Vasectomy is a minor surgical procedure for permanent male fertility control, performed on over 500,000 men each year in the United States. The duct which carries sperm from the testicle (called the vas deferens) is cut and sealed in order to prevent sperm from leaving the testes. The vas deferens measures about 1/10th of an inch in diameter (2.5 mm), the majority of which is a thick muscular wall. The actual channel (or lumen) for the sperm measures less than 1/100th of an inch (0.25 mm).
The testes continues to manufacture sperm after vasectomy—this is what makes vasectomy reversal feasible. The challenge is to reconstruct the duct system, which is very tiny. While the vas is very easy to cut, it is much more difficult to successfully reconnect.
After vasectomy, there is continued production of a small amount of sperm fluid from the testes. This results in a slight increase in pressure in the vas below the site of the vasectomy, which over time will stretch the inside of the vas duct. As a result, the inside diameter of the vas below the vasectomy site is often 3-5 times larger than the original diameter above the vasectomy.
As the vas deferens gets closer to the testes (below the vasectomy site), its thick muscular wall disappears, and it merges into a structure called the epididymis. This portion of the duct is attached to the testes, and it contains nearly 20 feet of a delicate, coiled microscopic tubule. Back pressure from the vasectomy may cause this delicate tubule to become extremely thin and rupture over time. When this occurs, the resulting inflammation will cause scarring and a secondary blockage point below the vasectomy site. This problem becomes more likely as the time after vasectomy increases.
While most men have few problems after vasectomy, a small percentage will experience pain, either intermittently with sexual activity, or in some instances, on a chronic basis. When this occurs, it can be a difficult problem to overcome. Surgery to reverse the vasectomy is often the best solution to this frustrating situation.