Long-term results of outside "instructions for use" EVAR

Endovascular aneurysm repair (EVAR) has progressively expanded to more complex anatomies, frequently outside manufacturer's instructions for use (IFU). However, the long term results of off-label use of EVAR remain largely undocumented. The aim of this paper is to examine the long term results of outside IFU EVAR.

English literature was searched to identify publications on long term results for outside IFU EVAR. A follow-up extending for at least 5 years was the minimum required as inclusion criteria. The outcomes measured were: overall mortality, aneurysm-related mortality (ARM), freedom from postimplant aneurysm rupture, aneurysm sac enlargement, type I endoleaks and secondary interventions. Results were compared to randomized clinical trials (RCTs) with long term results published (EVAR-1, DREAM, OVER and ACE Trial).

Thirteen studies were included. 7 studies described outcomes associated to a specific breached IFU, while 6 studies presented general outside IFU results. In patients outside IFU, 3 to 8 years estimates of overall mortality ranged from 21.5% to 40% (RCTs:13.7-46%) and ARM from 0-11% (RCTs: 1.2-7%). Five-year estimates of sac enlargement was approximately 43%. Type I endoleak rates for outside IFU (follow-up 5-12 years) ranged from 3.8-15%, which is higher than found in RCT-derived data (6.6-6.9%). Comparable results are seen for postimplant rupture and secondary interventions.

The long term results of off-label use of EVAR are scarcely published. Although overall mortality and ARM does not seem to differ significantly at long-term, higher rates of type I endoleaks may be expected, mainly in short necks. However, for patients with severe angulation or high thrombus load in the proximal neck, results of outside IFU EVAR seem to match the results of inside IFU.