Doppler ultrasonography clinics exist near many large hospitals. They use hand scanners to check blood flow through the extremities and can spot all sorts of problems.
It reminds me of the sonarmen in submarines. The technicians are looking for *anything* unusual, working in a dimly lighted room, and they will take still frame pictures of it.
They will definitely spot clots, holes, aneurysms, twists, etc.
I mention this because clots generally do not form quickly, and if this is the case here, they will show up early.
However, I doubt these are ordinary blood clots that could be broken up or dissolved with anticoagulants. If they contain a fibrous construction they might only be surgically removed, *if* the mechanism that makes them is no longer working.
Here is a link I came across from The Western Journal:
“6 feet of Blood Clots Removed from High-School Football Player’s Legs, Ends His Career”
You might like reading it.