Filling Saline Implants Without Changing Them?

If you happen to have postoperatively adjustable implants, there would be a valve just beneath the skin that could be accessed by your surgeon in the office to add or remove saline simply with a needle.
Likely your implants are not the adjustable type, but the fill volume can still be adjusted. However, it requires a trip to the operating room to open up the incision and access the implant valve to make the desired adjustment. As long as there is no other problem noted with your implants and they are fairly new (within 1-3 years old), it is possible to make the volume adjustment without replacing them.

It’s not unusual for patients to be concerned about
breast size following breast augmentation surgery. When this situation arises,
the vast majority of patients want larger breasts. Although it’s possible to
increase the size of saline breast implants by adding additional volume, this maneuver
is very rarely indicated for a variety of reasons.Saline implants have a recommended fill range which is
relatively narrow. In addition, they can be over filled by about 10%. This
creates significant limitations when volume is added to existing implants.In some cases, these implants have already been filled
to their maximum fill levels. Even when they aren’t filled to this level the
amount of volume that can be added is relatively small. In most cases in the
range of 30 CC’s or two tablespoons. This added volume wouldn’t be expected to
significantly impact breast size and make a noticeable difference. In most
cases, 100-200 CC’s of volume would be necessary to create a visible
difference.Efforts to fill implants beyond these fill volumes can
result in secondary problems. These include implants distortion, an increased
potential for implant rupture, increased firmness, and negation of the implant
warranty.Adding volume to implants requires a secondary surgical procedure.
This may have warranty implications because these implants are intended for
one-time use.For all of these reasons, it’s probably appropriate to
use a new larger implant when patients want larger breasts, it’s also
appropriate to wait at least six months before proceeding with secondary breast
surgery. Under these circumstances, it’s important to discuss this issue with
your plastic surgeon before proceeding.

It is possible to refill recent breast implants without replacing them in some limited cases, depending on volume parameters set by the manufacturer. If the implants are old, I always advise replacement.