Flow Diversion Embolization Device Reduces Thrombogenicity

A proven flow diverter now features breakthrough biomaterial technology that modifies the implant surface to improve hemocompatibility.

The Medtronic (Dublin, Ireland) Pipeline Flex embolization device, developed 10 years ago, now includes Shield Technology, a modification of the surface implant in which a synthetic phosphorylcholine (PC) polymer is covalently-chemically-bonded to the strands of the device braid. The inert polymer mimics the outer membrane of a human red blood cell (RBC), so that other blood cells do not react to the braided cylindrical mesh tube.

“In addition to addressing material thrombogenicity, Shield Technology improves device performance by reducing the force required for both delivery and resheathing of the device,” said Dan Volz, president of the neurovascular business at Medtronic. “We believe that Shield Technology opens up a new range of options for physicians to continue to achieve improved patient outcomes, and we continue to challenge ourselves to deliver solutions that improve outcomes and increase value for all healthcare stakeholders.”

The third generation Pipeline Flex embolization device is designed to be placed in a parent vessel across the neck of an intracranial aneurysm (IA). Made of 48 braids, 36 of which are cobalt-chromium (CoCr) and 12 platinum wires for radiopacity, the implant provides approximately 30% metal coverage of the arterial wall surface area. In recent studies, Pipeline Flex with Shield Technology showed a strong record of safety and efficacy, with 77.2% complete aneurysm occlusion at 12 months, a 3.2% primary safety endpoint, and 93.1% complete wall apposition post-procedure.

Wide-neck IAs are defined as having a neck greater or equal to four mm, or a dome-to-neck ratio of less than two. They are often untreatable by surgical clipping, as many wide- neck aneurysms are in vessels deep within the brain that are not amendable to being treated by open brain surgery. Sufficiently dense coil packing of the AI to permanently exclude blood flow is also difficult to achieve. Flow diversion, on the other hand, is an endovascular technique whereby instead of placing a device inside the aneurysm sac, it is placed in the parent blood vessel to divert blood flow away from the aneurysm itself.