NUI Galway researchers hope blood clots will advance stroke research

What if the blood clots that caused stroke held the key to stroke prevention, and would understanding more about these clots make them easier to remove?

These are just some of the questions Irish researchers are hoping to answer with the creation of Europe’s first clot analysis centre in NUI Galway.

Stroke occurs when a blood clot moves from somewhere else in the body to the head and blocks off a major blood vessel in the brain. The vast majority or 85 per cent of strokes are caused in this way. Not all blood clots are the same. Some clots are easily dissolved by clot dissolving drugs, but many clots are not. More recently, a new surgical procedure called thrombectomy has been developed, in which the clot is mechanically removed. Some clots are easily removed, but many are very difficult to shift. It is estimated that when the brain is deprived of oxygen, 2 million brain cells die every minute, so rapid treatment is crucial.

Dr Karen Doyle, Senior lecturer in physiology in NUI Galway is leading a new project which aims to study the composition of blood clots that cause strokes. It is a collaborative study with Beaumont Hospital and international clinical and scientific partners. The project is funded through CURAM by Science Foundation Ireland and a Galway based stroke medical device company, Cerenovus.

Dr Doyle’s work will inform the development of new medical devices to help remove the difficult to shift clots and may even identify new biomarkers and therapeutic approaches to preventing and treating stroke.

Speaking to the Irish Heart Foundation, Dr Doyle explained that it was only relatively recently, thanks to the advent of thrombectomy, that clots are being removed and while initially they would have been simply discarded, she believes that clots may hold vital procedural and clinical information.

“All clots are not the same they can vary quite considerably in their composition but to be honest very little is known about that. So, we are analysing the composition of the clots to relate the difficulty of removal with the composition of the clot. We are going to get various procedural and clinical information regarding each case, so we will be able to build up a profile,” she explained.

Dr Doyle is collaborating with a number of international centres who have agreed to send her the clots they have removed via thrombectomy. The project aims to analyse 1,000 clots by 2020, making it the largest international collaborative study for the analysis of clots removed by thrombectomy. It is hoped that building up a large database of clots will help to inform and improve stroke treatment.

For example, she explained that a clot that has proven very difficult to remove by thrombectomy, may hold clues to help inform medical device design or simply inform the clinician of the best way to remove it.

“If you can tell on a CT scan before you try to take the clot out that this is likely going to be very difficult and just trying to suck the clot out won’t work, they will save precious minutes,” she explained.

Dr Doyle is also hoping to find something within the clot itself that may predict a person’s likelihood of stroke and perhaps lead to improved curative or preventative treatments for the condition.

“Clots are usually ignored, they are just discarded material. We are also going to look for novel biomarkers within the clots that might be indicators of disease states, that might indicate your likelihood of stroke,” she added.

To date Karen and her team have carried out basic analysis on 120 clots which have already yielded some interesting results relating to what type of clots are easier than others to remove with thrombectomy.

“This would be helpful for surgeons who carry out the thrombectomy and it may help them figure out the best approach to remove the clot in the first incidence, potentially speeding up the procedure. There may also be the potential to prevent the clot happening in the first place by developing new medicines. This could open up all kinds of new avenues,” Dr Doyle said.

Dr John Thornton, Consultant Interventional neuroradiologist at Beaumont Hospital in Dublin and the Director of the National Thrombectomy Service in Ireland who is one of the collaborators on this project said Dr Doyle’s work would “greatly improve our understanding of the mechanism of the disease and the potential treatment of the disease.”