Using FLIP

A recent review article (E Sararino et al. Am J Gastroenterol 2020; 115: 1786-06. Use of the Functional Lumen Imaging Probe in Clinical Esophagology) is a terrific article for understanding Functional Lumen Imaging Probe (FLIP) techonology and uses. Thanks to Ben Gold for this reference.

Link to patient explanation of EndoFLIP at Univ Michigan

The FLIP “measures luminal cross sectional area (CSA) and pressure in the esophagus using impedance planimetry and serves as an adjunct to existing esophageal investigative tests. A distensible balloon encasing a catheter with multiple pairs of impedance electrodes is used, and the balloon is distended with fluid of known conductivity and volume.”

FLIP can be done at time of endoscopy.

  • Distensibility index (DI). This is the ratio of EGJ cross sectional area to intraballoon pressure is generally considered the most useful FLIP metric. Normal DI values in adults range from 3.1 to 9.0 m3/mm Hg. Lower values indicated reduced EGJ opening.
  • FLIP can complement the diagnosis of achalasia when manometry and barium studies are inconclusive or negative in patients with typical symptoms.
  • FLIP can be used to assess fibrostenotic remodeling of the esophagus in eosinophilic esophagitis.
  • Lumen diameter measured using FLIP in complex strictures can potentially guide management.

This review has several helpful figures to illustrate the type of visual data available. It also provides a standard protocol for using FLIP. The current limitations for FLIP include the lack of real-time software analysis of the data which hinders reporting, and limited data supporting use.

Related blog post: #NAASPGHAN17 Eosinophilic Esophagitis Session

While this picture makes me look like a scofflaw, in fact one can sit on the sand below the median high tide mark. So there!

#NASPGHAN17 Eosinophilic Esophagitis Session

This blog entry has abbreviated/summarized these presentations. Though not intentional, some important material is likely to have been omitted; in addition, transcription errors are possible as well.

This is a long post –highlighting four separate talks on eosinophilic esophagitis.

PPI Use in Esophageal Eosinophilia: Recommendations from the recent AGREE conference

Glenn Furuta  Children’s Hospital of Colorado

Key points:

The term PPI-REE (proton pump inhibitor-responsive eosinophilic esophagitis) may not be needed.  PPI-REE is quite similar to eosinophilic esophagitis based on molecular and clinical features.  The main difference being that this subset responds to PPI therapy.

 

Characterization of CYP2C19*17 Polymporphisms Among Children with PPI Responsive EoE and EoE

James Franciosis et al.  Nemours Children’s Hospital Orlando

My take: This cool presentation offered a potential explanation of why some patients respond to PPIs (so called “PPI-REE”) from those with EoE that does not respond to PPIs.  This is pertinent because on a molecular basis the disease appears to be the same.  The difference in PPI-REE from EoE may be how the patient metabolizes PPI.  Those EoE patients who metabolize PPIs “extensively” are much less likely to respond to this therapy.

Eosinophilic esophagitis: Now an “Oldie” -But with increased interest and new research, a “Goodie”

Chris Liacouras  Children’s Hospital of Philadelphia

This lecture covered an enormous amount of material.  Here are a few slides.

Final Lecture (from November 3rd presentation):

Key points:

  • Endoflip is a new tool that helps determine esophageal distensibility.  Improved distensibility indicates less fibrostenotic disease which is one long-term goal.
  • Response to treatment has been correlated in improvement in Endoflip measurements.
  • There are no FDA approved medications at this point for EoE, though topical steroids may be approved soon.