Table of Contents
Even though tubes are re-opened and sperm is restored in as many as 85% of men who undergo vasovasostomy, pregnancy is not guaranteed. Several factors may play a role in the failure of reversal surgery.
Epididymis Obstruction. If the sperm count does not recover within a reasonable period after vasovasostomy, it is often due to blockage from scarring that has occurred in the epididymis. This sometimes can be corrected with a second procedure. The doctor may be able to detect obstruction before the vasovasostomy by pressing and manipulating (palpating) the epididymis. If any part seems swollen or larger than other parts, an obstruction is very likely to be present and the patient is likely to need a vasoepididymostomy, which creates a bypass around the obstruction.
Antisperm Antibodies. In many cases in which vasovasostomy fails, the reversal procedure reopens the tubes but fertility is impaired because of a process called autoimmunity. With this condition, important immune factors called antibodies attack the body's own cells, mistaking them for antigens (any foreign microinvader that the immune system perceives as a threat).
In the case of vasectomy, the autoantibodies attack the sperm, and so are called antisperm antibodies. Such antibodies develop when sperm continue to be produced after vasectomy, but, instead of being confined to the reproductive passages, they leak out into the body. Once out of their natural habitat, the immune system perceives them as foreign invaders and develops antibodies to attack them.
The antisperm antibodies bind to specific parts of the sperm (the head or tail) and cause problems depending on the site of attachment. Sperm may stick together (agglutinate), fail to interact with the woman's cervix, or fail to penetrate the egg. Even after vasovasostomy, such antibodies often persist.
Oxidation. The immune factors that trigger the autoimmune process may have other harmful effects as well. In a process called oxidation, they can trigger the release of particles called free radicals, highly reactive oxygen molecules that, in excess, can do considerable damage to cells and genetic material. When high levels of free radicals persist after a vasectomy, they may, in theory at least, injure sperm DNA, contributing to infertility.
Previous Section
Review Date: 10/20/2006
Reviewed By: Harvey Simon, M.D., Editor-in-Chief, Associate Professor of
Medicine, Harvard Medical School; Physician, Massachusetts General
Hospital
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)
