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Durcan C, Hossain M, Chagnon G, Perić D, Girard E. Characterization of the layer, direction and time-dependent mechanical behaviour of the human oesophagus and the effects of formalin preservation. J R Soc Interface 2024; 21:20230592. [PMID: 38593841 PMCID: PMC11003784 DOI: 10.1098/rsif.2023.0592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 03/05/2024] [Indexed: 04/11/2024] Open
Abstract
The mechanical characterization of the oesophagus is essential for applications such as medical device design, surgical simulations and tissue engineering, as well as for investigating the organ's pathophysiology. However, the material response of the oesophagus has not been established ex vivo in regard to the more complex aspects of its mechanical behaviour using fresh, human tissue: as of yet, in the literature, only the hyperelastic response of the intact wall has been studied. Therefore, in this study, the layer-dependent, anisotropic, visco-hyperelastic behaviour of the human oesophagus was investigated through various mechanical tests. For this, cyclic tests, with increasing stretch levels, were conducted on the layers of the human oesophagus in the longitudinal and circumferential directions and at two different strain rates. Additionally, stress-relaxation tests on the oesophageal layers were carried out in both directions. Overall, the results show discrete properties in each layer and direction, highlighting the importance of treating the oesophagus as a multi-layered composite material with direction-dependent behaviour. Previously, the authors conducted layer-dependent cyclic experimentation on formalin-embalmed human oesophagi. A comparison between the fresh and embalmed tissue response was carried out and revealed surprising similarities in terms of anisotropy, strain-rate dependency, stress-softening and hysteresis, with the main difference between the two preservation states being the magnitude of these properties. As formalin fixation is known to notably affect the formation of cross-links between the collagen of biological materials, the differences may reveal the influence of cross-links on the mechanical behaviour of soft tissues.
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Affiliation(s)
- Ciara Durcan
- Zienkiewicz Institute for Modelling, Data and Artificial Intelligence, Faculty of Science and Engineering, Swansea University, Swansea SA1 8EN, UK
- CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, Grenoble Alpes University, Grenoble 38000, France
| | - Mokarram Hossain
- Zienkiewicz Institute for Modelling, Data and Artificial Intelligence, Faculty of Science and Engineering, Swansea University, Swansea SA1 8EN, UK
| | - Grégory Chagnon
- CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, Grenoble Alpes University, Grenoble 38000, France
| | - Djordje Perić
- Zienkiewicz Institute for Modelling, Data and Artificial Intelligence, Faculty of Science and Engineering, Swansea University, Swansea SA1 8EN, UK
| | - Edouard Girard
- CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, Grenoble Alpes University, Grenoble 38000, France
- Laboratoire d’Anatomie des Alpes Françaises, Grenoble Alpes University, Grenoble, France
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2
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Durcan C, Hossain M, Chagnon G, Perić D, Girard E. Mechanical experimentation of the gastrointestinal tract: a systematic review. Biomech Model Mechanobiol 2024; 23:23-59. [PMID: 37935880 PMCID: PMC10901955 DOI: 10.1007/s10237-023-01773-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 09/10/2023] [Indexed: 11/09/2023]
Abstract
The gastrointestinal (GI) organs of the human body are responsible for transporting and extracting nutrients from food and drink, as well as excreting solid waste. Biomechanical experimentation of the GI organs provides insight into the mechanisms involved in their normal physiological functions, as well as understanding of how diseases can cause disruption to these. Additionally, experimental findings form the basis of all finite element (FE) modelling of these organs, which have a wide array of applications within medicine and engineering. This systematic review summarises the experimental studies that are currently in the literature (n = 247) and outlines the areas in which experimentation is lacking, highlighting what is still required in order to more fully understand the mechanical behaviour of the GI organs. These include (i) more human data, allowing for more accurate modelling for applications within medicine, (ii) an increase in time-dependent studies, and (iii) more sophisticated in vivo testing methods which allow for both the layer- and direction-dependent characterisation of the GI organs. The findings of this review can also be used to identify experimental data for the readers' own constitutive or FE modelling as the experimental studies have been grouped in terms of organ (oesophagus, stomach, small intestine, large intestine or rectum), test condition (ex vivo or in vivo), number of directions studied (isotropic or anisotropic), species family (human, porcine, feline etc.), tissue condition (intact wall or layer-dependent) and the type of test performed (biaxial tension, inflation-extension, distension (pressure-diameter), etc.). Furthermore, the studies that investigated the time-dependent (viscoelastic) behaviour of the tissues have been presented.
