Modeling and Analysis of a Novel Design for Application as an All-Carbon Vein Valve

Chronic Venous Insufficiency (CVI) is a disorder in the venous systems of patients that leads to chronically insufficient pumping of the venous blood out of, and away, from the venous regions. Most patients present symptoms of ulceration due to venous valve incompetence which in turn allows venous reflux.;This area of challenge has few, effective long term surgical treatment options. Here, a novel prosthetic carbon-based vein valve is described as designed and developed to resist venous reflux, provide thromboresistance and correct root cause issues leading to CVI. The prosthetic vein valve was designed in CATIA (Computer Aided Three Dimensional Interactive Interface by Dassault Systems Inc.) incorporating unique design features consisting of two asymmetric discs mounted on a rotating shaft mechanism which was constrained in motion using inset ridges. Shear rate values were observed to be large enough to prevent thrombosis accumulation. Oversized study versions of the model were fabricated using ABS (Acrylonitrile Butadiene Styrene) filament-based 3D printers to check for the mechanical integrity of the valve. The actual to-scale design was tested using ANSYS (Analysis Systems Inc.) FLUENT calculations. Simulations were conducted for the laminar flow condition with both continuous and pulsatile flows. ANSYS FLUENT calculations show consistent laminar flow, for calculation iterations as high as 250, with inlet velocity of blood at 1cm/s. The antegrade flow streamlines indicate good flow conditions while the mechanical design of the valve ensures good valve closure to resist venous reflux.;This valve design shows good mechanical function and has the potential to provide an effective treatment modality for CVI and should be further tested in animal models. Pyrolytic carbon, is forecast to be the most suitable material, for the vein valve construction due to its excellent thromboresistance and successful application in heart valves.