[A rabbit model for evaluation of a small-caliber vascular graft]

A method for experimental study for a long small-caliber vascular graft was developed and used to observe the healing process and antithrombogenicity of a high porosity fabric prostheses. Eight rabbits weighing 3 kg were used. A left thoracotomy was performed. The thoracic descending aorta was clamped with two vascular clamps and excised in the middle without temporary shunt. A 15 cm long by 4.0 mm ID segment of a fabric prostheses (porosity: 3000) was implanted end to end. After the blood flow of the aorta was restarted, the graft remained in a big loop shape in the thoracic cavity. Total operating time was less than one hour. Three animals were lost because of bleeding from the anastomotic sites (2) and bleeding from the lung (1) within 12 hrs, but paraplegia was not produced. One animal died because of an occlusion in the graft at 16 days after implantation. The remaining 4 animals survived. In two out of these four animals, an angiography was performed. Two grafts were still patent at four weeks. One of these two was explanted and its smooth surface was observed. The major advantage of this technique is that we could evaluate a long small-caliber vascular graft in a small animal.