What is the best management approach for a patient with suspected type 2B von Willebrand disease undergoing surgery?

Management of Type 2B von Willebrand Disease in Surgery

For patients with suspected type 2B von Willebrand disease undergoing surgery, VWF-containing concentrates should be used as the primary treatment, as desmopressin may worsen thrombocytopenia and increase bleeding risk. 1

Diagnosis and Classification

Type 2B von Willebrand disease is characterized by:

• Normal factor VIII levels but abnormal von Willebrand factor (VWF) function
• Decreased platelet count during hemorrhages (as observed in the patient's mother)
• Enhanced binding of VWF to platelets, causing platelet aggregation and clearance
• Loss of high molecular weight VWF multimers

Laboratory findings typically include:

• VWF:RCo <30 IU/dL
• VWF:Ag 30-200 IU/dL
• VWF:RCo/VWF:Ag ratio <0.5-0.7
• Loss of high molecular weight multimers
• Enhanced ristocetin-induced platelet aggregation (RIPA) at low doses 1

Perioperative Management Algorithm

Preoperative Phase

1. Comprehensive coagulation testing:

   • Complete blood count with platelet count
   • Prothrombin time (PT)
   • Activated partial thromboplastin time (aPTT)
   • VWF screening (VWF:Ag, VWF:RCo, FVIII:C)
   • VWF multimer analysis to confirm type 2B diagnosis 1

2. Treatment planning:

   • First-line treatment: VWF-containing concentrates are the treatment of choice for type 2B VWD 1, 2
   • Target VWF:RCo levels:
     • Minor procedures: ≥50 IU/dL
     • Major procedures: ≥80-100 IU/dL 1

Intraoperative Phase

1. Administration of VWF-containing concentrates:

   • Administer immediately before surgery to achieve target levels
   • Monitor VWF:RCo levels during prolonged procedures
   • Consider additional doses as needed based on monitoring 1

2. Adjunctive hemostatic measures:

   • Consider tranexamic acid at induction of anesthesia 1
   • Have blood products (FFP, platelets, cryoprecipitate) readily available 3
   • Use viscoelastic testing (TEG/ROTEM) if available for hemostatic monitoring 1

Postoperative Phase

1. Continued factor replacement:

   • Maintain target VWF:RCo levels based on surgical procedure type
   • Continue therapy until adequate wound healing is achieved 1

2. Monitoring:

   • Regular assessment of coagulation parameters
   • Close observation for bleeding
   • Monitor hemoglobin, hematocrit, and platelet count 1
   • Initiate thromboprophylaxis only after adequate hemostasis is achieved 1

Important Considerations and Pitfalls

Desmopressin Contraindication

Desmopressin (DDAVP) is generally not recommended for type 2B VWD patients undergoing surgery because:

• It can induce transient thrombocytopenia by releasing large, abnormal VWF multimers 3, 4
• This can worsen the bleeding tendency rather than improve it 2
• It may cause profound drops in platelet count (up to 90% in some patients) 5

Special Situations

While some case reports suggest that desmopressin might be effective in select type 2B patients 6, this approach carries significant risks and should not be routinely used without:

1. Prior testing in a non-surgical setting
2. Close monitoring of platelet count
3. Availability of alternative treatments if thrombocytopenia develops 4

Platelet Transfusions

Platelet transfusions often provide suboptimal results in type 2B VWD because:

• Transfused platelets may be aggregated by the patient's abnormal VWF
• This can lead to rapid clearance of transfused platelets 2

Follow-up Care

• Regular hematology follow-up to monitor bleeding symptoms
• Periodic VWF testing
• Assessment of iron status and response to supplementation
• Screening of first-degree relatives due to the hereditary nature of the disease 1

By following this management approach, patients with type 2B von Willebrand disease can undergo surgery with minimized bleeding risk and improved outcomes.