RESUMEN
<p><b>OBJECTIVE</b>To investigate the clinical effect of modified Koyanagi technique with coverage by tunica vaginalis of testis in severe hypospadias.</p><p><b>METHODS</b>49 cases with severe hypospadias treated from Jan. 2009 to Sep. 2011 were retrospectively studied. 25 patients underwent Koyanagi technique with coverage by tunica vaginalis of testis. 24 cases underwent one-stage Duplay + Duckett technique in the same term. The patients were followed up for 7-24 months.</p><p><b>RESULTS</b>Among the 25 children treated with Koyanagi procedure, 20 cases were cured, 5 patients had postoperative complications, including urethral fistula in 3 cases,urethral stenosis in 2 cases. At the same time, in the Duplay + Duckett group, 17 cases were cured, 7 children had postoperative complications, including urethral fistula in 4 cases, and urethral stenosis in 3 cases. All the patients with urethral fistula were repaired successfully 6 months after the first surgery; The urethral stenosis were cured by dilatation within 1 to 3 months. The successful rate in the 2 groups had no significant difference(P >0.05).</p><p><b>CONCLUSIONS</b>Koyanagi technique with coverage by tunica vaginalis of testis is relatively simple with similar effect as Duplay + Duckett technique for severe hypospadias.</p>