Sclerotherapy for low flow vascular malformations

Sclerotherapy is a procedure used to treat low flow vascular malformations. These malformations are made up of extra veins that have no use. Instead of flowing back to the heart, the blood collects inside the malformation causing it to stretch.

During sclerotherapy, a medicine is injected into the malformation. This medicine irritates the malformation and causes it to slowly shrink. One of the medicines that is used to inject into the malformation is bleomycin. Bleomycin is very good at causing the malformation to shrink and has very few side effects. Bleomycin is also used as an anticancer drug.

Sometimes, several treatments are needed a few weeks apart to treat larger malformations.

All treatments and procedures carry risks, and we will talk to you about the risks of sclerotherapy. Each case carries a different risk, and we will try to estimate your personal risk in our discussions with you.

The procedure will take place under a general anaesthetic. Your anaesthetist will discuss the risks of general anaesthesia with you. It is important to tell your doctor if there is a possibility you may be pregnant.

Problems that may happen straight away

During a sclerotherapy treatment, a contrast agent will be injected into your arteries; this allows the Interventional Neuroradiologist (INR) to see the blood vessels and the malformation when an X-ray is taken. Contrast agents are considered safe drugs. However, as with all drugs, they have the potential to cause an allergic reaction. The department and team are well equipped to deal with reactions in the rare event of this happening.

Problems that may happen later

The contrast agent used during a sclerotherapy treatment is iodine-based contrast and is excreted through the kidneys, which may affect kidney function. You will therefore have a blood test to test your kidney function beforehand to ensure it is safe for you to have contrast. The risk of you having contrast will be weighed against the benefit of having this treatment and is decided by the team referring you for your treatment. For further information on the use of iodine-based contrast agents please see the information leaflet 'Contrast Agents for X-ray, Fluoroscopy, CT and Angiography Examinations: An Information Guide' or alternatively visit the trust website.

The sclerotherapy causes irritation and swelling, so usually the area looks a little worse than usual after the procedure. This is usually good sign because it shows that the medicine is working. The area may also be slightly bruised and sore for a few days.

If Bleomycin is used in the sclerotherapy treatment, it can on rare occasions cause discolouration of the skin or nails, or cause some hair fall out. This usually, but not always, gets better over time. We think that the skin is more likely to be affected if there are plasters stuck to the skin at the time of the procedure, so we are careful to avoid this. Scratching of the skin during the first 48 hours after treatment may also cause skin marking and should be avoided.

There is also a small chance that the medicine injected into the malformation may irritate the overlying skin. There is more chance of this if the malformation is in a delicate area such as eyelids or lips. The skin may blister or develop sore patches. This is usually minor and settles within a few days. Occasionally, larger blisters may need special dressings to encourage them to heal.

The medicine may also irritate any nerves near the area, which cause numbness, tingling or ‘pins and needles’. Nerve damage is very rare and, if it does occur, is usually temporary.

Sclerotherapy works for most malformations, but occasionally it does not work. Experience helps us understand which malformations are more likely to respond.

Radiation Risk

The use of X-rays during any procedure results in a very small increase in the risk of developing cancer in the future. For the more complex cases, temporary hair loss and skin erythema (reddening) may occur a few weeks after the procedure. Our state-of-the-art imaging equipment and modern techniques ensure the radiation dose is as low as possible. In addition, your doctor will have made a judgement about your risk and benefit before agreeing to the procedure (including the risk to your health of not having the procedure).

Female patients of childbearing capacity between the ages of 12 and 55 years are required by law to be asked about possible pregnancy when undergoing examinations involving x-ray. Patients who either are, or think they may be, pregnant must inform the Neuroradiology Department as soon as possible. In some urgent cases the procedure may still go ahead but with additional precautions in place. To reduce the risk for early and unknown pregnancies, sclerotherapy treatments are usually performed within the first ten days of the menstrual cycle when pregnancy is much less likely.

The Interventional Neuroradiologist performing the procedure will discuss all possible risks with you and give you the opportunity to ask questions.

Some vascular malformations remain the same. However, your vascular malformation might continue to grow and give you worse symptoms.

Sometimes, the doctor may suggest surgery to remove the malformation. Sclerotherapy is still sometimes used before the surgery to shrink the malformation.

You should take all your usual medications as normal.

You will be brought into hospital the day before or on the morning of your procedure.

