Introduction
The Koyanagi technique has received a
lot of attention for its logical flap design since its development[1;
2]. Many modifications of the Koyanagi technique have been introduced
because of its high complication rate[3; 4; 5; 6]. But the
complication rate didn’t drop much. We believe that the high
complication rate is mainly due to the disruption of blood supply to the
flap. Here, we development a modified Koyanagi technique that improves
the blood supply of the flap for single stage repair of severe
hypospadias, thereby greatly reducing the occurrence of complications.
Similar to the Koyanagi technique, the urethral plate was recreated
using foreskin, but then a sealed Y-shaped incision was made on the
original and recreated urethral plate. Different from the Koyanagi
technique where the foreskin is cut, it only be cut to the skin layer,
we divide the foreskin into the epidermal layer and the subcutaneous
tissue layer. The epidermis is cut off, but the subcutaneous tissue is
separated and the vascular system is protected. In this way, the blood
supply of the flap is intact, reducing operation failures caused by
avascular necrosis of the flap.