Foam sclerotherapy

Foam sclerotherapy is a minimally invasive outpatient procedure used to treat the underlying condition of venous insufficiency that causes leg ulcers.

It is used together with, or as an alternative to, endovenous laser ablation (EVLA).


What is foam sclerotherapy

Foam sclerotherapy is a minimally invasive outpatient procedure used to treat the underlying conditions of venous insufficiency, superficial reflux and hypertension that can cause leg ulcers. It can be used together with, or as an alternative to, endovenous laser ablation (EVLA).

Foam sclerotherapy treatment usually only takes around 30-45 minutes per session, depending on how many veins need treating. Most patients describe the treatment as uncomfortable, rather than painful, although the sclerosant may sting slightly.

Foam sclerotherapy treatment requires little to no recovery time, so the chances are that you’ll be able to resume your normal activities straight away.

What does sclerotherapy involve?

Sclerotherapy comes from Greek – scleros meaning ‘to make hard’ and therapea referring to ‘services for the sick’.

The treatment involves injecting a diluted drug, known as a sclerosant, directly into the target vein. The sclerosant is mixed with foam and air. The foam displaces the blood in the veins and the drug destroys the cells in the vein lining. Following the procedure, the treated veins collapse and the dead tissue is naturally absorbed by the body. 

Foam sclerotherapy usually only takes around 30-45 minutes per session, depending on how many veins need treating. 

If you have a large number of veins that require treatment, you may need more than one session. This is due to a dosage safety limit on the amount of sclerosant we are able to administer at one time. Your consultant will advise how many sessions you are likely to need following your initial consultation appointment.

A detailed description of sclerotherapy treatment


As part of your initial consultation, you’ll have a colour duplex ultrasound scan to identify the underlying cause of your leg ulcer(s), and identify which veins require which treatment. Your consultant will then give you a full explanation of the treatment options, including the potential complications and success rates.

You may also have had EVLA treatment in the interim, to help treat the underlying condition of venous insufficiency that is contributing to your leg ulcers. This will all happen in advance of your appointment for foam sclerotherapy.

When you arrive for your foam sclerotherapy treatment appointment, you will be guided to one of our treatment rooms by your consultant and the assisting nurse. You will then have the opportunity to ask any further questions, before you sign the consent form required for us to proceed with the treatment. 

You can listen to your choice of music during your treatment and your nurse will be at your side throughout your appointment. 

The procedure

At the start of the procedure, the veins that require treatment are identified. If we’re treating large and/or deeper varicose veins, we’ll use ultrasound guidance during your procedure. For smaller thread veins closer to the skin’s surface, visual guidance is usually sufficient.

A fine needle (known as a butterfly needle) is then inserted into the first vein to be treated, so we can inject the foam sclerotherapy solution. The foam displaces the blood in the vein and the sclerosant attacks the lining of the vein wall, causing the vein to shrivel up. This procedure is then repeated for all the veins requiring treatment.

The shrunken veins are then broken down and absorbed gradually by your body. As with EVLA, once the veins have been destroyed, the blood is naturally rerouted to healthy veins, improving your circulation.

Due to the series of tiny injections involved in the foam sclerotherapy procedure, some patients find them uncomfortable or mildly painful. The sclerosant used can sting slightly. 

The procedure usually takes around 30-45 minutes per session.  

Post procedure

Following your treatment, your nurse will help you put on a compression stocking (or two if you’ve had both legs treated), which you will need to wear for one week following your procedure. Your nurse will explain how to wear these and bathe in them.

You’ll also be provided with aftercare advice, including any post-treatment symptoms to be aware of. 

We will ask you to take a 10 minute walk following your appointment, prior to making your way home, in order to limit the risks of blood clots or deep vein thrombosis (DVT).


You will need to wear a class II compression stocking, on the treated leg(s), constantly for seven days following sclerotherapy. This shouldn’t affect your movement, but we discourage you from going swimming with it on.

You are allowed to drive on the same day as foam sclerotherapy treatment.

We urge you to resume your normal activities as soon as possible. Throughout your recovery period we also advise you to go for a 20-minute walk every day, to prevent clotting and to aid blood flow and healing in the legs.

We do, however, advise you to listen to your body and give yourself time to heal. Your consultant will advise you if there’s anything you need to avoid following your procedure.

Over the next 4-6 weeks you may experience a slight feeling of tightness in your leg(s) as the vein shrinks and is reabsorbed into your body. The sclerosant used can also cause some bruising of the skin, the extent of which will depend on the number of veins treated.

Treatment risks

As with all medical procedures, it’s important that you weigh up the benefits of having foam sclerotherapy treatment for leg ulcers, versus the risks of side effects. You can find a full list of risks for all our vein treatments on our treatment FAQs page.

Foam sclerotherapy follow-up

The results of foam sclerotherapy for small varicose veins or thread veins are usually visible within 4 to 6 weeks, but it could take longer for larger varicose veins and leg ulcer healing. Following your initial foam sclerotherapy session, you may or may not need a follow-up appointment. 

You can assess whether you need to return yourself, based on how your legs look and feel. If your leg ulcer is healing well and you’re happy with the results, then there’s no need to pay for a follow-up appointment. 

If, however, you feel that you would benefit from further treatment, you can book either a reassessment follow-up or a further treatment appointment. We advise you to wait at least 4-6 weeks between appointments, to ensure you get the most benefit from each foam sclerotherapy session. 


Information on the total costs involved in the diagnosis and treatment of varicose veins is outlined on our leg ulcers self-funded pricing page. Alternatively, if you have medical insurance, please disregard our self-funding prices and refer to our health insurance page.

Frequently asked questions

What is the difference between microsclerotherapy and foam sclerotherapy?

What are the chances of foam sclerotherapy staining my skin?

You can find the answers to these questions and many more in the sclerotherapy section of our treatment FAQs page.

If you have any other questions, please do not hesitate to contact us, and a member of our clinic team will be pleased to help.

Take the plunge

Book your treatment today for summer-ready legs