The effects of some severe strokes can be completely reversed, and patients can make a full recovery if treated in a timely manner, thanks to a procedure called a thrombectomy.

Monday 23 April 2018

By June Shannon

Thrombectomy is a relatively new therapy for the treatment for acute ischemic stroke; this is where the stroke is caused by a blood clot in a major blood vessel in the brain. It is estimated that approximately 10 to 20 per cent of stroke patients would have this type of stroke.

Dr John Thornton is a consultant interventional neuroradiologist at Beaumont Hospital in Dublin and the Director of the National Thrombectomy Service. The first thrombectomy was carried out in Beaumont Hospital in 2010 and to date a total of 750 procedures have been performed at the hospital. Currently in Ireland thrombectomy is only carried out in two centres; Beaumont Hospital in Dublin and Cork University Hospital.

Dr Thornton will be speaking at the Irish Heart Foundation’s 6th Annual Stroke Survivors’ Day which takes place in Croke Park in Dublin tomorrow (Tuesday 24th April).

Unlike thrombolysis which uses drugs to try and dissolve a blood clot, thrombectomy is a radiologically guided interventional procedure where doctors use specialist equipment to mechanically remove the clot from the brain. Crucially unlike thrombolysis which is only effective up to four and a half hours post stroke, thrombectomy has been shown to be effective up to 24 hours.

“Using x ray guidance, we make a puncture in the artery in the groin and pass a tube through the blood vessels and up into the blood vessel in the head. Then we pass a small tube past the blood vessel in the head and pass a stent like device to try and catch the clot, retrieve it and restore blood supply,” Dr Thornton explained.

“It depends on the amount of time it has taken for the system to be organised, so the patient gets to the point of removing the blood clot and it depends on whether there has been permanent damage to the brain tissue while waiting to get the blood clot out. If no permanent damage has been done, then the patient makes an excellent recovery but if it has taken a little bit longer then the patient may have some residual stroke symptoms,” he added.

While thrombectomy has been proven to be effective up to 24 hours post stroke or 24 hours from the time the patient was last seen well, Dr Thornton said that patients still needed to be treated as fast as possible, as with every short interval of time that passes they may become unsuitable for treatment if the stroke becomes permanent.

“Most of the patients who are treated up to 24 hours after the onset of symptoms, those are patients in whom we don’t know exactly the time of onset stroke. That is why we say 24 hours from the time they were last seen well. So, somebody might go to bed at 10 o clock at night and wake up at 8 o clock in the morning with a stroke. We don’t know what time they had that stroke and they would be excluded from having thrombolysis because you would have to presume that they were more than 4 and a half hours from the onset of stroke, but they are not excluded for thrombectomy.”

According to Dr Thornton, on average for every minute that you save in removing the clot you gain a week of healthy living post stroke, so thrombectomy has “quite a dramatic effect.”

“Some patients when you treat them they will recover completely, and they will live several or many years with a completely normal life, and other patients when you treat them, and the treatment isn’t successful, or it is too late, they don’t gain as much healthy living. So, when you say save a minute gain a week, it is very much an average,” Dr Thornton explained.

Studies have shown that in eligible patients, thrombectomy can reduce the death rate from stroke by half and almost doubles the rate of recovery to complete independent living.

Dr Thornton said the message from his talk at tomorrow’s conference was if you are having a stroke or you see someone having a stroke you should get them to your local hospital as fast as possible.

“You should be aware that stroke is curable if treated within the first few hours. If it is a severe looking stroke, it is potentially completely curable first by getting the patient to your local hospital and subsequently to Beaumont or Cork University Hospital where the clot can be removed by a procedure known as a thrombectomy. We want people to know the name thrombectomy.”

Michael Dermody is one such stroke patient who was treated with thrombectomy and he will be speaking about his experience with Dr Thornton at tomorrow’s conference.