The great saphenous vein is the conduit of choice for vascular surgeons, when available, for performing peripheral arterial bypass operations [ see vascular bypass ]. The saphenous vein may undergo vein graft failure after engraftment, but still it has superior long-term patency compared to synthetic grafts (PTFE, PETE (Dacron)), human umbilical vein grafts or biosynthetic grafts . Often, it is used "in situ" (in place), after tying off smaller tributaries and destruction of the venous valves with a device called valvulotome, e.g. LeMaitre's valvulotome.