kell0 is spot on. I tried every possible option to get my hematologists to take me off Coumadin as a result of my DVT. Compression socks on planes, low dose aspirin regimen, you name it. Was told that aspirin was not effective for DVT treatment.
As I understand it, there are 2 types of thinners - ones that are effective for arterial issues (Plavix, and to a lesser degree aspirin) and those that are veinous (coumadin and some of the newer drugs). IOW, all blood thinners are not the same.