A Systematic Review and Pooled Meta-Analysis on the Incidence and Temporal Occurrence of Type II Endoleak Following an Abdominal Aortic Aneurysm Repair.

Background: The aim in this study was to systematically review the literature to identify the time of occurrence of a newly diagnosed Type II endoleak (T2E) following an endovascular aneurysm repair (EVAR) for an infrarenal abdominal aortic aneurysm (AAA) and its potential impact on aneurysmal sac diameter changes.

Methods: A comprehensive systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Eligible studies were identified through a search of PubMed, Scopus and Cochrane until January 2020. A meta-analysis was conducted with the use of a random effects model. The I-square statistic was used to assess for heterogeneity.

Results: Thirty-three observational studies were deemed eligible and provided data for 2643 T2E detected following EVAR. A total of 1432 (54.2%) T2E were diagnosed before 30 days follow-up, while 1035 (39.1%) T2E were diagnosed beyond 30 days following EVAR. A total of 222 (8.4%) T2E were diagnosed after 12 months of follow-up. A pooled meta-analysis of 6 studies, showed that early diagnosed T2E had a statistically significant higher odds of resolving as compared to those detected late (OR: 2.41; 95% CI: 1.14-5.09; P = 0.021; I = 68.9%). Sac expansion was documented in 313 (29%) T2E. The ruptured endoleaks were 14 (1.1%).

Conclusions: The occurrence of a T2E is a dynamic process detected throughout the lifetime of a patient with 8% detected beyond 12 months following EVAR. Long-term follow up is required with future prospective studies with consist reporting on changes in sac diameter, the thrombus characteristics. Long-term outcomes are needed to optimize management of patients with a newly diagnosed T2E.