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Family Health International |
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Additional Vasectomy Technique Recommended -- December 14, 2001 WASHINGTON -- Preliminary results from a vasectomy study in seven countries show conclusively that a surgical technique known as fascial interposition leads to a more rapid decrease in sperm counts, which may improve the effectiveness of some methods of vasectomy or male sterilization. The lower sperm counts occurred when fascial interposition was used with simple ligation and excision. The study was conducted by Family Health International (FHI), based in Research Triangle Park, NC, and EngenderHealth, based in New York, NY, and announced today at the annual meeting of the Association of Reproductive Health Professionals (ARHP). "Individuals all over the globe want and rely on permanent methods of contraception, making male and female sterilization the number one family planning method in the world," maintains Amy E. Pollack, M.D., M.P.H., president of EngenderHealth. "It is crucial that we continually work to improve the quality of vasectomy services and techniques, as vasectomy is the only permanent method available to men." "This new study indicates that some physicians providing vasectomy services should consider modifying their technique," reports David C. Sokal, M.D., Associate Medical Director at FHI. "Physicians who are currently practicing simple ligation and excision should strongly consider modifying their technique to include fascial interposition." During the study, when fascial interposition was used along with ligation and excision of the vas, about 93 percent of men had reached a low sperm count (less than 100,000 sperm per milliliter of semen) by 22 weeks after surgery compared to 81 percent of men without fascial interposition. Men who have not undergone vasectomy typically have between 20 million and 150 million sperm per milliliter of semen. Family planning handbooks typically describe vasectomy as nearly perfect, better than 99 percent effective at preventing pregnancy. However, different ways of performing a vasectomy may result in slightly different pregnancy rates. This study did not look at pregnancy rates, but it is likely that the risk of pregnancy would be higher among women whose partners take longer to reach a low sperm count. It is estimated that about 9 percent of vasectomies in the United States are done using simple ligation and excision, but that this method is much more commonly used in developing countries. The ongoing research, which began in 1999, is being carried out in Brazil, El Salvador, Nepal, Mexico, Panama, Sri Lanka and the United States. Recruitment of new participants into the FHI/EngenderHealth study was halted in May of 2001 because of the striking difference found in the preliminary or "interim" analysis based on an analysis of findings from 552 men. The men already in the study have been getting frequent semen analyses, and are advised to continue using condoms or another form of contraception until their sperm counts reach zero. One pregnancy has been reported among the partners of the men in the study. That pregnancy occurred in the partner of a man who had persistently elevated sperm counts following a procedure with fascial interposition. Final analysis of the study will be done after all men have completed follow-up. Vasectomy is a permanent form of contraception in which the vasa deferentia — the tubes that carry sperm from the testes — are occluded, by ligation (tying) or other means. In developing countries, ligation and excision of a small length of vas is the most common method of occlusion. In the United States and other high-resource countries where vasectomy is popular, cautery (burning) and/or metal clips, often with fascial interposition, are the most commonly used techniques to occlude the vas. Fascial interposition is a procedure where the sheath covering the vas deferens is pulled over one severed end and sewn shut to create a natural tissue barrier. This study suggests that adding this step may prevent a phenomenon known as recanalization, where the sperm can temporarily or permanently find a way through the healing vasectomy site, causing sperm to persist in the semen. In a related study being released today at the conference, Michel Labrecque, M.D., Ph.D. of Laval University, Quebec, Canada, analyzed clinical data comparing the effectiveness of using tiny clips to seal off the ends of a severed vas, versus fascial interposition plus cautery, where the inside of the ends of the vas are burned shut. Clips alone — usually four in number (one on each end of each severed vas) — resulted in persistent sperm in 7.6 percent of men. However, in cases where fascial interposition and cautery were used, persistent sperm were seen in only 0.1 percent. The Canadian study, in which FHI researchers helped with data analysis, involved more than 3,000 men in Quebec. Using clips may be similar to ligation with suture. If