Transpterygoid approach, step by step, close-up view. The pterygosphenoidal fissure fills up the lower compartment of the foramen lacerum. The pterygoid tubercle covers the anterior wall of the lower compartment of the foramen lacerum and separates the vidian nerve from the pterygosphenoidal fissure. The upper compartent is formed by the lacerum segment of the ICA, and the lingual process forms the lateral wall of the upper compartment. (Image courtesy of JC Fernandez-Miranda)