Research Triangle Park, NC – Modifying a simple ligation and excision technique commonly used in developing countries to perform male sterilization reduces vasectomy failures by about a half, according to a study published today in the journal BioMed Central Medicine.

Final analysis of a vasectomy study conducted among 841 men in seven countries showed that the modification – called fascial interposition – also reduced the time it took for vasectomized men to achieve low sperm counts. The study was conducted by Family Health International (FHI), based in Research Triangle Park, NC, and EngenderHealth, based in New York, NY.

"Vasectomy is a well-established, highly effective contraceptive method," says Dr. David Sokal, principal investigator for the study and an associate medical director at FHI. "But, like most things, it can be improved. This research indicates that physicians now practicing simple ligation and excision should consider modifying their technique to include fascial interposition. This may help some physicians doing vasectomies improve their results."

Failure rates for vasectomies with and without fascial interposition were 5.9 percent and 12.7 percent, respectively. Notably, failures rates were not based on pregnancies, but rather on semen analyses and some of the men initially classified as vasectomy failures were deemed successes later on, based on subsequent semen analyses. The number of vasectomy failures in all age groups was similar. No significant differences in terms of safety (adverse events, or mild or moderate scrotal pain at 12 months post-vasectomy) were noted for the two techniques. All vasectomies were performed by experienced practitioners.

This study, the first published large randomized controlled trial of a technique to block the vas deferens (the two tubes that carry sperm from the testicles to the penis), resolves some of the conflicting results from earlier studies of fascial interposition, Dr. Sokal says.

Presentation of these results at a meeting of vasectomy experts in December 2003 in Washington, led to the recommendation that training of vasectomy providers emphasize the potential increased effectiveness of adding fascial interposition to the standard technique of ligation and excision. Experts also recommended that providers now using simple ligation and excision consider adopting fascial interposition, with appropriate training as needed. The meeting, cosponsored by FHI and EngenderHealth, was attended by 55 representatives from 24 reproductive health research, service delivery, training, advocacy, and donor organizations and institutions, as well as universities.

During simple ligation and excision vasectomy, a short piece of the vas deferens is cut and removed, and the remaining two ends are tied. Fascial interposition involves pulling the sheath covering the vas deferens over one severed end, then sewing it shut to create a natural tissue barrier. The study results suggest that adding this step can prevent a phenomenon known as recanalization, in which sperm can temporarily or permanently find a way through the healing vasectomy site, causing sperm to persist in the semen.

Fascial interposition added approximately two minutes to the simple ligation and excision procedure. In the study, physicians reported that 14 percent of procedures involving fascial interposition were difficult to perform, but in only nine cases – 2 percent of 419 men – were the practitioners unable to perform the fascial interposition technique on one or both vas.

This final analysis confirms an interim analysis that showed a striking difference in sperm counts between men who underwent simple ligation and excision and those who underwent ligation and excision plus fascial interposition. Eighty-one percent of men reached a low sperm count (less than 100,000 sperm per milliliter of semen) by 22 weeks after simple ligation and excision, compared to 93 percent of men after ligation and excision with fascial interposition. As a result of those dramatic interim findings, recruitment of new participants into the study was halted in May of 2001.

In the United States, about 70 percent of physicians use cautery as part of the vasectomy procedure. Worldwide, however, ligation and excision – with or without fascial interposition – is the most common method of vas occlusion.  Some experts think cautery is a more effective technique, and that the combination of cautery and fascial interposition is the most effective method of vas occlusion.

For more information about vasectomy, see FHI's topic page on vasectomy and http://www.engenderhealth.org/wh/fp/cvas2.html.

Published Sources:

Sokal D, Irsula B, Hays M, et al. Vasectomy by ligation and excision, with or without fascial interposition: a randomized controlled trial. BMC Medicine 2004;2:6. Available online.

Chen-Mok M, Bangdiwala SI, Dominik R, et al. Termination of a randomized controlled trial of two vasectomy techniques. Controlled Clinical Trials 2003;24(1):78-84.

Sokal DC, Irsula B, Chen-Mok M, et al. A comparison of vas occlusion techniques: cautery vs. ligation and excision with fascial interposition. [Abstract] Contraception 2003;68:143. Presented at the Annual Meeting of the Association of Reproductive Health Professionals, September, 2003.

Family Health International is dedicated to improving lives, knowledge, and understanding worldwide through a highly diversified program of research, education, and services in family health and HIV/AIDS prevention and care. Since its inception in 1971, FHI has formed partnerships with national governments and local communities in countries throughout the developing world to support lasting improvements in the health of individuals and the effectiveness of entire health systems.
Founded in 1943, EngenderHealth is a nonprofit organization that has been working internationally for more than 30 years to support and strengthen reproductive health services for women and men worldwide. Since its inception, its work has improved the health and lives of more than 100 million individuals in 90 countries.