Converting lines to surface/planar structures

Hi,

I am working with the 3D Porous media model which allows for the specification of a fracture as a 2D object to be able to apply the Fracture Physics equation. To build my fractal geometry, I have generated a series of 1D lines using MATLAB to represent my fractal network. I have however tried to convert these 1D line to a 2D planar fractal with a certain extrusion depth along an orthogonal surface to the plane of each line fragment without success.
Can anyone please help with this problem?

Thanks
Toyin.