Arteriovenous Malformation (AVM) Treatment – A guide for patients

Introduction

This leaflet is for patients booked for patients who have been advised to have AVM treatment.

What is AVM?

AVM is an abnormal collection of blood vessels or abnormal communication between the arteries and veins in the body. Some patients are born with this and some may not even be aware that they have one until they start to develop symptoms (typically discomfort or occasional bleeding but sometimes other issues such as impaired blood flow around the body can occur).

They can be divided into “high flow” lesions where the arteries contribute to the lesion and “low flow” lesions which are mainly composed of either veins or lymphatic vessels.

Why do I need this procedure?

You have developed symptoms due to your AVM, to reduce your symptoms the consultant looking after you has decided to seek treatment for you.

Who has made the decision for me to have this procedure?

The consultant in charge of your case and the radiologist performing the AVM treatment will have discussed your case and come to the conclusion that this is the best way of treating your condition.

You will have the opportunity for your opinion to be taken into account, and if after discussion with your doctors, you do not want the procedure carried out, you can decide against it.

Who will be performing the procedure and other staff you are likely to meet?

• A specially trained doctor called an Interventional Radiologist will be performing your procedure.
• Radiologists have special expertise in using x-ray equipment and in interpreting the images produced, as well as performing minimally invasive procedures.
• They will look at these images whilst carrying out the procedure.
• The Interventional Radiologist will be assisted by a radiographer and nurses and/or other Radiology doctors or trainees.

Where will the procedure take place?

You will be taken to the Interventional Radiology Department.

What happens before my procedure?

• You will be admitted to hospital on the day of the procedure.
• A doctor will take a medical history from you.
• You may have a small needle put into a vein in your arm for painkillers and antibiotics to be given if necessary.
• Standard blood tests may be carried out.
• You may eat a light meal before your procedure.
• If you have any allergies you must let your doctor know and a red allergy band will be attached to your wrist.
• If you take any medications to thin the blood (anticoagulants or antiplatelets) please let us know beforehand, as these will need to be stopped a certain length of time before the procedure.
  • Examples include: warfarin, dalteparin, enoxaparin, tinzaparin, dabigatran, rivaroxaban, apixaban, clopidogrel, ticagrelor.
  • Low dose aspirin (75mg) is safe to continue.
  • Please discuss with a doctor before stopping any medicines, as sometimes other treatment will need to be given.
• If you have previously reacted to intravenous contrast medium (the dye used for CT scans), you must also tell your doctor about this.

What happens during the procedure?

• You will get dressed into a hospital gown.
• You will lie on the x-ray table, generally flat on your front. In some cases it can be performed lying on your side.
• You will have a monitoring device attached to your finger, and will have a blood pressure cuff placed around your arm.
• The procedure is performed under sterile conditions and the radiologist and scrub nurse will wear sterile theatre gowns and operating gloves.
• Antiseptic solution will be used to clean the skin and then local anaesthetic will be injected to make the skin go numb.
• Depending on the subtype of AVM, different procedures may be performed. For low flow malformations, a small needle may be placed into the lesion and STS foam may be injected. For high flow lesions, an embolisation procedure going through an artery or vein in the groin may be required.

Will the procedure hurt?

• Some discomfort may be felt in the skin and deeper tissues during injection of the local anaesthetic.
• There will be a nurse, or another member of the clinical staff, in the room looking after you.
• If the procedure does become uncomfortable, please let a member of staff know.
• Following the procedure most patients do not get significant pain. Painkillers will be provided as needed.

How long does the procedure take?

Every patient’s situation is different, and it is not always easy to predict how complex or straightforward the procedure will be. Generally, the procedure will last approximately 45 minutes.

What happens after the procedure?

• You will be taken back to your ward/ Radiology Day Unit.
• Nursing staff may carry out routine observations including taking your pulse and blood pressure and will also check the treatment site.
• If you experience pain, sickness, abnormal swellings or are generally feeling unwell, please let the nursing staff know.
• You will need to stay in bed for a few hours post procedure.
• Most patients will go home the same day of the procedure.
• If you were told to stop any medication before the procedure, your doctor will tell you when to start them again.

