Endonasal SurgeryEarly Phase 1NCT07546617
In Vivo Imaging of the Olfactory Epithelium Using Confocal Laser Endomicroscopy
A Early Phase 1 study testing CONVIVO system and Fluorescein injection, USP 10% in people with Endonasal Surgery and Endoscopic Sinus Surgery, run by Dartmouth-Hitchcock Medical Center at 1 site in United States.
Trial summary
This research is being done to better characterize the part of the nose that helps people smell. Currently, the only ways to study smell loss mostly rely on how people report it, rather than being able to see the underlying structures directly. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Endonasal Surgery, Endoscopic Sinus Surgery, Olfactory Dysfunction
- What is being tested?
- CONVIVO system and Fluorescein injection, USP 10%
- Type of treatment
- Injection or infusion, Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 36 participants
- Where
- 1 siteUnited States
- Study dates
- 3 Nov 2026to 31 Jul 2027
- Phase
- Early Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Adults aged ≥18 years
- Undergoing endoscopic sinus or endonasal skull base surgery while under - general anesthesia where the nasal turbinate is accessible
- Able to complete study questionnaires and psychophysical smell testing
- Able to provide informed consent.
Who cannot join
- Known allergy or hypersensitivity to fluorescein
- Pregnancy
- Medical instability precluding participation
- Severe anatomic obstruction preventing safe access to the olfactory cleft and nasal turbinate
- Any other safety concern identified by the investigator
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site
Dartmouth-Hitchcock Medical Center
Lebanon, New Hampshire, 03755
Ryan E Little, MD, 603-650-8123, Ryan.E.Little@Hitchcock.org
Ryan E Little, MD
About this study
Official title: In Vivo Imaging of Olfactory Epithelium in Humans With Olfactory Impairment Using Confocal Laser Endomicroscopy
This research is being done to better characterize the part of the nose that helps people smell. Currently, the only ways to study smell loss mostly rely on how people report it, rather than being able to see the underlying structures directly. In this study, the team will use a special microscope (Confocal Laser Endomicroscopy (CLE)), originally developed for brain tissue, to look at the part of the nose that helps to detects smell. The study team hopes to identify the tiny structures in that area and see how they might be different in people who have smell loss compared to those who do not. Participation in the study includes completing a smell test (Sniffin' Sticks Extended test), a cognitive screening test, and two questionnaires.
Read the detailed description
Aim 1: Evaluate the feasibility of in vivo CLE imaging of the olfactory cleft and nasal turbinate and determine whether CLE features correlate with validated psychophysical olfactory testing and patient-reported quality-of-life measures.
The study team will obtain preoperative Sniffin' Sticks threshold-discrimination-identification (TDI) scores and questionnaires in 36 surgical patients recruited from NH and VT, followed by intraoperative CLE imaging after intravenous fluorescein. CLE images will be assessed for epithelial features such as neuronal loss, epithelial thinning, basement membrane irregularity, and inflammatory changes.
Aim 2: Compare in vivo CLE imaging features with histopathologic findings from superior turbinate tissue, when available, to identify candidate in vivo imaging biomarkers. When routine surgery includes removal of superior turbinate tissue, CLE images will be paired with histopathology to assess concordance in features such as neuronal density, sustentacular cell integrity, and inflammation.
- Being tested
- CONVIVO system, Fluorescein injection, USP 10%
- Keywords
- Confocal Laser Endomicroscopy, Endoscopic Sinus Surgery, Smell Loss, Endonasal Skull Base Surgery, Olfactory Dysfunction
- Medical subject headings
- Anosmia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CONVIVO systemDevice
Approximately 2-5 minutes following administration of FNa in situ imaging will be performed by the participating surgeon ensuring proper technique. Prior to entering the surgical field, the probe will be covered in a disposable sterile sheath that is manufactured with quality assurance for this purpose. The probe will gently be held against the tissue interface while imaging occurs. Following image acquisition, a pathologist present in the operating room, will review and capture each image.
