The Effect of Neuraxial Versus General Anesthesia on Outcomes of Infrainguinal Bypasses in Vascular Quality Initiative-Medicare-linked Database

Abstract

BackgroundNeuraxial anesthesia (NA) has been hypothesized to decrease postoperative complications and reduce mortality. However, studies regarding the impact of anesthesia type on outcomes of infrainguinal bypass (IIB) have demonstrated mixed results. In this multi-institutional study, we aimed to investigate the association of neuraxial anesthesia (NA) versus general anesthesia (GA) and perioperative and one-year outcomes of IIBs. MethodsThe Vascular Quality Initiative-Medicare-linked database was queried for all patients that received IIB between 2011 and 2019. Patients undergoing concomitant suprainguinal bypass or endovascular interventions were excluded. Two cohorts, NA and GA were compared. Primary outcomes included postoperative complications, estimated blood loss (EBL) of ≥ 500 mL, need for red blood cell (RBC) transfusion, prolonged length of stay, and 30-day mortality. Secondary outcomes included one-year freedom from all-cause mortality, reintervention, amputation, and one-year amputation free survival. Chi-square test, logistic regression, and one-to-one propensity score matching (PSM) based on 33 variables were used to analyze the perioperative outcomes. Kaplan Meier survival and Cox regression analyses were used to analyze one-year outcomes. ResultsA total of 28,443 patients (NA=875, 3.1%; GA=27,568, 96.9%) were included in the study. Patients undergoing NA were more likely to be older, have COPD, and receive preoperative aspirin, while patients undergoing GA were more likely to receive preoperative P2Y12 inhibitor, have history of prior lower extremity arterial intervention, undergo urgent/emergent bypass, undergo infra-geniculate bypass and receive non-autogenous conduit. PSM produced two well-matched cohorts (706 pairs) and revealed significant greater rates of EBL ≥ 500 mL (RR=1.4 [95% CI: 1.1-1.9]; P=0.014) and need for RBC transfusion (RR=1.3 [95% CI: 1.0-1.5]; P=0.013) for patients undergoing IIB with GA. The type of anesthesia was not associated with 30-day mortality and postoperative complications. There were no significant differences in one-year outcomes when stratified by anesthesia type, both in unmatched and matched cohorts. ConclusionsIn this multi-institutional study, we have shown that patients undergoing IIB by GA have greater blood loss and require more transfusions compared to NA. However, NA anesthesia did not offer benefit in reducing postoperative mortality and complications. There were no differences in outcomes up to one year of follow-up. NA and GA are equally safe for IIBs.