Endograft Device type is a Significant Risk Factor for Limb Graft Occlusion After Endovascular Aortic Repair of Infrarenal Abdominal Aortic Aneurysm

Abstract

Introduction: Limb graft occlusion (LGO) is an uncommon yet serious complication after EndoVascular Aortic Repair (EVAR). It is reportedly influenced by several patient-specific anatomical variables. In a rapidly developing field of new vascular devices and an overall tendency toward endovascular treatment of complex aortic cases, minimising complications becomes increasingly important. Albeit worldwide clinical usage, there is still a lack of long-term follow-up data for many “second generation” endograft types. Our objective was to identify factors associated with LGO after EVAR. Methods: Between 2013-2018, all patients undergoing standard EVAR for infrarenal aortic aneurysms at two high-volume Vascular referral centers were included in this study. Cases treated with fenestrated or branched endografts were excluded. Patients were identified through a national registry for Vascular Surgery and all pertinent data was retrospectively collected from patient electronic medical records. LGO was defined as a symptomatic total limb occlusion requiring intervention. Results: Mean age at primary intervention for the 639 patients included was 75.3 years and 85.5% were men. Three graft manufacturers were predominantly used; Medtronic Endurant (n=274), Cook Zenith (n=243) and Gore Excluder (n=122). All grafts were bifurcated and the majority were deployed in an elective setting (77.5%). Median follow-up time for respective groups was 52, 21 and 25 months. A total of 29 patients presented with LGO (4.5%); 8 patients treated with Medtronic (2.9%), 19 with Cook (7.8%) and 2 with Gore (1.6%). Cox proportional hazard regression models were used to estimate multivariable hazard ratios (HR) with 95% confidence intervals (95% CI) of LGO during follow up. The multivariable HR of LGO was increased more than 6-fold in the Cook Zenith group, compared with Medtronic Endurant (HR, 6.14; 95% CI, 2.29 - 16.44), and Gore (HR 7.10; 95% CI, 1.55 - 32.57) respectively. There was no significant difference in rate of LGO when comparing Gore with Medtronic (HR, 0.87; 95% CI, 0.18-4.26). The observed point estimates in univariable models did not differ from those observed after adjustment for potential confounders in multivariable models. We observed no difference in rate of all cause mortality between the three groups. Conclusion: In this study, endograft device type was identified as an independent risk factor for LGO after EVAR. Specifically, limbs in the Cook Zenith endografts were observed to occlude at a 6 times higher rate compared with the Medtronic Endurant or Gore Excluder devices. [Rate of Limb Graft Occlusion] Disclosure: Nothing to disclose