Components for an endoscopic vessel harvesting system suitable for harvesting target vessels such as the saphenous vein or radial artery for cardiac artery bypass graft surgery. The main components of such systems include a vessel dissector and a vessel harvester, both of which work in conjunction with a separately provided endoscope. The vessel dissector is an elongated cannula having a blunt tip for separating layers of facial around vessels. The tip may be movable, and is typically transparent to permit viewing forward of the tip using the endoscope. Internal features of the tip may reduce glare back to the endoscope. Several devices improve visibility through the tip by reducing interference from tissue or fluid on the tip. The vessel harvester also has an elongated cannula for receiving the endoscope. Several tools within the harvester permit manipulation, severing, and sealing of vessels forward of the distal end. The tool for manipulating vessels may have a low-profile for increased visibility of operation, and may be coupled to the cannula with a damping mechanism to reduce the possibility of avulsion of the vessels. Various vessel cutting and sealing devices are provided that may accommodate various sizes of vessels and improve cutting and sealing efficacy,
