Clot formation in Syk-treated FeCl₃ and punctured wound murine model. (A) Perpendicular section approximately middle of a Syk + FeCl₃-treated nonocclusive thrombus/sample. (B) A zoomed area from FeCl₃-treated nonocclusive thrombus shows a dispersed distribution of elongated platelets leaving large pores in between. (C) Blood flow was monitored and measured with a transit-time perivascular flowmeter and sonic probe. Arrows indicate the timing of FeCl₃ treatment. The initial segment was the flow signal detected before FeCl₃ treatment. The flow probe signal dropped out as fluid in the vessel’s surroundings was removed to prevent FeCl₃ dilution. Fluid was reintroduced upon removal of FeCl₃ filter paper, and the flow probe again became functional. Following FeCl₃ application, ∼20 minutes of probe flow signal data were collected. No dip in flow signal following treatment indicates no occlusion. (D) Perpendicular section of a Syk-treated punctured model shows a normal clot formation with outer vault consisting of highly activated and tightly packed platelets, while inner crowning consists of elongated, mostly discoid, and loosely packed platelets. (E) The table shows comparison of bleeding time in punctured wound femoral artery model between controls and Syk (BI 1002494)–treated mice. The P value is from a Student t test comparison of the mean bleeding times for control and BI 1002494–treated samples. (F) Cartoon model of proposed relationship between femoral puncture thrombus and an occlusive clot.