Missing Vena Cava

Hi guys
Im sure Im posting in the wrong place, so maybe someone can point me in the right direction?  

My friend was really ill last year and they ended up finding twenty odd blots clots in the tops of her legs.  On further investigations they found that her vena cava is missing and recently said it was due to the clots and it dissolved at this point and wasnt congenital. Her collateral veins are re-routing the blood, but she seems to now have all sorts of health issues and no one seems to be able to give her any answers.  Im hoping someone out there will be in the same/similar situation and be a bit further down the line and offer some support generally.  She is 32 years old and on warfarin permently now. She also has a heart condition, but not sure what the technical term is.

Thanks muchly

Angie