Identification of Nerves Using Fluorescein Sodium

Intraoperative Nerve Identification With Fluorescein Sodium

The purpose of this study is to see if there is benefit in using an IV contrast (sodium fluorescein) to identify nerves during head and neck surgery.

Study Overview

• Status: Completed
• Conditions: Thyroidectomy; Thyroid Disease; Head and Neck; Head and Neck Disorder; Warthin Tumor; Pleomorphic Adenoma of the Parotid
• Intervention / Treatment: Drug: Fluorescein Sodium

• Study Type: Interventional
• Enrollment (Actual): 8
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • California
    • Palo Alto, California, United States, 94304
      • Stanford Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Male or female subjects
2. 18 years or older
3. Scheduled for open head and neck surgery

Exclusion Criteria:

1. Inability or unwillingness of a subject
2. Pregnancy
3. Vulnerable or disadvantaged population (pregnant women, decisionally impaired, homeless, employees, students)
4. Patients with severe medical condition(s) that in the view of the investigator prohibits participation in the study
5. History of adverse reaction to fluorescein including allergy.
6. History of renal failure or chronic kidney disease

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Fluorescein sodium during surgery; Subjects undergoing parotid surgery for benign conditions will have fluorescein sodium administered intravenously after induction, and fluorescence imaging will be performed to visualize nerves intraoperatively	Drug: Fluorescein Sodium; Intravenous administration of 1 mg/kg. If initial dosing is insufficient, additional doses may be administered up to a total of 3 mg/kg; Other Names: FLUORESCITE Injection 10%

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Facial Nerve Correlation of Fluorescein Sodium With Electrostimulation	Surgeon assessment of fluorescence correlation with electrostimulation using a Likert-style rating from 1-4 where 1=No correlation; 2=Some correlation; 3=Good correlation; 4=Excellent correlation	Intraoperative (day 1, up to 1 minute to assess)
Correlation of Fluorescein Sodium With Surgeons' Visual Assessment of Nerve	Survey of surgeon visual assessment of nerve under white light compared to fluorescence using a Likert-style rating from 1-4 where 1=No correlation; 2=Some correlation; 3=Good correlation; 4=Excellent correlation.	Intraoperative (day 1, up to 1 minute to assess)
Ratio of Nerve Fluorescence Compared to Background Tissue	Weber contrast ratio of nerve fluorescence intensity compared to background fluorescence intensity	Intraoperative (Day 1, Up to 20 minutes to assess)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Average Dose of Sodium Fluorescein Administration	Average dose of sodium fluorescein administered in mg/kg	Intraoperative (day 1)
Time to Nerve Visualization	Amount of time (in minutes) to nerve fluorescence after sodium fluorescein adminstration	Intraoperative (day 1, up to approximately 200 minutes for initial imaging)

Collaborators and Investigators

• Sponsor: Stanford University
• Collaborators: National Institute on Deafness and Other Communication Disorders (NIDCD)
• Investigators: Principal Investigator: Tulio Valdez, MD, Stanford University

Publications and helpful links

General Publications

• Park RK, Arus BA, Lee JY, Weitzenberg MM, Lee MC, Nyaeme MS, Barthel J, Balsamo G, Baik FM, Speirs K, Blume B, Heller-Algazi M, Chmyrov A, Plettenburg O, Megwalu UC, Weitz J, Distler M, Bruns OT, Valdez TA. Intraoperative nerve imaging with sodium fluorescein. medRxiv [Preprint]. 2025 Feb 17:2025.02.08.25321923. doi: 10.1101/2025.02.08.25321923.

Study record dates

Study Major Dates

• Study Start (Actual): November 7, 2024
• Primary Completion (Actual): May 22, 2025
• Study Completion (Actual): May 22, 2025

Study Registration Dates

• First Submitted: September 19, 2023
• First Submitted That Met QC Criteria: September 19, 2023
• First Posted (Actual): September 26, 2023

Study Record Updates

• Last Update Posted (Actual): May 20, 2026
• Last Update Submitted That Met QC Criteria: April 27, 2026
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Endocrine System Diseases; Neoplasms; Neoplasms by Histologic Type; Neoplasms, Complex and Mixed; Thyroid Diseases; Adenolymphoma; Organic Chemicals; Heterocyclic Compounds; Heterocyclic Compounds, Fused-Ring; Hydrocarbons; Hydrocarbons, Cyclic; Polycyclic Compounds; Heterocyclic Compounds, 3-Ring; Spiro Compounds; Fluoresceins; Xanthenes; Fluorescein
• Other Study ID Numbers: 71857; R25DC020174-03 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No