Thrombin inhibition decreases fibrin accumulation and thrombus size, but not vessel sealing. (A) Representative images of thrombi formed either in the presence of vehicle (left) or thrombin inhibitor hirudin (right) (∼0.7 mg/g) showing platelets (blue) and P-selectin (red) 3 minutes postinjury. (B) Quantification of average platelet area, (C) peak fibrin area, and (D) peak P-selectin area for both vehicle-treated (black) and hirudin-treated (white) thrombi (± SEM). (E) Time course of average cAlb extravasation (± SEM) and (F) dot plot of cAlb extravasation at 200 seconds for both vehicle-treated (black) and hirudin-treated (white) thrombi (vehicle n = 17, hirudin n = 18). P-sel, P-selectin.