Intraoperative flash visual evoked potentials (FVEPs) could monitor visual function during neurosurgery. There are fewer reports comparing the effects of sevoflurane-propofol balanced anesthesia and propofol-based total intravenous anesthesia under comparable bispectral index (BIS) levels on the amplitude and latency of flash visual evoked potentials (FVEPs) for sellar or parasellar tumors resection neurosurgeries.

The overall incidence rate of sellar tumors is 10-20% of brain tumors. Most of the initial symptoms of this tumor are visual or visual impairment. One of the primary complications of these operations is visual impairment, which directly relates to the quality of patients' life. Flash visual evoked potentials (FVEPs) is an important means of intraoperative visual function evaluation under general anesthesia. Intraoperative visual function damage can be avoided or reduced by observing the changing of FVEPs waves to guide the choice of surgical path.

However, since the diversity of anesthetic drugs and methods, there is still a great uncertainty impact on FVEPs, which will interfere with the interpretation and judgment of surgeons and neuroelectrophysiological physicians respect to the changes of FVEPs amplitude and latency, and further affect the operation decision-making. Therefore, it is urgent to establish a perfect anesthesia method for intraoperative monitoring of FVEPs. Although total intravenous anesthesia has been widely accepted for FVEPs monitoring, there are still some limitations, such as the possibility of intraoperative body movement and cough due to the restriction of muscle relaxant use under electrophysiological monitoring, as well as the depression on FVEPs of high maintained dosage under total intravenous anesthesia. The purpose of this study was to investigate the feasibility of FVEPs monitoring during endoscopic sellar tumor resection under combined intravenous anesthesia compared with total intravenous anesthesia.

Inclusion Criteria:

1. Age 18-65 years;
2. ASA I-III;
3. Elective sellar or parasellar tumors resection;
4. Informed written consent

Exclusion Criteria:

1. Preoperative visual acuity<0.3;
2. BMI>30kg/cm2;
3. Uncontrolled hypertension, diabetes or cardiac diseases;
4. Preoperative cognitive disorders;
5. Sedatives, alcohol or analgesic addiction history;
6. Allergy to drugs of this study or contact allergy to Silicone products

Enrolled subjects will be assigned a subject identification number