Chronic venous insufficiency arises when the one-way valves inside the superficial veins fail, allowing blood to reflux and pool against gravity. For decades the reference treatment for great saphenous vein (GSV) reflux was thermal ablation, which requires tumescent anesthesia to protect perivenous tissue from heat. Non-thermal, non-tumescent (NTNT) techniques were developed to remove both of those requirements, simplifying the procedure and improving the early recovery experience.
Why non-thermal, non-tumescent?
Thermal methods such as radiofrequency and endovenous laser ablation deposit energy into the vein wall to achieve fibrotic occlusion. They are highly effective, but the peri-venous heat mandates multiple tumescent anesthetic injections along the treated segment. NTNT approaches close the vein through a mechanical or chemical mechanism instead of heat, which eliminates the thermal injury risk to adjacent nerves and skin and removes the need for tumescent infiltration.
Mechanisms of action
- Cyanoacrylate closure. A medical adhesive is delivered in small aliquots along the vein under ultrasound guidance. The polymer triggers an inflammatory reaction and mechanical seal that occludes the lumen.
- Mechanochemical ablation. A rotating wire disrupts the endothelium while a sclerosant is delivered simultaneously, combining mechanical and chemical injury.
- Sclerosant-based occlusion. Liquid or foam agents induce endothelial injury and fibrosis, useful for tributaries and smaller vessels.
Procedural technique
The target vein is accessed with a micropuncture needle at the most distal point of reflux under duplex ultrasound. The delivery catheter tip is positioned a few centimeters distal to the saphenofemoral or saphenopopliteal junction. The closure agent is then delivered along the segment during controlled catheter pullback, with brief compression applied over each treated interval. Because no thermal energy is used, the procedure is generally performed with only local anesthesia at the access site and patients typically resume normal activity quickly.
Patient selection and outcomes
NTNT techniques are well suited to symptomatic GSV or small saphenous vein reflux, including patients who wish to avoid the multiple injections of tumescent anesthesia. Reported outcomes in the literature show high early and mid-term closure rates with low complication profiles, and meaningful improvement in venous clinical severity and quality-of-life scores. Careful duplex mapping remains essential to confirm the pattern of reflux and to plan treatment of associated tributaries.
INVAMED technologies in this space
INVAMED develops a dedicated venous portfolio for non-thermal treatment, including the VenaBLOCK cyanoacrylate closure system for truncal veins and the VeinOFF agent for smaller vessels, alongside thermal options for physicians who prefer them. Peer-reviewed evidence for these platforms is catalogued in the INVAMED Clinical Evidence Library.
Device availability and approved indications vary by country. This content is prepared for healthcare professionals and does not replace clinical judgment or the product instructions for use.