Extended endoscopic endonasal resection of craniopharyngioma using intraoperative visual evoked potential monitoring: technical note.

Abstract

BACKGROUND:

To avoid deterioration of visual function, extended endoscopic endonasal transsphenoidal surgery (TSS) for craniopharyngioma was performed with visual evoked potential (VEP) monitoring using light-emitting diodes (LEDs).

METHODS:

The position of the optic chiasm was carefully evaluated on the preoperative midsagittal magnetic resonance (MR) images. Intraoperatively, direct and sharp dissection of the tumor from the optic chiasm was performed under VEP monitoring with LEDs through extended endoscopic endonasal TSS. If the VEP finding changed and became unstable, the operator were informed and stopped the surgical manipulation for the optic chiasm to recover. After 5-10 min, recovery of VEP findings was checked and the procedure resumed.

RESULTS:

Extended endoscopic endonasal TSS with VEP monitoring was performed in consecutive 7 adult patients with newly diagnosed suprasellar craniopharyngiomas with maximum diameters of 25-41 mm (mean 33.7 mm). VEPs were stable throughout the surgery in 5 cases, but showed temporary instability and amplitude decrease in 2 cases, although the VEPs had recovered at the end of the surgery. Visual function, evaluated using visual impairment score, was improved after surgery in all patients. Gross total removal was achieved in 5 cases, and subtotal removal (90%) in 2 cases.

CONCLUSIONS:

Intraoperative VEP monitoring is the only way to test visual function during surgery, and may be important and helpful in extended endoscopic endonasal TSS, which requires direct dissection between the optic nerve and craniopharyngioma under the endoscope.

• Authors: Takaaki Miyagishima, Masahiko Tosaka, Rei Yamaguchi, Tomohito Nagaki, Nobukazu Ishii, Takeo Kojima, Yuhei Yoshimoto
• Journal: Acta neurochirurgica (Acta Neurochir (Wien)) Vol. 161 Issue 11 Pg. 2277-2284 (11 2019) ISSN: 0942-0940 [Electronic] Austria
• PMID: 31402418 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Topics

• Adult
• Aged
• Craniopharyngioma (surgery)
• Evoked Potentials, Visual
• Female
• Humans
• Intraoperative Neurophysiological Monitoring (methods)
• Male
• Middle Aged
• Natural Orifice Endoscopic Surgery (methods)
• Nose (surgery)
• Pituitary Neoplasms (surgery)