CSF – Venous fistula embolisation

CSF – venous fistula embolisation refers to the process of blocking an abnormal connection between CSF (the fluid that surrounds the brain and spinal cord) and a spinal vein. This condition is one of the causes of CSF leaks, which results in symptomatic intracranial hypotension – a condition characterised by severe position related headaches.

Embolisation can be performed to prevent continuing leaking of CSF. During an embolisation, special glue-like liquid is injected into the vein draining CSF from the spine. This has the effect of blocking the leak of fluid.

All treatments and procedures have risks and we will talk to you about the risks of having this procedure. The procedure will need to take place under a general anaesthetic or sedation; the anaesthetist will discuss the risks of these with you.

Problems that may happen straight away

During a CSF – venous fistula embolisation, a contrast agent will be injected into your veins. This allows the Interventional Neuroradiologist (INR) to see the blood vessels when an X-ray is taken. Contrast agents are generally 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 embolisation is iodine based contrast which is excreted through the kidneys. On rare occasions, this may affect kidney function. Therefore, you will 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 the embolisation. 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.

Problems that are rare, but potentially serious

CSF – venous fistula embolisations are relatively straightforward procedures: serious complications are unlikely, but are always present. Like all procedures involving injection of glue into a blood vessel, glue can migrate to an unwanted area – in some cases, the lungs. The percentage level of this risk is very low, and as far as we have seen from available research, asymptomatic.

Other Problems that occur

Haematoma, bruising or vessel damage around the groin or puncture site may also occur. Usually, pressure is applied over the femoral vein (in the groin) after the tube has been removed to stop the bleeding. Sometimes there is bruising, and on rare occasions, bleeding. It is rarely serious. Other problems can include pain at the injection site, or rebound intracranial hypertension (causing a different type of headache). Finally, there is a chance that the procedure is not successful.

Any problem is usually apparent during or immediately after the procedure, or during the next few days whilst you are still in hospital.

Radiation Risk

The use of X-rays during the procedure presents a very small risk of hair loss, skin erythema (reddening) or very rarely the development of cancers in the future. Our state-of-the-art imaging equipment and modern techniques help to 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 child-bearing 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 to the abdominal area. Patients who either are, or think they may be, pregnant must inform the Neuroradiology Department as soon as possible. In rare cases the procedure may still go ahead but with additional precautions in place.

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

If we think you will benefit from CSF – venous fistula embolisation we will offer this procedure. This decision will be arrived at after discussion between the Interventional Neuroradiologist and the Neurologist or Neurosurgeon whose care you are under. We will get your consent for the procedure. If you are too symptomatic to make a decision, it will be performed on a best interest basis guided by medical judgement. Your family / next-of-kin will also be contacted. Declining the procedure will not affect your personal care. However, it may mean that your doctor cannot be as certain or specific about any future treatment or procedures and it may affect some clinical decision making.

Your procedure may take place at any time during the day due to more emergency cases, but we will endeavour to perform your procedure as early 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.

The procedure is performed under minor sedation (this means you will be awake throughout). Your anaesthetist will talk to you about the anaesthetic, and what you can expect, both in clinic before the procedure and again briefly on the ward the day of your procedure. You will need to fast for six hours before your procedure. Your anaesthetist will confirm with you a specific time you must stop eating and drinking. You should still take all of your medications at the normal times throughout this period with a sip of water, unless advised otherwise.

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. In some circumstances if you are too symptomatic to make a decision, it will be performed on a best interest basis based on medical judgement. Your family / next-of-kin will also be contacted.

The CSF – venous fistula embolisation – may be performed either while you are awake or sedated. The procedure is performed by the INR in the angiography suite (a type of operating theatre) located in the radiology department. It usually takes approximately 1 – 2 hours. A dedicated team of radiologists, radiographers, anaesthetists and nurses will be in the angiography suite to monitor you closely throughout the procedure.

Once the procedure has commenced, the INR will place a thin, flexible, plastic tube (catheter) into the femoral vein in the groin. The catheter passes through the main vein in the body called the inferior vena cava and finally into veins running parallel to the spine. Before the embolisation begins, the INR will inject the veins to confirm the best approach to embolisation.

The catheter is placed in the vein at the level and side of the fistula. Following this, a second microcatheter is inserted inside the first. This microcatheter is placed directly next to the point of the fistula. Embolic material (a glue-like material) is then injected to seal off and close the fistula connection to the dura. Occasionally, small metal coils will be used too. This embolic material creates a blockage to the leak of CSF.

Once the INR is satisfied with the result, the catheters are removed and the blood vessel in the groin has pressure applied.

After the procedure, you will spend some time in the recovery unit before being transferred back to your ward. These units provide a high level of monitoring. You will be on bed rest for at least a few hours following the procedure to ensure the entry site of the catheter in your groin begins to heal and that you are stable.

You will usually be able to go home the same day or the day after the procedure.

You may also experience some pain or bruising at your groin or arm, depending on where the catheter was placed. This should reduce over a few days.

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

• The Brain & Spine Foundation UK
  Telephone: 0808 808 1000 

• CSF leak association

UCLH cannot accept responsibility for information provided by other organisations.

• CSF–venous fistula in spontaneous intracranial hypotension
  Wouter I. Schievink, Franklin G. Moser, M. Marcel Maya
  Neurology Jul 2014, 83 (5) 472-473; DOI:10.1212/WNL.0000000000000639
• A Novel Endovascular Therapy for CSF Hypotension Secondary to CSF-Venous Fistulas W. Brinjikji, L.E. Savastano, J.L.D. Atkinson, I. Garza, R. Farb, J.K. Cutsforth-Gregory.
  American Journal of Neuroradiology May 2021, 42 (5) 882-887; DOI: 10.3174/ajnr.A7014.
• Brinjikji W, Garza I, Whealy M, Kissoon N, Atkinson JLD, Savastano L, Madhavan A, Cutsforth-Gregory J. Clinical and imaging outcomes of cerebrospinal fluid-venous fistula embolization. J Neurointerv Surg. 2022 Jan 24:neurintsurg-2021-018466. doi: 10.1136/neurintsurg-2021-018466. Epub ahead of print. PMID: 35074899.
• Kranz PG, Gray L, Malinzak MD, Amrhein TJ. Spontaneous Intracranial Hypotension: Pathogenesis, Diagnosis, and Treatment. Neuroimaging Clin N Am. 2019 Nov;29(4):581-594. doi: 10.1016/j.nic.2019.07.006. Epub 2019 Aug 26. PMID: 31677732.

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: 020 3456 7890

Extension: 83444/ 83446

Fax: 020 344 84723

Website: www.uclh.nhs.uk/nhnn

Neurovascular Clinical Nurse Specialists 

National Hospital for Neurology and Neurosurgery, Queen Square, London, WC1N 3BG

Direct line: 020 344 83523

Switchboard: 020 3456 7890

Extension: 83523

Email: uclh.neurovascularnurse@nhs.net

Website: www.uclh.nhs.uk/nhnn

The Lysholm Department of Neuroradiology reception is located in the 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.