Safety and Efficacy of Using SightSaver Visual Evoked Potential (VEP) for VEP Monitoring in Prone Spine Surgery (SightSaver)
Primary Purpose
Ischemic Optic Neuropathy
Status
Completed
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
VEP under TIVA
VEP under balanced anesth.
Propofol
Desflurane
Sponsored by
About this trial
This is an interventional prevention trial for Ischemic Optic Neuropathy focused on measuring Visual Evoked Potentials
Eligibility Criteria
Inclusion Criteria:
- Male or Female older than 18 years of age
- American Society of Anesthesiologists (ASA) status of I to IV and scheduled to undergo elective spinal prone position procedures under general anesthesia or TIVA only with intraoperative neurophysiological monitoring with an expected duration of surgery to be at least 2 hours
- If female, have been surgically sterilized or are postmenopausal; if of child-bearing potential, must have a negative serum pregnancy test the day of surgery
- Ability and willingness to sign informed consent
- Literate in the English language
Exclusion Criteria:
- Prisoner status
- Women who are pregnant or lactating/breast feeding
- Patients with a history of contact allergies to foam and/or plastic devices
- Any condition, which, in the opinion of the investigator, would make the subject ineligible for participation in the study, such as a history of unstable cardiovascular, pulmonary, renal, hepatic, neurologic (seizures), hematologic or endocrine abnormality (hyperthyroidism, unstable Diabetes type I/II)
Sites / Locations
- The Ohio State University Wexner Medical Center
Arms of the Study
Arm 1
Arm 2
Arm Type
Experimental
Experimental
Arm Label
VEP under TIVA
VEP under balanced anesthesia
Arm Description
Patients undergoing prone spine surgery will receive an anesthesia regimen using propofol (TIVA) for maintenance
Patients undergoing prone spine surgery will receive an anesthesia regimen using Desflurane as part of balanced general anesthesia
Outcomes
Primary Outcome Measures
Efficacy in Detecting Subtle Intraoperative VEP Changes Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA.
Number of Participants with Subtle Intraoperative VEP Changes Observed Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA
Secondary Outcome Measures
The Difference in VEP Changes in Amplitude Among Both Groups
VEP waveforms were evaluated using either present baseline - reproducible positive-negative-positive complex of substantial amplitude (≥2 µV) that appeared 100-200 ms after pulse stimulus onset; marginal Baseline - low amplitude (<2 µV) reproducible P100 waveform; or absent baseline - no repeatable response present. Any activity of <0.5 µV was not considered a response. Best derivation for each particular patient was used for monitoring electroretinogram (ERG) recording and confirming the stimulation.
The Difference in VEP Changes in Amplitude Among Both Groups
The difference in VEP changes in amplitude with a single and double stimuli using the SightSaver visual stimulator under balanced general anesthesia versus TIVA.
Safety of Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA
Number of participants experiencing adverse events related to the study procedures during prone surgery and 24 hours after surgery under balanced general anesthesia versus TIVA
Full Information
1. Study Identification
Unique Protocol Identification Number
NCT02643615
Brief Title
Safety and Efficacy of Using SightSaver Visual Evoked Potential (VEP) for VEP Monitoring in Prone Spine Surgery
Acronym
SightSaver
Official Title
A Pilot Study to Determine the Efficacy and Safety of Detecting Subtle Visual Changes During Visual Evoked Potential (VEP) Monitoring Using SightSaver ™ Flash Visual Evoked Potential Stimulator in Spine Prone Surgery
Study Type
Interventional
2. Study Status
Record Verification Date
July 2017
Overall Recruitment Status
Completed
Study Start Date
September 2014 (undefined)
Primary Completion Date
March 2016 (Actual)
Study Completion Date
March 2016 (Actual)
3. Sponsor/Collaborators
Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Ohio State University
4. Oversight
Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
Yes
Data Monitoring Committee
No
5. Study Description
Brief Summary
Post-operative visual loss (POVL) following non-ocular surgical procedures is an infrequent but severe complication. Little is understood about this complication, but most cases seem to result from loss of blood flow to the optic nerve. This is a pilot, single center, prospective, randomized, two-arm study involving 20 subjects at The Ohio State University Wexner Medical Center who are scheduled to undergo spine surgery that requires prone position and at least two hours of general anesthesia or total intravenous anesthesia (TIVA) and intraoperative neurophysiological monitoring. Patients will be randomized to either general anesthesia or TIVA, and wear the SightSaver device to monitor visual evoked potentials (VEPs) during surgery in order to detect possible changes in optic nerve function that may lead to POVL. We hypothesize that this new, flexible, disposable device will yield better results and more patient satisfaction than devices currently used for visual monitoring during prone spine surgeries.
