This page has been written by the Lysholm Department of Neuroradiology at The National Hospital for Neurology and Neurosurgery (NHNN). The aim of the page is to provide information about post procedural care following a diagnostic angiogram or endovascular treatment and possible complications that may occur.
It is intended for use by patients (or their families or carers) who have had a diagnostic angiogram or endovascular treatment in the angiography suite at NHNN. If you have any questions about this, a member of the Neuroradiology team will be happy to answer them for you.
Diagnostic angiograms and endovascular treatments are procedures performed by a Neuroradiologist in order to assess and treat abnormalities of the blood vessels that supply your brain and spinal cord.
Diagnostic angiograms are performed to produce detailed images of the arteries in your brain and/or spine, in order to diagnose pathologies and medical conditions or plan future treatments.
Endovascular treatments are carried out to treat your neurovascular pathology and protect it from bleeding or causing worsening symptoms.
You may have been referred for a diagnostic angiogram or endovascular treatment as you previously suffered an intracranial hemorrhage (bleed) or you have experienced common symptoms of neurovascular pathologies such as seizures, headaches or neurological deficit. You may also have been referred to our service as you’ve had pathology identified on previous imaging that requires further investigation.
All treatments and procedures have risks and we will talk to you about the risks of having a diagnostic angiogram or endovascular treatment before your procedure.
Problems that may happen straight away
During a diagnostic angiogram or endovascular treatment, a contrast agent will be injected into your arteries; this allows the Interventional Neuroradiologist (INR) to see the blood vessels and certain pathologies when X-rays are taken. Contrast agents are 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 diagnostic angiogram or endovascular treatment is iodine-based contrast and is excreted through the kidneys; this may affect your kidney function. You will have a blood test to test your kidney function beforehand to ensure it is safe for you to receive contrast.
The risk of you having contrast will have been weighed against the benefit of having this procedure and is decided by the team referring you to Neuroradiology.
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 serious
Diagnostic angiograms and endovascular treatments are difficult and complex procedures: serious complications are unlikely, but are always possible. Like all procedures involving the blood vessels of the brain, they carry a risk of stroke which results from either a blockage of a blood vessel or from a hemorrhage. This can range from a minor problem which improves over time to a severe disability involving movement, balance, speech or vision or may even be a threat to life.
The risk of stroke is normally higher for endovascular treatments than diagnostic angiograms; this is due to the complexity of an endovascular treatment by comparison. The percentage level of this risk occurring will be specific to you and to the procedure you are having.
Haematoma, bruising or vessel damage around the puncture site may also occur. Usually manual compression and/or a closure device are placed in the groin or wrist artery after the catheter has been removed. Often there may be some bruising and sometimes bleeding in the groin or wrist. It is rarely serious but can go on for a few hours. Very occasionally, there is damage to the blood vessel requiring a further surgical operation.
Any problem is usually apparent during or immediately after the procedure, or during the next few days whilst you are still in hospital.
Diagnostic angiogram:
Diagnostic angiograms are usually performed under local anaesthetic, meaning you are awake for the procedure. However, there may be occasions where these are performed under general anaesthetic (when you are asleep) - this will be discussed with you, including all risks of a general anaesthetic beforehand.
The procedure is performed by the Interventional Neuroradiologist (INR) in the angiography suite (operating theatre) located in the neuroradiology department. It usually takes around one hour. A dedicated team of radiologists, radiographers and nurses are present in the angiography suite to reassure you and monitor you closely throughout the procedure.
Once the procedure has commenced, the INR uses local anaesthetic to numb your groin or wrist before placing a thin, flexible, plastic tube (catheter) into the femoral artery in the groin or radial artery in the arm. You may feel some stinging while this local anaesthetic is given, this is normal. The catheter passes through the main artery in the body called the aorta and finally into the arteries close to your brain or spine, depending on what area we are investigating.
The INR injects contrast agent into the arteries and uses X-rays to obtain images/movies of your blood vessels. You may feel slightly hot, flushed or even see flashing lights during these injections; this is a known side-effect of the contrast agent and will pass shortly after the injection.