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Affiliation(s)
- Ciara Durcan
- Zienkiewicz Centre for Modelling, Data and AI, Faculty of Science and Engineering, Swansea University, Swansea, SA1 8EN, UK
- Université Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000, Grenoble, France
| | - Mokarram Hossain
- Zienkiewicz Centre for Modelling, Data and AI, Faculty of Science and Engineering, Swansea University, Swansea, SA1 8EN, UK.
| | - Grégory Chagnon
- Université Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000, Grenoble, France
| | - Djordje Perić
- Zienkiewicz Centre for Modelling, Data and AI, Faculty of Science and Engineering, Swansea University, Swansea, SA1 8EN, UK
| | - Edouard Girard
- Université Grenoble Alpes, CNRS, UMR 5525, VetAgro Sup, Grenoble INP, TIMC, 38000, Grenoble, France
- Laboratoire d'Anatomie des Alpes Françaises, Université Grenoble Alpes, Grenoble, France
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Elisha G, Halder S, Carlson DA, Kahrilas PJ, Pandolfino JE, Patankar NA. A mechanics-based perspective on the pressure-cross-sectional area loop within the esophageal body. Front Physiol 2023; 13:1066351. [PMID: 36699676 PMCID: PMC9868904 DOI: 10.3389/fphys.2022.1066351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 12/12/2022] [Indexed: 01/12/2023] Open
Abstract
Introduction: Plotting the pressure-cross-sectional area (P-CSA) hysteresis loops within the esophagus during a contraction cycle can provide mechanistic insights into esophageal motor function. Pressure and cross-sectional area during secondary peristalsis can be obtained from the functional lumen imaging probe (FLIP). The pressure-cross-sectional area plots at a location within the esophageal body (but away from the sphincter) reveal a horizontal loop shape. The horizontal loop shape has phases that appear similar to those in cardiovascular analyses, whichinclude isometric and isotonic contractions followed by isometric and isotonic relaxations. The aim of this study is to explain the various phases of the pressurecross-sectional area hysteresis loops within the esophageal body. Materials and Methods: We simulate flow inside a FLIP device placed inside the esophagus lumen. We focus on three scenarios: long functional lumen imaging probe bag placed insidethe esophagus but not passing through the lower esophageal sphincter, long functional lumen imaging probe bag that crosses the lower esophageal sphincter, and a short functional lumen imaging probe bag placed in the esophagus body that does not pass through the lower esophageal sphincter. Results and Discussion: Horizontal P-CSA area loop pattern is robust and is reproduced in all three cases with only small differences. The results indicate that the horizontal loop pattern is primarily a product of mechanical conditions rather than any inherently different function of the muscle itself. Thus, the distinct phases of the loop can be explained solely based on mechanics.
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Affiliation(s)
- Guy Elisha
- Department of Mechanical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, United States
| | - Sourav Halder
- Theoretical and Applied Mechanics Program, McCormick School of Engineering, Northwestern University, Evanston, IL, United States
| | - Dustin A. Carlson
- Division of Gastroenterology and Hepatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Peter J. Kahrilas
- Division of Gastroenterology and Hepatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - John E. Pandolfino
- Division of Gastroenterology and Hepatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, United States
| | - Neelesh A. Patankar
- Department of Mechanical Engineering, McCormick School of Engineering, Northwestern University, Evanston, IL, United States
- Theoretical and Applied Mechanics Program, McCormick School of Engineering, Northwestern University, Evanston, IL, United States
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Acharya S, Halder S, Carlson DA, Kou W, Kahrilas PJ, Pandolfino JE, Patankar NA. Assessment of esophageal body peristaltic work using functional lumen imaging probe panometry. Am J Physiol Gastrointest Liver Physiol 2021; 320:G217-G226. [PMID: 33174457 PMCID: PMC7948118 DOI: 10.1152/ajpgi.00324.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The goal of this study was to conceptualize and compute measures of "mechanical work" done by the esophagus using data generated during functional lumen imaging probe (FLIP) panometry and compare work done during secondary peristalsis among patients and controls. Eighty-five individuals were evaluated with a 16-cm FLIP during sedated endoscopy, including asymptomatic controls (n = 14) and those with achalasia subtypes I, II, and III (n = 15, each); gastroesophageal reflux disease (GERD; n = 13); eosinophilic esophagitis (EoE; n = 9); and systemic sclerosis (SSc; n = 5). The FLIP catheter was positioned to have its distal segment straddling the esophagogastric junction (EGJ) during stepwise distension. Two metrics of work were assessed: "active work" (during bag volumes ≤ 40 mL where contractility generates substantial changes in lumen area) and "work capacity" (for bag volumes ≥ 60 mL when contractility cannot substantially alter the lumen area). Controls showed median [interquartile range (IQR)] of 7.3 (3.6-9.2) mJ of active work and 268.6 (225.2-332.3) mJ of work capacity. Patients with all achalasia subtypes, GERD, and SSc showed lower active work done than controls (P ≤ 0.003). Patients with achalasia subtypes I and II, GERD, and SSc had lower work capacity compared with controls (P < 0.001, 0.004, 0.04, and 0.001, respectively). Work capacity was similar between controls and patients with achalasia type III and EoE. Mechanical work of the esophagus differs between healthy controls and patient groups with achalasia, EoE, SSc, and GERD. Further studies are needed to fully explore the utility of this approach, but these work metrics would be valuable for device design (artificial esophagus), to measure the efficacy of peristalsis, to gauge the physiological state of the esophagus, and to comment on its pumping effectiveness.NEW & NOTEWORTHY Functional lumen imaging probe (FLIP) panometry assesses esophageal response to distension and provides a simultaneous assessment of pressure and dimension during contractility. This enables an objective assessment of "mechanical work" done by the esophagus. Eighty-five individuals were evaluated, and two work metrics were computed for each subject. Controls showed greater values of work compared with individuals with achalasia, gastroesophageal reflux disease (GERD), and systemic sclerosis (SSc). These values can quantify the mechanical behavior of the distal esophagus and assist in the estimation of muscular integrity.
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Affiliation(s)
- Shashank Acharya
- 1Department of Mechanical Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois
| | - Sourav Halder
- 2Theoretical and Applied Mechanics Program, McCormick School of Engineering, Northwestern University, Evanston, Illinois
| | - Dustin A. Carlson
- 3Division of Gastroenterology and Hepatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Wenjun Kou
- 3Division of Gastroenterology and Hepatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Peter J. Kahrilas
- 3Division of Gastroenterology and Hepatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - John E. Pandolfino
- 3Division of Gastroenterology and Hepatology, Department of Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois
| | - Neelesh A. Patankar
- 1Department of Mechanical Engineering, McCormick School of Engineering, Northwestern University, Evanston, Illinois,2Theoretical and Applied Mechanics Program, McCormick School of Engineering, Northwestern University, Evanston, Illinois
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5
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Carlson DA, Kou W, Masihi M, Acharya S, Baumann AJ, Donnan EN, Kahrilas PJ, Pandolfino JE. Repetitive Antegrade Contractions: A novel response to sustained esophageal distension is modulated by cholinergic influence. Am J Physiol Gastrointest Liver Physiol 2020; 319:G696-G702. [PMID: 33026823 DOI: 10.1152/ajpgi.00305.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND & AIMS A unique motor response to sustained esophageal distension, repetitive antegrade contractions (RACs), is observed using functional luminal imaging probe (FLIP) panometry. However, physiologic mechanisms related to this response are unexplored. This study aimed to evaluate the impact of cholinergic inhibition with atropine on the esophageal contractile response to sustained distention, including RACs, among healthy volunteers. METHODS 8 asymptomatic volunteers (ages 22-45) were evaluated in a crossover study design with 16-cm FLIP positioned across the esophagogastric junction and distal esophagus during sedated upper endoscopy. The FLIP study involving stepwise volumetric distension was performed twice in each subject, at baseline and again after atropine (15 mcg/kg) was administered intravenously. FLIP panometry was analyzed to assess the contractile response to distension. RESULTS Antegrade contractions, lumen-occluding contractions, and a RAC pattern were observed in 8/8, 8/8, and 7/8(88%) subjects, respectively, at baseline and in 5/8 (63%), 2/8 (25%) and 2/8 (25%) subjects after atropine. The rate of contractions in the RAC pattern was similar (6-7 contractions per minute) before and after atropine. Compared with the baseline study, distension-induced contractility was triggered at higher fill volumes after atropine. FLIP pressures were lower in response to volumetric filling after atropine than at baseline. CONCLUSIONS The vigor and triggering of the esophageal contractile response to distension is reduced by cholinergic inhibition in asymptomatic controls. The observation that the rate of contractions did not change when patients developed repetitive contractile responses suggests that this rate is not modified by cholinergic inhibition once contractility is triggered.
