The Study Of Establishment Of Testis Transplantation Model And Mechnism Of Graft Injury In Rats

Rat testis transplantation with a segment of donor abdominal aorta end-to-side anastomosed to recipient's abdominal aorta was firstly reported by Lee S. et al. in 1971. But thrombus was formed in the donor abdominal aorta segment which became a blood storehouse and whirling fluid was formed in it. Goldstein and Sunlee improved this technique. They employed end-to-side anastomosis of an aortic patch with testicular artery to the recipient's aorta. The testicular vein was anastomosed to the vena cava of the recipient. In this method the donor with the tersticular artery and vein paralleling and originating no more than 4.0mm apart was requrid . Therefore the suitable donors were lack for the reasion of the variability of testicular vessels; moreover adept and speedy microsurgical suture skill is essential in this producture. These problems have limited the widespread use of rat testicular transplantation. To simplify this producture we devised a three-cuff method with simple microsurgical techniquer and high success rate of rat testicular transplantation.Materials and MethodsIsogenic mature male Wistar rats with 3-4 months of age , were used as donors and recipients. Surgery was performed with clean but not sterile technique using sodium pentobarbitital (100mg/kg) administered intraperitoneally.Donor preparation was performed firstly. After carefully dissected free from thesurrounding structures ,the left common iliac vein was ligated just below the entrance of the left testicular vein and transected below these ligatures and 0.5cm above the entrance of the left testicular vein. Similarly, a segment of aorta between the right renal artery and the left iliolumbar artery with the left testicular artery was harvested. The left vas deferens was then transected near the bladder and the testis was removed from the scrotum with a 2-mm patch of gubernaculums attached . The entire grafts with its blood supply was placed in a petri dish filled with cold saline (4 C).The graft was perfused from the upper opening of the segment of aorta into testicular artery with a blunt needle attached to a syringe including 5.0ml of cold physiologic saline solution to which 50u of heparin had been added, until the testis was pale and fluid from the vein was clear.The cuff preparations of donor aorta and common iliac vein segments were performed according to Kamada's method.Recipient was prepared through a middle abdominal incision. The left common iliac vein and aorta bellow the left renal vessel were dissected free of all surrounding tissue. The left common iliac vein was doubly ligated above the entranc of left spermatic vein and cross-clamped with microvessel clip at the point of its origin; and a venotomy was made in its anterior wall above the ligatures and the lumen was irrigated with heparinized saline to avoid gas embolism. Then the cuffed common iliac vein of donor was inserted into the lumen of left common iliac vein of recipient through the venotomy by holding the cuff extension. The anastomosis was completed with a circumferential 9-0 nylon suture . The extension on the cuff was then cut off. Similarly, recipient aorta below the left renal vessel was blocked with two microvessel clips above and below an appropriate anastomotic area and a anteriotomy was made in the middle of the anterior wall of the blocked aortic segment. After the lumen irrigated , the cuffed donor aorta segment was inserted into the lumen through the anteriotomy . The upper and the lower anastomosed sites were ligated with circumferential 9-0 nylon sutures respectively. The vessel reconstructions of donor testicle were completed. The clamps on the left common iliac vein and aorta were released in turn. The graft recovered blood supply immediately. The recipient's testicles were removed and the end-to-end anastomosis of vas deferens was performed with 4 interrupted sutures of 9-0 nylon microsuture. The donor scrotal epithelium was sutured to the recipient scrotal epithelium , allowing the donor testicle to be pulled into the scrotal sac.