Sunday, January 19, 2014

A True Story About the Limits of Surgical Effectiveness

Here’s the last of three straight posts related to surgery. No more for a while!

I never had any kind of surgery for my (now-healed) bad knees. Today, I’m very, very happy I didn’t. Surgery has an understandable allure -- the promise of returning our bodies to a perfect, pre-injury state. But the reality is rarely so simple.

That was underscored again by an article last year in Harvard Magazine called “The Cardiac Conundrum.”

If pressed to name two successful surgical procedures, one might come up with heart bypass surgery and the insertion of stents in clogged blood vessels. Both of these appear unambiguously beneficial. Yet a closer look reveals otherwise.

The article tells us the history of heart bypass surgery goes back to 1910. The patient, a dog, apparently didn’t survive. Success operating on humans came much later. By 1977, 100,000 bypass operations were being done each year.

That’s a big number, considering this is a major kind of surgery -- it’s not like removing someone’s tonsils. So, was it worth it?

A 1977 paper showed that most patients who underwent the procedure had no survival benefit over others who took medications. Other trials were done. Survival improved for a few patients with the most severe cases of coronary artery disease, but the rest just got relief of symptoms.

Was the surgery worthwhile if it usually didn’t extend the patient’s life?

Then along came the angioplasty in the 1980s. This operation too made sense: Open up clogged vessels using a tiny balloon. The problem: Plaques just reformed within weeks. So that led to the development of stents to keep the arteries open.

But the stents, as foreign objects, were actually found to promote clotting. So they were then coated with drugs.

Problem solved? Maybe not, if you look at the larger picture. A 2007 study showed that stents and drug therapy combined were no better than drug therapy alone for lowering the risk of a heart attack or improving survival odds during a seven-year follow-up period.

David S. Jones relates these histories of open heart surgery and angioplasty in his book Broken Hearts: The Tangled History of Cardiac Care. He argues that the prevalent explanation of what causes heart attacks -- coronary vessel blockages -- is mainly to blame for a misplaced faith, which still runs strong, in procedures such as the angioplasty. That “blocked vessel” perspective puts emphasis on highly visible plaques, when “smaller, often invisible lesions in the heart vessels are now understood to cause most heart attacks.”

Jones summarizes what needs to be done:
We need interventions, especially lifestyle changes or medications, that address the causes of atherosclerosis, and not just the largest plaques. And we need to accept that there are some large plaques that might not need intervention.
Obviously, I’ve chosen this “Cardiac Conundrum” story for its relevance to knee pain, and the dilemmas over whether or not to undergo surgery. In fact, the except above could be tweaked to read, “And we need to accept that there are some large cartilage defects that might not need intervention” -- and it would be just as true.

2 comments:

  1. Some point here about that blend of empiricism and human nature called science: insight, hubris, foible, progress, greed... the whole nine yards of enchilada and something too about the road paved with good intent.

    So, orthopaedia are not trailblazers, nor are they apparently alone in the arena of medical procedures gone bad, and medicine clearly does not have a monopoly on the circuitous use of scientific invention: the atom has been split for both war and peace... Bombs on one end of the continuum and on the other, sophisticated kettles that create steam to turn turbines, at what has turned out to be and is still, considerable risk to the environment.

    What's my point? You tell me.

    RX

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  2. Your point is we foolishly put God-like trust in surgeons, when in fact surgery is a bigger lottery than they would usually have us believe.

    TriAgain

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