Arm numbness 5 years after transaxillary approach?

After 5 years it is unlikely the sensation will return. One commonly injured nerve with breast augmentation is the intercostal brachial nerve which can cause numbness on the inner aspect of the arm. Some of the symptoms you are describing are more significant. I'd suggest consulting with a neurologist and perhaps getting NCV and EMG testing.

I would suggest meeting with a neurologist and having the nerves tested to see if releasing scar tissue could be helpful. it might even help to place the implants in front of the muscle or go with smaller implants.

Nerves have very specific anatomic distributions.
Nerve injuries are usually very specific to the nerve involved.
Plastic surgeons are most likely not going to be very helpful when it comes to nerve injuries, arm, numbness, or arm pain.
Most likely a neurologist would be more appropriate, though at this point probably isn’t very much they can do.
There are also other Ideologies for arm/hand pain and numbness and it may be a good idea to confirm there isn’t something else going on.
I suggest you start with your primary care provider.
Best,
Mats Hagstrom MD