110 lb. weight loss - What type of surgery can make my arms thinner and remove the fat between my armpits and breasts? (Photo)

Unfortunately, arms are extremely stubborn after massive weight loss.

Brachiaplasty (arm lift with skin excision) extending into axillae and along S curve of breast if needed will address excess arm and armpit skin for better contour and balance.

Around the elbow can be addressed with liposuction at the same surgery and/or possibly extending incision- however, usually try to stay above the elbow.

An exam and consultation with a plastic surgeon who performs these procedures is recommended to confirm you are a candidate as well as discuss your options and expectations.

I think the two best options for your scenario are either Longitudinal brachioplasty + Bra strap excision vs. Extended longitudinal brachioplasty
In a Longitudinal brachioplasty, excess and fatty tissue are removed from the upper arm from the elbow to about the level of the armpit. The next thing to consider is how much excess tissue there is underneath the armpit and where that excess tissue is located. If it extends around the flank to the back area, a decent might would be a Bra strap excision. In that procedure, the excess is tissue is cut out from the back, which improves the contour from the back to the area underneath the breasts. One of the downsides of that option is that is results in a horizontal scar across the back to the underside of the breasts.
An alternative option would be the Extended longitudinal brachioplasty. In the "Extended" longitudinal brachioplasty, the excess tissue is removed from the elbow to the armpit (like in the Longitudinal brachioplasty), but then incision is continued down past the armpit to remove tissue from underneath the armpit. This results in a long scar from the elbow all the way down onto the torso (vertically). The end point for the scar will depend on how much tissue needs to be removed to achieve the desired contour.

Extended arm lift surgery is better for you. But this surgery should be done under general anesthesia.