Scanning electron microscopic analysis of endoscopic versus open vein harvesting techniques.
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 been raised regarding the potential for trauma to the vein in the form of intimal disruption which would theoretically predispose to early graft thrombosis and/or development of stenoses. Unfortunately no long term data is yet available for determining if conduits harvested in this fashion are prone to such events. We have examined vein segments harvested by both endoscopic and open 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 study, and both the SEM technician and cardiac pathologist who evaluated the scans were blinded to the technique used for harvesting. For each vein segment examined, views were obtained of four different sections and were analyzed at magnifications ranging from 10 yen to 100 yen. Both thrombus formation and visible intimal disruption were identified quite rarely, and overall were not linked significantly to the type of harvesting technique used. These results suggest that endoscopic vein harvesting techniques do not subject the conduits to more trauma than open techniques and therefore may not predispose to the development of earlier stenoses. This data will need to be confirmed by both other methods of identifying intimal injury and by long-term follow-up of conduit patency in both groups.