IntroductionLength of stay (LOS) is a major driver of cost and resource utilization following lower extremity bypass (LEB). However, the variable comorbidity burden and mobility status of LEB patients makes implementing enhanced recovery after surgery (ERAS) pathways challenging. The aim of this study was to utilize a large national database to identify patient factors associated with ultrashort LOS among patients undergoing LEB for peripheral artery disease (PAD). MethodsAll patients undergoing LEB for PAD in the National Surgical Quality Improvement Project database from 2011-2018 were included. Patients were divided into two groups based on the length of postoperative stay: ultrashort (<=2 days) and standard (>2 days). Thirty-day outcomes were compared using descriptive statistics, and multivariable logistic regression was used to identify patient factors associated with ultrashort LOS. ResultsOverall, 17,510 patients were identified who underwent LEB, of which 2,678 (15.3%) patients had an ultrashort postoperative LOS (mean 1.8 days) and 14,832 (84.7%) patients had a standard LOS (mean 7.1 days). When compared to patients with standard LOS, patients with an ultrashort LOS were more likely to be admitted from home (95.9% vs 88.0%, p<0.001), undergo elective surgery (86.1% vs. 59.1%, p<0.001) and to be active smokers (52.1% vs. 40.4%, p<0.001). Ultrashort LOS patients were also more likely to have claudication as the indication for LEB (53.1% vs. 22.5%, p<0.001), have a popliteal revascularization target rather than a tibial/pedal target (76.7% vs 55.3%, p<0.001) and had a prosthetic conduit (40.0% vs. 29.9%, p<0.001). There was no significant difference in mortality between the two groups (1.4% vs 1.8%, p=0.21); however ultrashort LOS patients had a lower frequency of unplanned readmission (10.7% vs. 18.8%, p<0.001) and need for major reintervention (1.9% vs. 5.6%, p<0.001). On multivariable analysis, elective status (OR:2.66, 95%CI:2.33-3.04), active smoking (OR:1.18, 95%CI:1.07-1.30) and lack of vein harvest (OR:1.55, 95%CI:1.41-1.70) were associated with ultrashort LOS. Presence of rest pain (OR:0.57, 95%CI:0.51-0.63), tissue loss (OR:0.30, 95%CI:0.27-0.34) and totally dependent functional status (OR:0.54, 95%CI:0.35-0.84) were negatively associated with ultrashort LOS. When examining the subgroup of patients who underwent vein harvest, totally dependent (OR:0.38 95%CI:0.19-0.75) and partially dependent (OR:0.53, 95%CI:0.32-0.88) functional status were persistently negatively associated with ultrashort LOS. ConclusionsUltrashort LOS (<= 2 days) following LEB is uncommon but feasible in select patients. Preoperative functional status and mobility are important factors to consider when identifying LEB patients who may be candidates for early discharge.