Fluorescein injection, USP 10%Drug
Also called AK-FLUOR, FNa
Sodium fluorescein will be administered intravenously or topically (applied directly to nasal mucosa) at doses of 5-10 mg/kg (not exceeding 20 mg/kg cumulative). Administration will be performed by the anesthesia team in the operating room.
| Study group | Role | What they receive |
|---|---|---|
| Target Group (Patients with Olfactory Complaints) | Other | Patients who have olfactory complaints and are undergoing endoscopic sinus or endonasal skull base surgery while under general anesthesia where the nasal turbinate is accessible, per their standard of care. Receives: Device: CONVIVO system; Drug: Fluorescein injection, USP 10% |
| Control Group | Other | Controls will consist of surgical patients without subjective olfactory complaints and with expected normal psychophysical testing. Patients who are already undergoing endoscopic sinus or endonasal skull base surgery while under general anesthesia where the nasal turbinate is accessible, per their standard of care. Receives: Device: CONVIVO system; Drug: Fluorescein injection, USP 10% |
What is being measured
The primary outcome is the main question the study is designed to answer.
Evaluate the feasibility of in vivo CLE imaging of the olfactory cleft and nasal turbinate and determine whether CLE features correlate with validated psychophysical olfactory testing and patient-reported quality-of-life measures.
(1) High feasibility (≥85% interpretable images); (2) identifiable CLE signatures associated with OD severity; (3) significant correlations between CLE features, TDI scores, and symptom burden.
Measured: On day of Surgery, Day 0
Secondary outcomes (1)
Compare in vivo CLE imaging features with histopathologic findings from superior turbinate tissue, when available, to identify candidate in vivo imaging biomarkers.
When routine surgery includes removal of superior turbinate tissue, CLE images will be paired with histopathology to assess concordance in features such as neuronal density, sustentacular cell integrity, and inflammation.
Expected Outcomes: Identification of CLE features corresponding to gold-standard histopathology, generating preliminary in vivo imaging biomarkers.
Measured: On day of Surgery, Day 0
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Apr 2026
- Study start3 Nov 2026 (estimated)
- Primary completion30 Apr 2027 (estimated)
- Study completion31 Jul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Endonasal SurgeryStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Early Phase 1
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Single group
- Model description
- This study contains one interventional arm, where all subjects are assigned to the same intervention. All enrolled participants undergo the same study procedures (preoperative assessments and intraoperative CLE imaging), stratified descriptively into two groups: patients with olfactory dysfunction and surgical controls without olfactory complaints.
- Masking
- None (open label)
- Enrolment
- 36 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Dartmouth-Hitchcock Medical Center
- Sponsor type
- University, hospital or other
- Collaborators
- National Center for Advancing Translational Sciences (NCATS)
- Responsible party
- Principal investigator, Ryan.E.Little, Dartmouth-Hitchcock Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07546617
- Sponsor's protocol ID
- STUDY02003356
- Other IDs
- UM1TR004772
- Status last verified
- Oct 2026
- First submitted
- 16 Apr 2026
- Last updated
- 20 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- Yes
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 20 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- In Vivo Imaging of Olfactory Epithelium in Humans With Olfactory Impairment Using Confocal Laser Endomicroscopy
- ClinicalTrials.gov ID
- NCT07546617
- Acronym / sponsor ID
- STUDY02003356
- Keywords
- Confocal Laser Endomicroscopy, Endoscopic Sinus Surgery, Smell Loss, Endonasal Skull Base Surgery, Olfactory Dysfunction
- Phase
- Early Phase 1
- Study type
- Interventional
- Recruitment status
- Not yet recruiting
- Enrolment
- 36 participants (estimated)
- Lead sponsor
- Dartmouth-Hitchcock Medical CenterUniversity, hospital or other
- Collaborators
- National Center for Advancing Translational Sciences (NCATS)
- Study start
- 3 Nov 2026 (estimated)
- Primary completion
- 30 Apr 2027 (estimated)
- Study completion
- 31 Jul 2027 (estimated)
- First posted
- 23 Apr 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This research is being done to better characterize the part of the nose that helps people smell. Currently, the only ways to study smell loss mostly rely on how people report it, rather than being able to see the underlying structures directly. In this study, the team will use a special microscope (Confocal Laser Endomicroscopy (CLE)), originally developed for brain tissue, to look at the part of the nose that helps to detects smell. The study team hopes to identify the tiny structures in that area and see how they might be different in people who have smell loss compared to those who do not. Participation in the study includes completing a smell test (Sniffin' Sticks Extended test), a cognitive screening test, and two questionnaires.
Detailed description
Aim 1: Evaluate the feasibility of in vivo CLE imaging of the olfactory cleft and nasal turbinate and determine whether CLE features correlate with validated psychophysical olfactory testing and patient-reported quality-of-life measures.
