Optimal conduit choice for open lower extremity bypass in chronic limb-threatening ischemia.

ABSTRACT

Open bypass surgery remains a major tool for limb salvage in chronic limb-threatening ischemia (CLTI). Although rest pain and tissue loss both fall into the category of CLTI, goals of revascularization are markedly different for each context. Rest pain mandates long-term patency considerations. Tissue loss, however, requires consideration of infection risks and patency enough to heal the wound. Of the major conduit options, autologous saphenous vein graft continues to be the conduit of choice, given both superior patency and low risk of infection. When saphenous vein graft is not available or not available in appropriate length, arm vein, small saphenous vein, and spliced combinations of these have acceptable patency rates. Heparin-bonded polytetrafluoroethylene and Dacron grafts are prosthetic conduits with excellent patency rates when vein is not available. For infected wounds without other options, cryovein continues to provide acceptable patency for limb salvage. Creation of a bypass is only part of CLTI management. Appropriate postoperative surveillance with noninvasive studies, including ankle-brachial index and duplex ultrasound, can alert to impending graft failure, with a drop in ankle-brachial index of 0.15 and velocity ratios of 3 or more suggestive of significant stenoses. Anticoagulation has only been found in limited contexts (such as poor conduit or poor outflow) to offer some patency benefit, however, findings from the VOYAGER PAD (Vascular Outcomes Study of ASA [Acetylsalicylic Acid] Along With Rivaroxaban in Endovascular or Surgical Limb Revascularization for PAD) trial were a major breakthrough, showing a reduction in the composite outcome of major adverse limb, cardiac, and cerebrovascular events in revascularized patients taking low-dose rivaroxaban in conjunction with aspirin, without a substantial increase in bleeding risk.