Is there anything i can do to help dissolve a blood clot in my portal vein? i am taking warfarin, allergic to heparin, & clot is delaying my surgery.

No: You are doing everything correctly, assuming your inr is therapeutic. No form of anti coagulation has proven better than another for portal vein thombosis.

Stay on meds: Your body will reabsorb a clot if it can although this is not always possible. Staying on anticoagulants will keep clot from propagating.

Not in chronic: Usually after few weeks of portal vein thrombosis there is nothing to do except taking warfarin . In acute cases within first two weeks a physician can place intra arterial catheter in your mesenteric (intestinal) artery and infuse t-pa ( clot buster) and that may help but really it is not the standard of care in most places in the country.