A vasectomy reversal is most often accomplished by reconnecting the vas deferens (the tubes that carry the sperm) by a procedure called a vasovasotostomy. As the interval from vasectomy increases, especially when more than eight years, a procedure called a vasoepididymostomy may need to be preformed.
The epididymis is a tightly coiled tube, measuring about 6 meters (20 feet) in length, and lies tightly packed within the scrotum. Each epididymis attaches to its testis and then descends along the posterior (back) side of the testicle. As the end or terminal portion or the epididymis is less coiled and thicker it becomes the vas deferens. Functionally, the epididymis stores spermatozoa before ejaculation and propels spermatozoa towards the urethra during ejaculation.
After a vasectomy there is often a build-up of pressure because of blockage at the vas deferens. This increased back-pressure in the epididymis may cause “epididymal blowout” or “rupture,” which results in scarring and blockage of the epididymal tube. This is painless and unknown to the patient until surgery is performed to reverse the vasectomy. If there is sperm at the site of the vasectomy or clear fluid, the blockage is probably at the vas deferens, and a vasovasostomy will be performed. If there is no sperm and the fluid is cloudy white at the time of the vasectomy, there is most likely a blockage in the epididymis above the blockage (i.e. vasoepididymostomy). A decision on whether or not a vasovasostomy is necessary is made during surgery. If at all likely blocked, a vasovasostomy will not help and an vasoepididymostomy is necessary.
There is a 90% chance of sperm in the ejaculate after a vasovasostomy and a 50-70% chance of sperm in the ejaculate after a vasoepididymostomy. The success rate varies based on several factors, including the interval from vasectomy. The pregnancy rate will also vary depending on the fertility potential of your partner.