Variation in Transfusion Practices and the Association with Perioperative Adverse Events in Patients Undergoing Open Abdominal Aortic Aneurysm Repair and Lower Extremity Arterial Bypass in the Vascular Quality Initiative

Abstract

Blood transfusions are associated with adverse events. We examined perioperative transfusion practices and associated complications following open vascular procedures nationwide in the Vascular Quality Initiative (VQI). Adults undergoing open abdominal aortic aneurysm repair (OAR) and lower extremity arterial bypass (Bypass) within VQI (2003-2016) were identified. All emergent cases, patients with preoperative hemoglobin <7g/dL, preoperative hospitalization >1day, or a return to operating room during the index hospitalization were excluded. Units of red blood cells transfused were the primary outcome. Secondary outcomes were postoperative myocardial infarction (MI) and death. Patient, center, and procedural factors were evaluated. Multivariable mixed effects negative binomial regression and multivariable logistic regression were performed. We identified 24,131 procedures (OAR 3885, 16.1%; Bypass 20,246, 83.9%) among 22,532 patients (10.1% had >1 procedure). Overall, 37.5% of OAR and 19.5% of Bypass were transfused. Transfusion rates varied across estimated blood loss quartiles and across various preoperative hemoglobin levels. The overall rate of postoperative MI and death was 4.0% and 1.8% for OAR, and 2.2% and 0.7% for Bypass, respectively. In univariate and multivariable analysis, transfusions were associated with an increased risk of postoperative MI and death. A mixed effects negative binomial model demonstrated variation in transfusions across centers (P<0.001). Female gender and preoperative anemia were significantly associated with transfusions. Blood transfusions are variable across centers in VQI. Transfusions are associated with a higher postoperative MI and death after OAR and Bypass. Efforts to reduce transfusion may focus on center variability, gender, and preoperative anemia.