Early development of suture holding capacity in vascular anastomoses in the rat.

Early development of suture holding capacity (SHC) of end-to-end anastomoses in the infrarenal aorta and inferior vena cava (IVC) of the rat was studied by measuring the resistance to tensile forces at 0, 3, 5, 8, 11, or 14 days postoperatively. Comparable anastomoses were histologically evaluated. The SHC of the aortic wall decreased following anastomoses and did not regain the strength of nonanastomosed vessels during the first two weeks. The SHC of the IVC also decreased following anastomoses, but regained the strength of nonanastomosed vessels by the 5th day. The relative ultimate strain of the arterial and venous perianastomotic walls decreased slightly, while the relative compliance increased in the aorta and decreased in the IVC. Perianastomotic media necrosis was found exclusively in the arteries. The reduced perianastomotic SHC in the aorta indicates impaired healing, compared to the IVC. Changes in biomechanical properties of the aortic wall following anastomosis may increase its susceptibility to anastomotic complications such as pseudoaneurysms.