After filler injection in the nose can the filler migrate and block an artery weeks/months later causing skin loss or blindness?

Hi there - filler when injected can enter blood vessels through the use of sharp needles or cannulae. If injected under high pressure and in large volumes it can block blood vessels and enter crticial vessels that can cause skin loss or blindness. Experienced injectors therefore inject slowly, constantly move their needles, and inject with blunt cannulae in higher risk sites. If a complication was to occur it would occur immediately, and there is no way for filler once placed outside the blood vessel to move intravascular of its own accord. Hope this helps.