Swelling Supraclavicular Area 7 Months Post- Lower Facelift

At this point you likely have around 80% of your healing. We usually tell people that they will have 60% of their healing / recovery complete by 6 weeks, 80-90% by 6 months. 100% can take as long as 2 years. This is based on wound healing studies and tensile breaking strength of a heal wound.

What I have experienced based on doing more than 1200 face and neck lifts is that the swelling could be related to old fluid accumulation. The fluid tends to settle at the bottom of the neck lift which is right above the clavicles, only your surgeon would know what he did during surgery. This swelling can be improved with steroid injections, pressure dressings, taping etc.
 

It does sound like a lymph problem but is extremely uncommon. I have not had this issue before. You should visit with a plastic surgeon to do a formal physical exam.

This is an unusual problem especially this far out from the procedure. It is too low to be a sialocele or saliva fluid collection. Given that the fullness appears to fluctuate with activity, it may be a pre-existing venous abnormality (e.g. high riding  subclavian vessel, AVM, prominent thoracic duct) that has become more appearant after debulking or correcting the sagging of neck tissue. You do not describe any erythema, induration or tenderness which would suggest an inflammatory process. Does it pulsate? It is possible that this may be a Chyle fistula or lymphatic fluid collection but I would expect that it would continue to fill up and not return to normal in the intervening period. There is no substitue for hands on physical exam by your doctor. If I was concerned with a fluid collection or a vascular process, I would investigate with an imaging study and likely start with an Ultrasound. I strongly recommend you schedule a follow up visit with your surgeon.