Prognostic Value of D-Dimer Dynamics for Aneurysm Enlargement in Patients With Persistent Type 2 Endoleaks After Endovascular Aneurysm Repair

Purpose: Persistent type 2 endoleaks (pT2ELs) following endovascular aortic aneurysm repair (EVAR) pose surveillance challenges. Although previous studies demonstrated that low D-dimer levels at single time points indicate lower risk of aneurysm enlargement (AnE), the value of longitudinal D-dimer monitoring remains unexplored. This study examined associations between D-dimer dynamics and AnE in patients with pT2ELs. Methods: This is a retrospective single-center cohort study. Consecutive patients undergoing elective EVAR (2007-2022) were reviewed. Inclusion criteria were isolated pT2ELs confirmed at 12 months, >2 years of follow-up, and available annual D-dimer data. Primary outcome was AnE (≥5 mm sac diameter increase) within 5 years. D-dimer trajectories were retrospectively classified as consistently low (<5.3 µg/mL throughout), transitioned to high (≥13.5 µg/mL at any point), or intermediate (all others). Analyses used multivariable trajectory-based Cox regression, time-dependent Cox regression, and generalized estimating equations (GEEs), adjusting for chronic kidney disease, inferior mesenteric artery patency, and number of patent lumbar arteries (≥6). Results: Among 118 patients, 43 (36.4%) experienced AnE. Kaplan-Meier analysis showed significantly lower freedom from AnE in the transitioned to high group (overall log-rank P = .002). In trajectory-based Cox regression, the transitioned to high group had significantly increased AnE risk versus the consistently low group (adjusted hazard ratio = 4.76, 95% confidence interval [CI]: 1.62-14.00, P = .005). Generalized estimating equation sensitivity analysis confirmed a dose-response relationship, with high D-dimer showing the strongest association (odds ratio 3.45, 95% CI: 1.69-7.05, P < .001). Conclusion: D-dimer dynamics were associated with AnE in patients with pT2ELs. Multiple complementary analyses demonstrated consistent dose-dependent associations. Retrospective trajectory classification defined distinct prognostic phenotypes: patients maintaining levels <5.3 µg/mL demonstrated superior sac stability, whereas elevations ≥13.5 µg/mL identified a higher-risk group. These findings support a biomarker-guided dynamic surveillance strategy, pending prospective validation before clinical deployment. Clinical Impact Current surveillance of persistent type 2 endoleaks relies solely on imaging, lacking validated biomarkers to guide follow-up. This retrospective study shows that longitudinal D-dimer trajectory patterns were independently associated with aneurysm enlargement over 5 years, and D-dimer levels at each annual visit were associated with enlargement risk in the subsequent year. A routinely available blood test may therefore complement imaging-based surveillance: levels below 5.3 µg/mL were associated with low enlargement risk, whereas elevations ≥13.5 µg/mL defined a higher-risk phenotype warranting closer follow-up. If prospectively validated, this biomarker-guided approach could support individualized surveillance and more efficient use of imaging resources.