Factors Associated With Increased Mortality After Isolated Abdominal Aortic Dissection Repair

Abstract

Postoperative mortality after open and endovascular repair of thoracic aortic dissection (AD) has been the focus of previous research. However, a little has been published on the far less common isolated abdominal aortic dissection (IAAD). The aim of our study was to identify risk factors associated with 30-day postoperative mortality in patients with IAAD. The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) was queried for patients who underwent open or endovascular AD repair from January 2010 to December 2015. Information regarding patient demographics, comorbidities, preoperative laboratory values, procedure details, and postoperative complications were analyzed, and predictors of 30-day mortality were identified. Risk stratification by the type of aortic repair and surgery setting was performed, and patient characteristics associated with mortality in each setting were determined. We employed chi-squared test, Student's t-test, and Mann-Whitney U test for the univariate analysis, while the multivariate analysis was performed using a stepwise binary logistic regression test. There were 229 patients who met the specified criteria, 15 died within 30days postoperatively, and 214 survived beyond the same period (mortality rate was 6.5%). Among preoperative factors, a history of chronic obstructive pulmonary disease (COPD), preoperative ventilator dependence, preoperative transfusion of ≥1 unit packed RBCs, emergent operation, and advanced American Society of Anesthesiologists (ASA) class were associated with increased risk of mortality. Postoperative complications associated with a higher risk of mortality were acute kidney injury, mechanical ventilation ≥48hours, unplanned intubation, myocardial infarction, septic shock, and blood transfusion. On multivariate analysis, risk factors independently associated with increased risk of mortality were a history of COPD (adjusted odds ratio [AOR], 10.5; P=0.013), postoperative acute renal failure (AOR, 12.8; P=0.003) and septic shock (AOR, 15.3; P=0.014). Multiple preoperative and postoperative factors are associated with a high risk of death after IAAD repair. A better control of COPD and prevention of postoperative acute renal failure and septic shock may result in better outcomes.