Preoperative anemia is a risk factor for worse 30-day outcomes in both open and endovascular repair of non-ruptured infrarenal abdominal aortic aneurysm

Abstract

Background Anemia is a highly prevalent condition potentially linked to chronic inflammation. Preoperative anemia is an independent risk factor across many surgical fields. However, the relationship between anemia and abdominal aortic aneurysm (AAA) repair outcomes remains unclear. This study aimed to examine the effects of preoperative anemia on 30-day outcomes of non-ruptured infrarenal AAA repair. Methods Patients who underwent open surgical repair (OSR) and endovascular aneurysm repair (EVAR) for infrarenal AAA were identified in National Surgical Quality Improvement Program (NSQIP) targeted databases from 2012 to 2021. Anemia was defined as preoperative hematocrit less than 39% in males and 36% in females. Multivariable logistic regression was used to compare 30-day perioperative outcomes between anemic and non-anemic patients, adjusting for demographics, comorbidities, indications, aneurysm extents, operation time, and surgical approaches. Results There were 408 (22.13%) anemic and 1436 (77.88%) non-anemic patients who underwent OSR for non-ruptured AAA, while 3586 (25.20%) patients with and 10,644 (74.80%) without anemia underwent EVAR. In both OSR and EVAR, anemic patients had higher risks of bleeding requiring transfusion (OSR, aOR = 2.446, p < .01; EVAR, aOR = 3.691, p < .01), discharge not to home (OSR, aOR = 1.385, p = .04; EVAR, aOR = 1.27, p < .01), and 30-day readmission (OSR, aOR = 1.99, p < .01; EVAR, aOR = 1.367, p < .01). Also, anemic patients undergoing OSR had higher pulmonary events (aOR = 2.192, p < .01), sepsis (aOR = 2.352, p < .01), and venous thromboembolism (aOR = 2.913, p = .01), while in EVAR, anemic patients had higher mortality (aOR = 1.646, p = .01), cardiac complications (aOR = 1.39, p = .04), renal dysfunction (aOR = 1.658, p = .02), and unplanned reoperation (aOR = 1.322, p = .01). Moreover, in both OSR and EVAR, anemic patients had longer hospital length of stay ( p < .01). Conclusion In OSR and EVAR, preoperative anemia was independently associated with worse 30-day outcomes. Preoperative anemia could be a useful marker for risk stratification for patients undergoing infrarenal AAA repair.