Obstructive infertility: changes in the histology of different regions of the epididymis and morphology of spermatozoa.

In the present study, the effects of prolonged obstruction in different regions of the human epididymis on its histology and on the spermatozoa retained at the site of obstruction were assessed. Men who were confirmed of having obstruction of the epididymis underwent vasoepididymostomy (VEA) for surgical correction of the obstruction. At the time of surgery, fluid from the epididymal tubule above the site of obstruction was aspirated and examined for sperm profile. Epididymal tissue, collected at the site of obstruction, was processed for assessment of histological changes and also used to identify the site of obstruction. Prolonged obstruction of the epididymis has caused degeneration of the epididymal epithelium, gradual decrease in the diameter of the tubule and tubular lumen and increase in the intertubular connective tissue. Sperm aspirated from the caput epididymal fluid showed sluggish pattern of motility only in one out of the six subjects, whereas spermatozoa collected from the cauda epididymal fluid showed rapid linear progressive motility in one of three subjects. A major percentage of spermatozoa in the aspirated fluid showed various types of morphological abnormalities, irrespective of the site of obstruction. These results are discussed in relation to the role of the epididymis in investing spermatozoa with motility and fertilizing capacity.