动物模型,颌下腺自体再植 z-bo 2020-08-05 566

　　Dry eye is a common clinical disease. About 30 million people in my country suffer from dry eye of varying degrees. For mild patients, traditional treatment methods such as artificial tear drugs and lacrimal duct closure have a certain effect, but there is no effective conservative treatment method for severe patients. The free transplantation of the autogenous submandibular gland into the temporal region and the transplantation of the submandibular gland duct into the ocular fornix. Submandibular gland secretion instead of tears is a treatment method explored in recent years. Since the submandibular glands of mini-pigs are similar to humans, the mini-pig model can be used to explore the surgical techniques of human autologous submandibular gland transplantation, as well as the application of various methods or drugs to regulate the secretion of the glands after transplantation.

　　1. Experimental methods Eight Chinese experimental miniature pigs aged 3 to 4 months were selected, weighing 10 to 20 kg. Three sets of autologous transplantation experiments at different parts were carried out.

　　The first group: transplant the submandibular glands to the groin, a total of 4 sides. Miniature pigs are conventionally anesthetized with a submandibular incision. The submandibular gland is separated from the inside of the mandibular angle. The catheter is freed as far as possible in the direction of the oral cavity, the proximal end of the submandibular artery of the submandibular gland is freed, and the submandibular vein is freed near the hilum. In the groin of miniature pigs, a transverse incision was made to cut the subcutaneous tissue of the skin, about 3 to 4 cm long, to find and cut off the saphenous artery and the saphenous vein to prepare a vascular anastomosis. Ligation and cut off the arteries and veins of the submandibular glands and ducts, remove the glands to be transplanted, and inject 4℃ heparin saline solution (100ml containing 12.500U heparin and 10ml of 2% lidocaine) into the end of the artery to heparinize it until the gland becomes white OK. With 10-0 non-injury suture, the submandibular gland artery was anastomosed with the saphenous artery, and the submandibular gland vein was anastomosed with the saphenous vein. The veins were first followed by the arteries, the blood flow was opened, the glands turned from pale to rosy, and clear fluid was flowing out of the catheter port. Make an opening next to the surgical incision, lead the catheter out, and use 9-0 non-injury sutures to sew 6-8 stitches between the catheter port and the surrounding skin to make it open to the skin. Prepare a gap for placing the glands, suture the glands and surrounding tissues with several stitches, flush to stop bleeding, and close the wound.

　　The second group: autologous in situ replantation, the catheter opening in the skin, a total of 6 sides. The submandibular incision was made to separate the inner mandibular angle to expose the submandibular glands. Free the proximal end of the external mandibular artery of the submandibular gland, and free the submandibular gland vein to the anterior vein. The blood vessels near the hilum should not be separated to avoid damage to the small blood vessel branches. Try to free the catheter in the direction of the mouth. The ipsilateral lingual artery was dissected, and its caliber was cut close to the diameter of the proximal port of the external maxillary artery, and the vascular anastomosis was prepared. Cut off the submandibular gland arteries, veins and ducts, remove the glands to be replanted, and infuse them with heparin saline according to the first set of methods. With 10-0 non-injury suture, the submandibular gland artery was anastomosed with the lingual artery, and the vein was anastomosed in situ at the anterior vein cut. The veins are first followed by the arteries to open up blood flow. Make an opening next to the surgical incision, lead the catheter port out, use 9-0 non-invasive sutures to suture the catheter port and the surrounding skin with 6-8 stitches to make the catheter open to the skin. The gland and surrounding tissues were sutured with several stitches, flushed to stop bleeding, drainage strips were placed, and the incision was sutured in layers.

