Lines from CAD export not intersecting

Hi all,

I am trying to get some conceptual masses in Revit by extruding the profiles I have designed in Autocad.
I have exported the coordinates of the geometry from Autocad to Excel, and from some list operations I got to the lines by points and curves defining my profile in Dynamo. The problem is that I am having troubles to extrude (or create by loft) my solids because the curves are not closed, I guess this is a matter of rounding numbers from CAD to Excel and so on.

I was wondering if there is any way to create a closed curve or to close mine, I have tried both close with line and with line and tangent arc the polycurve or even arc by fillet in the corners but without satisfactory results so far.

Any ideas? Maybe there is a better way to import my profiles from Autocad, the matter is that these are changing quite often in CAD along the design process so I need a way to refresh them easily.