Transpterygoid approach, step by step. The pterygoid process has been drilled between vidian canal andforamen rotundum to access the lateral recess of the sphenoid sinus. The pterygoid process has also been drilled between vidian canal and Eustachian tube to expose the lateral aspect of the pterygosphenoidal fissure, and the floor of the sphenoid sinus has been removed to expose the medial aspect of the pterygosphenoidal fissure. Both vidian nerve and pterygosphenoidal fissure converge at the lower aspect of the foramen lacerum, and therefore they represent key surgical landmarks to safely expose the foramen lacerum. (Image courtesy of JC Fernandez-Miranda)