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Flow Diverter OK for Smaller Wide-Neck Brain Aneurysms

— 'Reasonable' safety profile and high technical success rate in study

Last Updated February 27, 2017
Ƶ MedicalToday

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HOUSTON -- The Pipeline flow diverter device worked well for smaller unruptured, wide-necked aneurysms in the internal carotid artery, according to a single-arm study expected to support an expanded indication.

In the PREMIER study, 83.5% of patients had complete aneurysm occlusion and less than 50% had parent artery stenosis or retreatment at 1 year post-procedure, with a lower confidence interval that well exceeded the 50% performance threshold for this primary efficacy endpoint.

Action Points

  • Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.

For the primary safety endpoint, 1.4% of patients (two of 140) had a major stroke in the territory supplied by the treated artery or neurological death by 30 days after the procedure, reported, of the Baptist Neurological Institute in Jacksonville, Fla., at the International Stroke Conference (ISC).

One additional major stroke (a case of intracerebral hemorrhage) occurred beyond 30 days to the 1 year follow-up, for a total rate of 2.1% to the 1-year endpoint.

The one death was due to distal intraparenchymal hemorrhage on day 1 in a patient treated for a right ophthalmic segment aneurysm, for which the first device failed to detach and was removed, with a second device successfully implanted.

There were no intraoperative aneurysm ruptures, ruptures at 1 year, or aneurysm recurrence at 1 year. Retreatment was required in 2.2% of target aneurysms by 1 year, with two aneurysm necks not fully covered according to the core laboratory.

"These are difficult aneurysms to treat with the current armamentarium of devices. This new device based on this Pipeline trial here shows it's reasonably safe and can be treated," said of the University of Miami who served as a discussant at the ISC press briefing. Sacco is also past president of the American Heart Association and president-elect of the American Academy of Neurology.

The Pipeline mesh device has been for adults with large or giant wide-necked intracranial aneurysms in the internal carotid artery from the petrous to the superior hypophyseal segments. Hanel said that device maker Medtronic would file for an expanded indication to smaller such aneurysms based on the data.

The study included aneurysms measuring 12 mm or less in diameter, located in the internal carotid artery (up to the terminus) or the vertebral artery segment (up to and including the posterior inferior cerebellar artery). Among them, 84% were small aneurysms of less than 7 mm diameter and 16% were 12 to 7 mm.

Hanel cautioned that the study was not designed to define who should be treated.

"We should tackle that, but it's very hard as a country to tackle ... that question: Who should be treated for aneurysms under 7 mm?" he said at the press briefing, noting risk factors that can play into the decision. "For under 7 mm, we probably treat a fourth or a fifth of those who come to clinic. [Cases watched without treatment] aren't represented here; we don't capture them in the study. It's a very import decision. It's a case-by-case decision."

In the study, the biggest factors contributing to the decision to treat were patient preference (63%), hypertension (47.5%), and aneurysm multiplicity (34.8%). Successful deployment of the device was seen in 99.3%. The mean number of pipeline devices per aneurysm was 1.1.

Minimally invasive treatments are preferred over surgical clipping for safety and cognitive decline risk, noted Hanel. While stent-assist coiling is an option, the Pipeline device "adds to our armamentarium if -- capital, bold, neon, pointing shining lights 'if' -- you decide to treat that aneurysm, it empowers us to treat our patient better."

Disclosures

The study was funded by Medtronic.

Hanel disclosed relevant relationships with Medtronic, MicroVention, InNeuroCo, Stryker, and Codman.

Primary Source

International Stroke Conference

Hanel RA, et al "Prospective, multi-center study of flow diversion for small and medium-sized aneurysms: results of the Premier Trial" ISC 2017; Abstract LB3.