When you say "fall to the center", I assume you are talking about "symmastia" when the implants touch each other in the midline.
Revision surgery can address this but there are so many factors to go over.
-where was the implant originally placed? Was it over or under the muscle?
- are you switching to a textured implant?
- will the surgeon be placing adm to help reinforce the revision repair?
In order to optimize your chance of success, make sure you are seen by a board certified/eligible plastic surgeon.
i hope this helps.
Without seeing you in person it is very hard to say what could be done for you. Photos would be nice to get an idea of what is the problem.
You need a consolation and formal assessment or post your photos. Often in revisions it is possible to widen the pocket. Make sure to consult with an experienced PS who can show you pre and postop photos of patients similar to you.
How likely is it that my implants will fall back to the center after revision?
Impossible to respond without in person examinations of the present deformities of your implanted breasts...