Koyanagi- Snow-Hayashi Urethroplasty in Severe Hypospadias Repair: Between Hope and Reality.

Objective: To present the results of Koyanagi-Snow-Hayashi urethroplasty in severe hypospadias repair.

Methods: From June 2015 to December 2019, 43 patients with severe hypospadias associated with curvature underwent Koyanagi- Snow-Hayashi urethroplasty. All patients were treated for the first time and by a single surgeon. Thirty-five patients included in this study presented a form of disorders of sex development. The age of the patients at surgery varied from 12 to 120 months (mean age 21 months ± 6 months). The median follow-up was 28 months (range, 5-65 months).

Results: Functional and esthetic results were satisfactory with a straight and excellent appearance of the penis, without any complications in only ten patients (23%). While 30 of 43 patients (70 %) required additional procedures. Postoperative complications encountered in our patients were dominated by fistulas which were found in 17 of 43 patients (39.5%). Among them, 3 fistulas appeared in the penile shaft between 11 and 28 days and disappeared spontaneously. While proximal fistulas have been required surgical repair. Diverticulum seemed to be a significant complication of this technique, it was found in 4 of 43 (9%). This study also revealed the presence of a peculiar complication for this procedure, urethral meatus in the shape of fish lips.

Conclusion: The use of Koyanagi-Snow-Hayashi urethroplasty in severe hypospadias repair gives a complete penile straightening in all cases. However, Despite the modifications added by Snow and Hayashi to Koyanagi urethroplasty to improve the vascular supply of the flap, the rate of complications encountered with this technique remains high.