Urethral Plate Flap vs. Tunica Vaginalis Flap for Residual Severe Ventral Curvature in Hypospadias

Urethral Plate Flap Versus Tunica Vaginalis Flap Corporoplasty for the Correction of Residual Severe Ventral Curvature After Urethral Plate Transection in Hypospadias Repair: A Single-Center, Randomized, Controlled, Non-Inferiority Study

The correction of ventral curvature in hypospadias follows a stepwise principle. Clinically, in some cases of hypospadias, residual severe ventral curvature (VC ≥ 30°) persists even after thorough skin degloving and transection of the urethral plate, due to the unbalanced development of the ventral and dorsal tunica albuginea of the corpus cavernosum. In such cases, ventral tunica albuginea incision and corporoplasty with a graft are mandatory.

Although the currently commonly used pedicled Tunica Vaginalis Flap (TVF) corporoplasty can effectively correct the curvature, it requires additional dissection of the scrotum and tunica vaginalis sac. This prolongs the operative time and poses risks of donor-site complications, such as testicular retraction and scrotal hematoma.

The novel Urethral Plate Flap (UPF) corporoplasty utilizes local pedicled urethral plate tissue for homologous repair. This study adopts a prospective, single-center, randomized, controlled, double-blind, non-inferiority trial design, enrolling 90 subjects. The aim is to verify that the therapeutic efficacy of the UPF technique in correcting such residual severe ventral curvature is non-inferior to that of TVF, while demonstrating significant advantages in surgical efficiency and donor-site safety.

This study aims, through a single-center, double-blind, RCT design, and under the strict indication of "residual severe ventral curvature after urethral plate transection," to verify efficacy via a "non-inferiority" hypothesis, and to verify safety and efficiency via a "superiority" hypothesis. The goal is to provide Level I evidence for the update of hypospadias guidelines, while simultaneously exploring the establishment of postoperative imaging evaluation standards.

Inclusion Criteria:

• Age: 6 months to 14 years.
• Diagnosis: Primary hypospadias (no history of prior hypospadias repair).
• Intraoperative Condition: Residual ventral curvature ≥ 30° confirmed by artificial erection test after transection of the urethral plate.
• Consent: Signed informed consent provided by the participant's legal guardian.

Exclusion Criteria:

① Glans diameter < 1 cm; ② Combined with cryptorchidism; ③ Combined with severe bleeding disorders or coagulation dysfunction.