Ultrasound Evaluation for Suspected Recurrent DVT in Patients with Lymphedema

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 2
The American College of Radiology recommends ultrasound evaluation for patients with suspected recurrent DVT, particularly those with a history of lymphedema and DVT/PE 1, 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, 4

Complete duplex ultrasound (CDUS) is the preferred initial imaging modality for suspected recurrent DVT, according to the American Heart Association 2, 1
For patients with a history of DVT, ultrasound can identify new noncompressible segments in previously normal veins and significant increase (>4 mm) in residual diameter of previously affected veins 5
The American College of Chest Physicians recommends ultrasound as the initial diagnostic test for suspected DVT in patients with lymphedema 5

Asymmetric worsening of lower extremity swelling in a patient with history of DVT/PE is a concerning sign that warrants investigation, as stated by the American College of Radiology 1, 4
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, according to the American College of Radiology 4

If ultrasound confirms recurrent DVT despite therapeutic anticoagulation, consideration of alternative anticoagulation strategy may be needed, and evaluation for underlying hypercoagulable conditions might be warranted, as recommended by the American Society of Hematology 6
If ultrasound is negative but symptoms persist, consideration of iliac and pelvic veins evaluation, which may be missed on standard ultrasound, is recommended by the American Heart Association 2

Relying on D-dimer testing alone, which has limited utility in patients already on anticoagulation, is a common pitfall, as stated by the American Society of Hematology 6, 7
Failing to perform comprehensive ultrasound that includes both proximal and distal veins is another common pitfall, according to the American Heart Association 2