Objectives: Duplex ultrasonography was assessed for its advanced role as a contemporary guide for the safer management of venous malformation (VM) at the lower extremities through a comparison study with matching magnetic resonance imaging (MRI) and/or ascending phlebography findings.

Methods: A retrospective review of 50 patients with a VM in the lower extremities was performed using the duplex scan findings on the initial diagnosis and the subsequent follow-up assessment of the treatment response. The screening findings of deep vein thrombosis (DVT) development following ethanol sclerotherapy on 40 patients were also included. A marginal vein (lateral embryonal) compression test was also performed on 10 patients, who were candidates for a resection preoperatively, in order to assess its value in predicting the response to the subsequent resection. The duplex scan findings were compared with the available ascending phlebography results in 38 patients, and also with the MRI findings available for all 50 patients.

Results: The duplex scan on the 50 patients confirmed the existence of a normal deep vein system in the lower extremities in 43 patients as the true-positive test findings. One false-negative test finding was subsequently confirmed by an angiographic evaluation. The duplex scan also confirmed the absence of a normal deep vein system in four patients as a true-negative test. MRI subsequently confirmed two false-positive findings in one patient, and angiography confirmed two false-positive findings in another (sensitivity − 97.8%, specificity − 66.7%, positive predictive value − 95.6%, and negative predictive value − 80%). Among a total of 40 patients who received ethanol sclerotherapy, the duplex scan identified DVT in three patients, and also screened out properly in 37 patients through a total of 185 ethanol sclerotherapy sessions. The compression test predicted the surgical outcome successfully in the majority (7/8). The duplex scan appears to have comparable reliability to MRI and/or angiography for diagnosing and managing VM.

Conclusions: The duplex scan can provide the critical haemodynamic information of both the deep venous system and VM lesions quite effectively with the cost-effectiveness of a non-invasive test. In particular, the duplex scan is an excellent test for the safe management of VM of the lower extremity, including the early detection of DVT through multi-session ethanol sclerotherapy.