Diagnosis and Management of Von Willebrand Disease (VWD): Guidelines for Primary Care

Resident: J. Hencler
Date: 03/01/2011

Article title: Diagnosis and Management of Von Willebrand Disease (VWD): Guidelines for Primary Care
Author: Yawn, Nicholas, Rick
Journal: American Family Physician Vol80, #11, 12/2009
Major topic: VWD
Type of Article: Review

Main Purpose:
Summarize recent guidelines on the diagnosis and management of VWD.

Background and Pathophysiology:
VWD encompasses a group of inherited bleeding disorders related to qualitative or quantitative defects of von Willebrand factor (VWF), which is essential in hemostasis. The disease leads to bleeding from impaired platelet adhesion and aggregation. Synthesis of VWF occurs in the vascular endothelium and megakaryocytes. It is released from platelets and endothelial cells when they are activated and binds to factor VIII in the circulation, prolonging its half-life to approximately 12hours. With vascular injury, VWF bridges between exposed collagen and platelets. Factor VIII is also released from VWF and facilitates the formation of thrombin and a fibrin clot.

Classification:
Three major types and acquired von Willebrands syndrome (AVWS):
Type 1(75% of patients): Partial quantitative deficiency (low levels) of VWF
Type 2(25% of patients and 4 subtypes): Qualitative deficiency of VWF
Type 3(Rare): Complete deficiency of VWF
AVWS: less common than congenital VWD and typically associated with one of several mechanisms including complications from medication use (Ciprofloxin) or medical conditions including lymphoproliferative diseases or hypothyroidism.

Diagnosis:
Thorough personal and family history and lab tests including CBC, PTT, PT, Fibrinogen level or thrombin time, and VWD/VWF specific assays.

Management:
Three approaches to treatment of VWD used individually or in combination. These approached include 1) increasing plasma concentration of VWF by releasing endogenous VWF stores through stimulation of endothelial cells with desmopressin (DDAVP), 2) replacing nonexistent or ineffective VWF by using human plasma-derived, viral-inactivated concentrates, and 3) promoting hemostasis using hemostatic agents with mechanisms other than increasing VWF. Regular prophylaxis is seldom required, and treatment is initiated before planned invasive procedures or in response to bleeding.

Assessment of article:
This was a good review of VWD. Very detailed, most beyond the scope of what a pediatric dentist would need to know. The importance of some of the more general information will come into play when treating a child with VWD because it would be most important to frequently consult with the child PCP and other medical specialist caring for such a patient. Before any treatment, it would be very important to determine the VWD type what corresponding treatment is being carried out to ensure proper hemostatic function.