Do Abdominal Aortic Aneurysm Necks Increase in Size Faster after Endovascular than Open Repair?

IntroductionProgression of aneurysmal disease in the aortic neck poses a threat to durable abdominal aortic aneurysm (AAA) repair. We tested the hypothesis that 2 years after AAA repair the size of the aortic neck increased more after endovascular (EVAR) than open repair.Patients and methodsFor a subset of EVAR 1 trial patients, true outer-wall area at three levels of the aortic neck was measured using a Vitrea2 workstation, and rate of change over 2 years analysed.ResultsThe 67 EVAR patients and 56 open repair patients were well-matched, very similar to the total EVAR 1 cohort. The mean area change over 2 years at the Superior Mesenteric Artery was small for both groups. However at the Caudal Renal Artery (CRA), adjusted regression coefficient was 0.68 cm2/y greater after EVAR (p < 0.001) and 0.77 cm2/y at a level 15 mm distal to it (p < 0.001). The area at the CRA of 45 available post-procedure scans showed a large proportion of the increase had occurred by 3 months (mean 4.8 cm2 to 5.9 cm2 versus 6.7 cm2 at 2 years).ConclusionsThe increase in aortic neck size was much greater 2 years after EVAR versus open repair. Further research is ongoing to establish whether the dilatation is progressive after stent-graft placement.