Failure of extravascular fibrin polymer formation in FibAEK mice following liver needle puncture injury. Representative scanning electron micrographs of right medial liver lobes from WT, Fib−/−, and FibAEK mice from uninjured areas (top row) or of the injured zone following needle puncture injury (bottom 3 rows). Note that the injured zone of WT mice was characterized by fibrin polymer structures associated with platelets and RBCs. In contrast, the injured zones of livers from both Fib−/− and FibAEK mice displayed platelet-rich clusters and RBCs, but a distinct absence of fibrin polymer structures.