Implementation of the Updated European Society for Vascular and Endovascular Surgery Proposed Endovascular Aneurysm Repair Surveillance Algorithm in a Multicentre Cohort with a Minimum Five Year Follow Up Adherence: Further Improvement of Results via 1 Year Sac Dynamics

Objective: This multicentre, retrospective, observational study aimed to identify patients who are suitable for less frequent follow up (FU) controls after endovascular aneurysm repair (EVAR) through the validation and implementation of the recently updated European Society for Vascular and Endovascular Surgery (ESVS) surveillance algorithm. Methods: An analysis was performed on patients who underwent consecutive EVARs for abdominal aortic aneurysm (AAA) at four high volume centres that showed a FU adherence of at least five years. Patients were divided into high risk and low risk for adverse events, according to ESVS definitions, and compared. A subanalysis was conducted for patients categorised as low risk who exhibited sac regression and no evidence of endoleak at one year FU assessment. Results: Of 596 patients meeting the inclusion criteria, 300 (50.3%) fulfilled the ESVS criteria for classification as low risk. At five year FU, the rates of rupture (0.7% vs. 3%; p = .031), AAA related mortality (0.7% vs. 2.4%; p = .089), and re-intervention (9.7% vs. 17.2%; p = .007) were lower in the low risk group. Over the initial five years of FU, a total of 84 patients experienced adverse events such as re-interventions, ruptures, and/or AAA related mortality, with 28 occurring in the ESVS low risk group, indicating that the ESVS protocol has a five year capability of predicting 90.7% of potential adverse events in low risk patients. The subanalysis of ESVS low risk patients who exhibited sac regression and no evidence of endoleak at one year FU (20.1% of the total cohort) revealed a five year modified ESVS protocol capability of potentially predicting 97.6% of adverse events (three re-interventions recorded). Conclusion: The updated ESVS surveillance algorithm provides a consistent prediction of potential adverse events within five years of FU, although refining patient stratification may further improve outcomes. Patients initially classified as low risk and also exhibiting sac regression without endoleaks at one year could be better candidates for reduced surveillance.