Juvederm Ultra or Ultra plus wears off in 9-12 months. Juvederm Voluma last up to 24 months. It is highly, highly unlikely that there is residual Juvederm 6 years later. Without a photo, it's impossible to comment on what other things may be causing the malar edema.
I suggest removal of the juvederm if you have swelling and consider venus legacy treatments to speed up healing. Best, Dr. Emer.