BERKELEY, CA (UroToday Inc.) - Vasectomy is a male surgical sterilization procedure in which a segment of vas deferens is removed to prevent sperm from passing freely through the reproductive tract. Vasectomy is common method of contraception and thought to represent 5% to 10% of all contraceptive methods. A post-vasectomy semen analysis (PVSA) is the accepted method for determining the success or failure of the procedure. PVSA is performed to determine whether any sperm persists in the ejaculate of men after the procedure. The exact protocol used for PVSA is not universal and vary substantially among practitioners in the end points accepted (azospermia vs. only non-motile sperm) and the number and timing of tests.

In a recent review from T. Griffin and colleagues from Woodville, Australia, evidence based recommendations of the appropriate protocol for post-vasectomy testing to confirm sterility (i.e. achieve azospermia) based on systematic assessment of the peer reviewed literature. The review is published in the July, 2005 issue of the Journal of Urology.

A MEDLINE search was performed for all articles concerning PVSA up to and including March 2003. A total of 56 studies were included in the review. Analysis of results revealed that the median percent of patients not providing any PVSA was 19%. When the PVSA was obtained 3 months or greater after the procedure, the percentage of azospermic samples was consistently greater than 80%. In addition, more then 80% of men demonstrated azospermia after having between 11 and 20 ejaculations. Several studies showed that in some men who achieved a PVSA that demonstrated azospermia, a rare but present number of patients had the reappearance of sperm.

After data analysis, the review showed that the evidence presented supported a post-vasectomy testing protocol of one semen analysis that occurs after 3 months and after at least 20 ejaculations. The protocol recommended in this study has the potential to substantially decrease the cost of PVSA. Vasectomy failures can reliably be detected if the 3 month post-procedure semen analysis fails to show azospermia.

J Urol. 2005 Jul; 174(1):29-36