What precautions should be taken for a 65-year-old female patient with suspected type 2B von Willebrand disease and a mildly low platelet count (thrombocytopenia) undergoing a colonoscopy with potential biopsies?

Management of Colonoscopy with Potential Biopsies in a Patient with Type 2B von Willebrand Disease and Thrombocytopenia

For a 65-year-old female with suspected type 2B von Willebrand disease and a platelet count of 128,000/μL undergoing colonoscopy with potential biopsies, platelet transfusion is not necessary, but VWF concentrate should be administered to achieve VWF activity levels >50 IU/dL before the procedure.

Pre-Procedure Assessment and Planning

• The patient's platelet count of 128,000/μL is only mildly decreased and above the threshold of 50,000/μL required for safe invasive procedures with potential biopsies 1
• Type 2B von Willebrand disease is characterized by increased binding of VWF to platelet GPIbα receptors, causing increased platelet clearance and loss of high molecular weight VWF multimers 2
• Colonoscopy with biopsy is considered a low-risk procedure for bleeding, but the presence of VWD increases this baseline risk 3
• The procedure should be scheduled rather than performed emergently to allow for proper preparation 3

Laboratory Assessment

• Before the procedure, confirm current platelet count, VWF antigen level, and factor VIII activity level to guide appropriate treatment 3
• Assess coagulation parameters to evaluate potential bleeding risk 1
• A platelet count >50,000/μL is generally considered safe for invasive procedures including colonoscopy with biopsies 1

Treatment Recommendations

• Administer VWF concentrate before the procedure to achieve VWF activity levels of at least 50 IU/dL 1, 3
• Avoid desmopressin (DDAVP) in type 2B VWD patients as it may cause a transient decrease in platelet count, potentially increasing bleeding risk 2, 4
• Platelet transfusion is not necessary with the current platelet count of 128,000/μL, and may provide suboptimal results in type 2B VWD since transfused platelets may be aggregated by the patient's abnormal VWF 2
• Consider administering tranexamic acid as an adjunctive hemostatic agent 5

Procedure Considerations

• If multiple or large biopsies are anticipated, consider using cold biopsy techniques when possible, as they are associated with less bleeding than hot biopsy techniques 3
• Ensure that a post-treatment VWF level and platelet count are obtained to confirm that the desired levels have been reached before proceeding 1
• Have additional VWF concentrate readily available in case of intraoperative or postoperative bleeding 1

Post-Procedure Monitoring

• Monitor the patient for at least 2-4 hours post-procedure for signs of bleeding 3
• Maintain VWF activity levels >50 IU/dL until adequate hemostasis is achieved 1
• Consider a follow-up assessment of hemoglobin level if multiple biopsies were performed 3
• Instruct the patient to report any signs of delayed bleeding, which can occur up to 21 days after the procedure 3

Special Considerations for Type 2B VWD

• Type 2B VWD patients may experience worsening thrombocytopenia during periods of stress, including invasive procedures 6
• Minimize additional stressors that could exacerbate thrombocytopenia 6
• Be aware that the patient's age (65 years) represents an additional risk factor for post-polypectomy bleeding 3