The Sac Evolution Imaging Follow-Up after EVAR: an international expert opinion-based Delphi consensus study

Objective: Management of follow-up protocols after endovascular aortic repair (EVAR), vary significantly between centres and is not standardized according to the sac regression. By designing an international expert-based Delphi consensus, the study aimed to create recommendations on follow-up after EVAR according to sac evolution. Methods: Eight facilitators created appropriate statements regarding the study topic that were voted, using a 4-point Likert scale, by a selected panel of international experts using a three-round modified Delphi consensus process. Based on the experts' responses, only those statements reaching a Grade A (full agreement ≥75%) or B (overall agreement ≥80% and full disagreement <5%) were included in the final document. Results: One-hundred and seventy-four participants were included in the final analysis, and each voted the initial 29 statements related to the definition of sac regression (Q1-Q9), EVAR follow-up (Q10-Q14), and the assessment and role of sac regression during follow-up (Q15-Q29). At the end of the process, 2 statements (6.9%) were rejected, 9 statements (31%) received a grade B consensus strength, and 18 (62.1%) reached a grade A consensus strength. Out of twenty-seven final statements, fifteen statements (55.6%) were classified as grade I, while twelve (44.4%) were classified as grade II. Experts agreed that sac regression should be considered an important indicator of EVAR success and always be assessed during follow-up after EVAR. Conclusions: Based on the elevated strength and high consistency of this international expert-based Delphi consensus, most of the statements might guide current clinical management of follow-up after EVAR according to the sac regression. Future studies are needed to clarify debated issues.