Editor's Choice - Late Open Surgical Conversion after Endovascular Abdominal Aortic Aneurysm Repair.

Introduction: Late open surgical conversion following endovascular aneurysm repair (EVAR) may occur more frequently after performing EVAR in anatomy outside the instructions for use (IFU). This study reviews predictors and outcomes of late open surgical conversion for failed EVAR.

Methods: This retrospective cohort study reviewed all EVARs performed at the Ottawa Hospital between January 1999 and May 2015. Open surgical conversions >1 month post EVAR were identified. Variables analysed included indication for conversion, pre-intervention AAA anatomy, endovascular device and configuration, operative technique, re-interventions, complications, and death.

Results: Of 1060 consecutive EVARs performed, 16 required late open surgical conversion. Endografts implanted were Medtronic Talent (n = 8, 50.0%), Medtronic Endurant (n = 3, 18.8%), Cook Zenith (n = 4, 25.0%), and Terumo Anaconda (n = 1, 6.2%). Eleven grafts were bifurcated (68.8%), five were aorto-uni-iliac (31.2%). The median time to open surgical conversion was 3.1 (IQR 1.0-5.2) years. There was no significant difference in pre-EVAR rupture status (1.4% elective, 2.1% ruptured, p = .54). Indications for conversion included: Type 1 endoleak with sac expansion (n = 4, 25.0%), Type 2 endoleak with expansion (n = 2, 12.5%), migration (n = 3, 18.8%), sac expansion without endoleak (n = 2, 12.5%), graft infection (n = 3, 18.8%), rupture (n = 2, 12.5%). Nine patients (56.2%) underwent stent graft explantation with in situ surgical graft reconstruction, seven had endograft preserving open surgical intervention. The 30 day mortality was 18.8% (n = 3, all of whom having had endograft preservation). Ten patients (62.5%) suffered major in hospital complications. One patient (6.5%) required post-conversion major surgical re-intervention. IFU adherence during initial EVAR was 43.8%, versus 79.0% (p < .01) among uncomplicated EVARs.

Conclusions: Open surgical conversion following EVAR results in significant morbidity and mortality. IFU adherence of EVARs later requiring open surgical conversion is markedly low. More data are required to elucidate the impact of increasing liberalisation of EVAR outside of IFU.