This is a one-arm, open label, prospective, single center study to evaluate clinical standardization with Theraclion's Sonovein 2 HIFU device.

The original Sonovein device was tested in a clinical trial in 50 subjects and received CE Mark. That device has been updated yielding the current version of Sonovein 2. Based on the technical similarities between both devices in term of design, performance and principle of operation, the clinical data for Sonovein is sufficient to assure conformity of the Sonovein 2 with the respected essential requirements. At the same time, the compagny wishes to pursue the standardisation of the clinical practice with the second generation device and is, therefore, conducting this limited trial in 20 evaluable cases (from the planned 22 patients to be included). A "case" is defined as procedure conducted on a distinct vein.

The Sonovein 2 system provides high intensity focused ultrasound (HIFU) abaltion of soft tissue. The energy is delievered via an extra-corporeal treatment probe, which includes an imaging system. The high energy ultrasound waves propagate through the skin and are focused on a portion of the target tissue, generating intense heat and causing local cell apoptosis and progressive tissue volume reduction over the following months in the tissue within the focal area. The process is then repeated in a stepwize fashion to destroy the targeted tissues. The Sonovein 2 system is comprised of several components, including the console, treatment arm containing the visualization and treatment unit (VTU), a computer with touchscreen user interface. In addition, the Sonovein 2 system is intended to be used in conjunction with a disposable cooling and coupling system known as ePack.

Inclusion Criteria:

1. Candidate for venous procedure involving lower limb superficial insufficiency involving reflux in the segment to be treated
2. Physical condition allowing ambulation after the procedure
3. Availability of the patient for all the follow-up visits
4. Targeted tissue reachable for treatment with the device-meaning between 5mm and 26mm below the skin surface
5. Age over 18 years of age at the time of enrollment
6. No acute venous thrombosis
7. No complete, or near complete deep vein thrombosis
8. Patient has signed a written informed consent
9. Targeted structure sonographically visible

Exclusion Criteria:

1. Patient is pregnant or nursing
2. Known allergic reaction to anesthetic to be used
3. Legally incapacitated or imprisoned patients
4. Patient's vein target not clearly visible on the ultrasound images (B mode) at the inclusion visit
5. Patient participating in another clinical trial involving an investigational drug, device or biologic