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Gaber W, Khalil F, Mohamedien D. Prenatal developmental sequences of the esophageal epithelium in the New Zealand white rabbits: Light and electron microscopic analysis. Microsc Res Tech 2024; 87:753-766. [PMID: 38053441 DOI: 10.1002/jemt.24464] [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: 08/13/2023] [Revised: 10/20/2023] [Accepted: 11/19/2023] [Indexed: 12/07/2023]
Abstract
Several morphogenetic sequences occur during esophageal development and birth defects occur due to defects in foregut morphogenesis. This work aimed to record the cellular events in the morphogenesis of rabbits' esophageal epithelium. On the 16th day of gestation, the esophageal epithelium varied from stratified ciliated columnar to stratified squamous type. The surface epithelium presented mucous cells with mucigen granules of various sizes occupying their supranuclear cytoplasm. Cytoplasmic vacuolation was evident in all layers of the esophageal epithelium at this age. On the 18th gestational day, some light cells could be detected in the middle portion of the epithelium, while others occupied the whole epithelial length. On the 21st day, mucous cells are more frequently observed at the apical esophageal part as well as at the surface epithelium. Numerous elongated dark cells could be distinguished embedded between the basal cells. On the 24th gestational day the number of the mucous cells reached its peak. Reaching the 30th gestational day, several lamellar bodies, a keratinized layer and mitotic divisions could be demonstrated, and the number of both mucous and dark cells was greatly decreased. Collectively, detection of surface mucous and dark cells together with the non-cornified surface in some regions of the rabbit esophageal epithelium at the end of gestation ensure a postnatal development to reach the adult epithelium essential to sustain the passage of the harsh raw food. Future immunohistochemical studies are recommended to investigate the components of secretions in mucous cells and functional studies to highlight the dark cells significance. RESEARCH HIGHLIGHTS: Esophageal epithelium of fetal rabbit was analyzed by light and transmission microscopy. Surface epithelium presented mucous cells with mucigen granules of various sizes. They reached their maximum number on 24th day then decreased. On the 16th day, cytoplasmic vacuolation was evident in all epithelial layers. On the 21st day, numerous elongated dark cells could be distinguished embedded between the basal cells. Before birth, several lamellar bodies, a keratinized layer and mitotic divisions could be demonstrated, and the number of both mucous and dark cells was greatly decreased.
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Affiliation(s)
- Wafaa Gaber
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Assiut University, Assiut, Egypt
| | - Fatma Khalil
- Department of Histology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
| | - Dalia Mohamedien
- Department of Histology, Faculty of Veterinary Medicine, South Valley University, Qena, Egypt
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
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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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Zhao J, McMahon B, Fox M, Gregersen H. The esophagiome: integrated anatomical, mechanical, and physiological analysis of the esophago-gastric segment. Ann N Y Acad Sci 2018; 1434:5-20. [DOI: 10.1111/nyas.13869] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 04/27/2018] [Accepted: 05/04/2018] [Indexed: 12/24/2022]
Affiliation(s)
- Jingbo Zhao
- GIOME Academy, Department of Clinical Medicine; Aarhus University; Aarhus Denmark
| | - Barry McMahon
- Trinity Academic Gastroenterology Group; Tallaght Hospital and Trinity College; Dublin Ireland
| | - Mark Fox
- Abdominal Center: Gastroenterology; St. Claraspital Basel Switzerland
- Neurogastroenterology and Motility Research Group; University Hospital Zürich; Zürich Switzerland
| | - Hans Gregersen
- GIOME, Department of Surgery; Prince of Wales Hospital and Chinese University of Hong Kong; Shatin Hong Kong SAR
- California Medical Innovations Institute; San Diego California
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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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Zhao J, Gregersen H. Esophageal morphometric and biomechanical changes during aging in rats. Neurogastroenterol Motil 2015; 27:1638-47. [PMID: 26303784 DOI: 10.1111/nmo.12661] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Accepted: 07/30/2015] [Indexed: 02/08/2023]
Abstract
BACKGROUND Human studies have demonstrated aging-related changes in esophagus which may contribute to the increased rate of gastro-esophageal reflux in elderly. The aim of this study was to investigate esophageal morphometric and biomechanical remodeling in aging rats to obtain detailed information about aging-related changes. METHODS Twenty-four male Wistar rats, aged from 6 to 22 months, were studied. Morphometric data were obtained by measuring the wall thickness and cross-sectional area. The esophageal diameter and length were obtained from digitized images of the segments at preselected luminal pressure levels and at no-load and zero-stress states. Circumferential and longitudinal stresses (force per area) and strains (deformation) were computed from the length, diameter and pressure data, and from the zero-stress state geometry. KEY RESULTS The esophageal parameters such as the weight per unit length, the wall thickness and the wall cross-sectional area increased slightly from 6 to 22 months (p < 0.05 to p < 0.001). The opening angle gradually decreased during aging (p < 0.05). The interface between the mucosa-submucosa and muscle layers slightly moved outwards and the neutral axis moved inwards during aging. The stress-strain data showed that the esophageal wall became stiffer circumferentially and longitudinally during aging (p < 0.05, p < 0.01). However, the circumferential wall stiffness showed no further change after 12 months. CONCLUSIONS & INFERENCES A pronounced morphometric and biomechanical remodeling occurred in the rat esophagus during aging.
