Scanning electron microscopic analysis of endoscopic versus open vein harvesting techniques

Background. Endoscopic vein harvesting techniques are increasingly used for obtaining conduit for coronary artery bypass surgery. Although they offer advantages in healing over the conventional open technique, concern has bee n raised regarding the potential for trauma to the vein in die form of inti mal disruption which would theoretically predispose to early graft thrombos is and/or development of stenoses. Unfortunately no long term data is yet a vailable for determining if conduits harvested in this fashion are prone to such events. Methods. We have examined vein segments harvested by both endoscopic and op en techniques for evidence of intimal injury (either visible disruption of the intima and/or presence of thrombus) using scanning electron microscopy (SEM). Those harvesting the vein were unaware which patients were in the st udy, and both the SEM technician and cardiac pathologist who evaluated the scans were blinded to the technique used for harvesting. For each vein segm ent examined, views were obtained of four different sections and were analy zed at magnifications ranging from 10x to 100x. Results. Both thrombus formation and visible intimal disruption were identi fied quite rarely, and overall were not linked significantly to the type of harvesting technique used. Conclusions. These results suggest that endoscopic vein harvesting techniqu es do not subject the conduits to more trauma than open techniques and ther efore may not predispose to the development of earlier stenoses. This data will need to be confirmed by both other methods of identifying intimal inju ry and by long-term follow-up of conduit patency in both groups.