The effect of delayed repair on microvascular patency rates

The effect of delayed microsurgical arterial anastomosis on the patency rate in the rat femoral artery was evaluated. Sixteen Sprague-Dawley rats underwent ligation and repair of the right femoral arteries and repair of the left artery as a control. The rats were divided into four groups, and their right arteries were ligated for 24, 48, 72, or 96 hr. Patency was evaluated by the standard stripping test and flow after transection of the vessel. At 5 days after the arterial anastomosis, four of 16 arteries remained patent, two of which were in the 24-hr group. Histologic analysis revealed progressive damage to the arterial intima and media, as the time to repair was delayed. Delayed microsurgical arterial repairs of greater than 24 hr showed a poor patency rate, due to irreversible changes that occurred in the arterial intima and media.