FDA Grants Premarket Approval for WEB Aneurysm Embolization System

Adam Arthur, MD

The US Food and Drug Administration (FDA) has granted Premarket Approval (PMA) for the WEB Aneurysm Embolization System, announced MicroVention, Inc. The device is designed to treat intracranial wide neck bifurcation aneurysms and is first in the category of intrasaccular flow disruptors to receive Premarket Approval.

The WEB Aneurysm Embolization System is approved for use at the middle cerebral artery bifurcation, internal carotid artery terminus, anterior communicating artery complex, or basilar artery apex. The device is approved for the treatment of adults with saccular, wide neck, bifurcation intracranial aneurysms with dome diameter from 3-10 mm and either a neck size of ≥4 mm or the dome-to-neck ratio is >1 and <2.

"In the pivotal trial, patients benefited from the WEB System through a safe and effective treatment with excellent clinical outcomes, fast procedure times and limited radiation exposure. The WEB System is a first-to-market, innovative and highly studied intrasaccular solution that advances the treatment of wide neck bifurcation aneurysms," said David Fiorella, MD, PhD, Professor of Neurological Surgery and Radiology, Director of Neurointerventional Radiology, Stony Brook University Cerebrovascular and Stroke Center and a Principal Investigator of the WEB-IT Trial, in a statement.

Data from the WEB-IT clinical trial supported the FDA’s decision to approve the device. The prospective, single-arm trial included 150 participants with wide neck bifurcation aneurysms, who were enrolled at 27 sites. Patients’ mean age was 59 years (range 29-79) and 73.3% of participants were female (n = 110).

Aneurysms treated in the trial were located at the basilar apex (n = 59, 39.3%), middle cerebral artery bifurcation (n = 45, 30%), anterior communicating artery (n = 40, 26.7%), and internal carotid artery terminus (n = 6, 4%). The average size of these aneurysms was 6.4mm (range 3.6—11.4) and the mean neck size was 4.8mm (range 2.0–8.2). The mean dome to neck ratio was 1.34.

The device was successfully implanted in 98.7% of participants (n = 148). The study reported one primary safety event occurring during the first 30 days after the procedure, a delayed ipsilateral parenchymal hemorrhage that was unrelated to the treated aneurysm.

"The WEB System provides a valuable alternative for the treatment of bifurcation aneurysms. In the WEB-IT pivotal trial, the WEB System demonstrated 84.6% adequate occlusion, and an extraordinary safety profile for a subset of aneurysms that are challenging to treat with standard embolization coils and assist devices," noted Adam Arthur, MD, Director of Cerebrovascular & Endovascular Neurosurgery at Semmes Murphey Neurologic & Spine Institute, Associate Professor of Neurosurgery at University of Tennessee, and a Principal Investigator of the WEB-IT Trial, in a statement.

The WEB Aneurysm Embolization System has been approved and used in many European countries under the CE mark since 2010.

"We are proud to offer our latest innovation to the neuroendovascular market in the United States with the introduction of the WEB System, achieving the most rigorous standard of FDA approval through the PMA process," said Richard Cappetta, President and Chief Executive Officer of MicroVention.