Fig. 4.

Intimal trauma associated with endoscopic harvest. Serial OCT imaging of bypass conduits before and after harvest provided the opportunity to evaluate the safety of novel techniques for vessel procurement such as endoscopic harvest. Unlike traditional open harvesting techniques, this method requires the creation of dissection planes around the vessel pedicle using a blunt-tipped conical cannula. While this harvesting step is performed under endoscopic guidance, it creates tension at branch points that does not occur with the open method. This representative example of in situ OCT images obtained from a RA before (A) and after (B) blunt dissection illustrates a unique pattern of vessel injury to the intimal layer, localized within the ostia of branch points (B, arrowhead). Although less common than trauma in the RA, severe dissections were occasionally imaged within the endoscopically harvested SV [(C) and (E)]. This incidentally discovered finding was confirmed by comparison to histology [(D) and (F)] and was associated with increased local tissue factor activity, suggesting that this vessel segment was likely to be highly thrombogenic if used as a bypass graft.