Preliminary experience shows promising results with a new type of flexible stent for nonsurgical treatment of brain aneurysms, reports a study in the January issue of Neurosurgery.
Dr. David Fiorella and colleagues of Barrow Neurological Institute, Phoenix, Ariz., evaluated the new Neuroform stent to treat 19 patients with aneurysms of the blood vessels supplying the brain.
The new stents are similar to those used to reopen blocked coronary arteries in patients with heart disease. However, Neuroform stents are designed to be flexible enough to be navigated through the complex twists and turns of the brain blood vessels.
Neuroform stents were used to treat a total of 22 aneurysms. All of the patients had unfavorable aneurysm shapes or other conditions precluding the standard nonsurgical treatment, in which miniature coils are used to block off the aneurysm from the rest of the circulation. Most of the patients had wide-necked aneurysms, which have difficulty retaining the coils.
After being navigated through the patients' blood vessels, Neuroform stents were successfully placed in all of the aneurysms but one. Once the stents were in place, treatment could be completed in most patients by coil embolization. In four aneurysms, no further treatment was required after stenting.
The researchers encountered several types of technical difficulties, especially in deploying the Neuroform stents in their proper location. However, even in the most convoluted blood vessels, neurosurgeons were able to navigate the stent through the patient's circulatory system to the site of the aneurysm.
Despite these difficulties, Neuroform stent placement achieved a high success rate with a low risk of serious complications.
Stents are now widely used in coronary angioplasty, to aid in reopening blocked coronary arteries supplying blood to the heart. Although stents designed for the coronary arteries are small enough to use in brain aneurysms, they are not flexible enough to be navigated through the often-complex anatomy of the brain blood vessels.
Neuroform stents—in diameters of 3.0 to 4.5 millimeters and lengths of 15 to 20 millimeters—offer the flexibility to overcome this problem. In 2002, Neuroform stents were approved by the U.S. Food and Drug Administration under a Humanitarian Devices Exemption, under which treatments for relatively rare conditions can be used without the extensive scientific documentation usually required for new medical devices.
This preliminary experience suggests Neuroform stents offer a new alternative for patients with aneurysms that would otherwise have a low treatment success rate. In most cases, conventional coil treatment can be performed after the stent is in place; for some patients, stent placement may be the only treatment required. Although technically challenging, Neuroform stent placement offers a relatively safe new option for patients with difficult-to-treat aneurysms.
"Preliminary Experience Using the Neuroform Stent for the Treatment of Cerebral Aneurysms" by David Riorell, MD, PhD, et. al.NeurosurgeryVol. 54, No. 1, Pg. 6January 2004
RSS