The study team will obtain preoperative Sniffin' Sticks threshold-discrimination-identification (TDI) scores and questionnaires in 36 surgical patients recruited from NH and VT, followed by intraoperative CLE imaging after intravenous fluorescein. CLE images will be assessed for epithelial features such as neuronal loss, epithelial thinning, basement membrane irregularity, and inflammatory changes.
Aim 2: Compare in vivo CLE imaging features with histopathologic findings from superior turbinate tissue, when available, to identify candidate in vivo imaging biomarkers. When routine surgery includes removal of superior turbinate tissue, CLE images will be paired with histopathology to assess concordance in features such as neuronal density, sustentacular cell integrity, and inflammation.
Study design
- Primary purpose
- Diagnosis
- Allocation
- Non-randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- This study contains one interventional arm, where all subjects are assigned to the same intervention. All enrolled participants undergo the same study procedures (preoperative assessments and intraoperative CLE imaging), stratified descriptively into two groups: patients with olfactory dysfunction and surgical controls without olfactory complaints.
| Arm | Type | Receives |
|---|---|---|
| Target Group (Patients with Olfactory Complaints) | Other | Device: CONVIVO system, Drug: Fluorescein injection, USP 10%Patients who have olfactory complaints and are undergoing endoscopic sinus or endonasal skull base surgery while under general anesthesia where the nasal turbinate is accessible, per their standard of care. |
| Control Group | Other | Device: CONVIVO system, Drug: Fluorescein injection, USP 10%Controls will consist of surgical patients without subjective olfactory complaints and with expected normal psychophysical testing. Patients who are already undergoing endoscopic sinus or endonasal skull base surgery while under general anesthesia where the nasal turbinate is accessible, per their standard of care. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Adults aged ≥18 years
- Undergoing endoscopic sinus or endonasal skull base surgery while under - general anesthesia where the nasal turbinate is accessible
- Able to complete study questionnaires and psychophysical smell testing
- Able to provide informed consent.
Key exclusion criteria (5 listed)
- Known allergy or hypersensitivity to fluorescein
- Pregnancy
- Medical instability precluding participation
- Severe anatomic obstruction preventing safe access to the olfactory cleft and nasal turbinate
- Any other safety concern identified by the investigator
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| CONVIVO systemApproximately 2-5 minutes following administration of FNa in situ imaging will be performed by the participating surgeon ensuring proper technique. Prior to entering the surgical field, the probe will be covered in a disposable sterile sheath that is manufactured with quality assurance for this purpose. The probe will gently be held against the tissue interface while imaging occurs. Following image acquisition, a pathologist present in the operating room, will review and capture each image. | Device | Control Group, Target Group (Patients with Olfactory Complaints) |
| Fluorescein injection, USP 10%Also: AK-FLUOR, FNaSodium fluorescein will be administered intravenously or topically (applied directly to nasal mucosa) at doses of 5-10 mg/kg (not exceeding 20 mg/kg cumulative). Administration will be performed by the anesthesia team in the operating room. | Drug | Control Group, Target Group (Patients with Olfactory Complaints) |
Primary outcome
Evaluate the feasibility of in vivo CLE imaging of the olfactory cleft and nasal turbinate and determine whether CLE features correlate with validated psychophysical olfactory testing and patient-reported quality-of-life measures.
Time frame: On day of Surgery, Day 0
(1) High feasibility (≥85% interpretable images); (2) identifiable CLE signatures associated with OD severity; (3) significant correlations between CLE features, TDI scores, and symptom burden.
1 secondary outcome
Compare in vivo CLE imaging features with histopathologic findings from superior turbinate tissue, when available, to identify candidate in vivo imaging biomarkers.
Time frame: On day of Surgery, Day 0
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Oct 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Early Phase 1 study testing CONVIVO system and Fluorescein injection, USP 10% in people with Endonasal Surgery and Endoscopic Sinus Surgery, run by Dartmouth-Hitchcock Medical Center at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: opening soon, as of the sponsor's last update on 20 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Early Phase 1 (sometimes called Phase 0) studies give a very small amount of a treatment to a few people, mainly to see how the body handles it.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Michaela M Geffert, MS (603-650-2054, Michaela.M.Geffert@Hitchcock.org), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Evaluate the feasibility of in vivo CLE imaging of the olfactory cleft and nasal turbinate and determine whether CLE features correlate with validated psychophysical olfactory testing and patient-reported quality-of-life measures. (time frame: On day of Surgery, Day 0). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Oct 2026; AzTrials last refreshed its copy on 26 Oct 2026.