Patients Who Underwent Surgery for Blunt Abdominal Aortic Injury Have Higher Risk of Perioperative Mortality, Pneumonia, and Longer Hospital Length of Stay

Abstract

Introduction: Blunt abdominal aorta injury (AAI) is uncommon and not well studied. This study is intended to determine the outcomes of patients with blunt AAI that were managed conservatively and with surgery. Methods: Adults patients (>18 years) with blunt AAI were identified in National Trauma Databank (NTDB) (2002-2012) using ICD-9 th and CPT codes. Patients with AAI secondary to penetrating injury were excluded. Patients were divided into two groups based on treatment modality (surgery versus observation). Outcomes including perioperative mortality, morbidity and length of stay (LOS) were compared across the groups. Multivariable analysis was performed to adjust for possible confounding factors. Results: There were 975 patients with blunt AAI that were identified and included in the study cohort. Majority of the patients were male (71.9%), mean age was 47 years, and overall mortality was 31%. 202 patients (21%) required surgery while 773 (79%) were managed conservatively. Among the patients who underwent surgery, 81% (n=163) had open surgery and remaining endovascular surgery (n=39). Patients who require surgery had higher injury severity score (ISS) (36.6 vs. 33.5, p=.004), and different mechanism of injury (fall 6% vs. 12.4%, motor vehicle accident 79% vs. 77.6%, p=.009). Perioperative mortality (39.6% vs. 28.2%. p=.002), pneumonia (14.4% vs. 8.4%, p=.011), and amputation (5% vs. 1%, p<.001) were significantly higher in patients who required surgery. Mean hospital LOS (17 vs. 12.4 days, p<.001) and mean ICU LOS (9.9 vs. 6.1 days, p<.001) were also significantly longer in patients that underwent surgery. Patients who were treated with endovascular repair had similar ISS to open repair but had significantly lower risk of mortality (30.8% vs. 41.7%, p=.003). However, those who underwent endovascular repair had higher risk of pneumonia (23.1% vs. 12.3%, p=.005) and amputation (7.7% vs. 4.3%, p=<.001). In multivariable analysis, surgery was independently associated with risk of perioperative mortality (OR 1.8, 95% CI 1.2-2.7, p=.009) and pneumonia (OR 1.8, 95% CI 1.1-3.0, p=.02). Other factors associated with mortality were age (OR 1.1, p<.001) and ISS (OR 1.1, p<.001). Conclusion: Patients with blunt abdominal aortic injury have significant mortality and morbidity. Up to 20% of patients with more severe injuries required surgical repair, and have significantly higher mortality, pneumonia and required longer length of stay compared to those were managed conservatively. Endovascular repair can be associated with better survival than open repair.