The Koyanagi-Nonomura 1-stage bucket repair of severe hypospadias with and without penoscrotal transposition.

Purpose: We report our experience with 1-stage Koyanagi-Nonomura hypospadias repair, which may be performed even when penoscrotal transposition is present. Repair involves bilateral parameatal skin flaps based on the meatus and urethral plate.

Materials And Methods: A total of 14 boys 10 to 20 months old underwent 1-stage Koyanagi-Nonomura repair for severe hypospadias. The meatus was proximal to the penoscrotal junction in all patients, and in 8 penoscrotal transposition was corrected during the same operation.

Results: In 7 of the 14 boys 1 or more fistulas developed that were subsequently repaired. In all cases the fistula was on the proximal shaft and/or penoscrotal junction. In no case was there stenosis or breakdown of the distal neourethra.

Conclusions: The Koyanagi-Nonomura 1-stage repair provides excellent cosmetic results in severe hypospadias while preserving the available urethral plate tissue. It is particularly suitable when there is associated penoscrotal transposition. Most if not all 1-stage repairs are inappropriate in patients with severe hypospadias and penoscrotal transposition. In other repairs vascular supply to Byar's flaps and the neourethra may be compromised by mobilization of the anteriorly transposed scrotal tissue. We expect that the fistula rate will decrease with experience but now it is acceptable, considering the severity of hypospadias.