Intimal injury of ultrasonically skeletonized internal thoracic artery by a vessel clamp: morphological analysis

The skeletonized internal thoracic artery (ITA) has several advantages over a pedicled one in coronary artery bypass grafting. A skeletonized ITA, which lacks surrounding tissue, thus seems more susceptible to the mechanical force exerted by a vessel clamp than the pedicled ITA. The purpose of this study was to assess the detrimental effect of vessel clamps on the intimal integrity of the ultrasonically skeletonized ITA. We skeletonized twelve ITAs with an ultrasonic scalpel in patients who underwent coronary artery bypass grafting, and thereafter two types of clamp, namely a metal clamp and a fibrous jaw clamp, were applied to the terminal portion of the ITA for 30 min. The intimal integrity of the ITAs was morphologically assessed using scanning electron microscopy. A metal clamp can cause serious intimal injury which disrupts the internal elastic lamina, and thus should be avoided for the temporary clamping of the skeletonized ITA. A fibrous jay clamp, however, hardly ever causes intimal injury, and its clinical use for the temporary clamping of the ultrasonically skeletonized ITA is therefore recommended. Vessel clamps can cause intimal injury of the ultrasonically skeletonized ITA, and the degree of the injury depends on the type of the clamp used.