Long-term functional outcomes after penoscrotal hypospadias repair: A retrospective comparative study of proximal TIP, Onlay, and Duckett

Introduction A variety of techniques are available for proximal hypospadias repair. Onlay, proximal tubularized incised plate (TIP), and Duckett are among the popular choices because they can be performed as a one-step procedure. However, the decision to select a procedure often comes down to the surgeon's preference rather than that supported by evidence-based data. In particular, there is a paucity of literature on the long-term urinary outcomes after proximal hypospadias repair. Objective The aim of this study was to evaluate the evolution of long-term uroflowmetry parameters after proximal hypospadias surgery over a long-term follow-up including the adolescent period. Study design Files from patients who underwent primary proximal hypospadias repair at our institution between 1997 and 2001 were reviewed. Only patients with documented serial postoperative uroflowmetry profiles at follow-up visits were included. Comparison between surgeries (pTIP vs. Onlay vs. Duckett) was performed according to the following postoperative time interval endpoints: 0-1 years, 1-2, > 2-4, > 4-6, > 6-10, > 10-12, and > 12 years. Maximal urinary flow rate (Q(max)) in relation to voiding volume (VV) adjusted for age or body surface area (BSA) were also evaluated in comparison to normal children using established Miskolc nomograms and compared between surgery techniques. Results Fifty-two patients met the inclusion criteria with a median follow-up of 10 years: 25 (59.6%) TIP, 18 (34/6%) Onlay, and nine (17.3%) Duckett. Overall, Q(max) increased progressively according to time and age in particular during the period covering adolescence. At follow-up 12 years postoperatively, median Q(max) values were 18.5 mL/second, 13.8 mL/second and 16.6 mL/second for TIP, Onlay, and Duckett, respectively, with no significant differenced detected between groups (p=0.5) see figure). Compared with normal children when adjusted for voiding volume and BSA, the proportion of obstructive uroflowmetry patterns defined as Q(max)<25th percentile of nomograms was more prevalent in patients aged 3-7 years old at 83.8% but decreased to less than 21.2% in patients aged > 13 years for all procedures (see figure). Discussion These results are consistent with previous work showing frequently reduced Q(max) after hypospadias surgery with great potential for improvement at puberty. Conclusion These results suggest that the obstructive urinary flow pattern observed in patients early on is a frequent finding after proximal hypospadias surgery. However, because of the remarkable improvement observed at puberty a watchful waiting approach is proposed in order to avoid unnecessary intervention.