AZOOSPERMIA II: EXCURRENT DUCT OBSTRUCTION
Excurrent ductal obstruction results in azoospermia from blockage of the ductal system after sperm exit the testicle. The posttesticular reproductive tract includes the epididymis, vas deferens, seminal vesicles, and associated ejaculatory apparatus (see Plate 3-3). Ductal obstruction can be due to congenital or acquired causes. In cases of idiopathic obstruction, 65% of blockages will be found in the epididymis, 30% in the vas deferens, and 5% at the level of the ejaculatory duct. Rarely, intratesticular obstruction of testis efferent ductules (see Plate 3-3) may occur.