Speaking about Stroke Services

National Clinical Director of Hyperacute Stroke Services, Stefan Brew, shares with us what a stroke is and the ground-breaking treatment offered at Auckland City Hospital. We dive into the difference his team is making and how a dedicated treatment suite would mean more people receive this game-changing procedure, faster.

Strokes affect thousands of New Zealanders every year, and of those thousands, many die and many more are left with permanent disabilities requiring full-time care.

Can you introduce yourself and tell us a bit about what you do?

I’m Stefan Brew, one of the Interventional Neuroradiologists at Auckland City Hospital. We use imaging equipment to guide movement of catheters and other devices within the arteries that supply blood to the brain.

What is a stroke?

A stroke is loss of brain function due to a problem with its blood supply, which happens when a large artery supplying the blood to the brain becomes blocked. It’s very common; strokes affect thousands of New Zealanders every year, and of those thousands, many die and many more are left with permanent disabilities requiring full-time care.

Can you tell us about the clot retrieval process?

Clot retrieval is a stroke intervention performed in the hospital’s angiology suite, ideally in the bi-plane angiology suite.

The technique involves accessing an artery, usually the femoral artery in the groin, where we introduce a catheter (tube) into the patient’s body and navigate it past the heart, up into the large arteries in the neck. The catheter and a wire get put into the carotid artery and then a large catheter is maneuvered into the carotid artery.

Through that catheter, we introduce a smaller device to the blockage site. We maneuver a second catheter to the blockage site and either aspirate (suck out the clot), or use a stent or other mechanical retrieval device to pull out the clot. After this process, the artery that was blocked will open, allowing blood going to the brain beyond the blockage point.

Can you explain the difference in benefits between the previous clot retrieval process and this new process?

The previous technique, intravenous thrombolysis (where a dissolved clot – clot-dissolving agent was injected into a vein and carried by the circulating blood to the blockage site), was not very effective in large arterial occlusions; a very small proportion of patients derived benefits, and a very, very small proportion of patients were restored to living independently.

Using the new technique, we get the artery open more than 90% of the time. So a much higher proportion of patients benefit, and a significant proportion are converted from having disabilities that would require full-time care, to going home and living independently.

How many patients have you treated using this new procedure?

We’ve treated well over 1,000 patients over the last six years at Auckland City Hospital. Those patients come from all around the North Island and, of those patients, about 90% of the time we succeed in getting the blocked artery open. We will treat around 400 this year, and the number of patients continues to increase.

What is the current set-up for the treatment suites where this process can occur?

There are two single-plane angiology suites (with one image receptor), which allow us to look in real-time in one direction; they are primarily designed for performing interventions everywhere in the body, except the head.

There is a third room, the bi-plane suite, which has a second image receptor so we can look in two different directions at the same time; this is particularly important when working in the head. The existing three rooms are heavily utilised for a combination of acute and elective cases.

What difference would a second bi-plane treatment suite make?

Not infrequently, we find ourselves in the position where we are already treating a patient in the only bi-plane room, when an acute stroke comes in. This forces us to either delay the treatment, which lowers the probability of the patient getting a good outcome, or to perform the intervention in a single-plane suite, which is not ideal for being able to see what we want to see in the head.

A second bi-plane room would make a real difference in terms of enabling us to treat patients as promptly and efficiently as possible.