J Pediatr Urol. 2017 May 20. pii: S1477-5131(17)30202-4. doi: 10.1016/j.jpurol.2017.04.017. [Epub ahead of print]
Two-stage flap repair of severe hypospadias: Usefulness of the tubularized incised plate urethroplasty.
Tijani KH1, Idiodi-Thomas HO2, Elebute OA2, Alakaloko FM2, Ojewola RW3, Ademuyiwa AO2.
The use of flaps in the two-stage repair of posterior hypospadias associated with severe chordee has been well established. Despite the almost certain guarantee of flap take, complications such as diverticuli are still relatively high. While different applications of the tubularized incised plate have been described, experience with the application of the technique to the two-stage flap repair is very limited. A previous local review of 15 cases performed at the present institution during the period 1998-2003, using the technique as described by Rekit, revealed fistulae and diverticulum rates of 20% and 27%, respectively. With the primary objective of improving surgical outcome, the midline incision was incorporated into the two-stage flap repair.
MATERIALS AND METHODS:
Between 2004 and 2015, 35 boys (aged 2-15 years) with severe hypospadias that required excision of the urethral plate were operated using the two-stage flap technique. The first stage involved mobilization of preputeal or dorsal penile skin (if circumcised) to the ventral surface, as described by Retik. After a minimum interval of 6 months, the second-stage operation was performed in a way similar to the technique of tubularized incised plate urethroplasty, as popularized by Snodgrass, and involved a preliminary midline incision on the neo-urethral plate followed by tubularization and multilayered closure.
All but one flap took successfully. The outcome was satisfactory in 80% of patients, and there was a fistula rate of 14% ( Summary Table). One patient had a complete breakdown of the flap and was successfully treated about 12 months later by repeating the second stage of the operation. No case of diverticulum or stricture was recorded.
Even though there was a marginal improvement in the fistula rate, the most striking observation was the complete absence of diverticulum or stricture. With a reported incidence rate of 20-63%, different authors have reported diverticulum formation (despite the absence of distal obstruction) to be a major problem of the two-stage flap technique. Attempts by these authors at reducing the risk of diverticulum by reducing flap size have tended to increase the risk of strictures. This has been the main reason given by some authors for abandoning the technique. The main limitations of the present study included the wide age range of the patients and the small sample size.
The inclusion of a midline incision in a two-stage flap urethroplasty for proximal hypospadias appears to prevent the development of diverticulum.