Neo-yoke repair for severe hypospadias: A simple modification for better outcome

SummaryBackgroundAlthough staged repair for reconstructing severe hypospadias is more popular, various one-stage repairs have been attempted. Koyanagi repair (parameatal-based and fully extended circumferential foreskin flap urethroplasty) has enabled correction of severe hypospadias in one stage. However, its un-acceptably high incidence of complications has initiated a series of technical modifications, including the “yoke” repair.ObjectivesTo retrospectively analyze the outcome of a proposed modification of the originally described yoke repair, for patients with severe hypospadias. This modification was developed to reduce complications.Study designOver 4 years (between Jan 2011 and Jan 2015), all cases of severe hypospadias were included in this study; except those with prior attempts at repair, circumcised cases, and cases with severe hypogonadism - because of partial androgen insensitivity - not responding to hormonal manipulations. The make-up of the neo-urethra in this modification is the urethral plate with its spongiosal tissue proximally, a circum-coronal preputial pedicled flap in the middle, and an incorporated part of the augmented preputial flap and the preserved V-shaped glanular urethra, distally. Close postoperative follow-up was conducted to investigate the outcome.ResultsThirty-one children with a median age of 32.48 months had repair of severe hypospadias using the neo-yoke technique. After a median follow-up of 26.7 months, the overall complication rate was 16.1%. Four children developed urethrocutaneous fistula (12.9%). Meatal drop-back occurred in one case (3.2%). No meatal stenosis or urethral sacculation was detected during follow-up of the studied group. Almost all cases had cosmetically appealing outlook. Single-staged repair of severe hypospadias using parameatal foreskin-based urethroplasty has passed through different modifications, all aimed at optimizing the outcome (Table).ConclusionNeo-yoke repair for severe hypospadias is a natural development of established one-stage techniques, which resulted in better mid-term outcomes. However, an extended study is needed to declare the long-term results.Summary Table. Development of single-staged parameatal-foreskin based urethroplasty (PFU)AuthorsProcedure nameFlap designStudied seriesResultsOverall success rateComplicationsKoyanagi et al., 1994 [8]Original Koyanagi-Nonomura techniqueTwo parallel parameatal skin flaps extending distally into the inner-face prepuce, supplied solely by perimeatal spongiosal tissue7053%Ischemic long skin flaps resulted in strictures, fistulas, and disruptionsSnow and Cartwright, 1994 [9]Yoke hypospadias repairAll resembled a yoke drawn around the glans penis, being richly supplied by perimeatal spongiosal tissue and preserved preputial vascular pedicle450%2 penoscrotal fistulaEmir et al., 2000 [16]Modification of the Koyanagi technique2080%4 urethrocutaneous fistulaHayashi et al., 2001 [17]Modified Koyanagi repair1470%3 urethrocutaneous fistula3 meatal stenosisHayashi et al., 2007 [15]Neo-modified Koyanagi techniqueDivided the yoke at 12 o'clock to the root of penis, then rotated ventrally to be sutured to the sides of distally retracted urethral plate1292%1 urethrocutaneous fistula0 meatal stenosisPresented studyNeo-yoke repairThe urethral plate with its spongiosal tissue being retracted proximally, a circum-coronal yoke in the middle, and interdigitation of dorsally augmented preputial flap and V-shaped glanular urethra, distally3184%4 urethrocutaneous fistulas1 meatal drop-back