Detailed Description
The exact mechanism underlying POVL is poorly understood, but nearly all cases seem to involve ischemic optic neuropathy (ION). Posterior ION is more commonly the result of spinal procedures. The spine surgery associated risk factors include: prone position, Trendelenburg positioning, blood loss, prolonged procedure, use of vasoconstriction agents to correct blood pressure, direct ocular compression, and hypotension [1,2]. Given the fact that the suspected mechanism is a gradual infarction of the optic nerve, POVL could theoretically be prevented based on early detection of reversible optic nerve dysfunction. Visual evoked potentials (VEP) are a highly sensitive method for detecting optic nerve dysfunction, including ischemia.
During intraoperative neurophysiological monitoring (IONM), an emitted light passes through the lens, reaching the retina and causing hyperpolarization. The signal generated by the retina in response to a flash of light is known as the electroretinogram (ERG). This response may be recorded using conventional neurophysiological equipment and reflects overall retinal function. The VEP peaks are generated during the passage of electrical signal from the retina via the optic pathways to the primary visual cortex, and can also be registered during IONM. Measurements of VEP peaks under anesthesia can vary depending on type of anesthetic regimen, some producing more interference with the electrical impulses than others.
The problems encountered during VEP monitoring are numerous: a reusable device must be cleaned in between patients, tightly fitting goggles pose a risk of damaging the eyes, goggles may fall off or move intraoperatively and be difficult to reposition once the procedure is underway. Also, the light emitting diodes tend to be too weak to produce an adequate stimulus. This pilot study presents a new different approach from current methods. The SightSaverTM visual stimulator design consists of the following key advantages over the current technologies: hygienically superior to re-usable goggles, provides physical protection to the ocular region, use of higher intensity diodes and adhesive foam padding shaped to contours of periocular region.
This pilot, single center, prospective, randomized, two-arm study will involve 20 subjects at The Ohio State University Wexner Medical Center who are scheduled to undergo spine surgery that requires prone position and at least two hours of general anesthesia or TIVA and intraoperative neurophysiological monitoring. Eligible subjects that provide voluntary and written informed consent will be included in the study with a 1:1 randomization ratio of two arms, n=10 patients per each of two anesthesia regimen groups: general anesthesia and TIVA. All patients will wear the SightSaverTM visual stimulator. IONM of VEP with include insertion of half-inch needle electrodes placed just under the skin on either side of the eye, at the top of the forehead and three along the back of the head. Flashes of light, delivered at continuous intervals, will be emitted from diodes mounted in the SightSaverTM visual stimulator. After the baseline VEP is established for the patient, monitoring of VEP will occur at every 30 minutes during surgery. If during the monitoring process, a significant VEP waveform change has occurred, an alert will trigger the surgical staff to check four different parameters: technical issues with goggles, anesthetic changes, significant blood loss or a blood pressure change. Analysis of data collected will be used to evaluate the efficacy of SightSaverTM visual stimulator for intraoperative VEP-based detection of significant visual changes during prone spine surgeries.
6. Conditions and Keywords
Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Ischemic Optic Neuropathy
Keywords
Visual Evoked Potentials
7. Study Design
Primary Purpose
Prevention
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Masking
None (Open Label)
Allocation
Randomized
Enrollment
20 (Actual)
8. Arms, Groups, and Interventions
Arm Title
VEP under TIVA
Arm Type
Experimental
Arm Description
Patients undergoing prone spine surgery will receive an anesthesia regimen using propofol (TIVA) for maintenance
Arm Title
VEP under balanced anesthesia
Arm Type
Experimental
Arm Description
Patients undergoing prone spine surgery will receive an anesthesia regimen using Desflurane as part of balanced general anesthesia
Intervention Type
Device
Intervention Name(s)
VEP under TIVA
Intervention Description
Propofol will be administered for anesthesia maintenance in patients randomized to the TIVA arm of the study. In order to record the VEPs, standard half-inch sub-dermal needle electrodes will be inserted subcutaneously around the visual area and the SightSaverTM visual stimulator will be placed to monitor VEP during surgery.
