Vasectomy reversal is used to repair the continuity of the vas deferens in men who have previously been sterilised. Approximately 1% of men who have had a vasectomy subsequently want to have it reversed. Other blockages in the vas deferens or epididymis (where the sperm are stored) caused by breakages or inborn defects can also be repaired in the same way.

There are two different possibilities for a repair operation: re-attachment of the loose outer ends of the vas deferens (vaso-vasostomy) or, if that does not work, connecting one outer end of the vas deferens to the epididymis (vaso-epididymostomy).

In an operation in which the two outer ends of the vas deferens are re-attached (vaso-vasostomy), the surgeon stitches the inner and outer layers of the vas deferens to each other again. In this procedure the continuity of the vas deferens is restored. Vaso-epididymostomy is a bypass procedure in which the innermost and outermost layers of the vas deferens are attached to the epididymis.

Both surgical procedures are carried out on an out-patient basis under local or general anaesthetic. Semen analyses have to be carried out six weeks, 12 weeks and every three to four months after the procedure to see whether sperm cells are present in the seminal fluid. Recurrent checks are needed to be sure that possible scar tissue from the surgery does not itself block the vas deferens or the epididymis.

If no sperm has appeared one year after the surgery, the procedure must be viewed as having failed.

With both procedures, the repair of the tissue takes almost three weeks. Because the structures are so small, the scar tissue from the surgery can cause a new blockage.

Although rare, haemorrhages can occur and cause swellings and infections.

These surgical interventions do not always have the desired result. Depending on how long the vas deferens and the seminal vesicles have been blocked, it may be that the patient’s ejaculation still does not contain sperm cells after the surgery. Many men produce anti-sperm antibodies after a vasectomy, which can have an adverse effect on the sperm’s ability to move through the woman’s mucous.

If a man’s vasectomy was performed less than three years ago, there is a good chance fertility is restored. The sperm returns in 95% of such men and the pregnancy rate is 75%. If more than 15 years have passed, the respective percentages are 70% and 30%.