[The Multilayer Flow Modulator Stent (MFM) for the treatment of arterial aneurysms]

Arterial Aneurysms are traditionally treated surgically but the operative risks remain high. More and more interventional procedures are proposed: - For Visceral and Peripheral aneurysms covered stents, endografts, coils can be used, but these techniques have a lot of disadvantages, drawbacks. Aneurysms with collateral branches cannot be treated with covered stents. The stent can occlude these collaterals leading to severe complications. - For Aortic Aneurysms (AAA, TAAA) hybrid techniques, endografts have been used to reduce morbidity/mortality rates encountered with surgical procedures. Recently new techniques have been developed: branched grafts, fenestrated grafts, chimney techniques. The technical success of these techniques is high but the complications rate is always high despite experienced, skilled operators: high morbidity/mortality rates, endoleaks, renal impairment, neurological complications with paraplegiadue to spinal cord ischemia. For these reasons we used a new concept of stent, the Multilayer Flow Modulator Stent (MFM) to treat any aneurysm. This MFM is a 3 Dimensional braided tube made of several interconnected layers without any covering. Our earliest tests, through studies as theoritical simulation, computerized Fluid dynamics, Molecular Modelization and through in vitro and in vivo tests demonstrate that this MFM reduces the velocity in the aneurysmal sac up to 90% by modifying the hemodynamic conditions. A saccular aneurysm without collateral branch will thrombose quickly. If a collateral branch is present the flow is directed towards this branch leading to progressive shrinkage of the aneurysm. In a Fusiform Aneurysm (AAA, TAAA) the MFM eliminates the damaging flow vortex pressure, laminates and redirects its flow along the wall, directs and increases the flow in the collateral branches which remain patent. As demonstrated in animal and human studies this MFM preserves the collateral branches allowing the possibility to cover any artery without compromising the flow (renal, digestive arteries, supra aortic vessel). We will report our experience with the new device, summarize the main literature data and compare the results obtained with this stent, with the most recent techniques such as fenestrated, branched grafts, chimney technique. If we respect hard endpoints, important guidelines, technical points of stent implantation, the results are very promising and the MFM seems to be a breakthrough to treat any aneurysm.