The Impact of Anesthetics on FLIP

March 4, 2026 updated by: Vani Konda, Baylor Research Institute

Impact of Anesthetics on Esophageal Motility as Assessed by Functional Luminal Imaging Probe (FLIP) Topography

To understand the impact of commonly used anesthetics on esophageal motility during FLIP topography.

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Detailed Description

Achalasia is a disease of unknown etiology in which inflammatory cells destroy ganglion cells in the wall of the esophagus.[1,2 ] This inflammatory degeneration preferentially involves the inhibitory neurons in the esophageal myenteric plexus that are needed to effect normal peristalsis in the esophageal body and normal relaxation of the LES.[3] Thus, the classic manometric features of achalasia are: 1) absent esophageal peristalsis and 2) failure of the LES to relax with swallowing.[4] These physiologic abnormalities cause the typical achalasia symptom of dysphagia for both liquids and solids. No therapy is available to restore the lost esophageal ganglion cells in achalasia. Rather, treatments are directed at disrupting the LES muscle using invasive procedures that include pneumatic dilation, Heller myotomy, and per-oral endoscopic myotomy (POEM).

In 2008, using the technique of esophageal high resolution manometry, Pandolfino et al. identified three subtypes of achalasia.[5] In all three subtypes, there is no peristalsis and the LES does not relax normally with swallowing [recognized by an elevated integrated relaxation pressure (IRP) on high-resolution manometry]. In Type I achalasia, swallowing results in little or no distal esophageal pressurization. In Type II achalasia, swallowing is associated with panesophageal pressurization to a level >30 mm Hg. In Type III achalasia, swallowing is associated with spastic esophageal contractions. Patients with Type II achalasia have the best response to any form of achalasia treatment, whereas Type III patients have the worst response.

In the aforementioned study, the investigators also identified a group of patients who had abnormal LES relaxation with swallowing (i.e. an elevated IRP), but who had some preserved peristalsis in the body of the esophagus.[5] The investigators proposed that this was probably a heterogeneous group of patients, some having a variant form of achalasia and others having a mechanical obstruction at the esophago-gastric junction (EGJ). This manometrically-defined condition in which there is an elevated IRP with preserved peristalsis is now called EGJ-outflow obstruction.[6] A subset of patients with EGJ-outflow obstruction is a form of achalasia, likely due to the same process that causes esophageal ganglion cell loss in classic achalasia. There are additional spastic disorders of the esophagus such as diffuse esophageal spasm and hypercontractile esophagus.

Functional luminal imaging probe (FLIP) topography is a tool that has been increasingly helpful in characterization of patients with esophageal motor abnormalities, particularly those with achalasia, EGJOO and disorders with spastic elements.[7] In addition FLIP topography has been utilized to guide intervention and gauge adequacy of intervention pre and post myotomy. FLIP topography is now utilized in our standard algorithm for both diagnostic work ups of patients with motor diseases of the esophagus and during POEM procedures. During the course of some procedures, multiple FLIP assessments may be obtained for clinical purposes.

These patients with esophageal motor disorders are at increased risk of aspiration. We often perform endotracheal intubation for these patients with esophageal motor disorders to protect the airway and decrease the risk of aspiration. A common anesthetic gas is sevoflurane is used in endotracheal intubation. However, sevoflurane affects esophageal motility based on preliminary data from abstracts[8,9] but the appropriate anesthetic protocol with FLIP assessment remains unknown. Alternatives to sevoflurane include isoflurane or Propofol only sedation or total intravenous anesthesia (TIVA). Propofol only sedation is not thought to impact esophageal motility. The impact of isoflurane is unknown. At our institution we have generally performed FLIP topography assessments OFF sevoflurane. During the course of an entire procedure, both on and off gas may be used depending on the procedure and discretion of the anesthesia team. The exact impact of each anesthesia approach on the FLIP assessments.

To address the above-noted knowledge gaps in optimal sedation for FLIP topography achalasia and motility disorders of the esophagus, we propose to determine the impact of esophageal motility as assessed by FLIP topography.

Study Type

Interventional

Enrollment (Estimated)

30

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Texas
      • Dallas, Texas, United States, 75246
        • Baylor University Medical Center - Jonsson Building

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Study subjects will include male and female patients age ≥18 to 75 years with dysphagia caused by achalasia (Type I, II or III) or by EGJ-outflow obstruction, suspected motility disorder, or undergoing an endoscopy to rule out an esophageal motility disorder who have been seen by Drs. Konda, Spechler, Nguyen, Reddy, Ellison, or Podgaetz. These patients will be undergoing an endoscopy and POEM procedure.

Exclusion Criteria:

  • Age <18 or >75 years, patients unwilling or unable to provide informed consent; known gastrointestinal or thoracic or head and neck malignancy; known previous myotomy fundoplication, or other surgery involving the hiatus; and pregnancy.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Diagnostic
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: propofol-propofol
This is the control comparison of a subject undergoing FLIP imaging under the baseline scenario of propofol alone and then the again for a second time under propofol alone.
Diagnostic test: FLIP Imaging under various standard of care anesthetics in the context of endotracheal intubation.
FLIP imaging will occur twice per subject with the same baseline (propofol) assessment and then a second study assessment with propofol, sevofluorane, or isofluorane.
Active Comparator: propofol-SEVO
This is the the study comparison group of a subject undergoing FLIP imaging under the baseline scenario of propofol alone and then the again for a second time but this time under the anesthetic gas sevofluorane.
Diagnostic test: FLIP Imaging under various standard of care anesthetics in the context of endotracheal intubation.
FLIP imaging will occur twice per subject with the same baseline (propofol) assessment and then a second study assessment with propofol, sevofluorane, or isofluorane.
Active Comparator: propofol-ISO
This is the the study comparison group of a subject undergoing FLIP imaging under the baseline scenario of propofol alone and then the again for a second time but this time under the anesthetic gas isofluorane.
Diagnostic test: FLIP Imaging under various standard of care anesthetics in the context of endotracheal intubation.
FLIP imaging will occur twice per subject with the same baseline (propofol) assessment and then a second study assessment with propofol, sevofluorane, or isofluorane.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Distensibility
Time Frame: at 10 min
FLIP Imaging EGJ metric Distensibility at 60 mL fill volume
at 10 min
Diameter
Time Frame: at 10 min
FLIP Imaging EGJ metric Diameter
at 10 min
Contractile Response
Time Frame: at 10 min
Contractile response category
at 10 min

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
EGJ opening category
Time Frame: at 10 min
FLIP imaging EGJ opening category
at 10 min

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Baylor Research Institute

Investigators

  • Principal Investigator: Vani A Konda, MD, Baylor Health Care System

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 22, 2024

Primary Completion (Estimated)

July 1, 2026

Study Completion (Estimated)

July 1, 2026

Study Registration Dates

First Submitted

March 4, 2026

First Submitted That Met QC Criteria

March 4, 2026

First Posted (Actual)

March 9, 2026

Study Record Updates

Last Update Posted (Actual)

March 9, 2026

Last Update Submitted That Met QC Criteria

March 4, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 024-122

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Esophagogastric Junction Outflow Obstruction

Clinical Trials on FLIP Imaging under various standard of care anesthetics in the context of endotracheal intubation.

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Mozambique

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe