Pulmonary Arteriovenous malformation (AVM)

Pulmonary AVM refers to an abnormal connection between the arteries and veins in your lung. This is commonly something that a person is born with (congenital) and can occur in isolation (sporadic) or as part of syndrome (e.g., hereditary hemorrhagic telangiectasia; HHT). Most pulmonary AVMs do not cause symptoms, and may be identified incidentally (e.g., when you have an x-ray or CT scan for another reason). If there are symptoms, these may include:

• Haemoptysis (coughing up blood)
• Chest pain
• Shortness of breath on exertion
• Stroke

Pulmonary AVMs often require treatment even if there are no symptoms, as the AVM carries the risk of stroke if untreated. This is because the AVM provides an abnormal pathway for a blood clot that forms in the veins of your body (e.g., leg DVT) to travel directly into the artery supply system of your body including the brain. You may undergo a heart ultrasound "bubble" test that could confirm the present of this type of direct connection between artery and vein.

In general, embolisation treatment will be recommended if the pulmonary AVM:

• has a feeding artery greater than 2 mm in diameter
• has increased in size on imaging scans
• has caused symptoms such as shortness of breath or stroke

Embolisation is the recommended primary treatment for pulmonary AVM. This involves passing a catheter tube into the artery that feeds the AVM, or across the abnormal artery-to-vein connections, and placing coils or plugs in order to close off the abnormal blood vessels. The AVM then ceases to flow, typically improving symptoms and greatly decreasing the risk of stroke. 

Most (80%) pulmonary AVMs are "simple," meaning that they have just one feeding artery. The remaining 20% are deemed "complex," as they have multiple feeding arteries and draining veins. Complex pulmonary AVMs are more difficult to treat and more likely to require multiple treatment sessions with embolisation.

Effectiveness

• The success rate of embolisation for complete closure is <96% with simple pulmonary AVMs
• It is more likely that repeat embolisation treatments may be required with complex pulmonary AVMs

1. A specialist interventional radiologist will first consult and examine you to provide advice about the best management for your pulmonary AVM. If appropriate, you will be recommended to undergo an embolisation to treat the AVM.
2. Most pulmonary AVM embolisation procedures are performed under sedation and local anaesthetic via a small catheter tube inserted into the femoral vein in your groin. In some cases access into an upper limb (arm) vein may be required.
3. The procedure typically takes between 1 and 2 hours
4. You will be required to lie down and rest in bed for up to 4 hours post-operatively, which is to minimise bruising in the groin.
5. The procedure may be performed as a day-case or with an overnight hospital stay depending on complexity
6. After returning home, you will typically be able to resume usual activities with 2-3 days
7. The interventional radiologist will arrange follow up with you, including repeat imaging (e.g., CT scan) and "bubble test" as appropriate, to ensure resolution of the AVM.

The overall rate of major complications is low, however possible complications include:

• Chest pain
• Bleeding
• Stroke
• Coil / plug migration

Interventional Radiologists (IRs) are specialty trained in the treatment of pulmonary arteriovenous malformations (AMVs), including the pre-procedural assessment, embolisation operation and post-procedural care. Interventional Radiologists (IRs) are extensively experienced in angiography and embolisation procedures as they regularly perform angiography all throughout the body, including the chest, abdomen, pelvis, upper limbs and lower limbs.

If you would like to consult with an Interventional Radiologist about pulmonary arteriovenous malformation (AVM), please send a referral for consultation, including the following

• Imaging (e.g., CT scan) results
• Records of consultations with other doctors and specialists

Public eligible patients can undergo the treatment with no out-of-pocket expense in the public system.