The Koyanagi-Hayashi technique: An attractive technique for the severe hypospadias repair

Introduction

In the armamentarium of techniques used to reconstruct proximal hypospadias, deciding which to use is difficult, and the reoperation rate is high whichever procedure is chosen. The Koyanagi-Hayashi techniqueis an alternative for urethral reconstruction.

Objective

The main objective of our study is to focus on this technique and to evaluate its results in the pediatric visceral and urogenital surgery department of Mohammed VI Oujda University.

Materials and methods

22 patients (median age 7,5 years, range 12 months–14 years) presented with proximal hypospadias and were operated by the same surrgeon according to the modified Koyanagi - Hayashi technique. The average of following's patients was 04 years. Ventral chordée is found in 17 children (77 %), the average measured degree during surgery (artificiat erection test) was 15° (12–20°). A micropenis (penis lenth less than 25 mm) was assessed in 12 (54.5 %) of cases, and scrotal abnormality was found in 10 (45.5 %) cases. Hormone therapy before surgery using dihydrotestosterone gel 2.5 % for one month has been indicated by the pediatric endocrinologist in patients with a micropenis (in patients aged less than 2 years) (12 cases, 54.5 % of cases). Stents or catheters were used in all patients.

The mediane age for surgery was 7.5 years (12 months- 14 years).²

Results

The success rate from the first intervention is 59 % with penile straightening obtained in all patients. The complications observed were: fistula (36 %), meatal stenosis (13 %) and partial failure of uretroplasty (9 %). These complications led to 10 surgical revisions: urethrocutaneous fistula 8 of cases or 36 %), dehiscence of the glans (2 cases or 9 %).

A third intervention was necessary in a single patient whose indication was glans dehiscence (4.5 %). The final result in our series is considered satisfactory.

Conclusion

The modified Koyanagi-Hayashi technique is an attractive alternative for proximal hypospadias repair with satisfactory results and considerable but manageable complications. In our series the success rate was 58.6 %. The main limit of this study is shortness of study (only 22 cases).