Arteriographic and ultrasonic evaluation of vascular clamp injuries using an in vitro human experimental model.

A new experimental model was developed for dynamic in vitro evaluation of clamp effects in normal and atherosclerotic human arteries. Five normal and 25 atherosclerotic arteries obtained at autopsy were perfused by a pulsatile blood pump. Five vascular clamps--DeBakey, Satinsky, Fogarty, bulldog and Potts--were applied separately to 150 arterial segments, 30 each. The arterial segments were examined by single exposure arteriography and real time ultrasonography. The arteries were opened longitudinally and examined for traumatic lesions and atherosclerotic plaques. Except for a single intimal tear, there were no lesions produced by the clamps applied to normal arteries. In atherosclerotic arteries, the number of traumatic lesions, intimal tears and flaps, was comparable for all five clamps except the bulldog clamp which caused no intimal flaps. Intimal tears and flaps were observed in 14 and 26 per cent of all atherosclerotic vessels, respectively. The occurrence of clamp trauma in atherosclerotic arteries was independent of the age, sex and direct clamp application to plaques. Sensitivity of intimal tears by arteriography and ultrasonography was comparable low. Intimal flap sensitivity and accuracy of ultrasonography were greater than that of arteriography, p less than 0.01. It is concluded that the occurrence of important trauma by vascular clamps in atherosclerotic arteries is high and occurs whether or not discrete plaques are clamped. Clamp trauma is minimal in normal arteries. Imaging ultrasonography is superior to arteriography in detecting intimal flaps and can demonstrate the majority of intimal flaps produced by vascular clamps.