The research team at the Sree Chitra Tirunal Institute of Medical Science and Technology (SCTIMST), under the Department of Science and Technology has developed an intracranial flow diverter stent to treat aneurysms in the brain.
Flow diverters stents, when deployed in the artery with the aneurysms, divert blood flow away from the aneurysm, thus reducing the chances of its rupture from the pressure of blood flow.
Intracranial aneurysm is a localised ballooning, bulging or dilation of arteries in the brain caused by progressive weakening of the inner muscles of the wall of the blood vessels.
The spontaneous rupture of the aneurysm can result in bleeding into the space around the brain resulting in a condition called a subarachnoid haemorrhage (SAH). SAHs can lead to paralysis, comas or death, a press release explained.
The surgical treatment of an aneurysm involves opening the skull and a clip on the neck of the aneurysm, so that it is cut off from the path of blood flow.
There are three non-surgical, minimally invasive endovascular treatments of aneurysms of the brain. In two of these procedures, the aneurismal sac is filled with platinum coils or occluded using high viscosity liquid polymer, which solidifies when released into the sac and seals it. All these techniques have some limitation or the other, the release noted.
The third minimally invasive option is deploying a flow diverter stent to bypass the segment of the blood vessel which has the aneurysm.
Flow diverters have the advantage of being flexible and adaptable to the shape and course of the vessel. Also, flow diverters promote the healing of the vessel wall by removing the constant stress of blood flow on it.
The Chitra flow diverter is designed to have a better grip on the walls of arteries of complex shapes in order to reduce the risk of migration of the device.
The unique design is in its weave also makes the stent resistant to kinking or twisting, when it is placed in tortuous arteries and those with complex shapes. Even a 180 degrees bend does not occlude the lumen of the stent.
A portion of the wires is made radio-opaque for better visibility in x-rays and fluoroscopy, thus, aiding the accurate delivery of the diverter in the blood vessel.
Nitinol, a superelastic alloy with shape memory was acquired from the National Aerospace Laboratory, Bengaluru (CSIR-NAL). When the device is deployed at the site, it is released from its crimped locked position and assumes the desired and originally designed shape because of the shape memory property of Nitinol.
The flow diverter is delivered to the aneurysm in the brain using a delivery system. The delivery system has also been developed by the team.
Imported flow diverter stents cost around IN 8 lakhs (about US $10,888) and are not manufactured in India. With the availability of the indigenous technology from SCTIMST and Nitinol from NAL, a well-established industry should be able to manufacture and sell at a much lower price.
The device is expected to be transferred to the industry soon and will subsequently undergo testing in animal and human clinical trials before commercialisation.
SCTIMST has filed separate patents for the stent and the delivery system.
