Comparison of longitudinal onlay flap and dorsal inlay graft urethroplasty repair techniques in narrow urethral plate hypospadias: A multicenter, retrospective study

Background: This study compared follow-up outcomes between longitudinal onlay flap (LOF) and dorsal inlay graft urethroplasty (DIGU) in patients with hypospadias and a narrow urethral plate to determine which repair method yields more favorable results. Materials and Methods: A retrospective cohort of 1950 children with hypospadias was selected from a multicenter hypospadias database between August 2014 and July 2024. Children with proximal hypospadias, a urethral plate width >8 mm, a Plate Objective Scoring Tool score >1.2, non-LOF/DIGU urethroplasty, or missing data were excluded. A total of 331 patients (224 treated with LOF and 57 treated with DIGU) were included in the analysis. Complications, reoperation rates, urodynamic results, and Pediatric Penile Perception Score values were recorded. Propensity score matching was used to pair patients undergoing LOF and DIGU in a 1:1 ratio to establish the study cohort. Results: A study cohort was established with 1:1 matching between the LOF (n = 57) and DIGU (n = 57) groups. At follow-up, no significant differences were observed between the 2 groups with respect to the incidence of surgical complications, reoperation rates, or time-related economic costs. No significant differences in primary uroflowmetry parameters were observed between the 2 groups. Patients in the LOF group scored significantly lower than those in the DIGU group for “appearance of penile skin” and “shape of the glans” on the Pediatric Penile Perception Score. Conclusions: There was no significant difference in the incidence of complications or reoperation rates between LOF and DIGU repair in patients with hypospadias and a narrow urethral plate. Early postoperative urinary function was also comparable. However, patients treated with LOF demonstrated lower scores for penile skin appearance and glans morphology, likely owing to swelling and overgrowth of the transferred foreskin flap.