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

Abstract

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.

Exoscope as a Teaching Tool: A Narrative Review of the Literature

“…Numerous studies have already pointed out the viability of the exoscope as a visualization device in a multitude of neurosurgical settings, including glioblastoma surgery ( 17 ), nerve sheath surgery ( 18 ), anterior ( 5 ) cervical approaches, anterior lumbar approaches ( 3 ), pediatric neurosurgery (although the authors report an instance of switching to the OM over illumination concerns, possibly due to the model of exoscope used) ( 19 ), skull base procedures ( 4 ), transsphenoidal pituitary procedures ( 9 ), as well as many other procedures ( 20 – 29 ).…”

Expanded Transsphenoidal Trans-Lamina Terminalis Approach to Tumors Extending Into the Third Ventricle: Technique Notes and a Single Institute Experience

“…Access to these tumors is very difficult due to their deep location. King ( 1 ) described a trans-lamina terminalis approach (TLTA) through pterional craniotomy as a safe corridor to access these third ventricular lesions, as well as some other access options such as the transcallosal interforniceal approach ( 2 , 3 ) and transcortical transforaminal approach ( 4 ). Compared to other approaches, TLTA provides direct access to the retro-chiasmatic portion of the tumor with little optic nerve retraction.…”

The Exoscope in Neurosurgery: An Overview of the Current Literature of Intraoperative Use in Brain and Spine Surgery

“…Exoscopes represent the next generation of operative imaging, helping the neurosurgeon to operate in a more ergonomic sitting position, facilitating the surgery team and reducing surgeon fatigue by reducing the amount of time practitioners would have to view the images through a microscope eyepiece. These systems work to bridge the gap between OM and endoscopes by combining the form factor of the endoscope with the image quality of the microscope [ 43 , 49 , 78 , 94 ]. Some disadvantages of exoscopic visualization were reported, especially in the early 2D exoscope, such as a limited applicability in deep seated cranial pathologies and tissue identification in case of bleeding, a magnification of deep-seated pathologies and above all the lack of stereopsis.…”