Times of India
21 October 2010
Drug–Coated Balloon For Blocked Arteries Is Latest Offering
To understand the importance of drug–eluting balloons, Jaslok Hospital’s cardiology chief Dr Ashwin Mehta says one should look at the history of cardiac treatment. "In 1969, doctors in Cleveland Clinic introduced bypass surgery to treat blocked arteries.
They realized that the connections (grafts) they made in 70% of the cases closed down within five years," he said at a press conference on Wednesday. This spurred the entry of minimally invasive methods like angioplasty. "First, we used balloons and bare metal stents to open up arteries. This too had high rates of recurrence.
So in 2002, researchers came up with drug–eluting stents that kept releasing drugs at the site of blockage, thus keeping the constricted portion open for continuous blood flow. "But drug–eluting stents had their own problem," said Dr Mehta, adding, "Tissue would grow within the stent’s spurs."
It is to remove this in–stent growth or restenosis–the re–narrowing of a coronary artery–that the new drug–eluting balloon is best at. Cardiologist Dr Upendra Kaul from Delhi, who has treated over 100 patients so far using the drugeluting balloon, says: "If a previously fitted stent gets blocked, doctors are not too happy about using another stent there. In such a situation, a drug–eluting balloon is the best solution."
Dr Sunil Chandy, who heads the cardiology department at CMC in Vellore, "At the moment, we believe that the drugeluting balloon is best for three main conditions–for a patient with a blocked stent, for patients with arteries that are less than 2.5 mm in diameter and at bifurcation of vessels."
So, a cardiologist would put a stent in the main arm of the artery and a balloon in the smaller arm. How does this benefit the patients? As Dr Chandy puts it, the patient has less metal in his arteries (the balloon is withdrawn unlike the metallic stent) and less related complications. Research has shown that patients fitted with drug–eluting balloons need lesser amount of blood–thinning medicines after their hospitalization.
But can drug–eluting balloon replace drug–eluting stents? Doctors are not sure they would. Says Dr Mehta: "These balloons have so far shown results in limited settings. At best, it is complementary treatment to the existing ones."