흰쥐의 혈관문합후 봉합재료에 따른 치유과정에 관한 실험적 연구

An experimental study of healing process according to suture materials after microvascular anastomosis in rats

The most important cause of failure of microvascular anastomosis is the thrombotic occlusion at the site of anastomosis. The purpose of this study was to compare the patency rates and healing process according to suture materials after microvascular anastomosis using femoral arteries of rats. The right femoral arteries were exposed and cut, and they were sutured with microsurgical instruments. The left femoral arteries served as controls. Experimental terms were 1 day, 2, 4, 7, 14, 21, and 28 days after surgery. Patency rates and changes in blood vessels in the anastomotic sites were examined using light microscope. The obtained results were as follows: 1. The total patency rate was 87.5%(21/24), and patency rate about nylon was 91.7%(11/12) and 83.3%(10/12) about silk. 2. The difference of healing process according to suture materials was not observed in this study. Further investigation with electron microscope may be necessary to find out the minute difference of healing process. 3. At the early stages, desquamation and disappearance of endothelial cells, exposure of internal elastic lamina, and rupture of part of the media were observed. Blood platelets and fibrins adhering to the same areas resulted in mural thrombi. 4. After 4 days of microvascular anastomosis, new endothelial cells were formed at some distant, undamaged luminal surface of blood vessel. At the same time, previously formed mural thrombi was decreased gradually. 5. Re-endothelialization was almost complete between 7 and 14 days. After 7 days microvascular anastomosis, thickening of the intimal layer between the endothelium and the internal elastic lamina was observed. The thickening was maximal at 21 days after denudation, after 21 days the thickness of the intima was decreased gradually. The thickened intimal layer was mainly composed of smooth muscle like cells.