Extreme Lateral/Transcondylar

This approach is designed for exposing tumours involving lower clivus and involving vertebral artery. Retrosigmoidcraniectomy is extended to open the foramen magnum. Posterior arch of atlas is removed. Foramen transversorium of C1 is opened and the vertebral artery is rerouted posteriorly. Upto 1/3 of the occipital condyle can be drilled out to maximize the exposure. Dura is incised anterior to and around the point of dural entry of vertebral artery.