I may be laboring under a misapprehension, but I thought that Heparin was at least somewhat decent at dissolving thrombi. But, it's tricky stuff, and would have to be administered under strict supervision by medical staff.

If you don't mind consulting a bit more widely, Dr. Andrea Natale at the Texas Cardiac Arrhythmia Institute in Austin is a world class electrophysiologist who is approachable, if busy. He, or his nurse, might be willing to offer you some information or referrals to a place where they deal with intractable thrombi.

It's a thought...