Hemostatic effect of transfused Willebrand factor in porcine von Willebrand's disease. Similarities to the human disease.

Cryoprecipitate was infused into pigs with severe von Willebrand's disease, and the bleeding time was corrected when the plasmatic level of VIII R:AG (WF) was above 30 U/dl. The VIII R:AG (WF) was not completely recovered but none was found in the plasma or endothelial cells. A new method for measuring the bleeding time is described--the ratio bleeding time. These results in pigs are compared with the reported results in humans.