Does a patient with a history of lymphedema and DVT/PE on Eliquis (apixaban) 5mg BID require an ultrasound to rule out a new DVT given increased swelling in one lower extremity?

Ultrasound Evaluation for Suspected Recurrent DVT in a Patient with Lymphedema

Yes, an ultrasound is necessary to evaluate for recurrent DVT in this patient with a history of lymphedema and DVT/PE who presents with increased right lower extremity swelling despite being on therapeutic anticoagulation with Eliquis. 1

Rationale for Ultrasound Evaluation

• Patients with persistent or worsening symptoms despite being on anticoagulation therapy require imaging to rule out recurrent DVT, as clinical assessment alone is unreliable 1
• The Society of Radiologists in Ultrasound specifically recommends repeat ultrasound for patients with persistent symptoms despite a previous negative DVT result or ongoing anticoagulation 2
• Lymphedema can mimic DVT symptoms, but the presence of asymmetric worsening in a patient with history of DVT/PE raises concern for recurrent thrombosis 1

Diagnostic Approach for This Patient

• Complete duplex ultrasound (CDUS) is the preferred initial imaging modality for suspected recurrent DVT 1
• For patients with a history of DVT, ultrasound can identify:
  • New noncompressible segments in previously normal veins 1
  • Significant increase (>4 mm) in residual diameter of previously affected veins 1, 3
• The presence of lymphedema does not negate the need for DVT evaluation, as both conditions can coexist 4

Clinical Considerations in This Case

• Despite being on therapeutic anticoagulation (Eliquis 5mg BID), recurrent DVT can still occur 5
• Asymmetric worsening of lower extremity swelling in a patient with history of DVT/PE is a concerning sign that warrants investigation 1
• The absence of shortness of breath is reassuring but does not rule out DVT, as approximately one-third of patients with DVT do not have obvious symptoms 1

Management Implications

• If ultrasound confirms recurrent DVT despite therapeutic anticoagulation:
  • Consideration of alternative anticoagulation strategy may be needed 5
  • Evaluation for underlying hypercoagulable conditions might be warranted 1
• If ultrasound is negative but symptoms persist:
  • Consider evaluation of iliac and pelvic veins, which may be missed on standard ultrasound 1
  • Serial ultrasound may be indicated if clinical suspicion remains high 1, 2

Common Pitfalls to Avoid

• Assuming that therapeutic anticoagulation eliminates the possibility of recurrent DVT 5
• Attributing new or worsening symptoms solely to lymphedema without appropriate investigation 4
• Relying on D-dimer testing alone, which has limited utility in patients already on anticoagulation 1
• Failing to perform comprehensive ultrasound that includes both proximal and distal veins 1

Special Considerations for Lymphedema Patients

• Patients with lymphedema have baseline abnormal limb appearance, making clinical assessment for DVT particularly challenging 4
• Comparison with previous imaging is essential to differentiate chronic changes from acute thrombosis 1, 3
• Both conditions (lymphedema and DVT) require ongoing management, and compression therapy approaches may need modification if acute DVT is confirmed 4