When intracuff pressure exceeds this perfusion pressure, blood flow is interrupted, resulting in ischemia. If high pressure is maintained and ischemia persists, tracheal bleeding, erosion, and sloughing of the necrotic tissue may occur.
Eventually, as the over-inflated cuff continues to impair the blood supply, the cartilaginous tracheal rings are exposed, causing a condition known as tracheomalacia. This stage is characterized by softening and fragmentation of the cartilage, which weakens the tracheal wall and usually causes the trachea to dilate. Then later, as the tracheal tissue heals, there can be fiber scaring, or the growth of granulation tissue replacing the damaged cartilage, which causes a condition known as tracheal stenosis, or a narrowing of the trachea.