Functionality of the multilayer flow modulator (MFM) device for treating type-B aortic dissections.

Introduction

Multilayer flow modulator (MFM®) is a self-expanding mesh constitute of multiple overlaying cobalt alloy wire layers that redirects physiologically the flow in aneurysmal and dissected aortae healing these diseases. In particular, in dissection it has the peculiarity to act reestablishing the main flow in the true lumen and reducing false lumen area and flow. The MFM specific construct ensures flexibility and fatigue resistance but as a porous mesh retains side branch flow.

Methods

We evaluated the MFM device in 3D computational models of type-B aortic dissections constructed from patient computed tomographic images (CT) acquired at multiple time points: before and after MFM placement. Effect on vascular geometry including true and false lumen volumes, and perfusion including flow into distal side branches were examined.

Results

The MFM device was predicted to reestablish true lumen as main volume, and reduce flow and volume within the dissected false lumen, while restoring flow in the great vessels of the neck and aortic side branches (Figure).

Conclusion

Treatment of type-B aortic dissections with the MFM device progressively reduced the false lumen and improved blood flow to vital vascular beds, while coverage of aortic side branches with the device did not compromise collateral vascular perfusion.

Figure. True aortic luminal flow increased and stabilized and false lumen volume and flow was reduced in post MFM implantation (panels B, E, F & G). Aortic velocity stream lines turbulent pre (panels A, C & D) became more aligned at the arch and bifurcation commensurate with false lumen volume reduction.