Improved Visual Outcomes in Transphenoidal Surgery (TS): Use of Visual Evoked Potential (EVP) Monitoring

Raj K. Shrivastava, MD1, Abtin Tabaee, MD1

1New York, NY United States

Keywords: transsphenoidal, vision, evoked potentials, outcome, neurophysiological monitoring

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     The advent of endoscopic cranial surgery there has been an interest in resecting large suprasellar tumors through the transphenoidal route. These tumors present with significant visual loss. Open craniotomy is believed to provide the best visual improvement.
     Currently there is no way to systematically monitor vision during TS.
     We developed a Visual Evoked Potential (VEP) protocol using LED technology to directly monitor vision. Ultra-bright LED goggles were used. Parameters were duration of 5ms, with repetition rate of 0.4 to 4 Hz. 60-400 times average. Classical corkscrew electrodes placed with standard montages for recording. 25 patients underwent prospective VEP recording in endoscopic TS. Pathology consisted of 20 pituitary tumors and 5 craniopharyngiomas. All patients presented with significant visual loss. Average tumor size was 3.3 cm.
     91% of patients had improved vision. In 88% of patients the VEP led to a change or stop of surgery due to early visual compromise. A complete resection was achieved in 84% of patients.
     This is a retrospective study.
     VEP monitoring is a useful protocol in the resection of large sellar/suprasellar tumors through the endoscopic route.
     This allows for continuous real-time monitoring of visual function during the surgical manipulations. This can be used to guide the dissection and extent of resection in these complex tumors for improved visual outcomes and patient safety.


Project Roles:

R. Shrivastava (), A. Tabaee ()