Systematic Reviews
Copyright ©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Feb 21, 2017; 23(7): 1289-1297
Published online Feb 21, 2017. doi: 10.3748/wjg.v23.i7.1289
Esophagogastric junction distensibility assessed using the functional lumen imaging probe
Joan W Chen, Joel H Rubenstein
Joan W Chen, Joel H Rubenstein, Department of Gastroenterology and Hepatology, University of Michigan Health Systems, Ann Arbor, MI 48109, United States
Author contributions: Chen JW and Rubenstein JH contributed to the study concept and design, acquisition of data, analysis and interpretation, critical revision, and final approval of the manuscript; Chen JW drafted of the manuscript.
Conflict-of-interest statement: Chen JW and Rubenstein JH have no commercial, personal, political, intellectual, or religious conflict of interest.
Data sharing statement: Technical appendix and dataset available from the corresponding author at chenjoan@med.umich.edu.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Joan W Chen, MD, MS, Department of Gastroenterology and Hepatology, University of Michigan Health Systems, 3912 Taubman Center, 1500 E. Medical Center Dr., SPC 5362, Ann Arbor, MI 48109, United States. chenjoan@med.umich.edu
Telephone: +1-734-9366400 Fax: +1-734-9366400
Received: October 8, 2016
Peer-review started: October 9, 2016
First decision: November 9, 2016
Revised: December 8, 2016
Accepted: December 21, 2016
Article in press: December 21, 2016
Published online: February 21, 2017
Abstract
AIM

To assess reference values in the literature for esophageal distensibility and cross-sectional area in healthy and diseased subjects measured by the functional lumen imaging probe (FLIP).

METHODS

Systematic search and review of articles in Medline and Embase pertaining to the use of FLIP in the esophagus was conducted in accordance with the PRISMA guidelines. Cross-sectional area and distensibility at the esophagogastric junction (EGJ) were abstracted for normal subjects, achalasia, and gastroesophageal reflux disease (GERD) patients, stratified by balloon length and volume of inflation.

RESULTS

Six achalasia studies (n = 154), 3 GERD (n = 52), and 5 studies including healthy controls (n = 98) were included in the systematic review. Normative data varied widely amongst studies of healthy volunteers. In contrast, studies in achalasia patients uniformly demonstrated low point estimates in distensibility ≤ 1.6 mm2/mmHg prior to treatment that increased to ≥ 3.4 mm2/mmHg following treatment at 40mL bag volume. In GERD patients, distensibility fell to the range of untreated achalasia (≤ 2.85 mm2/mmHg) following fundoplication.

CONCLUSION

FLIP may be a useful tool in assessment of treatment efficacy in achalasia. The drastic drop in EGJ distensibility after fundoplication suggests that FLIP measurements need to be interpreted in the context of esophageal body motility and highlights the importance of pre-operative screening for dysmotility. Future studies using standardized FLIP protocol and balloon size are needed.

Keywords: Impedance planimetry, Gastroesophageal reflux disease, Esophageal distensibility, Achalasia

Core tip: Functional lumen imaging probe (FLIP) uses impedance planimetry to calculate the distensibility of a hollow organ. In this systematic review, we aimed to assess FLIP reference values for gastroesophageal junction distensibility in healthy and diseased states. We found available normative data to vary widely. In achalasia, patients uniformly demonstrated low distensibility that improved after treatment, highlighting the role of FLIP in assessment of achalasia treatment efficacy. In gastroesophageal reflux disease, distensibility fell to the range of untreated achalasia following fundoplication, emphasizing the importance of pre-operative screening for esophageal body dysmotililty. Future studies using a standardized FLIP protocol and balloon size are needed.