Potential of D-Dimer as a Tool to Rule Out Sac Expansion in Patients With Persistent Type 2 Endoleaks After Endovascular Aneurysm Repair.

Purpose: In managing type 2 endoleak (T2EL) following endovascular aortic aneurysm repair (EVAR), an indication for reintervention is aneurysm enlargement (AnE). A previous study found that low D-dimer levels (DDLs) at 1 year were associated with reduced AnE risk in patients with persistent T2ELs (pT2ELs). This study analyzed patients with pT2ELs to determine the correlation between DDLs at annual follow-ups and AnE and proposed a follow-up protocol incorporating DDL monitoring.

Methods: A retrospective review of elective EVAR cases between June 2007 and January 2021 identified "persistent" T2EL as confirmed at both 6- and 12-month contrast-enhanced CT studies. "Isolated" T2EL referred to cases without other endoleak types within 12 months. Inclusion criteria comprised >2 years of follow-up, isolated pT2ELs at 1 year, and DDL data at any annual follow-up over 5 years. The association between DDL and AnE, defined as ≥5 mm expansion within 5 years, was analyzed.

Results: A total of 109 patients with DDL data at 288 time points were enrolled. During a median follow-up of 49 months [31-60, IQR], 43 AnE were observed. In patients without AnE and with DDL data at 1 and 2 years (N=77 and 56), lower DDLs were associated with a reduced AnE risk (p=0.03 and 0.01). Optimal cutoff points were 5.4 and 5.3 µg/mL (AUC=0.651 and 0.702) with high negative predictive values (86.9% and 93.8%). Cox regression analyses confirmed that DDLs surpassing the cutoff values correlated significantly with AnE (p=0.042 and p=0.038). Our simulated protocol for omitting imaging studies in patients with stable aneurysms and low DDL might have overlooked one AnE but could have saved 28 imaging studies over 3 years if implemented on our patients.

Conclusion: Low DDLs at the 1- and 2-year follow-ups can potentially exclude AnE in pT2EL patients, suggesting DDL monitoring as a resource-saving approach.

Clinical Impact: The management of type 2 endoleaks in post-EVAR patients has been a topic of debate. This retrospective single-center study, featuring strict inclusion criteria, included 109 patients with persistent type 2 endoleaks. The findings indicate that patients with lower D-dimer levels at 1- and 2-year follow-ups are unlikely to experience sac enlargement ≥5 mm within 5 years, even in the presence of type 2 endoleaks. This study suggests that D-dimer monitoring has the potential to reduce reliance on imaging studies for the follow-up of patients with type 2 endoleaks, leading to significant savings in medical resources.