Decortication refers to a surgical procedure done to free a fibrous capsule that has formed around the lung, secondary to an inflammatory process, such as an infection. Ordinarily, there is a space between the lung and the inside of the chest wall, with this space “lubricated” by a thin layer of fluid. In some conditions, such as pneumonia, or after an episode of bleeding in the chest, this space can fill with fluid which can eventually solidify and form a capsule around the lung.
This type of infection is called an “empyema”. The infected material deposited onto the lung is called a pleural peel.