The modified Ulaanbaatar procedure: Reduced complications and enhanced cosmetic outcome for the most severe cases of hypospadias

Introduction/objective: Proximal hypospadias is one of the most challenging conditions that pediatric urologists have to deal with. Many procedures have been devised over the years, but nothing has been proven to be the best option. Although there have been some attempts at correcting severe hypospadias in one procedure, most have advocated a staged approach. The classic approach - laying penile skin or a graft within a split glans followed by glanuloplasty at the second stage - by definition requires two operations on the glans. In the Ulaanbaatar procedure the distal glanular urethra is constructed at the first stage, allowing for a single glans procedure and thus potentially better cosmetic outcomes. The present study discusses experience with the Ulaanbaatar procedure for severe hypospadias.

Study design: The study retrospectively reviewed every child who underwent both stages of this procedure at the present institution. It reviewed age, associated diagnoses, surgical technique and outcomes.

Surgical technique: The first stage was analogous to a classic first-stage procedure with regard to division of the urethral plate and correction of penile curvature. However, an island flap of preputial skin was mobilized and tubularized to create the glanular urethra. No attempt was made to bridge the native meatus and this reconstructed urethra, and the remaining penile skin was placed between the two. The second stage was performed 6 months later by tubularizing the penile skin between the two meatuses.

Results: The series consisted of 34 boys. Mean age at surgery was 18.3 months (range 6-118). Nineteen underwent evaluation for genital ambiguity at birth (56%). Thirty (88%) received pre-operative testosterone or human chorionic gonadotropin (HCG). After urethral plate transection, persistent curvature was addressed during the first stage, with dorsal plication in 12 (35%), urethral plate transection alone in six (18%) or ventral grafting with small intestinal submucosa in 16 (47%). Twenty-three boys (67%) had the neourethra tunneled through the glans, and 11 (33%) had the glans split followed by glanuloplasty. Average time between the two stages was 7 months (range 4.0-13.9). Four patients (12%) developed urethral diverticula that required repair. One developed recurrent epididymitis related to an abnormal ejaculatory duct (no stricture) and underwent vasectomy. No patient developed a fistula. Mean length of follow-up was 15.2 months (range 0.3-55.5).

Discussion: This modification of the classic staged hypospadias repair may allow for better cosmetic outcome, since the majority of boys required no formal glanuloplasty. There were reduced complications, perhaps because the urethral defect acted like a controlled fistula, allowing for better tissue healing prior to final urethral reconstruction.