It is important to tell the doctor that you are on Coumadin before undergoing any type of procedure.
EVLT seems to have a good success rate. This procedure treats varicose veins by inserting an optical fiber into the vein. Infrared laser lights then illuminate in the middle of the vein. This causes the treated vein to contract.
Naturally, as with most if not all procedures, complications are possible (but mostly minimal). From what I understand, if scarring does occur, it tends to be minor.
Homeopathic treatments can sometimes be effective, also. Again, tell any practitioner you see that you are taking Coumadin. Homeopathic supplements can further discourage clotting, which might lead to bruising/bleeding.
Anyway, I hope this helps!