When the level of epididymal obstruction is clearly demarcated by the presence of markedly dilated tubules proximally and collapsed tubules distally, the site at which the anastomosis should be performed is readily apparent. The end-to-side approach has the advantage of allowing accurate approximation of the muscularis and adventitia of the vas deferens to a precisely tailored opening in the tunica of the epididymis. This is the preferred technique when vasoepididymostomy is performed simultaneously with inguinal vasovasostomy because it is possible to preserve the vasal blood supply deriving from epididymal branches of the testicular artery. This provides blood supply to the segment of vas intervening between the two anastomoses. Maintenance of the deferential artery's contribution to the testicular blood supply is also important in situations where the integrity of the testicular artery is in doubt due to prior surgery such as orchidopexy, non-microscopic varicocelectomy or hernia repair.
The testis is delivered through a 3-4 centimeter high vertical scrotal incision. The vas deferens is identified, isolated with a Babcock clamp and then surrounded with a Penrose drain at the junction of the straight and convoluted portions of the vas deferens. Using 8-15 power magnification provided by the operating microscope, the vasal sheath is longitudinally incised with a micro-knife and a bare segment of vas stripped of its carefully preserved vessels is delivered. The vas is hemi-transected with the ultrasharp knife until the lumen is entered. The vasal fluid is sampled. If microscopic examination of this fluid reveals the absence of sperm, the diagnosis of epididymal obstruction is confirmed. Patency of the vas and ejaculatory ducts is confirmed by cannulating the abdominal end of the vas with a 24 g angiocatheter sheath and gently injecting lactated Ringer’s solution with a 1 ml tuberculin syringe. Further confirmation of patency may be obtained by injecting indigo carmine, catheterizing the bladder and observing blue tinged urine. The vas is then completely transected using a 2.5 mm slotted nerve clamp and the vas is prepared as for vasovasostomy as described earlier.
After opening the tunica vaginalis, the epididymis is inspected under the operating microscope. An anastomotic site is selected above the area of suspected obstruction, proximal to any visible sperm granulomas, where dilated epididymal tubules are clearly seen beneath the epididymal tunica. A relatively avascular area is grasped with sharp jeweler’s forceps and the epididymal tunica tented upward. A 3-4 mm bottonhole is made in the tunica with microscissors to create a round opening that matches the outer diameter of the previously prepared vas deferens. The epididymal tubules are then gently dissected with a combination of sharp and blunt dissection until dilated loops of tubule are clearly exposed, If the level of obstruction is not clearly delineated, after the buttonhole opening is made in the tunic, a 70 µm diameter tapered needle from the 10-0 nylon microsuture is used to puncture the epididymal tubule beginning as distal as possible and fluid sampled from the puncture site. When sperm are found, the puncture sites are sealed with micro-bipolar forceps, a new buttonhole made in the epididymal tunic just proximally and the tubule prepared as described previously. The vas deferens is drawn thru an opening in the tunica vaginalis and secured in proximity to the anastomotic site with 2 to 4 interrupted sutures of 6-0 polypropylene placed through the vasal adventitia and the tunica vaginalis. The vasal lumen should reach the opening in the epididymal tunica easily, with length to spare. The posterior edge of the epididymal tunica is then approximated to the posterior edge of the vas muscularis and adventitia with two to three interrupted sutures of double-armed 9-0 nylon .This is done in such a way as to bring the vasal lumen in close approximation to the epididymal tubule selected for anastomosis.