Stents: can they bypass the bypass?

There’s a growing debate in medical circles whether drug-eluting and non-invasive stents can finally replace cut-slice-and-splice bypass surgery. While it is said to have reduced the incidence of heart attacks by 50 per cent globally, stenting has its downsides.

By Mukesh Khosla

It’s as big as a clenched fist, weighs no more than half a kilo, and pumps like there is no tomorrow, circulating about 9,000 litres of blood through the Byzantine system of veins and arteries of the human body. The heart today is the focus of almost half of the medical research worldwide. Obviously—if it stops, you’re as good as dead.

The good news is that of all the hearts currently doing service, almost 75 per cent are healthy. The bad news is that the remaining percentage of the world’s current population of 6,602,224,175 (July 2007 est)—or 1,650,556,044—has tickers that are precariously placed. It is these attenuated, damaged-heart lives made heart disease the number one killer in the 20th century.It is estimated that in India alone, 30 lakh people die every year of heart disease.

Although it is the complicated, insanely invasive bypass surgeries that grab the headlines—perhaps because they seek to heal the organ that is traditionally viewed as the seat of the soul and, thus, imperative to human health from both a bodily and metaphysical point of view—only a very small percentage of cardiac sufferers require such surgical intervention. In fact, many surgeons are today trying to find ways around the scalpel and opting for non-invasive devices which don’t require serious muscle as well as deftness but can restore a diseased heart to normalcy in a more congenial manner.

One such device introduced in India some years ago is the medicated stent. It is a tiny stainless steel mesh tube that is mounted on a balloon catheter and inserted into the heart artery. The technique is similar to balloon angioplasty. The benefit of using a stent is that the patient, usually already in a precarious state, doesn’t have to go under: the insertion is performed under local anaesthesia. The doctor inserts a thin plastic tube into a leg or an arm and gently shoves it up to the heart. A thin metal wire is steered into the tube, with a balloon being advanced over this wire. The balloon is then inflated and pushes against the artery’s walls, keeping it open. A stent follows the balloon, shoring up the artery and the balloon is deflated and withdrawn. The procedure takes an hour or so, and the patient is able to return to normal activity within a couple of days at most.

The surgery might sound simple, and because of its simplicity, very desirable. But there is a global debate raging whether the stent can really replace the saw-slice-and-splice of bypass surgery. While a growing section of heart surgeons feels that a bypass can, in fact, be a health hazard, hitting the quality of life of a patient, another camp feels that the device cannot replace the ungainly butchery of bypass surgery in patients who have life-threatening blockages in the left main coronary artery, which supplies blood to the heart.

Who better to ask than the Escorts Heart Institute & Research in Delhi? Says Dr T S Kler, executive director, Cardiac Sciences at Escorts, “The drug-eluting stent has revolutionised the treatment of heart diseases. It reduces chances of recurrence of a blockage by more than 50 per cent. “Moreover”—and perhaps most importantly for the great majority of patients—“the cost of this treatment is far less than that of open heart surgery. And it does not have any serious after-effects.”

Kler is, however, quick to qualify that stents are not about to replace surgery “for the time being. A stent can prove to be very effective if a patient has less than 70 per cent blockage. But if he has multiple blockages, then surgery is superior.” Which basically leaves the debate wide open.

But such is the distaste of patients for looking down at chests sawed up from throat to sternum and stapled shut that the popularity of stents, which leave no mark, is booming. Stents are also less bothersome for cardiac surgeons, many of whom are encouraging patients with 50 to 60 per cent blockages to go in for the technique. “Elective angioplasty”—or stenting—essentially means heading off a cardiac arrest at the pass before it has had a chance to attack. Medical experts say that the introduction of stents has reduced heart attack deaths by almost 50 per cent.

Then, again, the day has not yet come when a patient can decide her or his course of medication. Only a cardiologist can determine whether a patient requires a bypass or a stent, which, given the screaming popularity of stents, might be rather a lot to leave in a surgeon’s hands. Stenting depends on how many coronary arteries are blocked: if it’s one, a stent is a better option. But a recent study of nearly 60,000 people with multiple artery blockages suggests that it is conventional surgery that promises a significantly lower chance of dying over three years after the surgery and that has lower chances of repeat procedures.

But Piyush Vidyasagar is among the people who swear by stents. A chartered accountant, he had a 95 per cent blockage in what doctors alarmingly call the “widowmaker” artery, and thus technically outside the stent category. An angioplasty was performed on him and a drug-eluting stent was inserted. He was home in two days flat, and no one, he says, could have known he had a problem at all. No scars, no recuperation time, and within two weeks he was off on his morning walks.

Inputs by Nag Mani