Portal vein and superior mesenteric vein thrombosis

[dreamwolker]

My mother had gone through a sleeve gastrectomy operation 3 weeks ago. On the 22nd post-operative day, due to severe pain in the epigastric zone, her doctor ordered an abdominal CT. It turns out that portal vein and superior mesenteric vein are thrombosed. They put her on enoxaparin and wanted her to rest for 5 days until the next control. She refused to be put on heparin or warfarin because of her history of gastrointestinal bleeding and recent surgery. We've been told thrombectomy would be extremely risky, given her medical history.

I read somewhere enoxaparin only prevents further occlusion of the vein and does not lyse existing clot. Since she won't be on heparin/warfarin and thrombectomy is not an option, what would be the prognosis? Should I be worried about her decision? Is her condition deadly?