Sclerotherapy has been in use in the UK mainly for treatment of spider or reticular veins(smaller skin veins unrelated to varicose veins). Its use for larger truncal varicosities has received some attention in recent years.
The sclerosant solution, usually Sodium Tetradecyl Sulphate (STD) 1-3% or Polydocanol 0.5-1%, causes an occlusion(thrombosis) of the veins by inducing inflammation of the inner lining of the vein wall. Using it as a foam allows a smaller volume of the solution being used to avoid toxicity.
Foam sclerotherapy is usually carried out under local anaesthetic with patient lying down flat. Using ultrasound the position of the vein is determined and a cannula (a fine needle) is placed through the skin into the vein. The foam solution is introduced in the vein under and followed using ultrasound as it fills the vein up. More than one cannula may need to be inserted if different veins are being sclerosed.
Once the long truncal vein (long saphenous vein) is closed blood flow is re-routed to other healthy veins in the limb. The occluded varicose veins will then be obliterated and slowly removed by the body in the following months.
How good are the results of foam sclerotherapy ablation?
The success of any foam sclerotherapy procedure is measured by:
- Limited available evidence suggests that, performed efficiently, foam sclerotherapy achieves comparable results to surgery both in terms of causing fibrosis and disappearance (92% at 1 month and 82% at 1 year). The recurrence rate is significantly higher than endovenous and traditional surgery.
- Although the complication rates of sclerotherapy are generally minor, more serious adverse events have been reported. These include deep vein thrombosis and anaphylaxis (sudden allergic reaction to the sclerosant solution). For these reasons, the National Institute for Clinical Excellence (NICE) in the UK has advised that it should only be used with special arrangements for consent and audit, or in research settings. We only recommend it in certain unusual situations; for example in treatment of side branch veins left after treatment of varicose veins; i.e.; micro-injection foam sclerotherapy.
Criticisms of minimally invasive procedures
One of the criticisms of endovenous ablation is that if phlebectomies (avulsion of the varicosed tributaries of side branches) are also required, a more extensive procedure needs to be planned possibly in an operating suite using general anaesthetic.
Foam injection sclerotherapy produces an intense thrombophlebitis (inflammatory process extending outside the vein wall) which can be painful and frequently leave brown skin-staining that may not resolve. The incidence of this in the available literature is around 4.7%.