Re-endothelialization stages at the microvascular anastomosis

After microsurgical suturing, the wound healing process at the rat femoral artery anastomosis was studied with scanning electron microscopy. The re-endothelialization was divided into four successive stages, based on the development of a fibrin network and the rate of endothelial regrowth. Within 5 minutes of blood flow re-establishment the fibrin network formation started to cover the wound surface; it was completed by the 3rd or 4th day. The endothelial recovery started on the 2nd day and continued to the base of the suture by the 6th day. Re-endothelialization from the wound edge, which was formed between intact and injured endothelium toward the suture-restrained site, was a two-fold process: initially, a single endothelial film covered the anastomosis site, then, the singled endothelial sheet proliferated and thickened to complete the endothelialization. A better understanding of the stages involved in microvascular repair is beneficial in evaluating vascular recovery and its relationship to patency rates in microvascular surgery.