['It has been reported that a failed endovascular intervention adversely affects results of lower extremity bypass (LEB). We reviewed rates of prior endovascular intervention (PEI) in patients undergoing LEB with autologous vein for critical limb ischemia (CLI) to determine effects on graft patency, limb salvage, and amputation-free survival.', 'Retrospective review was conducted of consecutive autologous vein LEBs performed for CLI between 2005 and 2012 at a tertiary care academic medical center.', 'Overall, 314 autologous vein LEBs were performed for CLI, 71% for tissue loss. TransAtlantic Inter-Society Consensus II type D or type C lesions were present in 62% and 25%, respectively. The great saphenous vein was used as a conduit in 83%, and the distal target was infrapopliteal in 60%. The 30-day mortality rate was 3.5%. Primary patency rates at 1\xa0year and 5\xa0years were 61% and 45%. Secondary patency rates at 1\xa0year and 5\xa0years were 88% and 64%, with 23% requiring an intervention to maintain patency. The 5-year limb salvage rate was 89%, and the 5-year amputation-free survival was 49%. There were 61 patients (19%) who had undergone a PEI and 253 (81%) who underwent bypass with no prior endovascular intervention (NPEI). There were 19 iliac stents, 29 femoral interventions, 13 popliteal interventions, 9 crural interventions, 9 infrainguinal thrombectomies, and 13 infrainguinal thrombolyses. PEI and NPEI patients had similar demographics and prevalence of\xa0atherosclerotic risk factors. The 1-year primary patency rate was 62% for NPEI patients vs 59% for PEI patients (P\xa0=\xa0.759). The 1-year and 2-year secondary patency rates were 87% and 79% for NPEI patients vs 89% and 78% for PEI patients (P\xa0= .947). The 3-year limb salvage rate was 89% for NPEI patients vs 92% for PEI patients (P\xa0= .445). The 3-year amputation-free survival was 59% for NPEI patients vs 52% for PEI patients (P\xa0= .399). Median follow-up time was 323\xa0days for NPEI patients (interquartile range, 83-918) vs 463\xa0days for PEI patients (interquartile range, 145-946; P\xa0= .275).'] Is lower extremity autologous vein bypass for critical limb ischemia adversely affected by prior endovascular procedure?