Balloon Angioplasty After Carotid Stenting Deemed Dangerous

A new study suggests that inflating a balloon inside the carotid artery after placing the stent greatly increases patients' risk of serious complications.

Researchers at the Johns Hopkins University School of Medicine (Baltimore, MD, USA) analyzed data from 103 patients who underwent placement of a carotid stent between 2005 and 2012. All patients underwent pre-stent ballooning, and 75% also underwent post-stent ballooning. The results showed that the patients who underwent post-stent ballooning were four times more likely to suffer from dangerously low blood pressure and/or a dangerously slow heart rate during or immediately after the procedure.

Placing a carotid stent is a minimally invasive procedure that involves threading a catheter from the groin area up to the site of the blockage in the neck. Physicians then gently inflate a balloon in the area that is constricted to open the artery wide enough to safely insert the stent. Those who again inflate the balloon afterward say it enables the stent to open as wide as possible and to show surgeons if the opening is large enough to reduce the risk of closing off in the future.

But according to the researchers, the metals used in the stent will naturally expand over time and the second ballooning step is unnecessary. There is also added risk that repeating the balloon step can send unstable plaque emboli into the brain, causing the very stroke the procedure is designed to prevent. An additional danger is that post-stent ballooning wreaks havoc on blood pressure and heart rate, since receptors around the carotid artery falsely sensing that blood pressure is high, which causes signals to the heart to slow down and to the peripheral small arteries to dilate, leading to hypotension. The study was published ahead of print on December 13, 2013, in the Journal of Vascular Surgery.

“In my mind, this is a study that should change medical practice. Our work suggests that doctors should never balloon a stent after placing it. There is no upside,” said lead author associate professor of surgery Mahmoud Malas, MD, MHS. “Every time we use the balloon, there can be a major drop in heart rate, so we have to use it judiciously. It's just not needed after the stent is in place.”

Patients are typically referred for a carotid stent when they have a blockage of 70% or more in the carotid artery and are unsuitable candidates for endarterectomy, a procedure that involves general anesthesia, which could be dangerous for people with severe carotid blockages since they often also have blockages in other arteries, including the coronary arteries.

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Johns Hopkins University School of Medicine