“The majority of patients eligible for EVAR [endovascular aneurysm repair] when entering a surveillance programme for small AAA [abdominal aortic aneurysm] remain eligible after two years,” write Annalise M Panthofer (University of Wisconsin, Madison, USA) and colleagues in the Journal of Vascular Surgery (JVS). They add that substantial changes in AAA neck anatomy leading to loss of EVAR treatment options are “infrequent,” and that patients with anatomical AAA progression beyond EVAR eligibility “remain candidates for complex EVAR and open repair”.
In patients who have a large infrarenal AAA, the authors write that EVAR is a “widely used” treatment option. While patients with small AAAs are managed with “careful surveillance,” it is often a concern among this group that their anatomy may alter with AAA growth, Panthofer and colleagues state, and that their suitability for EVAR may diminish.
Despite these concerns, Panthofer et al note that device innovation has resulted in “expanded ranges of anatomy that may be eligible for EVAR”. In this study, the investigators sought to identify how the availability of newer devices might have changed the anatomic eligibility for repair.
In order to analyse this hypothesis, they monitored small AAAs in patients from N-TA3CT (Non-invasive treatment of abdominal aortic aneurysm clinical trial) by computed tomography (CT) over the course of two years
Writing in JVS, Panthofer and colleagues report that the same proportion (85%) of the 192 patients (168 male; 24 female) included in the study was eligible for EVAR at baseline and at two-year follow-up.
In the discussion of their findings, the investigators comment that the high rate of baseline EVAR, as well as the sustained eligibility, are both testament to the expanding market of devices compared to earlier EVAR eligibility studies. They also acknowledge some limitations of their research, including the fact that non-anatomical factors—such as comorbidities and age—were not considered. In addition, they recognise that they studied predominantly male patients, which they state “may lead to an overestimate of population-wide eligibility rates”. However, they stress that N-TA3CT included a higher percentage of female candidate compared to past studies.
Based on these findings, the authors write that concern for outgrowing EVAR eligibility is “unwarranted” in the two-year timeframe assessed. However, they suggest that this conclusion “does not justify increased CT imaging surveillance […] as AAA growth patterns and optimal predictive biomarkers are still being debated”.