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Affiliation(s)
| | - Wenjun Kou
- Medicine, Northwestern University, United States
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6
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Hoff DAL, McMahon B, Gregersen H. Esophageal multimodal stimulation and sensation. Ann N Y Acad Sci 2018; 1434:210-218. [DOI: 10.1111/nyas.13730] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 03/16/2018] [Accepted: 03/21/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Dag Arne Lihaug Hoff
- Division of Gastroenterology and Hepatology, Department of Medicine, Ålesund HospitalMøre and Romsdal Hospital Trust Ålesund Norway
| | - Barry McMahon
- Trinity Academic Gastroenterology Group (TAGG)Trinity College and Tallaght Hospital Dublin Ireland
| | - Hans Gregersen
- Department of Surgerythe Chinese University of Hong Kong Shatin Hong Kong
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7
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Gregersen H, Lo KM. Pathophysiology and treatment of achalasia in a muscle mechanical perspective. Ann N Y Acad Sci 2018; 1434:173-184. [PMID: 29756656 DOI: 10.1111/nyas.13711] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 03/07/2018] [Accepted: 03/14/2018] [Indexed: 12/11/2022]
Abstract
This review provides a biomechanical perspective on the pathophysiology and treatment of achalasia. The esophagus is efficient in transporting ingested material to the stomach in healthy subjects. A fine balance exists between the peristaltic forces generated in the esophageal body (which herein is defined as the preload) and the resistance in the outlet, the esophago-gastric junction (which is defined as the afterload). Achalasia is a rare esophageal disease that progressively over many years challenges esophageal efficacy. Clinical features and current literature are interpreted using well-known muscle mechanics models and terms from cardiac mechanophysiology. The preload, afterload, length-tension, and strain softening concepts in particular are useful for understanding the remodeling induced by achalasia. The concepts are also useful in understanding the treatment that aim to reduce the lower esophageal sphincter pressure that does not relax sufficiently in achalasia. These treatments cover endoscopic or laparoscopic myotomy, pneumatic balloon dilation, and Botox injections. In addition to the intended reduction of the afterload for aboral transport of ingested materials, the treatments tend to induce gastroesophageal reflux in some patients because they obliterate an important component in the reflux barrier.
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Affiliation(s)
- Hans Gregersen
- GIOME, Department of Surgery, the Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong.,California Medical Innovations Institute, San Diego, California
| | - Kar Man Lo
- GIOME, DoubleCove, Wu Kai Sha, New Territories, Hong Kong
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Liao D, Lottrup C, Fynne L, McMahon BP, Krogh K, Drewes AM, Zhao J, Gregersen H. Axial Movements and Length Changes of the Human Lower Esophageal Sphincter During Respiration and Distension-induced Secondary Peristalsis Using Functional Luminal Imaging Probe. J Neurogastroenterol Motil 2018; 24:255-267. [PMID: 29605981 PMCID: PMC5885725 DOI: 10.5056/jnm17084] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Revised: 09/29/2017] [Accepted: 12/12/2017] [Indexed: 12/16/2022] Open
Abstract
Background/Aims Efficient transport through the esophago-gastric junction (EGJ) requires synchronized circular and longitudinal muscle contraction of the esophagus including relaxation of the lower esophageal sphincter (LES). However, there is a scarcity of technology for measuring esophagus movements in the longitudinal (axial) direction. The aim of this study is to develop new analytical tools for dynamic evaluation of the length change and axial movement of the human LES based on the functional luminal imaging probe (FLIP) technology and to present normal signatures for the selected parameters. Methods Six healthy volunteers without hiatal hernia were included. Data were analyzed from stepwise LES distensions at 20, 30, and 40 mL bag volumes. The bag pressure and the diameter change were used for motion analysis in the LES. The cyclic bag pressure frequency was used to distinguish dynamic changes of the LES induced by respiration and secondary peristalsis. Results Cyclic fluctuations of the LES were evoked by respiration and isovolumetric distension, with phasic changes of bag pressure, diameter, length, and axial movement of the LES narrow zone. Compared to the respiration-induced LES fluctuations, peristaltic contractions increased the contraction pressure amplitude (P < 0.001), shortening (P < 0.001), axial movement (P < 0.001), and diameter change (P < 0.01) of the narrow zone. The length of the narrow zone shortened as function of the pressure increase. Conclusions FLIP can be used for evaluation of dynamic length changes and axial movement of the human LES. The method may shed light on abnormal longitudinal muscle activity in esophageal disorders.
