| Liquid in the gastroesophageal segment promotes reflux, but compliance does not: a mathematical modeling study. | |
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MedLine Citation:
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PMID: 18718998 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The mechanical force relationships that distinguish normal from chronic reflux at sphincter opening are poorly understood and difficult to measure in vivo. Our aim was to apply physics-based computer simulations to determine mechanical pathogenesis of gastroesophageal reflux. A mathematical model of the gastroesophageal segment (GES) was developed, incorporating the primary anatomical and physiomechanical elements that drive GES opening and reflux. In vivo data were used to quantify muscle stiffness, sphincter tone, and gastric pressure. The liquid lining the mucosa was modeled as an "effective liquid film" between the mucosa and a manometric catheter. Newton's second law was solved mathematically, and the space-time details of opening and reflux were predicted for systematic variations in gastric pressure increase, film thickness, muscle stiffness, and tone. "Reflux" was defined as "2 ml of refluxate entering the esophagus within 1 s." GES opening and reflux were different events. Both were sensitive to changes in gastric pressure and sphincter tone. Reflux initiation was extremely sensitive to the liquid film thickness; the protective function of the sphincter was destroyed with only 0.4 mm of liquid in the GES. Compliance had no effect on reflux initiation, but affected reflux volume. The presence of abnormal levels of liquid within the collapsed GES can greatly increase the probability for reflux, suggesting a mechanical mechanism that may differentiate normal reflux from gastroesophageal reflux disease. Compliance does not affect the probability for reflux, but affects reflux volume once it occurs. Opening without reflux suggests the existence of "gastroesophageal pooling" in the distal esophagus, with clinical implications. |
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Authors:
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Sudip K Ghosh; Peter J Kahrilas; James G Brasseur |
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Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural Date: 2008-08-21 |
Journal Detail:
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Title: American journal of physiology. Gastrointestinal and liver physiology Volume: 295 ISSN: 0193-1857 ISO Abbreviation: Am. J. Physiol. Gastrointest. Liver Physiol. Publication Date: 2008 Nov |
Date Detail:
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Created Date: 2008-11-12 Completed Date: 2009-01-06 Revised Date: 2010-09-21 |
Medline Journal Info:
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Nlm Unique ID: 100901227 Medline TA: Am J Physiol Gastrointest Liver Physiol Country: United States |
Other Details:
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Languages: eng Pagination: G920-33 Citation Subset: IM |
Affiliation:
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The Pennsylvania State Univ., Dept. of Mechanical Engineering, University Park, PA 16802, USA. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Biomechanics Computer Simulation Esophagogastric Junction / physiology* Gastroesophageal Reflux / metabolism* Humans Models, Biological* |
| Grant Support | |
ID/Acronym/Agency:
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R01-DK56033/DK/NIDDK NIH HHS |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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