OBJECTIVE: To report the method and results of a modified one-stage Koyanagi repair (urethroplasty with a parameatal-based and fully extended circumferential foreskin flap) to preserve the vascularity to the peripheral portion of the neourethra, in the repair of severe hypospadias. PATIENTS AND METHODS: Using a skin-incision line as in the original Koyanagi repair, a circumferential incision is made approximately 5 mm proximal to the corona and the urethral plate incised as for repair of chordee. A U-shaped skin incision is then made surrounding the meatus, extended to the dorsal prepuce for approximately 8 mm and parallel to the first incision. The tissue between the prepuce and dartos is dissected on the dorsal side to fix the prepuce as a neourethra to the dartos and to maintain blood supply. After mobilizing the loop-shaped skin flap through the button-hole of the pedicle, the internal and external sides of the loop are sutured to construct a neourethra. Twenty patients (aged 10 months to 9 years) with severe proximal hypospadias underwent the one-stage modified Koyanagi repair. RESULTS: The repair was successful after the initial procedure in 14 patients, but urethrocutaneous fistulae developed in three and meatal stenosis in three. The overall success rate was thus 70%. CONCLUSIONS: There were fewer complications than reported with the original Koyanagi repair, suggesting that the attempted vascular preservation of the neourethra was effective.
OBJECTIVE: To report the method and results of a modified one-stage Koyanagi repair (urethroplasty with a parameatal-based and fully extended circumferential foreskin flap) to preserve the vascularity to the peripheral portion of the neourethra, in the repair of severe hypospadias. PATIENTS AND METHODS: Using a skin-incision line as in the original Koyanagi repair, a circumferential incision is made approximately 5 mm proximal to the corona and the urethral plate incised as for repair of chordee. A U-shaped skin incision is then made surrounding the meatus, extended to the dorsal prepuce for approximately 8 mm and parallel to the first incision. The tissue between the prepuce and dartos is dissected on the dorsal side to fix the prepuce as a neourethra to the dartos and to maintain blood supply. After mobilizing the loop-shaped skin flap through the button-hole of the pedicle, the internal and external sides of the loop are sutured to construct a neourethra. Twenty patients (aged 10 months to 9 years) with severe proximal hypospadias underwent the one-stage modified Koyanagi repair. RESULTS: The repair was successful after the initial procedure in 14 patients, but urethrocutaneous fistulae developed in three and meatal stenosis in three. The overall success rate was thus 70%. CONCLUSIONS: There were fewer complications than reported with the original Koyanagi repair, suggesting that the attempted vascular preservation of the neourethra was effective.
Authors: Tuan Hong Vu; Hoa Viet Nguyen; Quan Quy Hong; Hung Quang Pham; Tung Thanh Pham; Đang Hai Do; Thanh Đo Truong Journal: Ann Med Surg (Lond) Date: 2021-11-02