a clip or suture is put on too loosely, the sperm can leak out of the vas and may persist in the semen. If a clip or suture is put on too tightly, it will cause necrosis of the vas and the end will drop off, again letting the sperm leak out of the end of the vas. Results from another vasectomy study, released in Nepal earlier this year and also reported at this conference, complement the findings from the seven-country study by providing data on pregnancy rates. The study by the Ministry of Health, His Majesty's Government of Nepal, in collaboration with FHI, estimated a first-year pregnancy rate of 17 per 1,000 — or 1.7 percent — for ligation and excision vasectomies done in rural areas of Nepal. Pregnancies were more common in younger women, especially under 30 years of age. This contrasts with an estimated first-year pregnancy rate of about 1 to 2 per 1,000 vasectomies in the United States, where (a) different techniques are typically used; (b) men's partners are often older and less fertile at the time of vasectomy; and (c) follow-up semen testing is available. The Nepal study was a cross-sectional survey, involving men who had had vasectomies between one and four years prior to the survey. "Vasectomy is effective, safe, quick to perform, and has few side effects," says Dr. Sokal of FHI. "But even in the United States, where multiple surgical techniques are often used on the same man (clips, cautery and/or fascial interposition), vasectomy is not 100 percent effective. This is especially true if backup contraception and follow-up testing are not done." Dr. Sokal says it is vital that both partners are counseled about the slight risk of pregnancy and are encouraged to follow the recommended precautions. Also, knowing that pregnancy is still possible — though unlikely — may avoid charges of infidelity if a pregnancy does occur. When only simple ligation and excision are used and only a short segment of the vas is removed, numerous sperm may be found in the semen for up to six months in as many as 10 percent of men, but the risk of pregnancy for the partners of these men is not known. In some of these men, high sperm levels continue to be found in the semen, and those men require repeat vasectomies. There have also been cases reported in other studies where the semen samples indicated azoospermia (no sperm present), but a pregnancy occurred months or even years later. Follow-up tests revealed that recanalizations had taken place. Mark Barone, D.V.M., M.S., of EngenderHealth, notes that while some doctors consider fascial interposition to be a simple technique, others feel that it is more difficult, "like trying to sew cotton candy." EngenderHealth and FHI are planning additional studies to examine cautery as an occlusion method. The cautery technique requires more equipment than ligation and excision with fascial interposition, and may pose cost problems for doctors in developing countries. However, the studies reported today suggest that the costs may be justified. Cautery can be done using various devices, including small hand-held instruments powered by AA alkaline batteries. The process of recanalization can begin when sperm from the testicular ends of the vas leak out and cause a mild inflammation. This results in a condition known as a sperm granuloma, which is part of the body's healing process. A granuloma is made up of white blood cells and other cells involved in the healing process. This process can lead to the formation of a honey-combed "bridge" that can eventually connect the two severed ends. Viable sperm can then cross and make their way to the other end. Recanalization is often not a permanent condition. Often, the "bridge" will eventually solidify as part of the wound healing process, and scar tissue (fibrosis) will close off the recanalization. There is relatively little precise data on the frequency or persistence of recanalization after different occlusion methods. The final analysis of the FHI/EngenderHealth study may provide new insights into this process. All the vasectomies in the FHI/EngenderHealth and Labrecque studies were done using the no-scalpel vasectomy (NSV) approach to the vas. The NSV method of vasectomy concerns the approach to the vas, i.e. how the surgeon gets to the vas. The NSV method can be used with various methods of blocking the vas, and it has been shown to have fewer side effects, although it may be a little more difficult for surgeons to learn. This research was supported in part with funds from the U.S. Agency for International Development. For additional information, please contact: Carrie Svingen Kim Best Some of the data presented today were also presented and discussed at an "Expert Consultation On Vasectomy Effectiveness," co-sponsored by Family Health International and EngenderHealth. For a summary of that meeting, click here: http://www.fhi.org/en/fp/fpother/conferences/vascet/vasectomymtg.html or here: http://www.engenderhealth.org/news/newsreleases/010914.html |
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