Koyanagi urethroplasty for proximal hypospadias: A stage procedure?

Objective: To report experience and technical refinements with the Koyanagi urethroplasty for proximal hypospadias.

Methods: A retrospective study was conducted between 2004 and 2017. Medical records of patients treated by the Koyanagi technique were investigated. The penile ventral skin was closed either with a Byars flap or using an "Ombredanne's chasuble" (OC). The cohort was divided chronologically into two groups of the same number of patients (early -E- and late experience group-LEG-). Demographics, anatomical findings and surgical outcomes were compared between groups using univariate analysis. A logistic regression was performed to assess factors associated with the occurrence of a postoperative urethrocutaneous fistula or urethroplasty dehiscence (UD).

Results: The Koyanagi urethroplasty was performed in 67 patients, 33 in the EEG and 34 in the LEG. The overall surgical complication rate was 64.2% (n=43), including 42 fistula or UD, higher in the EEG (81.8%) than in the LEG (44.1%, P<0.01). However, in the LEG, patients underwent the surgery older and the use of OC more frequent. After multivariate analyses, factors associated with a postoperative fistula or UD were the year of surgery (OR=0.71 [0.53-0.96] P=0.02), the age at surgery (OR=1.11 [1.01-1.22], P=0.03); contrary to the skin coverage method or the stenting duration (P>0.05). An urethral stenosis occurred in 1 patient (1.5%). At last follow-up, 64.2% of patients required a further procedure and 80.6% of urethral meatus were glandular.

Conclusion: In this study the complication rate, particularly the urethrocutaneous fistula, remained high. Urethral stenosis, were rare but the follow-up was too short to clearly identified them. Considering as a 2 stage procedure koyanagi uretroplasty allows to obtain finally good results.

Level of evidence: III.