Experimental Study On The Microcirculation Of Congested Flap

Congestion is a common complication after skin flap grafting. If it has not been rectified in time, it could develop into venous crisis and harm the flap's survival. Although it has often been met clinically, because the doctors are not very familiar with it's course of disease and the mechanism of it's leading the flap to dead ,the doctors often feel deficiency of strategy. For many years, flap's venous crisis has been a tough problem in plastic surgery.In order to understand the course of disease of congestion more clearly and make clear the mechanism of it's pathological and physiological change, we set up an animal model of congested flap for long-term study of microcirculation, studied the varying rule of the microcirculation of congested flap, and further observed the pathological change of congested tissue.1. Preparation of a kind of chamber suited for long-term study of microcirculationThe traditional rabbit ear chamber usually had a very limited space in it (about 100μm) ,after it was assembled on the rabbit ear , the capillaries could grow into the space and form a vascular layer. But the manufacture graft was subtle and difficult, moreover, the formed vascular layer was often unintegrated in lack of valid lymphatic return and innervation, so it could hardly represent the real microcirculatory status in the region. As a result, we designed a kind of chamber with ability to retain the tergal vascular layer of the rabbit ear, which has been proved fairly lucent meanwhile not destroying the original vascular structure of the rabbit ear. Similar reports have not been found in literature by now.2. Set-up of an animal model of congested flapThe rabbit's ear was selected to make the flap model. Firstly, the observation chamber was prepared on the rabbit ear .About one week later, when the chamber was suited to being observed, the second stage operation was performed. With protection of the central artery and lateral marginal vein of the rabbit ear from injuring, the rabbit ear was cut off from the root and sutured again, then the most majority of anastomotic branches between the central vein and the lateral marginal vein were cut off with only one branch at the distal end preserved. After the central vein and medial marginal vein were ligated, the animal model of congested flap was set up. The flap model could well simulated the venous crisis flap clinically with an advantage of long-term observation for microcirculation.3.Experimental study on the varying rule of microcirculation for congested flap3.1 After the flap model was set up, we observed the microcirculation of the flap carefully through the chamber at several time points, and the results were:(1)Following the congestion, the number of the capillaries in the congested flap were decreasing, the velocity of the bloodstreams were getting slower, and the aggregation of the red blood cells and the formation of the white thrombus were becoming more serious. About 72 hours later, the original microcirculation system of the flap was nearly exhausted. (2)About 36 hours later, the neogenetic capillaries could be observed, with clear neogenetic capillaries observed and consummate...