This sounds like something a surgeon would say. It means that they made an incision in the woman's chest or abdomen in order to perform a surgical operation.

"We cut her open" most likely refers to using a knife or other sharp blade to cut the skin of "her" body, revealing the organs on the inside. Example sentence: "After looking at the medical x-rays, we decided to cut her open at the torso to preform the surgery." "If she doesn't tell us what we want to know try using pain to make her talk. Cut her open."

'Her' could potentially be other things, such as a ship. You need to give more context.

What does "........" mean? or What does this mean; "........"? :)