Local alterations of hemostatic-fibrinolytic mechanisms in reforming subdural hematomas.

Multiple chemical and coagulation determinations were undertaken on the subdural hematoma fluid from the reformed effusions of two patients. It was found that plasma or blood repeatedly reentered the subdural cavity. Coagulation studies compared the in vitro effects of subdural fluid with those of cerebrospinal fluid, serum, and a buffer control. Despite some chemical differences, the subdural fluids from both patients behaved similarly by (1) accelerating the intrinsic clotting system, (2) producing defective clot formation, and (3) accelerating the fibrinolytic system. It is presumed that these continuous hemostatic-fibrinolytic alterations, acting in the subdural sac, may have important implications in the growth and reformation of subdural hematomas, and a hypothesis of the mechanisms involved is presented.