Urethral Extensibility Applied to Urethral Advancement

BACKGROUND: The male urethra in humans has a large capacity to extend under traction. This property is the main principle of the urethral advancement technique. AIM: We aimed to determine the safe limits of urethral mobilization and extensibility for reconstructive surgery of distal to midshaft hypospadias by applying urethral extensibility on the urethral advancement technique. Also, we wanted to evaluate the variable application of the gap-to-urethra (G:U) ratio from a cadaver to a live human body. METHODS: From November 2004 to February 2006, 20 boys aged from 2 to 16 years old underwent repair of midshaft to glanular hypospadias by urethral advancement technique. The ratio of G:U proposed for a safe limit of urethral extensibility (measured from normal, fresh human cadaveric urethras) applied to know if its application can help in decreasing the rate of late complications. The mean follow-up period was 10 months, which ranged from 4 to 16 months. RESULTS: Late complications were as follows: 25% meatal retraction (MR), 15% meatal stenosis (MS), and 5% fistula. Besides, MR and MS late complications associated with urethral mobilization of G:U ratio of less than 73%. CONCLUSION: The more the approximation in the application of the G:U ratio, the less the rate of MS and MR. Besides, urethral mobilization to the base of the penis helps to decrease the frequency of MS and MR. Furthermore, the type of complication, MR or MS, in urethral advancement correlates with the extent of urethral mobilization.