My doc did not remove capsules when he performed breast implant removal and lift. Is it true that they will be dissolved?

I published a paper many years ago that identifies that the scar tissue from breast implants does not dissolve after you remove the breast implants.  Despite this fact, the presence of the scar tissue is likely NOT the cause for your drainage.  I agree with your surgeon that it is not necessary to remove the scar tissue, but very strongly disagree with the statement that the scar tissue dissolves.
You need to see your plastic surgeon to determine what is causing your chronic drainage.  Dr. Welsh's advice (below mine) is very solid and important to follow.  There could be additional reasons for drainage including, but not limited to: fat necrosis, seroma or hematoma (that could be either in the scar tissue or not), or infection.

hello luckysmom525252  The removal of breast implants that have been placed either for cosmetic or reconstructive purposes is a surgical operation.  Breast implant removal may be performed as a single surgical procedure or combined with additional procedures, as follows:

Simple breast implant removal, without removal of capsule tissue around implant
Removal of tissue surrounding the breast implant (capsulectomy)
Removal of escaped silicone gel in breast tissue (extracapsular, outside of capsule layer) from silicone gel-filled implants (breast biopsy)
Breast lift (mastopexy following breast implant and/or capsule removal)

Thank you for sharing your question.  This is a difficult question to answer as the quality of your capsules is unknown.  If thick, calcified, or otherwise concerning the capsules should be removed.  If thin they are unlikely to cause issues and can be left behind.  They do not get absorbed.  Hope this helps.

Capsules are often left behind after breast implant removal as long as there are no issues with them or the implants.  If there is a rupture, thickened capsules, or evidence of contracture they should be removed along with the implants.

If I can safely remove a capsule at the time of explantation, I will do so. Some capsules, however, are very thin and can be adherent to the underlying tissues, especially if the implant were under the muscle. Removing this type of capsule can cause more problems than benefit. The capsule is made up of collagen fibers and is a normal reaction to a foreign body, whether a breast implant, pacemaker, or hip prothesis. Removing the foreign body removes the body's stimulus to make a capsule, so it isn't always necessary to remove the entire capsule.