title: A New Modification of the Koyanagi Technique for the One-stage Repair of Severe Hypospadias.
abstract: OBJECTIVE
  To describe a new modification of the Koyanagi technique for the one-stage repair of severe hypospadias and its short-term outcomes.
  
  
  METHODS
  Our modified Koyanagi technique was performed in 24 patients with severe hypospadias between February 2012 and January 2015. The age of the patients ranged from 1.9 to 11.9 years (mean = 3.5 years). The flap design was similar to the Koyanagi technique, but our modified technique highlighted the following points: after the chordee was completely corrected, the urethral plate was recreated using foreskin, and then a U-shaped incision was made on the original and recreated urethral plate (as in the Duplay technique); a pedicled flap of the tunica vaginalis or scrotal dartos was used for additional coverage of the neourethra.
  
  
  RESULTS
  The operation time lasted from 120 to 150 minutes (mean = 140 minutes). There were 5 patients (20.8%) who developed complications: 4 patients (16.7%) developed a fistula and 1 patient (4.2%) developed dehiscence of the urethra. There were no reported urethral strictures, meatal stenosis, or urethral diverticula. The complications in the 5 patients were successfully addressed with secondary repair, and all patients achieved satisfactory cosmetic and urethral functional results.
  
  
  CONCLUSIONS
  The modified Koyanagi technique simplified the operation and better preserved the blood supply to the flap. The additional coverage of the neourethra using a pedicled flap of the tunica vaginalis or scrotal dartos significantly decreased the rate of fistula formation. This technique is highly suitable for the one-stage repair of severe hypospadias with penoscrotal transposition.
authors.affiliation: Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Kang
authors.affiliation: Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Guizhen
authors.initials: G
authors.lastname: Huang
authors.affiliation: Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Li
authors.initials: L
authors.lastname: Zeng
authors.affiliation: Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Yidong
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Ma
authors.affiliation: Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Miao
authors.initials: M
authors.lastname: Yuan
authors.affiliation: Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Pediatric Surgery, West China Hospital, Sichuan University, Chengdu, China. Electronic address: lugang992001@aliyun.com.
authors.forename: Lugang
authors.initials: L
authors.lastname: Huang
mesh_terms: D002648:Child; D002675:Child, Preschool; D052816:Foreskin / Q000601:surgery; D006801:Humans; D007021:Hypospadias / Q000601:surgery*; D007223:Infant; D008297:Male; D012720:Severity of Illness Index; D013524:Surgical Flaps; D013997:Time Factors; D016896:Treatment Outcome; D014521:Urethra / Q000601:surgery; D013521:Urologic Surgical Procedures, Male / Q000379:methods