AB023. Scrotal exploration and microsurgical vasoepididymostomy in azoospermic patients due to non-vasectomy, non-traumatic etiologies

BACKGROUND: Non-iatrogenic, non-traumatic obstructive azoospermia (OA) includes causes like congenital bilateral absence of vas deferens (CBAVD), blockage at rete testis, or obstruction distal to internal inguinal rings. The blockage could be potentially identified at scrotal exploration and corrected with microsurgical vasoepididymostomy (VE). The purpose of this study is to analyze patients with non-iatrogenic, non-traumatic OA who underwent scrotal exploration with or without VE anastomosis in our institution. METHODS: Retrospective chart review was done for patients treated from 2000 to 2015. Normal spermatogenesis confirmed by testis needle biopsy in all patients with OA. The operation method for VE anastomosis was two-stitch longitudinal intussusception technique. Patients who had prior vasectomy or history of vas deferens trauma/injury were excluded. The age, hormone profile, semen parameters, level of obstruction, semen quality at proximal epididymal cut-end and patency rates were analyzed. RESULTS: Totally 96 patients with mean age 35.4±5.6 y/o were collected. The obstruction level was at: bilateral rete testis blockage (n=17), bilateral epididymis (n=49), bilateral intra-abdominal blockage (n=7), CBAVD variants (n=3). There were 68 patients received VE anastomosis. The patency rates 6 months after operation for patients with bilateral epididymal blockage were 88%. They were 90.9% for blockage at both epididymal tails, 88.9% at epididymal body, and 83.3% at epididymal head. Motile sperm at proximal cut-end had patency rates at 80.6%, while they were 50% in cases showing only immotile sperm. The mean patency rates were 79.5% for all cases 6 months after operation. Twenty-eight percent of patients failed to proceed the correction procedure, including 25% with high or low blockage, and 3.1% with CBAVD variants. Patients with CBAVD variants showed lower semen pH (6.67±0.1, P=0.001). CONCLUSIONS: For patients with non-iatrogenic non-traumatic OA receiving scrotal exploration, 28.1% are not eligible for correction. The mean patency rates for all patients 6 months after micro-anastomosis were 79.5%. They were 90.9% and 88% for cases with obstruction at bilateral epididymal tails and body respectively. Motile sperm in proximal end predicts higher patency rates.