Temporal Lobectomy-Epilepsy Surgery
Temporal lobectomy is most commonly done to remove scarring in the deep portion of the temporal lobe. A standard anterolateral temporal lobectomy involves removing 4-5 cm of lateral cortex (superior, middle, and inferior temporal gyri) and the parahippocampal formation (parahippocampal gyrus and hippocampus). This is done through an incision that resembles a question mark just in front of the ear on the correct side (picture). The temporalis muscle (used for chewing) is incised and stripped off the underlying skull. A hole in the skull (craniotomy) is made with an air drill and the covering of the brain is encountered (dura mater) (picture). This covering is opened with a small scalpel and the underlying temporal lobe is visualized. The posterior aspect of the resection is measured from the anterior aspect of the middle compartment (the tip of the temporal lobe) and resection starts by coagulating and cutting the blood vessels and transparent membrane covering the portion of the temporal lobe to be removed. This continues until the ventricle (brain fluid space) in the deep portion of the lobe is encountered. Once this is found the lateral lobe is removed. Next, the operating microscope is utilized to peel the hippocampus, amygdala, and parahippocampal gyrus off the deeper structures (picture). These deeper structures include the brainstem, the third and fourth cranial nerves, the posterior cerebral artery, the posterior communicating artery, and the anterior choroidal artery. Once the scar is removed, the brain is irrigated and signs of bleeding looked for. Once the operative site is clean, the dura is sutured closed and the skull bone replaced and held in place with small titanium plates and screws (picture). The temporalis muscle is then repaired and the skin closed. The head is sterilely wrapped and the patient taken to the recovery room.
