The clinical application of intraoperative visual evoked potential in recurrent craniopharyngiomas resected by extended endoscopic endonasal surgery

Clin Neurol Neurosurg. 2022 Mar:214:107149. doi: 10.1016/j.clineuro.2022.107149. Epub 2022 Jan 29.

Abstract

Objective: The protection of visual function is a major challenge for recurrent craniopharyngioma due to the interface between tumor and surrounding structure (esp. optic nerve) is more unclear. Intraoperative visual evoked potential (VEP) has been integrated into transsphenoidal surgery for pituitary adenomas and primary craniopharyngiomas in the prediction of postoperative visual outcome. In the present study, we firstly analyzed the clinical value of the VEP in the prediction of postoperative visual outcome for recurrent craniopharyngiomas by extended endoscopic endonasal surgery (EEES).

Methods: Thirty-six patients with recurrent craniopharyngiomas who underwent EEES with intraoperative VEP monitoring were retrospectively reviewed. The association between the changes in the VEP amplitude and postoperative visual outcome was determined. In addition, other potential prognostic factors with regard to postoperative visual outcomes were also included in the analysis.

Results: Gross total resection (GTR) was achieved in 32 patients (88.9%). Reproducible and stable VEP was recorded in 72 eyes. We recorded that there were 29 eyes remained stable VEP amplitude intraoperation, 4 (13.8%) of which suffered new visual acuity (VA) and 5 (17.2%) suffered new visual field (VF) defects after surgery. A transient VEP decrease was recorded in 41 eyes, 8 (19.5%) of which suffered from visual deterioration. Of 2 eyes with a permanent VEP decrease, 2 (100%) experienced postoperative visual impairment. Clinical variable analyses revealed a significant correlation between recurrent craniopharyngioma and age, adhesion with optic nerve, postoperative VA, and intraoperative VEP amplitude. Unstable VEP amplitude during operation and tight adhesion were independent risk factors for postoperative VA. Tight adhesion and a larger tumor volume were independent risk factors for postoperative VF defects.

Conclusions: EEES provides a unique view for the lesions under and behind the chiasm and achieve higher rates of GTR with improved visual outcomes. Tight adhesion and unstable VEP amplitude were strong predictors of postoperative visual impairment. Recurrent craniopharyngiomas are more likely to adhere to the optic nerve, VEP is more likely to be unstable during operation, and the improvement rate of postoperative visual function is lower than primary craniopharyngiomas. So intraoperative VEP is more necessary for recurrent craniopharyngiomas.

Keywords: Extended endoscopic endonasal surgery; Primary craniopharyngioma; Recurrent craniopharyngioma; Visual evoked potential; Visual outcome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Craniopharyngioma* / pathology
  • Craniopharyngioma* / surgery
  • Evoked Potentials, Visual
  • Humans
  • Pituitary Neoplasms* / pathology
  • Pituitary Neoplasms* / surgery
  • Postoperative Complications
  • Retrospective Studies
  • Treatment Outcome
  • Vision Disorders / etiology