Left arm pain months after Breast Lift. Surgeon says it is unrelated to surgery. Is he right?

The pain may or may not be related. A second opinion from another board certified plastic surgeon in the area may help. You may have some lymphatic cording or irritation as a result of the delayed healing.

It is unusual for a person to have arm pain following breast surgery.  Certainly a blood pressure cuff or the arm placement during surgery may lead to some transient discomfort, but should not be the cause four months later.  Further investigation is probably warranted.

Sorry to hear about your discomfort following mastopexy.  It is not unusual to experience discomfort in the arm following a breast procedure.  Additionally, a blood pressure cuff circulates up and down during surgery.  This often leads to post operative pain.  However, pain in the arm that exists following surgery for months is unusual.  X rays are unlikely to yield any findings that will help.  Hopefully, with time, this will resolve on its own.If it fails to resolve, a neurologist may be asked to perform nerve conduction studies.I have had patients with transient arm pain following surgery.  This is "referred pain".  It means that pain originates elsewhere and is referred to a different site.  I believe you may be experiencing referred pain or it could be unrelated.  I would give it time, and if it fails to resolve, see a neurologist.  Good Luck!