Severed or damaged 4th intercostal nerve? Can it be surgically repaired?

Nerves are very sensitive to trauma, ad take months or even years to recover. $ years after surgery I would not expect any more changes with the issues you are having. Explant with or without capsulectomy can certainly cause changes in sensation - a capsulectomy is more risky because of the extra tissue manipulation/trauma to remove all the capsule. It is uncommon in my experience that sensation gets worse (but it could) and in a few cases sensation did improve (probably from stretch/traction on the nerves that were relieved with implant removal, but still unpredictable). Brian Buinewicz MD

While permanent changes in sensation from breast augmentation are not common, they can occur. Sensation after augmentation typically begins to return to normal within the first 3 months, but can take up to one year. It is not possible to determine if implant removal will improve your sensation, but it is promising that you are noticing differences 8 days post op.