<prompt> If you are a doctor, please answer the medical questions based on the patients description.When is an IVC filter necessary for surgery? My daughter is having surgery to remove a paraganglomia near her liver. My daughter has a blood clotting discorder of factor 5 and low protein s. She has not had any clots nor is she on any blood thinning medicine. Her father has a blood clotting disorder and is on coumidin to regulate it. The surgeon is suggesting heprin after surgery and then lovenox for 21 or 28 days. Is this appropriate?  <response>: Hi and welcome to Chat Doctor. Thank you for your query. I am Chat Doctor and I will try to help you as much as I can. I suggest it too since surgery is in abdomen and prolonged resting may be required. She has positive family history of clot disorders and this is not worth risking. I hope I have answered you query. If you have any further questions you can contact us. Kindly regards. Wish you a good health. 