Intervention Type
Device
Intervention Name(s)
VEP under balanced anesth.
Intervention Description
Balanced general anesthesia with desflurane will be administered for anesthesia maintenance in patients randomized to the balanced general anesthesia arm of the study, In order to record the VEPs, standard half-inch sub-dermal needle electrodes will be inserted subcutaneously around the visual area and the SightSaverTM visual stimulator will be placed to monitor VEP during surgery.
Intervention Type
Drug
Intervention Name(s)
Propofol
Other Intervention Name(s)
Diprivan
Intervention Description
Propofol will be administered for anesthesia maintenance in patients randomized to the TIVA arm of the study. In order to record the VEPs, standard half-inch sub-dermal needle electrodes will be inserted subcutaneously around the visual area and the SightSaverTM visual stimulator will be placed to monitor VEP during surgery.
Intervention Type
Drug
Intervention Name(s)
Desflurane
Other Intervention Name(s)
Suprane
Intervention Description
Balanced general anesthesia with desflurane will be administered for anesthesia maintenance in patients randomized to the balanced general anesthesia arm of the study, In order to record the VEPs, standard half-inch sub-dermal needle electrodes will be inserted subcutaneously around the visual area and the SightSaverTM visual stimulator will be placed to monitor VEP during surgery.
Primary Outcome Measure Information:
Title
Efficacy in Detecting Subtle Intraoperative VEP Changes Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA.
Description
Number of Participants with Subtle Intraoperative VEP Changes Observed Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA
Time Frame
VEP waveforms recorded every 30 minutes during the entire procedure for up to 6 hours.
Secondary Outcome Measure Information:
Title
The Difference in VEP Changes in Amplitude Among Both Groups
Description
VEP waveforms were evaluated using either present baseline - reproducible positive-negative-positive complex of substantial amplitude (≥2 µV) that appeared 100-200 ms after pulse stimulus onset; marginal Baseline - low amplitude (<2 µV) reproducible P100 waveform; or absent baseline - no repeatable response present. Any activity of <0.5 µV was not considered a response. Best derivation for each particular patient was used for monitoring electroretinogram (ERG) recording and confirming the stimulation.
Time Frame
Every 30 minutes during surgery for up to 6 hours
Title
The Difference in VEP Changes in Amplitude Among Both Groups
Description
The difference in VEP changes in amplitude with a single and double stimuli using the SightSaver visual stimulator under balanced general anesthesia versus TIVA.
Time Frame
every 30 minutes during the entire procedure for up to 6 hours
Title
Safety of Using SightSaver Visual Stimulator During Spine Prone Surgeries Under Balanced General Anesthesia Versus TIVA
Description
Number of participants experiencing adverse events related to the study procedures during prone surgery and 24 hours after surgery under balanced general anesthesia versus TIVA
Time Frame
From start of surgery up to 24 hours after surgery
10. Eligibility
Sex
All
Minimum Age & Unit of Time
18 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria:
Male or Female older than 18 years of age
American Society of Anesthesiologists (ASA) status of I to IV and scheduled to undergo elective spinal prone position procedures under general anesthesia or TIVA only with intraoperative neurophysiological monitoring with an expected duration of surgery to be at least 2 hours
If female, have been surgically sterilized or are postmenopausal; if of child-bearing potential, must have a negative serum pregnancy test the day of surgery
Ability and willingness to sign informed consent
Literate in the English language
Exclusion Criteria:
Prisoner status
Women who are pregnant or lactating/breast feeding
Patients with a history of contact allergies to foam and/or plastic devices
Any condition, which, in the opinion of the investigator, would make the subject ineligible for participation in the study, such as a history of unstable cardiovascular, pulmonary, renal, hepatic, neurologic (seizures), hematologic or endocrine abnormality (hyperthyroidism, unstable Diabetes type I/II)
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Sergio D Bergese, MD
Organizational Affiliation
Ohio State University
Official's Role
Principal Investigator
Facility Information:
Facility Name
The Ohio State University Wexner Medical Center
City
Columbus
State/Province
Ohio
ZIP/Postal Code
43210
Country
United States
12. IPD Sharing Statement
Plan to Share IPD
No
IPD Sharing Plan Description
Enrolled subjects will be assigned a subject identification number and we will not collect any identifiable data
Learn more about this trial
Safety and Efficacy of Using SightSaver Visual Evoked Potential (VEP) for VEP Monitoring in Prone Spine Surgery
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