RECONSTRUCTIVE UROLOGY

One-sided anterior urethroplasty: a new dorsal onlay graft technique
Kulkarni S, Barbagli G, Sansalone S, Lazzeri M
Centre for Reconstructive Urethral Surgery, Pune, India
BJU Int. 2009; 17 [Epub ahead of print]

• Objective: To investigate the feasibility, tolerability, safety and efficacy of using a new surgical technique for the repair of anterior urethral strictures to preserve vascular supply to the urethra and its entire muscular and neurogenic support.
• Patients and Methods: In all, 24 patients (mean age 46 years) underwent a new one-sided anterior dorsal oral mucosal graft urethroplasty while preserving the lateral vascular supply to the urethra, the central tendon of the perineum, the bulbospongiosum muscle and its perineal innervation. The cause of stricture was instrumentation in three cases (12%), unknown in five (21%), infection in four (17%), and lichen sclerosus in 12 (50%). The stricture site was bulbar in 12 cases (50%) and panurethral in 12 (50%). The mean stricture length was 4.2 cm in patients with bulbar strictures and 10 cm in patients with panurethral strictures. Of 24 patients, 20 patients (83%) had received previous treatments. Clinical outcome was considered a failure when any postoperative instrumentation was needed, including dilatation.
• Results: The overall mean (range) follow-up was 22 (12-55) months. Of the 24 patients, 22 (92%) had a successful outcome and two (8%) were failures. One failure was treated using definitive perineal urethrostomy and another failure underwent successful internal urethrotomy.
• Conclusions: The preservation of the one-sided vascular supply to the urethra and its entire muscular and neurogenic support should represent a slight but significant step toward perfecting the surgical technique of urethral reconstruction using a minimally invasive approach.
  
  
• Editorial Comment
  The authors describe modifications to the standard substitution anterior urethroplasty that help preserve the bulbospongiosum muscle and perineal nerve fibers. Previously, Yucel and Baskin showed that perineal nerves innervate the bulbospongiosus muscle and send fine branches that penetrate the corpus spongiosum, mainly in the bulbar area. Moreover, these authors demonstrated that branches of the dorsal nerve of the penis at the junction of the corpus cavernous and corpus spongiosum assemble into a network with the perineal nerves (1). Contraction of the bulbospongiosum and ischiocavernosal muscles help propel the ejaculate out of the urethra. The contraction of those is thought to help prevent urine pooling at the end of voiding. The perineal nerve endings provide sensation to the scrotum, perineum and ventral penis and frenulum. Given that the risk of weakness of ejaculation is reported to be up to 39% after substitution urethroplasty, and post void dribbling in up to 50%, the role of muscle preservation during urethroplasty has been the subject of a lot of interest.
  Both series report success rates that are comparable to the published rates of about 90%. No post void dribbling or semen sequestrations were reported in up to 12 months of follow up in the first study, while the second study lacks data on erectile or ejaculatory dysfunction.
  There are inherent limitations to both studies especially in the fact that they lack a control group comparison, and randomization was not performed. It would be of interest to evaluate whether the preservation of the one-sided vascular supply to the urethra and its entire muscular and nerve support or limiting the dissection to the midline would decrease morbidity from ejaculatory and erectile dysfunction in a setting of a randomized controlled trial. Still, both studies are major steps in the refinement of the technique of minimally invasive urethroplasty. It remains to be seen whether this anatomical preservation of the neurovascular supply and muscular support is going to translate into decreased morbidity.

Reference
1. Yucel S, Baskin LS: Neuroanatomy of the male urethra and perineum. BJU Int. 2003; 92: 624-30.

Dr. Sean P. Elliott
Department of Urology Surgery
University of Minnesota
Minneapolis, Minnesota, USA
E-mail: selliott@umn.edu