V.A.S.C. (Vacuum Assisted Sclerotherapy Performed by Catheter) (VASC)

Description

V.A.S.C. is a multicentric prospective, open label, non-randomized PMCF study of VelexTM venous catheter for patients with varicose veins of lower limb.

The study is designed as a post-market clinical follow-up, aimed at collecting clinical data of VelexTM venous catheter used according to the indication of use within the scope of the CE mark.

The study will enrol a maximum number of 36 patients at the participating sites. All the subjects will be evaluated at immediate post-procedure, 7 days, 1, 3 and 6 months after the procedure.

The eligibility criteria are compliant with the indication of use within the scope of the CE mark.

Several preclinical tests were carried out for assessing the safety of VelexTM venous catheter: in vitro tests, biocompatibility and preclinical-vivo test.

In-vitro test All the in-vitro tests were performed on samples at time zero and after aging, in order to simulate conditions of transport and storage of the device Biocompatibility The biocompatibility assessment included the overall evaluation of the device, including the manufacturing materials of the various components, the manufacturing processes, the clinical use of the device, including the expected anatomical location, and the frequency and duration of exposure.

According to ISO 10993-1, VelexTM venous catheter is classified as an external communication device with limited contact duration (≤24 hours), with contact with circulating blood. According to this category, dedicated tests were performed to provide data regarding specific biological effects:

• Cytotoxicity
• Sensitization
• Irritation or intracutaneous reactivity
• Pyrogenicity
• Acute systemic toxicity
• Hemocompatibility In all the biocompatibility test, the samples met the acceptance criteria. On the basis of biocompatibility tests carried out, VelexTM venous catheter device complies with the biocompatibility requirements according to ISO 10993-1: 2018.

Preclinical in-vivo test A preclinical in-vivo test was performed on ovine animal model in order to evaluate the safety of the device in conditions consistent with the clinical use and to verify the echogenicity of the device under ultrasound. Sclerotherapy procedure was simulated in jugular vein of adult sheep.

Most of the procedures (9/15) were successfully completed. Among the remaining 6 cases, 4 cases resulted in an incomplete procedure due to out of procedure (not conform to the IFU); in 2 procedures with the same catheter the user encountered resistance to catheter movement, therefore the catheter was retrieved but no damage to the device or to the vein was detected.

In order to simulate the dynamic method, the catheter with inflated balloons was repeatedly moved along the vessel without any issue.

By means of diagnostic imaging, the position of the catheter was checked, as well as balloons inflation and deflation, confirming the safety of the mechanism of action of the device. Hereafter, the device features positively assessed by these tests are listed:

• Safe compatibility with Seldinger technique;
• Good pushability/trackability;
• Excellent echogenicity;
• Safe inflation/deflation of balloons;
• Safe isolation of vein segment;
• Safe fluid injection;
• Safe displacement of the catheter;
• Safe fluid aspiration;
• Safe retrieval of the catheter;
• Safe synchronism mechanism (handle). In addition, it is remarkable that no damages to the vein nor to catheter were observed. Damages to catheter were observed only when out of procedures occurred.

The in-vivo test confirmed the results of the in-vitro test in term of safety and ease of use of VelexTM venous catheter.

Evaluation of clinical data that are relevant to the proposed clinical investigation At the moment, the clinical evaluation of VelexTM catheter is based on literature data regarding the use of catheters for sclerotherapy.

Sclerotherapy is a well established treatment for small varicose vein but there are some limitations due to lack of standardization of the technique and the anatomical recurrence rate remains higher than the other endovenous options. The use of long catheters for sclerotherapy has been described since 1997. Through the use of catheters with occlusion balloons, the sclerosing agent can be maintained in contact with the venous inner wall for the period necessary to stimulate an endothelial response; furthermore, the occlusion balloon decreases the probability of damage to the structures of the deep venous system due to the migration of the sclerosant.

The major challenge that remains with any type of catheter is how to standardize the dose of therapeutic agent to be used during the procedure and to be able to distribute it evenly along the vascular wall.

Clinical data from scientific literature show that sclerotherapy with a catheter under echo guidance is safe and leads to clinical benefit for patients. The use of VelexTM is consistent with the current medical knowledge in the treatment of varicose veins. Indeed, VelexTM is a catheter with features that allow to control the concentration of sclerosant agent in an isolated venous segment emptied from blood and to keep it in place for the time deemed necessary.

VelexTM Venous Catheter is a venous catheter for temporary use to treat a vein isolated segment, designed for the treatment of varicose veins of lower limbs by means of chemical ablation or empty-vein sclerotherapy.

The device allows to isolate the vein section to be treated, to release the sclerosant agent in the lesion to be treated through the medication administration holes and to recapture the injected liquid, preventing undesired side effects.

It is composed by the following parts:

• Three-balloon catheter: main body and invasive part of the device;
• Handle: it manages the balloon and the medication infusion;
• Syringe preparation lines: silicone tubes to be connected to the handle in order to fill the syringes;
• Depth marker: sliders (C-shape rings) connected by a spacer. VelexTM venous catheter is intended to temporary inhibit blood flow in isolated sections of the peripheral veins of the lower limbs to infuse therapeutic agents (foam excluded) prescribed by physician for sclerotherapy.

The intended purpose of VelexTM venous catheter in the PMCF study coincides with the indication of use within the scope of the CE mark.

VelexTM venous catheter is intended for patients affected by lower limb CVD. The suitability of the patient is to be verified case by case by the specialized physician, by means of proper physical examination and evaluation of superficial and deep venous system by means of color Doppler echocardiography.

VelexTM venous catheter should be used by physicians having a deep knowledge of:

• vascular anatomy
• venous system pathology
• endovascular peripheral procedures and endovascular methods
• Seldinger technique or techniques for surgical isolation of a superficial vein
• diagnostic methods, especially peripheral echo color Doppler echocardiography of deep and superficial venous system and angiography.

VelexTM venous catheter shall be inserted in a vein of the lower limb by means of direct phlebotomy or Seldinger technique with 7 Fr introducer, and placed in the desired position under echo guidance.

Details