hypospadias (hypospadias group) between 2016 and 2019 were prospectively included as part of this study. The control group consisted of 40 patients with a normal urethra who underwent surgery due to conditions other than hypospadias (phimosis, undescended testis, hernia). Uroflowmetry was performed preoperatively in these patients. Postoperative uroflowmetry was performed at three and six months following hypospadias surgery. Uroflowmetric results [maximum flow rate (Q_max), average flow rate (Q_ave), voided volume, void duration, flow start time, time to maximum urine flow rate, post-void residual urine, flow curve] were compared between the groups.

Results: The mean age for the patients with distal hypospadias was 35.9±29.6 months and 40.8±26.1 months for the control group. Pre- and postoperative Q_max values (three and six months after surgery) were 6.9 mL/s (0.1-15), 6.4 (0.2-14), and 7.5 (2.5-15). Qave values were preoperatively 4.0 (0.1-12.1), 3.8 (0.3-8.1), and 4.7 (1.0-11.1) mL/s three and six months after surgery, respectively. Bell-type flow was the most frequent uroflow flow curve in the preoperative hypospadias and control groups (95% and 66.6%, respectively). Postoperatively, bell-type flow remained the most common pattern, while a significant reduction in plateau-type flow was observed. Four boys (10.3%) had symptoms of obstruction.

Conclusion: Surgery improved urination dynamics and partial urethral obstruction of hypospadias cases that were present from the baseline. The urinary flow rates improve over time as the reconstructed neourethra regains functionality six months after the tubularized incised plate procedure.