What are the benefits and possible risks of the procedure?

Benefits

This treatment should relieve the symptoms from the AVM.

Risks

• AVM treatment is a safe procedure but as with any medical procedures there are some risks and complications.
• The main risk is failure to treat the AVM. Sometimes more than one procedure is required.
• There may be some bleeding and mild discomfort depending on the location of the AVM.
• There is a chance of infection following the procedure.
• There is a very small chance of injury to nearby organs during the procedure.
• The exact risk depends on the location of the AVM - for superficial lesions there is a chance of skin injury or breakdown radiation.
• You have been referred for an Interventional Radiology procedure to help deliver your treatment. A specialist in radiology agrees that this is the best procedure to treat your clinical condition and that the benefit of the examination is greater than the risk.
• The x-ray involves a dose of ionising radiation equivalent to a few months or years of natural background radiation which we are all exposed to every day.
• Ionising radiation can cause cell damage that may turn cancerous, however the risk of this happening from your examination is considered low.
• Depending on the length of the procedure there may also be a small risk of an excess radiation dose to the skin leading to short term and long-term effects (e.g. reddening of the skin and burns).
• If this happens as a result of this procedure, you will receive further advice following the procedure. The dose delivered will be kept as low as is practicable.
• For further information please see the information on our webpage.

Accessibility requirements

If you require support for your appointment, e.g. if you find it hard to hear, see or be understood by others, please let the receptionist or healthcare professional know on arrival or contact us by email (opens in a new tab) or telephone 01223 256998.

Pregnancy status

We have a legal responsibility to enquire if you are pregnant. Any patient aged between 12-55 years will be asked if there is a possibility they could be pregnant. This is important for us to know before you have your examination involving ionising radiation.

You can discuss this with a healthcare professional in private if you wish.

Medication

Bring all of your medicines (including inhalers, injections, creams, eye drops or patches) and a current repeat prescription from your GP.

Can I bring someone with me?

Those accompanying you may be required to stay out of the examination room during the procedure and remain in the waiting area.

Childcare whilst in the department

Staff are unable to look after or supervise children whilst your procedure is taking place. Please make alternative arrangements for the care of your children whilst you attend for your procedure. If you attend an appointment with children with no one to look after them whilst you have your procedure, then your appointment will unfortunately have to be cancelled and rescheduled.

Personal belongings

Patients are advised to bring minimal belongings and not to bring valuable items. Any valuable belongings (mobile phone, wallet etc.) will go with the patient while having their procedure and can be secured in a locked box/safe.

How, when and by whom will my results be communicated?

Imaging examinations are reported in order of clinical priority to ensure those with the highest urgency are reported first.

Your referring team or clinician will be responsible for communicating reports back to you.

Test results are made available via MyChart but there is 3-week delay from when an examination has been reported to when it is available on MyChart, in order to allow time for your clinical team to be able to see and action the results prior to them being released to the individual patient.

Contacts/Further information

Please call the Radiology Day Unit and speak to the Imaging Nurses, on telephone number 01223 254639 if you have any questions or concerns about this procedure.

Some of your questions about the procedure should have been answered by this leaflet, but remember this is only a starting point for discussion about your treatment with the doctors looking after you and you will be able to discuss any questions you have with them.

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Question, concern or complaint?

Firstly speak to your nurse, doctor or other staff member as soon as you can so they can do their best to put things right straightaway.

If you don’t feel able to speak directly to the people caring for you, contact the patient advice and liaison service (PALS). Please call 01223 216756 9am to 4pm Monday to Friday, via email (opens in a new tab), or via a form available via link on the CUH PALS webpage.

PALS is open every weekday, and you can leave a message in the evenings and weekends.

MyChart

We would encourage you to sign up for MyChart. This is the electronic patient portal at Cambridge University Hospitals that enables patients to securely access parts of their health record held within the hospital’s electronic patient record system (Epic). It is available via your home computer or mobile device.

More information is available on our website.

Reference

This document has been adapted from one prepared by the British Society of Interventional Radiology (BSIR).