Serious complications after foam injections are very rare.
Some of the more common complications of foam sclerotherapy include:
- Superficial thrombophlebitis, phlebitis
- Matting (growth of very fine spider veins in treated area)
- Skin discolouration (hyperpigmentation, more rarely - haematoma & ecchymosis
These are seen in about 1 in 100 of every patient. There are some very rare and serious side-effects of foam seen in approximately 1 in 1000 to 1 in 10,000 patients.
These include but are not limited to:
- Deep vein thrombosis and pulmonary embolism (blockage of lung artery)
- Chest tightness, dry cough, headache, 'pins and needles' or problems with their vision are rare short-term events that are normally very short-lived
One study reported on 3 patients who had strokes after the procedure. All had a kind of heart defect called a patent foramen ovale. All 3 patients recovered completely and had no further symptoms of stroke. In a study of 1025 patients treated with foam injections,1 patient had a type of 'mini-stroke' called a transient ischaemic attack. This patient recovered completely with no long-term effects within 30 minutes.
In a report on about 6400 foam sclerotherapy sessions, there were 37 adverse events (less than 1%). These included brief problems with vision (eight cases), while some people with vision problems also had headache, nausea or fainting (eight cases). In all 16 cases the problems disappeared on their own, with no after effects. Six patients fainted, three had thrombosis and one had deep vein thrombosis. One patient had a stroke shortly after having foam sclerotherapy. The risks with foam sclerotherapy and liquid sclerotherapy are about the same.
In 2019, we were asked as one of the major UK vein treatment centres to participate in one of the largest European foam sclerotherapy studies documenting the outcomes and side-effects of this intervention. At the time of writing, the results are still awaited.
Skin Pigmentation
Darkening of the skin can occur after foam sclerotherapy in about 1 in 4 patients. It may take up to 2 or more years to resolve but can occasionally be permanent.