General and anomalous sperm disappearance characteristics found in a large vasectomy series
Alderman, P.M.
Fertility and Sterility 51(5): 859-862
1989
ISSN/ISBN: 0015-0282 PMID: 2707463 DOI: 10.1016/s0015-0282(16)60680-5Document Number: 361149
The records of 5233 vasectomy patients who had had at least 12 ejaculations and had completed semen tests were reviewed to help address the issue of no accepted standard for the time after vasectomy before infertility is achieved. Patients were requested to start semen tests at 3 months postoperatively, after which monthly tests were requested until at least 2 consecutive azoospermic specimens were obtained. This constituted proof of success. If sperm had persisted for more than 6 months after vasectomy, a 3rd such test was requested. patient records provided for up to 10 tests. 4197 (80% of the study group's initial specimens, performed at a median 98 days after surgery, were azoospermic, but 188 of these (45% revealed sperm in the following specimen. At a median 137 days postoperative, 4640 (88.7%) of tests were azoospermic. Azoospermia was not regarded as synonymous with success, for which the criterion was a minimum of 2 negative and consecutive monthly samples. For the study group as a whole, there was a rapid increase with time in the proportion of successful vasectomies, with, for example, 76% of men achieving success at 137 days, 93.3% at the 215th days, and 97.2% by the 301st day. The records of the 8879 men were screened for manifestations of individual anomalous sperm persistence, disappearance, or reappearance. In 8 men, small numbers of sperm appeared intermittently over prolonged periods. These 8 individuals each had 7 or more sequential specimens reported as either "occasional sperm" or azoospermic, with the last appearances of sperm ranging from 297 to 448 days after vasectomy. 5 cases demonstrated either azoospermia or just an occasional nonmotile sperm at the initial semen test, toe be followed in 2 or 3 by substantial concentrations of sperm and then by 1 or more azoospermic tests. 4 men who had had 2 negative and consecutive semen tests, and therefore "successful" operations, were later found to have pregnant partners and significant sperm in their semen. These 4 failures followed their vasectomies by an average of 5.5 years. While for the study group as a whole, sperm disappearance rates were a function of time, the total group contained instances of considerably individual variability. The cause of these variations is unclear.