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Affiliation(s)
- Donghua Liao
- GIOME Academia, Department of Medicine, Aarhus University, Aarhus, Denmark
| | - Christian Lottrup
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Lotte Fynne
- Neurogastroenterology Unit, Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Barry P McMahon
- TAGG Research Center, Tallaght Hospital and Trinity College, Dublin, Ireland
| | - Klaus Krogh
- Neurogastroenterology Unit, Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Asbjørn M Drewes
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Jingbo Zhao
- GIOME Academia, Department of Medicine, Aarhus University, Aarhus, Denmark
| | - Hans Gregersen
- GIOME, Department of Surgery, Chinese University of Hong Kong and Prince of Wales Hospital, Hong Kong
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9
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Gregersen H, Lo KM. What Is the Future of Impedance Planimetry in Gastroenterology? J Neurogastroenterol Motil 2018; 24:166-181. [PMID: 29605974 PMCID: PMC5885717 DOI: 10.5056/jnm18013] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 02/09/2018] [Indexed: 12/13/2022] Open
Abstract
The gastrointestinal (GI) tract is efficient in transporting ingested material to the site of delivery in healthy subjects. A fine balance exists between peristaltic forces, the mixing and delivery of the contents, and sensory signaling. This fine balance is easily disturbed by diseases. It is mandatory to understand the pathophysiology to enhance our understanding of GI disorders. The inaccessibility and complex nervous innervation, geometry and mechanical function of the GI tract make mechanosensory evaluation difficult. Impedance planimetry is a distension technology that assesses luminal geometry, mechanical properties including muscle dynamics, and processing of nociceptive signals from the GI tract. Since standardized models do not exist for GI muscle function in vivo, models, concepts, and terminology must be borrowed from other medical fields such as cardiac mechanophysiology. The review highlights the impedance planimetric technology, muscle dynamics assessment, and 3 applied technologies of impedance planimetry. These technologies are the multimodal probes that assesses sensory function, the functional luminal imaging probe that dynamically measures the geometry of the lumen it distends, and Fecobionics that is a simulated feces providing high-resolution measurements during defecation. The advanced muscle analysis and 3 applied technologies can enhance the quality of future interdisciplinary research for gaining more knowledge about mechanical function, sensory-motor disorders, and symptoms. This is a step in the direction of individualized treatment for GI disorders based on diagnostic subtyping. There seems to be no better alternatives to impedance planimetry, but only the functional luminal imaging probe is currently commercially available. Wider use depends on commercialization of the multimodal probe and Fecobionics.
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Affiliation(s)
- Hans Gregersen
- GIOME, Department of Surgery, The Chinese University of Hong Kong, Shatin, Hong Kong.,California Medical Innovations Institute, San Diego, California, USA
| | - Kar Man Lo
- GIOME Doublecove, Wu Kai Sha, New Territories, Hong Kong
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10
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Du P, Yassi R, Gregersen H, Windsor JA, Hunter PJ. The virtual esophagus: investigating esophageal functions in silico. Ann N Y Acad Sci 2016; 1380:19-26. [PMID: 27310396 DOI: 10.1111/nyas.13089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 04/11/2016] [Accepted: 04/17/2016] [Indexed: 12/24/2022]
Abstract
Esophageal and gastroesophageal junction (GEJ) diseases are highly prevalent worldwide and are a significant socioeconomic burden. Recently, applications of multiscale mathematical models of the upper gastrointestinal tract have gained attention. These in silico investigations can contribute to the development of a virtual esophagus modeling framework as part of the larger GIome and Physiome initiatives. There are also other modeling investigations that have potential screening and treatment applications. These models incorporate detailed anatomical models of the esophagus and GEJ, tissue biomechanical properties and bolus transport, sensory properties, and, potentially, bioelectrical models of the neural and myogenic pathways of esophageal and GEJ functions. A next step is to improve the integration between the different components of the virtual esophagus, encoding standards, and simulation environments to perform more realistic simulations of normal and pathophysiological functions. Ultimately, the models will be validated and will provide predictive evaluations of the effects of novel endoscopic, surgical, and pharmaceutical treatment options and will facilitate the clinical translation of these treatments.
