How to import large stl files

I have been using SolidWorks for some time, but I have recently come across an issue when importing a large *stl file of an anatomical model. When I attempt to import this file, I am notified that there are too many surfaces and the file must be imported as a graphics file. This file is not a surface and despite the lack of errors or gaps, it cannot be made solid (I assume because it is not a surface). I am not sure how to get around this and I am hoping that I do not have to delete part of my model.

Is there something I can do to make this file a solid? Do I need to attempt to crate another file type? Would that even help?

Any suggestions will be greatly appreciated! Thanks!

how about exporting it as an IGS? in some instances i’ve had better luck with IGS than STL

I was thinking about that, but the software that the original file is exported from does not export IGES. How do you think I can best convert it? Do you know if Rhino will do this?

yeah. rhino should support IGS export