The typical straightforward vasectomy reversal is known as a vasovasostomy. This means that the portion of the vas deferens that was blocked with the previous vasectomy is excluded, and the ends above and below this area are sutured back together. Depending on the part of the vas deferens that the repair is made in, the opening that is being connected is between 0.7 mm and 0.4 mm in diameter, about the size of the period at the end of this sentence. In men who have had a longer time frame since the time of their vasectomy when they choose to have their vasectomy reversal (especially in men when it has been longer than 15 years), or in men who’s blockage from the vasectomy is very low on the vas deferens near the testicle, it may not be possible to perform a vasovasostomy, and a vasoepididymostomy may be required.
Vasoepididymostomy is a much more technical challenging procedure and should only be performed by specialty trained reproductive urologists with microsurgical expertise. This is a microsurgical procedure where the abdominal (upper) end of the vas deferens has to be connected to a tubule of the epididymis (the comma shaped structure on the testicle connected the testicle to the vas deferens, where sperm learn how to swim and mature), rather than connecting one end of the vas deferens to the other end of the vas deferens, as would be done with a vasovasostomy. The opening that is made in the tubule of the epididymis to connect is about 1/10th of that made for a vasovasostomy, so it requires a much higher and more delicate level of microsurgery.
The decision on who needs a vasovasostomy versus a vasoepididymostomy is made at the time of surgery depending on intraoperative findings. So how does the surgeon decide? Prior to making the connection for a vasectomy reversal, the reproductive urologist should take fluid from the testicular end of the vas deferens and examine it under the microscope to look for sperm and decide from there. Based on the best data on vasectomy reversal outcomes, this decision is made by the following intraoperative findings including the appearance of the fluid from the testicular end of the vas deferens and the presence or absence of sperm in the fluid. If the fluid reveals sperm with tails, a vasovasostomy is performed. If the vas is dry, there is no fluid, and no sperm; a vasoepididymostomy should be performed. If the fluid is thick, white, and toothpaste like and no sperm are seen microscopically, a vasoepididymostomy should be performed. If there is copious, clear fluid with no sperm, vasovasostomy is performed. If there is thick fluid with many sperm heads, vasovasostomy should be performed. There are findings in each individual case which direct the decision making on which should be performed, but because it is impossible to predict for sure which type of vasectomy reversal will be required prior to surgery, it is recommended that only fellowship trained reproductive urologist with high levels of microsurgical expertise perform vasectomy reversals, because one cannot be certain when a higher level vasoepididymostomy may be required ahead of time. Dr. Kavoussi published a study revealing that patient characteristics preoperatively cannot accurately predict who will need which type of reversal prior to surgery.
To read this article click on: http://www.fertstert.org/article/S0015-0282(08)00973-4/fulltext
To read more about vasectomy reversals, click on the following for the review article published by Dr. Kavoussi: https://www.wjgnet.com/2219-2816/full/v4/i1/48.htm