Von Willebrand's disease is a hereditary bleeding disorder caused by a deficiency of von Willebrand factor. Von Willebrand factor helps platelets to stick to the blood vessel wall and to each other, which is necessary for normal blood clotting.
Causes, incidence, and risk factors
Von Willebrand's disease is the most common hereditary bleeding disorder. It affects both sexes approximately equally. Most cases are mild, and bleeding may occur after a surgical procedure or tooth extraction. The condition is worsened by the use of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs). Bleeding may decrease during pregnancy .
The disease is very common, affecting at least 1% of the population. There are no racial or ethnic associations with this disorder. A family history of a bleeding disorder is the primary risk factor.
Signs and tests
Normal platelet count
Prolonged bleeding time
Reduced von Willebrand factor level Reduced platelet aggregation ( platelet aggregation test )
Ristocetin co-factor is reduced This disease may also alter the results of the following tests:
Factor VIII level von Willebrand factor multimers
Treatment
For most patients, bleeding is mild under most circumstances. However, if trauma occurs or surgery is scheduled, cryoprecipitate or DDAVP can be given to raise the levels of von Willebrand factor, which will decrease the tendency towards bleeding . Fresh plasma or certain Factor VIII preparations may also be used to decrease bleeding.
Some subtypes of von Willebrand disease do not respond to DDAVP. Because of this, the subtype should be determined prior to reliance on DDAVP for a significant bleeding challenge. In addition, a trial of DDAVP can be done prior to surgery to test whether von Willebrand factor levels increase. Patients with this disorder should not take nonsteroidal anti-inflammatory drugs (NSAIDs) such as aspirin or ibuprofen without consulting their health care provider.
Expectations (prognosis)
Females giving birth usually do not experience excessive bleeding . Life span is usually normal. Since this disease is genetically transmitted, genetic counseling may be recommended for parents.
Complications
Postoperative hemorrhage ( bleeding ) may occur.
Calling your health care provider
Call your health care provider if bleeding occurs with no reason. If you have this disorder and are scheduled for surgery or are in an accident, be sure to notify the health care providers about your condition.
Prevention
There is no known prevention.