Sac Shrinkage after Endovascular Aneurysm Repair: Multicentre Comparative Data from Three Stent Grafts.

Objective: Abdominal aortic aneurysm (AAA) sac shrinkage has been reported as a surrogate marker of treatment success after endovascular aneurysm repair (EVAR). This study aimed to compare sac shrinkage after treatment with the Aorfix stent graft with that of Endurant and Excluder devices.

Methods: This retrospective, multicentre cohort study analysed data for 444 patients with AAA after EVAR who were treated with Aorfix, Endurant, or Excluder devices between 2014 and 2021. Sac shrinkage was defined as a decrease in the maximum aneurysm diameter of ≥ 5 mm. Primary endpoints included sac shrinkage and factors related to sac shrinkage within one year after EVAR. Secondary endpoints included re-intervention, type Ia endoleak (T1aEL), aneurysm related death (ARD), and overall survival.

Results: Of the 444 patients, 88 were treated with Aorfix, 191 with Endurant, and 165 with the Excluder. Sac shrinkage rates within one year in the Aorfix, Endurant, and Excluder groups were 52.1%, 32.8%, and 34.0%, respectively (p = .003). Multivariate analysis revealed that Aorfix device (ref. Endurant, p < .001; ref. Excluder, p = .010), smaller proximal neck diameter (p = .004), and number of patent lumbar arteries less than four (p = .033) were positive factors for sac shrinkage within one year. Rates of re-intervention and T1aEL were lower in the sac shrinkage group within one year than in the group without sac shrinkage within one year. The ARD rate at ten years was 3.8% in the no shrinkage group and 0.7% in the shrinkage group (p= .29).

Conclusion: Sac shrinkage within one year was better in patients treated with the Aorfix device than in those treated with Endurant or Excluder devices, and sac shrinkage was a good surrogate marker for freedom from re-intervention and T1aEL after EVAR. However, the retrospective study design may introduce bias.