The outlook for this kind of problem is quite good. Instead of one big clot, this is a buildup of lots of little ones. Those both dissolve faster and cause less trouble should they break free; only in large clumps do they cause problems. Thus, if the patient doesn't die right away, recovery is usually complete. He will probably be on anticoagulants for the rest of his life, though.
I'm not too worried at the moment. Of course, things change unpredictably in this business, so we won't know for sure until it's completely cleared up.