Feasibility of endovascular abdominal aortic aneurysm repair outside of the instructions for use and morphological changes at 3 years after the procedure.

INTRODUCTION We retrospectively analyzed outcomes of patients who had undergone endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA) more than 3 years previously in a single institution. We compared outcomes between patients who underwent EVAR within and outside of the devices' instructions for use (IFU) and examined mid-term morphological changes in AAA. METHODS A total of 275 patients who underwent EVAR for AAA were selected. IFU parameters included aneurysmal neck length, angulation and presence of massive atheroma. Patients were divided into 2 groups: the Within IFU group (W-IFU: n = 193) and the Outside of IFU group (O-IFU: n = 82). RESULTS Patients in the O-IFU group were older and had a larger AAA diameter. Other comorbid factors were similar between the 2 groups. There was no difference in overall survival rates and reintervention rates between the 2 groups. The most common cause for reintervention was AAA enlargement 3 years after EVAR. Irrespective of the IFU, mid-term morphological changes, including neck angulation, neck diameter, sac re-expansion, and Palmaz stent displacement, were found. CONCLUSION Outcomes of EVAR were considered acceptable in the O-IFU group. Careful follow-up is necessary considering the morphological changes in AAAs after EVAR.