Collapse her lungs in order to do the operation in this part of the upper back (thoracic vertebrae), what does this mean?

Routine: Means the operation will be done through the chest. Exposure of the spine requires collapsing the lung on that side. The anesthesiologist uses a special breathing tube that allows him or her to selectively ventilate one or both lungs. At the end of the operation, the lung is reinflated. A drain is often left in the chest for a day or two and then removed. This is fairly routine stuff.