0330 058 1850

Ultrasound Guided Foam Sclerotherapy


Sclerotherapy is a technique where a liquid is injected into a vein, to destroy it.
AI Classification Score - C31 Penetrating Pinhole

What is Ultrasound Guided Foam Sclerotherapy?

Ultrasound guided foam sclerotherapy is a highly effective sclerotherapy technique to treat small varicose veins.

Sclerotherapy comes from Greek – “scleros” – to make hard and “therapea” – a service done to the sick.

When the vein is destroyed using sclerotherapy, the liquid kills the cells in the vein wall causing inflammation. When inflamed, the vein becomes hard to the touch. Over a period of several months the body eats away the dead vein, leaving only a tiny bit of scar tissue behind.

However, sclerotherapy only works in small veins and if there is no blood in the vein. If there is blood in the vein, the sclerotherapy liquid attacks the blood as well as the vein wall, causing it to clot. Clot inside the vein is called “thrombus” – or if caused by sclerotherapy, is called “sclerothrombus”.

In order to get rid of the blood from inside the vein, the sclerotherapy liquid can be mixed with gas to form a foam. When mixed, the foam is like shaving foam. When injected into a vein, the foam pushes all of the blood out of the vein leaving the sclerotherapy liquid in the bubble wall to destroy the vein.

Ultrasound guided foam sclerotherapy - small veins seen on Ultrasound before injection of foam at The Whiteley Clinic

Ultrasound guided foam sclerotherapy – small veins seen on Ultrasound before injection of foam at The Whiteley Clinic

Although foam was originally made with air, the nitrogen in the air does not dissolve very well in the blood, and so can go up through the vein system, reaching the heart and, in some people, the brain.

This doesn’t cause a problem in most people although a few people can get an alteration in their sight for up to 20 minutes.

At The Whiteley Clinic, we make foam sclerotherapy from a mixture of oxygen and carbon-dioxide. This allows the bubbles to dissolve quicker and so reduces the risk of any problems. We have won a national research prize for our work in understanding how to make optimal foam sclerotherapy (see: https://thewhiteleyclinic.co.uk/first-prize-venous-forum-2014-whiteley-clinic-research/)

Ultrasound is used to direct the injection of foam sclerotherapy directly into the required vein. Hence the name “ultrasound guided foam sclerotherapy”.

As soon as the ultrasound guided foam sclerotherapy is in the vein, the leg is bound, holding the vein shut and keeping the blood out of the dying vein, preventing sclerothrombus and the resulting painful lumps and brown stains.

It takes 21 days for the vein walls to scar together. For the whole of that time, the vein walls have to be held shut together preventing blood from getting back into the dying vein. Failure to do this means that the vein will fill with blood, which will clot and become sclerothrombus.

To see our research publications on Ultrasound Guided Foam Sclerotherapy see:




  1. Whiteley, M. S., Davey, S. E., & Placzek, G. M. The AI classification (access and invasiveness) of medical procedures to clarify non-invasive from different forms of minimally invasive and open surgery. CoP Preprints. 2023:43.