Abstract 15047: Aortic Neck Length and Mortality After Repair of Ruptured Abdominal Aortic Aneurysm
Introduction: Aneurysm morphology indicates whether a patient with ruptured abdominal aortic aneurysm (rAAA) is eligible for endovascular aneurysm repair (EVAR) and may influence the outcome of both EVAR and open surgical repair. In the emergency setting, the morphological criteria for EVAR (IFU, instructions for use) may be relaxed, but by how much?
Hypothesis: aneurysm morphology influences mortality from rAAA repair.
Methods: Patients randomised to either an endovascular strategy or open repair in the IMPROVE trial (ISRCTN48334791), with a proven diagnosis of rAAA, who underwent repair and with admission CT scan sent to the core laboratory, were included in this analysis of 30-day mortality and re-interventions, according to a pre-specified plan, focusing on IFU and 6 morphological variables: maximum aortic diameter, neck diameter, neck length, proximal neck angle, neck conicality & maximum common iliac diameter.
Results: 458 patients (364 men), mean age 76 years were included, with EVAR commenced in 177 and open repair in 281 cases, with 155 deaths and 88 re-interventions. The mean maximum aortic diameter was 8.6cm. There were no important correlations between the 6 morphological variables. Patients within IFU (58%) had lower mortality, adjusted* OR 0.64 [95%CI 0.41,1.01]. Only aortic neck length (mean(SD), 23.2(16)mm) was associated significantly (inversely) with mortality, particularly for open repair: overall mortality reduced for each SD increase in length, adjusted** OR 0.72 [95%CI 0.56,0.91]. With fewer re-interventions, only iliac diameter showed a borderline association.
Conclusions: Short aneurysm necks preclude EVAR and strongly adversely influence mortality after open repair of rAAA. This is an important reason why observational studies, but not randomised trials, have shown an early survival benefit for EVAR.
*(**) for age, sex, Hardman index, blood pressure and randomised group (and other morphological variables).
Author Disclosures: J.T. Powell: None.
- © 2014 by American Heart Association, Inc.