It is estimated that 2 to 6 percent of men who have had a vasectomy eventually request a microsurgical vasectomy reversal each year. In the U.S., the most common reason given for seeking reversal is remarriage following a divorce. Prior to the advent of microsurgical methods, the outcome of vasectomy reversals were comparatively inferior; successful pregnancy rates ranged from 5 to 30 percent. The technical challenge of producing a precise, leakproof surgical connection of structures with widths of three tenths of a millimeter was daunting. Microsurgical vasectomy reversals today return sperm to ejaculate in greater than 90 percent of men, and pregnancy rates in the partner of more than 50 percent.
In vasectomy reversal, also known as vasovasostomy, the vas deferens tubes which supply sperm in the ejaculation are reconnected. During the reversal, the surgeon examines the fluid contained in the vas tubes for the presence of sperm. This makes sure that they are healthy, normal and mobile. Once this is confirmed, the tubes are rejoined. Since the vas deferens tubes are so small, the use of optical magnification throughout the microsurgery vasectomy reversal is vital.
The Microdot Technique
Developed at Cornell University to improve the vasovasostomy procedure, the microdot technique guarantees accurate placement of sutures by exactly mapping each suture that is planned. If sperm are found in the fluid in the vas, this technique returns sperm to the ejaculate in 99.5% of cases.
This method is a two step process. Separating the pre-planning of suture positions from the physical operation of suture placement, much as an engineer draws up plans for a skyscraper before it is built, suture placement planning is decisive to a successful surgical outcome. This lets the surgeon focus on one task at a time during suture placement. Microtip skin-marking pens are used to mark out intended needle exit points.
To give an idea of the complexity of this operation, six monofilament nylon sutures are used for every connection of the mucosal layer, always resulting in a water-tight closure, even when the diameters of the vas tubes being joined are significantly different. Following completion of the mucosal layer portion, six deep muscular sutures are placed midway between mucosal sutures, not penetrating the mucosa. A third layer of six additional nylon sutures are then sewn between each muscular suture. The connection is then completed by simulating the vasal sheath using six interrupted sutures of polydioxanone, entirely covering the connection and mitigating any tension; this is the fourth layer, for a total of 24 sutures.
Microsurgical vasoepididymostomy is an even more technically demanding procedure than vasovasostomy. A vasoepididymostomy is performed at the time of vasectomy reversal, if after examination of the fluid in the vas, sperm is determined to be not present. This will usually be due to an obstruction in the epidymis, which is situated between the testis and the vas. The procedure is also performed in other situations than vasectomy reversal, such as azoospermia with epidymal obstruction due to infection or injury.
A microsurgical vasoepididymostomy also involves multiple sets of sutures and the microdot technique of pre-marked placement is frequently used. Several tmethods of connection have been developed, and as this procedure is highly dependant upon the skill and experience of the performing surgeon, each has their preferred method.