Excision of a Retrochiasmatic Craniopharyngioma by Transcallosal, Interforniceal ApproachWith Exoscope Assistance: 2-Dimensional Operative Video

Retrochiasmatic craniopharyngiomas are difficult to treat due to their close proximity to critical neurovascular structures. Several surgical approaches with distinct advantages and limitations have been described to access these tumors, including extended transnasal endoscopic approach (ETEA), subtemporal, translamina terminalis, and transpetrosal approach.(1-3) We present a 51-yr-old male with a large retrochiasmatic craniopharyngioma extending into the third ventricle, causing obstructive hydrocephalus. Preoperative magnetic resonance imaging (MRI) showed a tumor cyst abutting the fornices expanding the space between two internal cerebral veins (ICV). After surgical consent, we decided to take advantage of this corridor to approach the tumor in its long axis. Surgical goal was to achieve cyst decompression with safe maximal resection of the solid component at last to preserve the pituitary function. Though the long axis of the tumor could be approached using ETEA, we preferred this approach in view of cyst decompression early in the surgery while completely avoiding risks such as cerebrospinal fluid (CSF) rhinorrhea, internal carotid artery (ICA) injury, and sinonasal complications. We utilized a 3-dimensional 4 K exoscope, which provides an excellent ergonomic position, and a high-resolution immersive view compared to a microscope or endoscope. Cyst decompression and near-total resection of the solid component was achieved. Postoperatively, his headaches improved and he was neurologically intact with intact neuroendocrine function. Approach-related risks may include but not limited to hemorrhage due to the rupture of venous sinuses or ICV, stalk or hypothalamus injury, and memory disturbances due to forniceal injury. To conclude, the transcallosal, interforniceal approach to retrochiasmatic craniopharyngiomas may provide a safe surgical corridor in select cases. Patient consented to the proposed procedure. All radiological images have been anonymized. IRB/ethics committee approval was not required.