Invisalign can be quite successful in completing the initial phases of an orthodontic case that requires extractions.
However, the finishing stages may still require fixed braces and the duration you need to wear fixed braces depends on how well your initial alignment ends up with Invisalign.
Extraction cases can be managed by Invisalign, but this needs a very dedicated and disciplined patient that can keep up with the 22 hours of daily Invisalign wear required.
To ensure better tracking of tooth movements, your dentist may also suggest additional treatments to assist Invisalign like micro-osteoperforations. This procedure helps your teeth to move more easily into alignment.
Ask your dentist to give you all the options so that you can make an informed choice whether to proceed with extractions and whether to choose Invisalign or fixed braces.