It involves connection of the severed vas deferens to the epididymis and is more technically demanding than the vasovasostomy.
After the findings from the vasal fluid are reviewed showing epididymal obstruction, the epididymis is exposed by opening the outer testis covering (tunica vaginalis).
[2] With this technique, one, two or three "vest" sutures of 10-0 suture should be placed near the opening of the epididymal tubule to allow the epididymal tubule to "invaginate" into the vas deferens, theoretically creating a connection, that, based on studies in animal models, has an improved watertight seal and possibly a higher chance for success.
The procedure requires anastomosis of a single epididymal tubule (luminal diameter 0.15–0.25 mm) to the lumen of the vas deferens (diameter 0.3–0.4 mm), and is reserved for patients with congenital or acquired epididymal obstruction, or patients who have failed previous attempts at surgical reconstruction of the vas deferens.
This surgery attaches the vas deferens directly to the epididymis, the coiled tube on the back of each testicle where sperm matures.