Discuss von Willebrand disease as another important cause of surgical bleeding

Discuss von Willebrand disease as another important cause of surgical bleeding.

von Willebrand disease is not as common as hemophilia A but is more common than the other types of hemophilia. It occurs in both males and females with an autosomal dominant pattern in Type 1 and Type II diseases.

Patients with this disease often have frequent mucosal bleeding and females may have excessive menses and post-partum bleeding. Unlike hemophilia A, spontaneous hemarthroses are uncommon. von Willebrand disease, like hemophilia A, has a broad spectrum of clinical features seen within the same family members afflicted by this disease. All types of von Willebrand disease are associated with the laboratory finding of a prolonged bleeding time (not seen with hemophilia A), a decrease in factor VIII levels, and a mild to moderate prolonged PTT. Platelet count and PT are normal. Type I patients, with classic von Willebrand disease, have reduced plasma levels of von Willebrand protein, von Willebrand factor activity and fac-tor VIII activity. Absent or diminished platelet aggregation occurs in the presence of ristocetin.

Cryoprecipitate is rich in factor VIII and von Willebrand factor and, therefore, corrects both deficiencies. Factor VIII concentrates lack sufficient amounts of von Willebrand factor and are not considered effective treatment. Patients with mild to moderate disease with minor trauma or scheduled for surgery and/or dental extraction should receive DDAVP. As noted above, DDAVP increases factor VIII levels (Table 53.1).