Potential Risks

Interventional Neuroradiology is a rapidly evolving subspecialty that permits physicians to treat a multitude of neurovascular disorders through a minimally invasive, endovascular route, obviating the need for open neurosurgery. For some diseases such as aneurysmal subarachnoid haemorrhage, this has been shown to be associated with superior clinical outcomes, shorter hospital stay, reduced health costs, and a more rapid recovery. However, as with any surgical procedure, neurovascular interventions are associated with a small but finite risk of procedural complications, the magnitude of which is generally comparable to that of the open neurosurgical alternative or equivalent.

In most cases, the risk of therapeutic endovascular neuro-interventional procedures includes those as outlined for diagnostic angiography and a small additional risk associated with the treatment of a particular disorder.  Your doctor will discuss these with you in greater detail and provide an opportunity for you to ask questions before your procedure.

Diagnostic Cerebral Angiography

In most patients, the arterial system can be accessed through an artery in the groin. By using a guidewire and small, hollow plastic tube called a catheter, your doctor can access virtually any artery in the body. There is a small possibility of scratching the lining of and causing bleeding into the wall of the artery anywhere from the groin to the neck where the catheter is positioned for diagnostic cerebral angiography. This complication, known as a "dissection" could lead to blood clot developing at the point of arterial injury or result in arterial closure. There is also a potential for a blood clot to form within the catheter which could then be injected into the circulation and be carried away by bloodflow. Such an "embolus" could lodge in a small downstream artery and block blood flow beyond that point. If a dissection were to occur in the carotid or vertebral arteries in the neck or an embolus impede blood flow to part of the brain (ischaemia), a stroke could result. Similarly, if such an event were to occur in a spinal artery, there is a potential risk of paraplegia. The overall risk of a serious neurological complication such as stroke or paraplegia from cerebral/spinal angiography in experienced hands is approximately 1 in 250-500.

There is a very small risk of an allergic reaction with the iodine-based x-ray dye (contrast) that is injected to outline the arteries and veins. The risk is tiny with the current range of non-ionic contrast agents which have replaced the older ionic media that were used up to a decade or so ago. Serious, life-threatening anaphylactic reactions occur rarely with an estimated mortality rate of less than 1 in 75 000 patients. Urgent management using adrenaline, anti-histamines, and mechanical ventilation may be required. Minor allergic reactions in the form of rash or wheeze may occur more commonly and may be treated with anti-histamines, corticosteroids and observation. If you have a known allergy to iodine you MUST inform your doctor before attending the angiogram so that prophylactic (preventative) medications against allergic reactions can be prescribed.

Contrast agents can have a toxic effect on kidney function. The risk is increased in patients with pre-existing renal impairment and diabetics taking metformin, but can be minimised with prehydration +/- prophylactic administration of N-acetylcysteine and withholding metformin for 48 hours afterwards respectively. Deterioration in renal function is usually mild and self-limiting if it occurs.

At the conclusion of your angiogram, the catheter in your groin is removed and bleeding is prevented by your doctor applying pressure to the point of arterial puncture for 10-15 minutes. In some cases, your doctor may choose to use an closure device such as an "Angioseal" or "Perclose" which negates the need for prolonged manual compression. In either case, the is a small chance that you may develop a haematoma or bruise around the groin. The majority of these resolve spontaneously over the ensuing weeks. In rare instances, there may be localised leakage of blood around the artery into a "pseudo" or "false" aneurysm that may require treatment. If you notice persistent or increasing pain or swelling at the groin access site, you should contact us or your local doctor for advice.

There is a potential risk of infection being introduced at the site of arterial access. Patients who have had previous arterial graft surgery may be given prophylactic antibiotics. Infection associated with neuroangiographic procedures is rare but is slightly increased when using arterial closure devices.

In summary, the risks of diagnostic neuroangiography include: stroke, paraplegia, death, renal impairment, arterial damage, infection, haematoma/bruising, and allergic reactions.