Risks and Possible Problems of Foam


Foam Sclerotherapy: Effectiveness and Patient Outcomes


Foam sclerotherapy is a safe, minimally invasive treatment for varicose veins. It avoids the use of heat and large volumes of local anaesthetic, making it particularly useful for smaller or recurrent veins. While the initial cosmetic results are excellent in most patients, larger varicose veins often respond better to endovenous laser ablation (EVLA) or radiofrequency ablation (RFA). For this reason, foam is usually offered as an adjunct treatment or as a first‑line option in carefully selected cases.




Guidance from NICE


The National Institute for Health and Care Excellence (NICE) has evaluated ultrasound‑guided foam sclerotherapy and confirmed that it is safe and effective when performed by trained specialists.

Read the NICE guidance.




Our Results



  • Patients treated: Over 60 foam procedures audited between September 2023 and September 2025

  • Success rate: 89% of treated veins were successfully closed

  • Retreatment: 9% of patients required a second session

  • Complications: 13% experienced temporary phlebitis; 5% had mild skin staining

  • Recovery: Most patients returned to normal activities within days, with high satisfaction and durable symptom relief






Safety and Complications


Serious complications after foam injections are very rare. Most side effects are mild, short‑lived, and settle with time and simple measures.



The most common effects include superficial phlebitis (tenderness or redness along the treated vein), matting (fine spider veins in the treated area), and skin discolouration. Brown staining is seen in some patients and usually fades within 6–12 months, though in a small number it may persist longer. Bruising or small haematomas at injection sites are also possible but resolve with time and compression.



Rare risks include deep vein thrombosis (DVT) or pulmonary embolism (PE), which are extremely uncommon. Some patients may experience brief visual disturbance, headache, tingling, or cough immediately after treatment, but these usually resolve quickly. Allergic reactions to the sclerosant are very rare.



Darkening of the skin (hyperpigmentation) can occur in about 1 in 4 patients. Most cases lighten over time, though a small proportion may last longer. Good aftercare, including compression and walking, helps reduce this risk.



Patients should expect mild aching, tightness, or small lumps along treated veins as part of normal healing. You should contact us promptly if you develop increasing calf pain or swelling, chest pain, shortness of breath, new neurological symptoms, or worsening redness and fever.