Thousands of men undergo vasectomy each year as a permanent means of birth control, yet for some of these men life brings unexpected turns, which leads them to change their mind. For some, there is a strong desire to have another child a few years later. For others, there may be a tragic loss of a child. For many men, a new marriage brings a new opportunity for creating a family. Regardless of the circum- stances, a vasectomy can be reversed. When a man consents to undergo a vasectomy, he is usually instructed that the procedure should be considered to be permanent and irreversible. This is an appropriate admonishment, because a vasectomy reversal is not 100% guaranteed to work, and it is a significantly more complex operation than a vasectomy. Therefore, before undergoing a vasectomy, a man should be as sure as possible that he is finished having children. Nonetheless, even the most insightful, thoughtful decision can ultimately prove wrong. When that decision is a vasectomy, a man may still change his mind.

What is a vasectomy?
To understand the vasectomy reversal, it is important to understand the vasectomy. A vasectomy is the surgical removal of a small piece of the vas deferens. The vas deferens is the long narrow muscular tube through which sperm travel from the testicle to the urethra. It feels like a piece of undercooked spaghetti in each side of the scrotum. The sperm are produced in the testicle, and then they exit out the top of the testicle and into the epididymis. The epididymis is a very tiny, tightly coiled tubule, which runs along the back of the testicle from top to bottom. It then turns a corner, heading back north towards the pelvis, and becomes the thicker, straighter vas deferens. During ejaculation, the muscular walls of the vas deferens tube contract to propel the sperm up to the urethra of the prostate. In the urethra, the sperm are then joined by fluids from the prostate and then ejaculated out of the penis. When a vasectomy is performed, the doctor feels for these "pieces of spaghetti" and surgically removes a small segment of vas deferens from each side. The cut ends are then clipped, sutured or cauterized. Suddenly, the sperm can go no further than this new point of blockage.

So what happens to all the sperm?
What most men don't realize is that once the vasectomy is performed, sperm production does not stop! Ever! Unlike women, men produce their gametes (sperm) for their entire life. A vasectomy does not stop sperm production, rather it simply blocks the entry of sperm into the urethra. Like other cells, the blocked sperm are eventually broken down by the body and reabsorbed. New sperm are continually being produced. Avariable amount of pressure can build up in the tubes behind the vasectomy scar. In some cases, so much pressure builds up that the tiny tubule of the epididymis can rupture. This is commonly referred to as an epididymal "blow out." If this happens, the site of the blow out develops scar tissue, and this actually becomes the new level of blockage to the sperm. This is neither painful or dangerous, but it is significant in that for a vasectomy reversal to be successful, it must be performed in such a way that bypasses this new level of blockage at the epididymal blow out site.

Technique of vasectomy reversal:
Avasectomy reversal is the rejoining of the blocked tubes. In cases where there is no excess pressure build up and no epididymal blow out has occurred, the vas deferens can be rejoined to the vas deferens. This is called a vaso-vasostomy. The surgery is technically challenging, and it is performed with an operating microscope utilizing sutures which are finer than a human hair. The vas deferens is reconnected so as to precisely line up the inner passage ways which are a much smaller diameter than the outer wall of the vas deferns itself. In cases where there has been an epididymal blow out, the vas deferens north of the vasectomy scar must be rejoined with the epididymal tube (tiny and tightly coiled) south of the blow out scar. This procedure is called a vaso-epididymostomy. This surgery is even more technically challenging than a vaso vasostomy and should only be performed by a microsurgeon experienced with this procedure. An epididymal blow out is diagnosed during surgery by examining the fluid from the cut end of the vas deferens under a microscope. Because an epididymal blow out cannot be accurately diag- nosed until the time of surgery, it is important for the patient to select a surgeon ahead of time who can perform this procedure. Vasectomy reversal is typically perormed with general anesthesia, and the patient goes home the same day. The recovery is typically rapid, but only light duty work and refraining from heavy exercise or sex is recommended for the first two to three weeks.

Success rates:
Success rates for vasectomy reversal are surprisingly good. A variety of factors determine the outcome for an individual patient. In cases where there is no epididymal blow out, the fluid from the cut end of the vas deferens has motile sperm, the time interval since vasectomy is moderate (less than 10 years), and the procedure is performed by a skilled microsurgeon, success rates approach 95%. If the time interval is greater than 15 years, the success rate is about 75%. In cases where vaso-epididymostomy is required, the success rates are closer to 75%. Success, in this case, is defined as restoration of sperm to the ejaculate. Actual pregnancy rates are less: 75% for vaso-vasostomy and about 40% for vaso-epididymostomy. The lowered pregnancy rates are due to a variety of biological variables including female infertility factors as well as a 15% incidence of clinically significant antisperm antibodies.

Alternatives:
An alternative to vasectomy reversal is minimally invasive sperm retrieval. This sperm cannot be used for artificial insemination. It must be injected directly into the woman's eggs (Intracytoplasmic Sperm Injection-ICSI) as part of an in-vitro fertility (IVF) cycle. This alternative is more appropriate for some couples. In cases where there is no female infertility factor and the time since vasectomy is less than 15 years, vasectomy reversal is clearly recommended over sperm retrieval with IVF/ICSI by both the American Society for Reproductive Medicine and the American Urological Association.