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Affiliation(s)
- Peng Du
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.
| | - Rita Yassi
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Hans Gregersen
- GIOME Center, College of Bioengineering, Chongqing University, Chongqing, China
| | - John A Windsor
- Department of Surgery, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,HBP/Upper GI Unit, Department of General Surgery, Auckland City Hospital, Auckland, New Zealand
| | - Peter J Hunter
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
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11
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Gregersen H, Liao D, Brasseur JG. The Esophagiome: concept, status, and future perspectives. Ann N Y Acad Sci 2016; 1380:6-18. [PMID: 27570939 DOI: 10.1111/nyas.13200] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 07/13/2016] [Accepted: 07/14/2016] [Indexed: 12/23/2022]
Abstract
The term "Esophagiome" is meant to imply a holistic, multiscale treatment of esophageal function from cellular and muscle physiology to the mechanical responses that transport and mix fluid contents. The development and application of multiscale mathematical models of esophageal function are central to the Esophagiome concept. These model elements underlie the development of a "virtual esophagus" modeling framework to characterize and analyze function and disease by quantitatively contrasting normal and pathophysiological function. Functional models incorporate anatomical details with sensory-motor properties and functional responses, especially related to biomechanical functions, such as bolus transport and gastrointestinal fluid mixing. This brief review provides insight into Esophagiome research. Future advanced models can provide predictive evaluations of the therapeutic consequences of surgical and endoscopic treatments and will aim to facilitate clinical diagnostics and treatment.
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Affiliation(s)
- Hans Gregersen
- GIOME, College of Bioengineering, Chongqing University, China. .,GIOME, Department of Surgery, Prince of Wales Hospital, College of Medicine, Chinese University of Hong Kong, Hong Kong SAR.
| | - Donghua Liao
- GIOME Academy, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - James G Brasseur
- Aerospace Engineering Sciences, University of Colorado, Boulder, Colorado
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12
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Farmer AD, Franchina M, Gregersen H, Penagini R, Shaker A, Soffer E. Provocative testing of the esophagus and its future. Ann N Y Acad Sci 2016; 1380:33-47. [DOI: 10.1111/nyas.13109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 04/21/2016] [Accepted: 04/25/2016] [Indexed: 12/25/2022]
Affiliation(s)
- Adam D. Farmer
- Centre for Digestive Diseases, Wingate Institute of Neurogastroenterology, Blizard Institute, Barts and the London School of Medicine & Dentistry; Queen Mary University of London; London United Kingdom
- Department of Gastroenterology; University Hospitals of North Midlands; Stoke on Trent Staffordshire United Kingdom
| | - Marianna Franchina
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi of Milan and Gastroenterology and Endoscopy Unit; Fondazione IRCCS Cà Granda - Ospedale Maggiore Policlinico; Milan Italy
| | - Hans Gregersen
- GIOME, College of Bioengineering; Chongqing University; Chongqing China
- Department of Surgery; Prince of Wales Hospital; Shatin Hong Kong SAR
| | - Roberto Penagini
- Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi of Milan and Gastroenterology and Endoscopy Unit; Fondazione IRCCS Cà Granda - Ospedale Maggiore Policlinico; Milan Italy
| | - Anisa Shaker
- Department of Medicine; University of Southern California; Los Angeles California
| | - Edy Soffer
- Department of Medicine; University of Southern California; Los Angeles California
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Carlson DA, Lin Z, Rogers M, Lin CY, Kahrilas PJ, Pandolfino JE. Utilizing functional lumen imaging probe topography to evaluate esophageal contractility during volumetric distention: a pilot study. Neurogastroenterol Motil 2015; 27:981-9. [PMID: 25898916 PMCID: PMC4478241 DOI: 10.1111/nmo.12572] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 03/24/2015] [Indexed: 12/14/2022]
Abstract
