Sclerotherapy

Sclerotherapy is a type of minimally invasive treatment that involves the injection of special chemical agents into a vascular (blood vessel) malformation to shrink it and relieve the symptoms it is causing. It can be used to treat various slow-flow vascular malformations, including venous and lymphatic malformations. It is performed under image guidance by interventional radiologists.

• How does sclerotherapy work?
  Special chemical agents, called sclerosants, cause an inflammatory reaction to vessel walls when injected into a lesion/vessel, causing a localised blood clot to form, resulting in scarring within the malformation and eventually leading to shrinkage.
  
  There are many sclerosants with differing properties that may be used alone or in combination for sclerotherapy. Common ones include sodium tetradecyl sulphate (STS), alcohol, doxycycline, and bleomycin.
  
  
• How is sclerotherapy performed?
  Under image guidance (e.g. ultrasound, X-ray, CT or MRI), the lesion or malformation is targeted across the skin with a needle. Careful imaging such as injection of a dye that is visible on X-ray may be used to assess for communication with adjacent blood vessels prior to injection.
  
  Depending on the type of vascular malformation, the fluid within might be drawn out both to reduce swelling and potentially diluting the sclerosant. The amount of sclerosant to be injected is carefully estimated on imaging and injected into the lesion or malformation.
  
  For larger lesions or malformation with more fluid, a drainage catheter might be placed for exchange of fluid and sclerosant. Eventually all the needles and catheters will be removed at the end of the procedure.
  
  This procedure is generally performed under sedation or general anaesthesia (GA) in children and adults with more extensive lesions.
  
  
• How soon will I see results and how many sessions are required?
  Although some vascular malformations may reduce in size after just 1 or 2 treatment sessions, multiple (6 to 10) sessions at two-monthly intervals are often required to adequately treat a malformation. It may take some time before the patient notices a significant difference.
  
  Not all malformations can be successfully treated in this way, and the results can vary between individuals with the same diagnosis. However, in majority of cases, clinically significant improvement is achieved.
  
  Sclerotherapy is not a ‘cure’ but is aimed at symptom-control and management of lesion size. Sclerotherapy may not treat skin discolouration associated with some malformations.
  
  
• What are the risks of sclerotherapy?
  Immediately after the injection, swelling and pain can occur, worsening over the first 2 days then reducing from day 7. Oral medications such as paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs) are usually prescribed to manage the pain or discomfort.
  
  There is a low risk of infection as sclerotherapy is carried out via a needle puncture and not an incision. However, this is very rare.
  
  Bruising may occur after sclerotherapy due to internal bleeding. This may reduce in size over days to months or sometimes persist.
  
  There is a small risk that the skin over the malformation may blister or even breakdown (ulcerate). With appropriate, sometimes prolonged wound care, the wound will improve in time and possibly leave a scar. This is more common in superficial malformations that involve the skin or occupy a large area directly under the skin (subcutaneous). Laser therapy or surgical revision of such scars can be done later if required.
  
  If a malformation is near a nerve or group of nerves, the swelling induced by sclerotherapy can sometimes compress the nerve, leading to a loss of sensation in the area or even local muscle weakness. However, this is uncommon. This condition is termed ‘neuropraxia’ and is often temporary and seldom permanent. With the use of alcohol, however, the nerve can be permanently damaged.
  
  If bleomycin is used as a sclerosant, flu-like symptoms can occur after the procedure. There is also a risk of skin discolouration, usually over sites of pressure or occluded areas (e.g. below pressure dressings). This discolouration may last for months and can be permanent in some instances.
  
  When bleomycin is used in much higher systemic doses (e.g. if injected into the blood system to treat cancers) there is a small risk of causing lung damage or hardening. Fortunately, when injected locally for sclerotherapy of vascular anomalies, the risk has not been reported.
  
  As sclerotherapy is not curative, there is a chance of recurrence, sometimes years after the initial treatment. Repeat treatments may then be required.
  
  Every case is different, and your doctor will explain details of the treatment plan with you.

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