Analysis of spermatozoa from the proximal vas deferens of vasectomized men.

ABSTRACT

PIP: Vasectomy is a widely used birth control method. Although spermatogenesis continues in the testis after vasectomy, the secretion and absorption functions of the epididymis and proximal vas deferens are changed. Spermatozoa stored in the epididymis may therefore be affected. Some men regret having been sterilized and seek to reverse their vasectomy. While the development of microsurgery has increased the success rate of vasovasostomy, the rate at which such men are able to impregnate fertile women remains only in the 50-58% range. Defects of spermatozoa in the epididymis following vasectomization may contribute to this low fertilizing capacity of men who have attempted to reverse the effects of their vasectomy. This study assessed the condition of spermatozoa from the proximal vas deferens of 67 men after vasectomy. Subjects were aged 25-40 years with duration of vasectomy three months to ten years with no chronic medical illnesses. The men's fluids were collected from both proximal vas deferens by cannulating the vas deferens at the time of vasectomy reversal. Selected sperm parameters were then analyzed after incubation of the spermatozoa for 30 minutes at 37 degrees Celsius. Sperm concentration in the proximal vas from vasectomized men was significantly higher than that of fertile men and was maintained at a constant level independent of the duration of vas obstruction. The means of sperm motility, spermatozoa with morphology, sperm viability, and hypo-osmotic swelling test were statistically lower than the respective values for normally fertile men, while no significant correlation was observed between the duration of vas obstruction and the above semen parameters. In 46.4% of vas fluids all spermatozoa were immotile, especially after three years of vasectomy, suggesting that immotile spermatozoa in the proximal vas fluids at the time of vasectomy reversal may be an important factor for predicting semen quality and fertilizing ability after vasovasostomy. There were not, however, significant differences in the results of sperm-cervical mucus penetration test between spermatozoa from vasectomized and fertile men. It is noted that the presence of antisperm bodies on the spermatozoa from the vas of vasectomized men, as determined by the immunobead test, may partially explain the lower pregnancy rate after vasovasostomy, with spermatozoa parameters potentially closely reflecting those in the cauda epididymis after vasectomy.