The procedure is performed under a general anaesthetic which means you will be unconscious or ‘asleep’ throughout. Your anaesthetist will talk to you about the anaesthetic, pain relief and what you can expect when having a general anaesthetic. You will need to fast for some hours before your procedure.

Your anaesthetist will confirm with you what time you must stop eating and drinking. You should still take all your usual medications at the normal times throughout this period with a sip of water.

You will be asked to change into a hospital gown. A member of staff, usually the nurse caring for you, will accompany you to the Neuroradiology department.

Your procedure may take place at any time during the day due to emergency cases, but we will endeavour to keep you informed and perform your procedure as early in the day as possible.

The procedure is performed by specialist doctors called Interventional Neuroradiologists (INR). The INR will see you on the ward to explain the procedure and any associated risks. Please feel free to ask any questions at this time.

It is important that you are involved in all the decisions about your care and treatment. If you decide to go ahead with treatment, by law we must ask for your consent and will ask you to sign a consent form. This confirms that you agree to have the procedure and understand what it involves. Staff will explain all the risks, benefits and alternatives before they ask you to sign a consent form. If you are unsure about any aspect of your proposed treatment, please don’t hesitate to speak with a senior member of staff.

The procedure is performed by an interventional neuroradiologist in an operating theatre located in the Neuroradiology department.

It usually takes less than an hour. A dedicated team of neuroradiologists, radiographers, anaesthetists and nurses will be in the operating theatre. They will be monitoring you closely throughout the procedure.

Once the anaesthetic has commenced, the neuroradiologist uses ultrasound to check and measure the malformation. Using this ultrasound, the neuroradiologist will insert a small needle through the skin into the abnormal veins within the malformation. They will inject a small amount of X-ray dye to give a clear map of the malformation. They will then inject a very small amount of medicine through the needle, which irritates and inflames the malformation over the following few weeks. The neuroradiologist will then remove the needle. No stitches or dressings are required.

Once you have woken up from the anaesthetic you will return to the ward. The malformation will almost certainly look worse after the procedure: the bruising and swelling usually last for several days. The treated area may feel uncomfortable, but standard pain relief is usually all that is required.

You would usually be able to go home the following day.

After the procedure you will be given an indication of whether another treatment is required or alternatively you will be reviewed in the outpatient clinic. If several treatments are required, the aim is to reduce the malformation slowly and not cause too much swelling and discomfort.

As the sclerotherapy just shrinks the malformation rather than completely curing it, occasionally the malformation might get bigger again, and this may mean that further treatments are required in the future.

You should seek medical advice (either from your GP or our nurse specialist) if:

• You are in a lot of pain and pain relief does not help.
• The skin near the treated area becomes blistered or blackened.
• You experience numbness or ‘pins and needles’ near the treated area or there are signs of muscle weakness or spasm.
• The treated area becomes unusually hot, red and painful or if you develop a temperature.

For any non-urgent questions or concerns you may have following your procedure, please contact the Neurovascular Clinical Nurse Specialists.

• Sclerotherapy for low flow vascular malformations of the head and neck: A systematic review of sclerosing agents. Horbach et al J of Plastic, Reconstructive & Aesthetic Surgery (2016) 69, 295 – 304
• Percutaneous sclerotherapy for facial venous malformations: subjective clinical and objective MR imaging follow-up results. Spence J, Krings T, terBrugge KG et al AJNR 2010:31;955-960
• Outcome Measures After Sclerotherapy of Venous Malformations: A Systematic Review Cardiovasc Intervent Radiol. 2018 Aug;41(8):1141-1151.
• London Cancer Guidelines for Administration of Systematic Anti-Cancer Therapy - June 2018

Neurovascular Clinical Nurse Specialists, National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG

Direct line: 020 344 83523

Switchboard: 0845 155 5000

Extension: 83523

Email: uclh.neurovascularnurse@nhs.net

Website: www.uclh.nhs.uk/nhnn

Lysholm Department of Neuroradiology, National Hospital of Neurology and Neurosurgery, Queen Square, London, WC1N 3BG

Email: uclh.referrals.neurorad@nhs.net

Direct line: 020 344 83444

Switchboard: 0845 155 5000

Extension: 83444/ 83446

Fax: 020 344 84723

Website: www.uclh.nhs.uk/nhnn

The Lysholm Department of Neuroradiology reception is located in Chandler wing, on the lower ground floor of the National Hospital for Neurology & Neurosurgery, Queen Square.

Please turn left when you exit the chandler wing lifts on the lower ground floor to find our main departmental reception.