The relationship between aortic aneurysm sac thrombus volume on coagulation, fibrinolysis and platelet activity

AimAbdominal aortic aneurysm (AAA) is associated with chronic mural inflammation and a pro-thrombotic diathesis. It has been suggested that both may be related to biologically active intra-sac thrombus. The aim of this study was to examine the relationship between thrombin generation, fibrinolysis, platelet activity and AAA sac thrombus volume.Methods30 patients (29 men) of median (IQR) age 75 (71–82) years with an infra-renal AAA > 5.5 cm in antero-posterior diameter were prospectively studied. AAA, lumen and thrombus volumes were calculated using a CT workstation (Vitrea). Plasma thrombin-antithrombin (TAT), plasminogen activator inhibitor (PAI)-1, and soluble (s) P-selectin were measured as biomarkers of coagulation, fibrinolysis and platelet activity, respectivelyResultsMedian (IQR) AAA total, lumen and thrombus volumes were 188 (147–247) cm3, 80 (54.3-107) cm3 and 97.6 (63–127) cm3 respectively.TAT levels were significantly higher (median, QR, 7.15 [4.7-31.3] μg/L, p = < 0.001) and sP-selectin levels significantly lower (median, IQR, 80.5 [68–128] ng/ml, p = < 0.0001) than the normal range. PAI-1 levels (median, IQR, 20.9 [8.4-50.7] ng/ml) were normal. There was no correlation between AAA thrombus volume and PAI-1 (r = − 0.25, p = 0.47), sP-Selectin (r = 0.26, p = 0.43) or TAT plasma levels (r = − 0.21, p = 0.54).ConclusionThe present study confirms that patients with AAA demonstrate haemostatic derangement, but the extent of the haemostatic derangement does not correlate with AAA sac thrombus volume.