Diagnostic accuracy of computed tomography in patients with suspected abdominal aortic aneurysm rupture

Objectives: This study was planned to evaluate the accuracy of computed tomography angiography (CTA) for suspected rupture of abdominal aortic aneurysm (AAA). Design: Retrospective, observational study. Patients: A total of 97 patients who underwent open aneurysm repair for suspected rupture of AAA. Methods: The accuracy of preoperative and post hoc evaluation of CTA scans was evaluated by using the intra-operative findings as reference. Results: At surgery, 58 patients were found to have a ruptured aneurysm. Interpretation of CTA findings at admission resulted in one false-negative and two false-positive diagnoses of aneurysm rupture as observed at surgery (sensitivity 98.3%, specificity 94.9%, positive predictive value 96.6%, negative predictive value 97.4%). Post hoc, blinded review of CTA findings resulted in one false-negative and three false-positive diagnoses of aneurysm rupture (sensitivity 98.3%, specificity 92.3%, positive predictive value 95.0%, negative predictive value 97.3%). Agreement between initial and post hoc assessment of CTA-findings was statistically significant (kappa 0.978, p < 0.0001). Conclusions: CTA is highly accurate in the diagnosis of suspected rupture of AAA. The risk of false-positive diagnosis is very low and it is not likely to affect the correct analysis of the results of comparative studies on endovascular versus open repair of ruptured AAA.© 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.