Patients with carotid artery disease – caused by plaque buildup in the carotid arteries that reduces blood flow – are at risk of a stroke because of the potential for clots to form on the plaque and block the blood flow. But carotid artery stenting (CAS), a procedure commonly used to treat the disease, also poses a risk of stroke because sometimes a piece of the plaque can break away and travel to the brain.
That's why companies like Invatec (Roncadelle, Italy) are developing cerebral protection devices that can be used during CAS procedures to prevent debris from reaching the brain. On Friday Invatec said it received FDA 510(k) clearance for its Mo.Ma Ultra Proximal cerebral protection device for use during CAS. According to the company, the device reduces and captures debris released during the stenting. The company also said it has completed the ARMOUR trial, which demonstrated low stroke and major adverse cardiac and cerebrovascular event rates.
Jack Springer, president of Invatec USA (Bethlehem, Pennsylvania), told Medical Device Daily that most of the other protection devices on the market require the surgeon to cross over the lesion first before the protection device is inserted. That results in the opportunity to push or shoot debris into the brain via the blood stream, he said.
Mo.Ma Ultra is a proximal protection device, which establishes full-time cerebral protection and control during the carotid stenting procedure prior to crossing the internal carotid artery lesion, thereby preventing distal embolization, Invatec said. Small balloons on the tip and proximal shaft are inflated in the external carotid artery and the common carotid artery to suspend blood flow during the stenting process. These balloons act like endovascular surgical clamps, protecting the brain during the procedure, according to the company.
"Our device doesn't require you to cross over the lesion first, it shuts down blood flow, stops flow into the brain so any debris ... would actually stop where the lesion is, where the problem is, and then you actually suck the debris out," using a suction, or retrievable, catheter, Springer said.
The percutaneous Mo.Ma Ultra requires no surgery, Invatec noted. Guide wires, stents and balloon catheters are used in this protected environment to treat the target lesion through the Mo.Ma Ultra device, which provides stability, control and access to the internal carotid artery like a guiding catheter or sheath. The suspended blood is then aspirated along with any embolic debris to complete the procedure safely, the company said.
"The fundamental aspect of it is you create a protected and safe environment before you cross that lesion at all," Chris Frederick, VP of marketing at Invatec USA, told MDD. "Therefore you're not going to cause a potential emboli breaking off in your actual treatment of the patient."
W. L. Gore & Associates (Flagstaff, Arizona) makes a similar device that was approved earlier this year by the FDA. The Gore device is designed to reverse the flow of blood during stenting procedures. According to Gore, its neuroprotection technology reverses the flow of blood at the treatment site prior to crossing the lesion so there's almost no chance that particles could escape to the brain (Medical Device Daily, Feb. 11, 2009).
Springer said there has been a lot of research published on the concept of protection devices and that many experts believe these devices are the most important part of the CAS procedure and they create the highest risk. Thus, creating a protection device that doesn't throw any debris into the blood stream is expected to make the stenting procedure safer.
According to Invatec, results of the 262-patient ARMOUR trial support the safety and effectiveness of Mo.Ma Ultra for patients at high surgical risk for carotid endarterectomy undergoing CAS. Mo.Ma Ultra's full-time protection and control contributed to a low 30-day stroke rate of 2.3% and complication rate of 2.7% in the primary endpoint 220-patient population set.
"Proximal Embolic Protection is an important advance that gives us more options in the treatment of carotid artery disease," said L. Nelson Hopkins, MD, of State University of New York (Buffalo) and co-principal investigator of the ARMOUR trial. "The Mo.Ma Ultra combines the advantages of carotid endarterectomy with the minimally invasive benefits of carotid artery stenting."
The Mo.Ma Ultra device is indicated as an embolic protection system to contain and remove embolic material (thrombus/debris) while performing angioplasty and stenting procedures involving lesions of the internal carotid artery and/or the carotid bifurcation. The reference diameter of the external carotid artery should be between 3 mm and 6 mm and the reference diameter of the common carotid artery should be between 5 mm and 13 mm, the company noted.
"The primary endpoint results of the ARMOUR trial are impressive and support the benefits of proximal protection. We look forward to the availability of Mo.Ma Ultra in the U.S. market," said Gary Ansel, MD, of Riverside Methodist Hospital (Columbus, Ohio) and co-principal investigator of the ARMOUR trial.
Frederick told MDD that the device appeals to surgeons because it is similar to the traditional approach they are used to. "Create this environment, clean it out, and it's a very safe way to treat patients with carotid artery disease," he said.
In addition to being easy to use, Frederick said the system will allow physicians to treat more patients – patients who really need an endovascular procedure but may not have been eligible for the procedure previously.
"Certain lesions are so tight that you can't cross with a distal protection device or the anatomy is too difficult ... [the Mo.M Ultra] expands the number of patients that are going to be able to have a carotid stent procedure who did not have that opportunity previously," Springer said.
Amanda Pedersen; 229-471-4212