In Defense of Stents

The following was written by Steven W. Hetts, M.D, Assistant Professor of Radiology and Attending Interventional Neuroradiologist at UCSF, and Chief of Interventional Neuroradiology at San Francisco General Hospital and the San Francisco VA Medical Center.

A recent study, commonly known as “SAMMPRIS,” examined “Stenting vs. Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis.”  The results of the SAMMPRIS study raised questions about the value of stents for the treatment of strokes.

The lay press, including The New York Times, reported on the SAMMPRIS study.  Unfortunately, their interpretation of the study’s results was that stents have no value for any type of stroke-related event.  As an interventional neuroradiologist – a physician who treats patients with strokes, aneurisms and other brain maladies – I can say that this interpretation is wrong.

While many aspects of the SAMMPRIS trial are solid, the study did not differentiate among the three categories of ischemic strokes.  While stents may not have value in two of those categories, there is a third type of stroke that can certainly benefit from stenting.  In a pressure-dependent stroke with a fixed narrow artery (that might be on the order of 95 percent blocked), angioplasty (inflating a balloon inside an artery) and stenting are often necessary to restore adequate blood flow.

Those of us who treat stroke patients have all had cases where a patient with recurrent or worsening strokes comes to the hospital with a drop in blood pressure.  In those cases, if we open the affected blood vessel with a balloon and/or stent, the patient’s health improves, and he or she can then leave the hospital.

Currently, the FDA is considering pulling the Wingspan stent (a specific kind of stent designed for delicate navigation into the brain) from the market, and many of us in the field have lobbied against that action.  When a patient has a very narrow opening in an artery in the brain, we must find some way to widen that opening to increase blood flow.  While angioplasty is one option, that technique does not always work.  In some cases, an artery wall can tear during angioplasty, which requires the immediate use of a stent to prevent a worse stroke or even death.

We want to be sure that intracranial stents – the Wingspan stent is one example – are available on the market for just those emergency situations.  Without them, we would be forced to use stents designed for other areas of the body or other medical conditions in a manner that is not their indicated purpose.

So, while the SAMMPRIS study raised legitimate questions about the value of stenting in the treatment of some strokes, it was inappropriate for the lay press to suggest that cerebral stenting is unconditionally worthless.