Once the INR is satisfied we have enough images to provide a comprehensive report to your doctor, the catheter is removed and the blood vessel in the groin or wrist is sealed by manual compression on the puncture site for 10 minutes or more, or occasionally sealed with a closure device.
Endovascular treatment:
Endovascular treatments are performed while you are under general anaesthetic. The anaesthetic team put you to sleep in the anaesthetic room prior to transfer to the angiography suite. Similar to the diagnostic angiogram, these procedures are performed by the INR and involve a dedicated team of radiologists, anaesthetists, radiographers and nurses who monitor you closely.
Endovascular treatments tend to take longer to perform than diagnostic angiograms, it usually takes between one and three hours. As previously described, the INR will place a catheter into your artery through a groin or wrist approach. This catheter will pass through your aorta and into the arteries in your brain or spine. The INR will then place a second smaller microcatheter into the first; this is designed to go directly into the pathology or area we are treating. Contrast agent will be injected throughout the procedure, whilst taking X-rays to visualise the pathology and progress of the treatment.
Small metal coils, permanent balloons, embolic (glue-like) material, stents or intrasaccular devices will be placed to treat your pathology, depending on the pathology, its size and location.
Further X-rays are taken to ensure sufficient treatment. Once the INR is satisfied with the result, the catheters are removed and the blood vessel in the groin or wrist is usually sealed with a closure device in the groin or manual pressure in the wrist.
After the procedure you will spend some time in hospital, if you have had a diagnostic angiogram under local anaesthesia you will return to your admitting ward and if you feel well enough you may go home the same evening.
If you have had an endovascular treatment or general anaesthetic you will spend some time in the recovery unit or high dependency unit (HDU) while waking from the anaesthetic, before returning to your ward. You can expect to remain in hospital for a minimum of two to three days after an endovascular treatment, until you are walking around and feeling back to normal. In case you underwent a diagnostic angiogram under general anaesthesia, you may most likely go home later the same day or the next morning.
You will be on bed rest for at least a few hours following your diagnostic angiogram or endovascular treatment to ensure the entry site of the catheter in your groin or wrist begins to heal and that you are neurologically stable.
You can expect to have routine checks by your nurse during this bed rest. Your nurse will check your blood pressure, heart rate and pulse rate, as well as other neuro observations. They will check your groin or arm (depending where the catheter was placed) for any swelling, bruising or bleeding and check if you are experiencing any pain (some mild pain/ discomfort can be expected). If you notice severe pain localised to the area, swelling, wide-spread bruising or bleeding of the puncture site please notify the nurse looking after you.
If any bleeding or increased swelling is noticed, we may compress the puncture site again for a longer period of time or place a special pressure applying dressing on your groin or arm.
As mentioned before, if the bleeding is continuous or there is damage to the blood vessel you may require a further surgery to resolve this, which we will discuss with you in the rare event of this occurring.
As mentioned, it is common to experience some pain or bruising at your groin or wrist, this should reduce over a few days following your procedure.
It is also common to experience mild headaches in the days or weeks following endovascular treatment of the blood vessels in your brain. You will be given painkillers to help.
For any non-urgent questions or concerns you may have following your procedure, please contact the Neurovascular Clinical Nurse Specialists. For urgent concerns, please present to your nearest Emergency Department.
The Brain & Spine Foundation UK
UCLH cannot accept responsibility for information provided by other organisations.
- Brain & spine foundation. 2017. Vascular malformations of the brain. [Online]. [20 April 2020]. Available from: www.
brainandspine.org.uk/ our-publications/ booklets/ vascular-malformations-of-the-brain/
Lysholm Department of Neuroradiology,
National Hospital of Neurology and Neurosurgery, Queen Square, London, WC1N 3BG
Email: uclh.
Direct line: 020 344 83444
Switchboard: 0845 155 5000
Extension: 83444/ 83446
Fax: 020 344 84723
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.
Website: www.
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.
Services
Page last updated: 29 January 2025
Review due: 01 January 2027