Wednesday, September 05, 2007

Robotic Marketing

Imagine buying a Mercedes Benz luxury car to take a trip. You save your hard-earned cash and spend handsomely for the car because of its human engineering, reputation and admire its comfort during a test drive. You drive it from the dealer and find the car’s the rage as it sits in your driveway. You gloat over its finish and detailing. You’re the envy of the neighborhood.

And then you find out the trip is a transatlantic one, and you should have bought a boat instead.

Such is the lure of technology in medicine. It seems all too often the development, manufacturing, and marketing of devices, especially high-tech robotics, has exceeded our understanding of the mechanisms and etiologies of the very diseases we hope to treat. And it is sexy.

But others have argued that such technology does nothing but contribute to hospitals' technical arms race.

Such is the case of atrial fibrillation ablation.

I am struggling with the decision of obtaining a device to perform robotic-assisted catheter ablation of atrial fibrillation. There are several devices now on the market. One is a mechanical robotic sheath system from Hansen Medical that purports to "extend my reach" to locations within the left atrium better and with more precision, and the other a system from Stereotaxis that uses a powerful magnetic field to provide "a softer touch to the treatment of heart disease."

Both systems have their pros and cons. Both are expensive.

But despite huge leaps in our understanding of atrial fibrillation and its mechanisms, the more I understand the arrhythmia, the more I have come to believe that we still don’t understand the mechanisms at play in the individual patient. For instance, why do some patients with normal-sized hearts get atrial fibrillation while others do not? Why do some patients with huge left atria from mitral stenosis sometimes never manifest the arrhythmia, while others are debilitated by it? What are the long-term mortality data with ablation compared to drug therapy? With the complications of the procedure (which admittedly are rare in skilled hands), are these still less than the complications of anticoagulation or drug therapy? What really is the role of neurologic (ganglionic) inputs to the heart at supporting atrial fibrillation versus fibrous remodeling or pulmonary disease?

And while these robotics are ingenious instruments, can they really replicate the remarkable tactile feedback of the human hand and assure the safety of these uncharted waters? Will they respond as quickly to visual and tactile clues afforded by our senses at the patient's bedside? And where should we ablate? Do we really need such complicated and expensive machinery before more basic questions are answered?

Certainly the FDA has approved these devices as safe. But this does not guarentee improvements in ablation efficacy. These early approvals to little to reassure those of us in the day-to-day clinical grind of these devices' cost effectiveness. For instance, despite all of the testing in human volunteers of the magnetically-driven system by Stereotaxis, I was left to wonder how this system was approved with its propensity to developing large char formation compared to more conventional approaches. Was this not seen in earlier trials? Didn't this affect the movement of their catheter as it welded to the left atrial surface? Wasn't this considered important? How much additional time did correcting these problems add to the procedure?

Perhaps in the end it won’t matter. Perhaps the ablation lesion sets during atrial fibrillation ablation procedures will be so defined so accurately through brute force trial-and-error that we will simply push a button and, like a car wash, a catheter will be dragged through a pre-defined course that’s the same for everyone and everyone's atrial fibrillation will be magically cured. As if everyone's atrium was the same size and shape.

But then again, maybe before buying our "Mercedes," we should first look to see if we need a boat instead.


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