Foam sclerotherapy is a widely used technique for treating varicose veins, reticular veins, and smaller venous networks that are not always ideal candidates for thermal ablation. Instead of a liquid solution alone, a physician converts a sclerosant into a foam and injects it directly into the affected vein under visual or ultrasound guidance. The foam displaces blood within the vessel, allowing the sclerosant to contact the vein wall more thoroughly, which supports a more even closure response along the treated segment. This article outlines how the technique is prepared, performed, and where it is typically applied within a broader venous treatment plan.
What Is Sclerosant Foam Made Of?
Sclerosant foam is created by mixing a liquid chemical sclerosing agent with a gas, commonly air or a low-solubility gas mixture, in a defined ratio. The resulting foam has a texture that allows it to remain in contact with the vessel wall longer than a liquid injection would, since it is less readily diluted or washed away by circulating blood. This physical property is one reason foam-based approaches are commonly reported to be useful for veins of varying diameters, from fine reticular and spider veins to larger tributary varicosities. The specific sclerosant concentration and foam-to-liquid ratio are selected by the treating physician based on vein size, location, and patient-specific factors.
How Does the Tessari Method Work?
The Tessari method is one of the most frequently described techniques for preparing sclerosant foam in clinical settings. It uses two syringes connected by a three-way stopcock, through which the liquid sclerosant and gas are passed back and forth repeatedly. This rapid mixing action shears the liquid into small, relatively uniform microbubbles, producing a stable foam consistency. A stable, homogeneous foam is generally considered important because it influences how evenly the agent distributes along the vein segment being treated. Variations of this manual mixing approach exist, and some practices use standardized kits, but the underlying principle of mechanically agitating liquid and gas remains consistent.
Injecting Foam Into Varicose and Reticular Veins
Once prepared, the foam is injected through a fine needle or catheter, often with ultrasound guidance for deeper or larger veins, or direct visualization for superficial reticular and spider veins. Ultrasound guidance allows the physician to confirm needle placement within the vein lumen and to track the foam as it fills the treated segment in real time. After injection, gentle compression is commonly applied to the area, and compression stockings are frequently recommended for a period afterward to support vessel closure and reduce the likelihood of trapped blood within the treated vein. The number of sessions needed varies depending on the extent and pattern of venous disease.
Where Does Foam Sclerotherapy Fit Among Vein Treatments?
Foam sclerotherapy is often used for reticular veins, spider veins, and residual or recurrent varicosities, including smaller tributary veins that may remain after treatment of a larger incompetent trunk vein such as the great saphenous vein. It is generally considered a flexible option because it can be adapted to tortuous or branching vessels that may be more difficult to access with a straight catheter. In many treatment pathways, foam sclerotherapy is used alongside other modalities; for example, a larger truncal vein may first be addressed with an endovenous thermal or non-thermal closure device, with foam sclerotherapy reserved for smaller residual branches. A qualified physician determines which combination of techniques, if any, is appropriate based on venous mapping and individual anatomy.
Are There Considerations Patients Should Discuss With a Physician?
As with any injection-based vascular procedure, foam sclerotherapy carries considerations that should be reviewed during a pre-procedure consultation, including vein size and location, skin sensitivity, and any prior reactions to sclerosing agents. Temporary bruising, mild discoloration, or a sensation of firmness along the treated vein are commonly reported during the recovery period and typically resolve over time. Because clinical presentations vary widely, a qualified physician evaluates each patient's venous anatomy and medical history before recommending foam sclerotherapy or an alternative approach. Patients considering broader options for varicose vein management can review the general category of devices and technologies at the INVAMED varicose vein products page to understand how different treatment modalities relate to one another.
Is foam sclerotherapy the same as liquid sclerotherapy?
No. Liquid sclerotherapy involves injecting a sclerosing solution directly, while foam sclerotherapy first converts that solution into a foam using a gas. The foam form is generally reported to have more prolonged contact with the vein wall, which is why it is often selected for larger or more extensive venous networks compared with liquid alone.
Does foam sclerotherapy hurt?
Patients commonly report a brief stinging or pressure sensation during injection, though experiences vary by individual and vein location. Any discomfort is typically described as short-lived. A qualified physician can discuss what sensations to expect based on the specific veins being treated.
How many foam sclerotherapy sessions are usually needed?
The number of sessions depends on the extent of venous disease, vein size, and how the veins respond to initial treatment. Some patients require a single session for limited reticular veins, while more extensive venous networks may need multiple sessions spaced over time, as determined by the treating physician.
Device availability and regulatory status vary by country. Please contact INVAMED or your authorized local distributor for current regulatory information applicable to your region.