Graft craft

IN ITS short span of research activities in medicine, the Sree Chitra Tirunal Institute for Medical Sciences and Technology (SCTIMST) in Thiruvananthapuram, Kerala, has again tasted sweet success. Its latest achievement has been developing an artificial blood vessel - the vascular graft. After successfully completing trials in pigs, this new medical technology would shortly undergo limited clinical trials.

"The vascular graft can replace the diseased and degenerated blood vessels," sais K Mohandas, director, SCTIMST. "The project was a joint venture by the South Indian Textile Research Association (SITRA), Coimbatore, and the SCTIMST," he informed. While SITRA prepares the graft fabrications, which range from 10 mm to 26 mm in diameter, by using woven polyester vascular plastics, the evaluation of the technique is done by the SCTIMST, adds Mohandas.

In its 15-year-long existence, the SCTIMST has come out with five major medical technologies which are of export quality. These include a blood bag, a bubble oxygenator, a cardiotomy reservoir, an artificial heart valve and a hydrocephalus shunt, and an implantable neuro-surgical device to control the cerebro-spinal fluid's pressure in the brain.

Four products are presently under clinical trial. "Currently, as mwy as 3.5 Million SCTIMST blood bags are being produced annually, of which two million are meant for exporting," informs G S Bhuvaneshwar, head, biomedical technology wing of the SCTIMST.

Since the animal trials were satisfactory, says Mohandas, "We have to convene a meeting of the five-member ethics committee for the approval for controlled clinical evaluation of the graft."

In fact, the institute began researching on developing an artificial blood vessel in 1981. "It took eight years," recalls Bhuvaneshwar, the project-incharge. "It is till in the i&D stage", cautions K Mohandas, "It will take at least two years to complete the clinical trial and presept it as a marketable product."

The SCTIMST is now looking forward to further involve the industrial sector in basic technology development. "In an era of economic reforms, we feel it is necessary," says Mohandas. "Our next project, developing a membrane oxygenator, will be carried out by the full tie-up with the South Petroleum Industrial Corporation. It is well known that in India, industries have been reluctant to involve themselves in basic technology development projects. But the magnificent track record of the SCTIMST in developing indigenous medical technologies attracts many industries to involve the projects undertaken by the institute."

In the post-World War ii era, when a multimillion dollar global industry for medical devices was emerging, "there had been a 'vacuum," observes Mohandas. "The SCTIMST, one of the 11 institutes in India having 'national importance' status, has been trying to fill this vaccum since its beginning. Development of the new artificial blood vessel is also another step in this direction," he said.

"It will lead to providing medical devices at a cheaper rate than the imported ones," he said. While the cost of an imported artificial heart valve ranges from Rs 20,000-30,000, the SCTIMST valves would be for Rs 12,000 each.

Bhuvaneshwar observes that the graft could be used to treat obstructions in the aorta and major arteries resulting from atherosclerosis, thrombosis, embolism, congenital lesions, disruptions and dissections by way of bypass, resection and replacement.