　　The third group: autologous in situ replantation, the catheter opening in the oral vestibule, a total of 6 sides. The submandibular incision and free dissection of the submandibular gland are the same as the second group. Intraoral irrigation is performed, and the bottom mucosa of the opening is circularly cut 3 to 4 mm away from the duct opening of the submandibular gland, leaving a small amount of normal mucosa around the duct opening. A longitudinal auxiliary incision was made at the transition point between the bottom of the mouth and the belly of the tongue to cut the mucosa at the bottom of the opening about 2 cm. After the submandibular duct was completely freed, the submandibular duct was pulled out from the submandibular incision. Dissect and cut the ipsilateral lingual artery and maxillary vein to prepare anastomoses. Cut off the external maxillary artery and cut off the anterior vein before entering the external jugular vein. Remove the glands to be replanted and infuse with heparin saline according to the first group method. Using a 10-0 non-invasive suture, the proximal end of the submandibular artery of the submandibular gland was anastomosed with the lingual artery, and the proximal end of the anterior vein was anastomosed with the maxillary vein. The veins are first followed by the arteries to open up blood flow. A stoma was made at the lower vestibular sulcus of the mouth of the miniature pig, and the catheter was pulled out from the mouth under the skin, and the mucosa around the nipple of the catheter was tightly sutured to the lower vestibular sulcus with 6-0 sutures. The gland is sutured with the surrounding tissues and fixed with several stitches. Rinse to stop bleeding, place drainage strip, and suture the incision in layers.

　　Perioperative treatment: Free drinking and eating after surgery. Remove the drainage strip after 24 hours. From the day of surgery, 800,000 units of penicillin were given intramuscularly to prevent infection for 3 days. The third group of small pigs were fed liquid food for 3 days. The catheter port was flushed with gentamicin saline daily for one week after surgery. After successful operation, the glands were taken 24 hours, 7 days, 14 days, 1 month, 3 months and 6 months after the operation. A secretion from the mouth of the submandibular duct within 1 week after the operation, and the secretion is colorless and clear, is a sign of successful vascular anastomosis.

　　2. Experimental results The first group of 4 glands did not secrete at the orifice for more than one week after the operation, and the glands became hard. Examination revealed that the transplanted glands had thrombosis, and all the operations failed. The vascular anastomoses of the second and third groups were all successful. Within 1 month after the operation, 3 cases of catheter obstruction occurred in the second group, 1 case occurred in the third group, and the rest had secretions for more than 3 months. The second and third groups of experimental methods use the lingual artery for blood supply, which is convenient for anastomosis and suitable for location. The vein is anastomosed with the anterior vein or the maxillary vein, with sufficient return, which solves the problem of blood supply and return vessels.

　　Successfully transplanted glands are roughly similar to the preoperative appearance, their volume is reduced compared with preoperatively, the color is ruddy, the touch is soft, and the bleeding is bright red after incision. The histology of the submandibular glands of normal miniature pigs taken during the anatomical study in the pre-experimental stage was used as a control. One day after the replantation of the glands, the structure was basically normal, the glandular lobules were clear, the tissue was slightly edema, the capillaries were slightly dilated and congested, and the gland cells were not changed significantly. Seven days after gland replantation, tissue edema disappeared, vasodilation and congestion subsided, lymphocytes and plasma cells were occasionally seen, and the rest were normal. At 3 months, the acinar arrangement was disordered, and the number and volume of serous acinar decreased and the atrophy was more obvious than that of mucinous acinar. At 6 months of transplanted glands, the tissue structure of the acinar, glandular lobules and ducts at all levels is basically normal, the acinar cell arrangement is relatively regular, the glandular parenchyma increases, and the glandular lobule atrophy is restored, but the volume of the serum cells is still smaller than before transplantation The number of glands is also less than before surgery. In the submandibular gland ducts, the arrangement of ductal epithelial cells was disordered and subepithelial blood vessels proliferated at 3 months. The arrangement of ductal epithelial cells at 6 months was more regular than that at 3 months. The obstructed glands of the ducts have reduced volume and are harder to the touch, and mucus-like substances can be seen after incision. At 1 month, the submandibular duct showed vasodilation and hyperemia, fibrous tissue hyperplasia, disappearance of acinar, duct dilation, lymphocyte and plasma cell infiltration under HE staining light microscope. Some ductal epithelial squamous metaplasia, hyaline degeneration can be seen around the duct. At 3 months, the structure of acinar and ducts was completely disappeared under the microscope, replaced by collagen fibers, and lymphocytes and plasma cells infiltrated.