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Hope for brain stroke patients: How a stent can clear blood clots in 24 hours

Although the device is used in the West, AIIMS is testing a version that’s more suited to Indians and is cost-effective

Brain stroke patients in the West could avert brain damage as neurosurgeons used a sophisticated retriever stent to clear the blood clot from blocked arteries and restore blood flow within 24 hours. (Photo: Image by Gerd Altmann/Pixabay)

For sometime now, brain stroke patients in the West could avert brain damage as neurosurgeons used a sophisticated retriever stent to clear the blood clot from blocked arteries and restore blood flow within 24 hours. However, this device is out of reach for most Indians despite brain strokes increasing among them. That’s all set to change with the All India Institute of Medical Sciences (AIIMS), Delhi, now conducting a trial with an upgraded device that’s equipped to remove all kinds of blood clots, is better at opening blocked arteries and may cost one-fourth the original price.

The clinical trial, GRASSROOT (Gravity Stent-Retriever System for Reperfusion of Large Vessel Occlusion Stroke Trial), is looking at the effectiveness and accessibility of a new generation of advanced stent-retriever devices that can be used in mechanical thrombectomy, a minimally invasive stroke surgery to clear artery blockage in the brain. According to Dr Shailesh Gaikwad, professor and head, Department of Neuroimaging and Interventional Neuroradiology, Neurosciences Centre, AIIMS, and one of the investigators of the trial, “We are finding out how the device works on the Indian population. The new stent-retriever has been designed specifically to tackle the unique features of a stroke clot in the Indian population, given that our arteries are narrower.” The new device was first used on August 25. The patient is doing well.

What’s a stent-retriever?

A stent-retriever is a thin, cylindrical mesh tube that is inserted through a catheter and expanded within the artery to widen the vessel walls. Once the clot gets trapped in the stent’s mesh, it is pulled out by the catheter. It doesn’t need permanent deployment. The removal can be done within 10 minutes and the blood flow to the brain can be restored rapidly.

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Is it better than existing protocols?

It achieves faster and complete restoration of blood flow to the brain compared to IV infusions, where 50 per cent of the dose is given immediately and 50 per cent is spread over 12 hours. “During these hours, the artery is supposed to open up but one cannot predict how soon. It can happen within 10 or 12 hours. Within this intervening period, there is no way to monitor whether the drug is effective or not, the clot is breaking or not. The stent-retriever has immediate results,” says Dr Gaikwad.

Besides, the IV infusion works only if the patient manages to reach within six hours of the brain stroke. After this, mechanical thrombectomy is the only effective means of care. But it is an expensive procedure and currently costs Rs 5-7 lakh as the devices are imported from the US. It is because of the high cost that only about 4,000 patients of the 17 lakh brain stroke cases reported in India get mechanical thrombectomy.

Why a stent?

Why is the study important for India?

According to Dr Deepti Vibha, additional professor, Department of Neurology, and one of the investigators, the primary aim of the trial is to evaluate the safety and efficacy of an advanced stent-retriever in the Indian population. The second priority is to see to what extent patients regain their functionality.
“We are generating clinical data for approval of the device in India. It is already approved in Southeast Asia and more than 120 patients have been successfully treated over the last six months,” she adds.
If successful, it could help India meet its critical stroke care challenge. “With only 4,500 of the estimated 3,75,000 eligible stroke patients receiving life-saving mechanical thrombectomy treatment each year, the need for accessible stroke intervention has never been greater,” Dr Vibha adds.

Why are our brain clots different from Western populations?

Dr Gaikwad explains that the blood vessels of Indians are not of the same size as their Western counterparts. “They have an average height of 6 ft, ours is 5 ft 6 inches. Their average age of developing a brain stroke is 60-70 years. Indians experience such strokes 10 years ahead, in the 40-50 age group. So if we are 10 years ahead in getting a stroke, we need to understand the long-term efficacy of the device. Our eating habits, sedentary lifestyle, early diabetes and hypertension as well as deranged lipid profiles mean that the nature of stroke is different from the Western population,” he says.

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Which hospitals are part of the trial?

The trial spans 16 hospitals across India, including AIIMS, Jawaharlal Institute of Postgraduate Medical Education & Research (JIPMER) and Zydus Hospital, Ahmedabad. “More and more people will get hands-on training and this will help in capacity building,” says Dr Gaikwad.

If approved, can the stent be manufactured in India?

Dr Gaikwad says if approved for use, AIIMS would approach the government and regulatory authorities to give permission for domestic manufacture of this device. “We have the technology and we have a research and development wing. This way we can reduce the cost by one-fourth,” he says.