BACKGROUND The functional lumen imaging probe (FLIP) measures luminal cross-sectional area and pressure during volumetric distension. By applying novel customized software to produce FLIP topography plots, organized esophageal contractility can be visualized and analyzed. We aimed to describe the stimulus thresholds and contractile characteristics for distension-induced esophageal body contractility using FLIP topography in normal controls. METHODS Ten healthy controls were evaluated during endoscopy with FLIP. During stepwise bag distension, simultaneous intra-bag pressure and luminal diameter measurements were obtained and exported to a MatLab program to generate FLIP topography plots. The distension volume, intra-bag pressure, and maximum esophageal body diameters were measured for the onset and cessation of repetitive antegrade contractions (RACs). Contraction duration, interval, magnitude, and velocity were measured at 8 and 3-cm proximal to the esophagogastric junction. KEY RESULTS Eight of ten subjects demonstrated RACs at a median onset volume of 29 mL (IQR: 25-38.8), median intra-bag pressure of 10.7 mmHg (IQR: 8.6-15.9), and median maximum esophageal body diameter of 18.5 mm (IQR: 17.5-19.6). Cessation of RACs occurred prior to completion of the distension protocol in three of the eight subjects exhibiting RACs. Values of the RAC-associated contractile metrics were also generated to characterize these events. CONCLUSIONS & INFERENCES Distension-induced esophageal contractions can be assessed utilizing FLIP topography. RACs are a common finding in asymptomatic controls in response to volume distention and have similar characteristics to secondary peristalsis and repetitive rapid swallows.
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Affiliation(s)
- DA Carlson
- Department of Medicine, Division of Gastroenterology and Hepatology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Z Lin
- Department of Medicine, Division of Gastroenterology and Hepatology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - M Rogers
- Department of Medicine, Division of Gastroenterology and Hepatology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - CY Lin
- Department of Medicine, Division of Gastroenterology and Hepatology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - PJ Kahrilas
- Department of Medicine, Division of Gastroenterology and Hepatology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - JE Pandolfino
- Department of Medicine, Division of Gastroenterology and Hepatology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
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Liao D, Krarup AL, Lundager FH, Drewes AM, Gregersen H. Quantitative differences between primary and secondary peristaltic contractions of the esophagus. Dig Dis Sci 2014; 59:1810-6. [PMID: 24682721 DOI: 10.1007/s10620-014-3070-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2013] [Accepted: 02/07/2014] [Indexed: 01/25/2023]
Abstract
BACKGROUND AND AIMS Differences in contraction characteristics between primary and secondary peristalsis have only been scarcely studied. Recently new measures of contractile activity in the human esophagus were developed. The study aims were to use combined manometry and impedance planimetry [pressure-cross-sectional area (P-CSA)] recordings from healthy volunteers to examine esophageal peristalsis, and, furthermore, to investigate the effect of the motility enhancing drug erythromycin to study differential effects on the two types of contractions. METHODS Sixteen healthy volunteers participated in the study [mean age 23 (range, 19-34) years, 6 females]. An esophageal probe with a bag for CSA measurement was positioned 10 cm above the lower esophageal sphincter. Bag volume was increased stepwise from 5 to 25 ml before and after intravenous infusion of 250 mg erythromycin. Swallow-evoked primary and distension-evoked secondary esophageal peristalsis were compared with regard to (1) pressure amplitude, (2) CSA amplitude, (3) preload tension (wall tension before an evoked contraction), (4) contractile tension, and (5) work outputs. RESULTS Primary peristalsis induced more efficient contractions as the contraction amplitudes, work output and contractile tension were higher compared to secondary peristalsis (P < 0.001). Erythromycin induced change in CSA during distension-evoked secondary peristalsis (CSA before 212.9 ± 26.8 vs. after 180.5 ± 23.3, P < 0.05). The sensitivity to esophageal distension increased with the distending volume both before and during erythromycin. The sensitivity was not changed by erythromycin (P = 0.6). CONCLUSIONS Esophageal primary peristaltic contractions were more forceful with longer duration, and higher work output compared to secondary peristalsis contractions. Erythromycin affected peristalsis only to a minor degree.
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Affiliation(s)
- Donghua Liao
- Giome Academia, Institute of Clinical Medicine, Aarhus University Hospital, Skejby, Brendstrupgaardsvej, 8200, Aarhus, Denmark,
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