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Affiliation(s)
- J Zhao
- Giome Academia, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.,GIOME and the Key Laboratory for Biorheological Science and Technology of Ministry of Education, Bioengineering College of Chongqing University, Chongqing, China
| | - H Gregersen
- GIOME and the Key Laboratory for Biorheological Science and Technology of Ministry of Education, Bioengineering College of Chongqing University, Chongqing, China
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Luc G, Durand M, Collet D, Guillemot F, Bordenave L. Esophageal tissue engineering. Expert Rev Med Devices 2014; 11:225-41. [PMID: 24387697 DOI: 10.1586/17434440.2014.870470] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Esophageal tissue engineering is still in an early state, and ideal methods have not been developed. Since the beginning of the 20th century, advances have been made in the materials that can be used to produce an esophageal substitute. Three approaches to scaffold-based tissue engineering have yielded good results. The first development concerned non-absorbable constructs based on silicone and collagen. The need to remove the silicone tube is the main disadvantage of this material. Polymeric absorbable scaffolds have been used since the 1990s. The main polymeric material used is poly (glycolic) acid combined with collagen. The problem of stenosis remains prevalent in most studies using an absorbable construct. Finally, decellularized scaffolds have been used since 2000. The promises of this new approach are unfulfilled. Indeed, stenosis occurs when the esophageal defect is circumferential regardless of the scaffold materials. Cell supplementation can decrease the rate of stenosis, but the type(s) of cells and their roles have not been defined. Finally, esophageal tissue engineering cannot provide a functional esophageal substitute, and further development is necessary prior to conducting human clinical studies.
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Affiliation(s)
- Guillaume Luc
- Department of Digestive Surgery, University Hospital Haut-Lévêque, Av de Magellan, 33604 Pessac cedex, France
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Lin Z, Nicodème F, Boris L, Lin CY, Kahrilas PJ, Pandolfino JE. Regional variation in distal esophagus distensibility assessed using the functional luminal imaging probe (FLIP). Neurogastroenterol Motil 2013; 25:e765-71. [PMID: 23965159 PMCID: PMC3793325 DOI: 10.1111/nmo.12205] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2013] [Accepted: 07/18/2013] [Indexed: 12/13/2022]
Abstract
BACKGROUND This study aimed to evaluate the spatial variation in esophageal distensibility in normal subjects using a novel multichannel functional luminal imaging probe (FLIP). METHODS Ten healthy subjects (four men, age 21-49 years) were evaluated during endoscopy with a high-resolution impedance planimetry probe (FLIP) positioned through the esophagogastric junction (EGJ) and distal 10 cm of the esophageal body. Stepwise bag distensions using 5-mL increments from 0 to 60 mL were conducted, and simultaneous measurements of cross-sectional area (CSA) and the associated intrabag pressure from each subject were analyzed using a customized MATLAB™ program. The distensibility along the esophagus was determined and compared between the EGJ and interval locations at 2-5 cm and 6-10 cm above the EGJ. KEY RESULTS The pressure-CSA relationship was nearly linear among sites at lower pressures (0 to 7.5 mmHg) and reached a distension plateau at pressures ranging from 8 to 24 mmHg. The location of greatest distensibility was 4 cm above the EGJ. Although the CSAs of individual recording loci were not significantly different, there was a significant difference between the mean CSAs when comparing the region 2 to 5 cm proximal to EGJ with that 6 to 10 cm proximal to the EGJ. CONCLUSIONS & INFERENCES There were significant regional differences in distensibility along the distal esophagus with lower values in the proximal part compared with more distal part. The greatest distensibility was noted to occur at about 4 cm above the EGJ in close proximity to the location of the contractile deceleration point and phrenic ampulla.
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Affiliation(s)
- Z. Lin
- Department of Medicine, Feinberg School of Medicine; Northwestern University; Chicago; IL; USA
| | - F. Nicodème
- Department of Medicine, Feinberg School of Medicine; Northwestern University; Chicago; IL; USA
| | - L. Boris
- Department of Medicine, Feinberg School of Medicine; Northwestern University; Chicago; IL; USA
| | - C.-Y. Lin
- Department of Medicine, Feinberg School of Medicine; Northwestern University; Chicago; IL; USA
| | - P. J. Kahrilas
- Department of Medicine, Feinberg School of Medicine; Northwestern University; Chicago; IL; USA
| | - J. E. Pandolfino
- Department of Medicine, Feinberg School of Medicine; Northwestern University; Chicago; IL; USA
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Yang J, Zhao J, Nakaguchi T, Gregersen H. Biomechanical changes in oxazolone-induced colitis in BALB/C mice. J Biomech 2009; 42:811-7. [PMID: 19264309 DOI: 10.1016/j.jbiomech.2009.01.028] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Revised: 01/28/2009] [Accepted: 01/28/2009] [Indexed: 01/08/2023]
Abstract
Ulcerative colitis (UC) is associated with intestinal and extra intestinal clinical manifestations. The profound organic changes in UC indicate that the colonic mechanical and mechanosensory functions are affected. The aim was to study acute morphological and biomechanical properties of the distal colon in oxazolone-induced UC in BALB/C mice. Six normal male BALB/C mice and 10 oxazolone-induced UC mice were studied. UC was induced by epicutaneous and intrarectal administration of oxazolone. The mechanical test was done as a distension experiment where the colon was distended up to 20 cmH2O. The pressure, outer diameter and length were recorded simultaneously. Circumferential and longitudinal stresses and strains were computed. The intestinal specimens were processed for histology. The mucosa was infiltrated with acute and chronic inflammatory cells. Mucosal bleeding, irregular ulcers crypt abscess, and destruction of the epithelial border were observed. Although, the mucosa in ulcers was much thinner than in the normal controls, the mucosa and submucosa around the ulcer were thicker than in the normal controls (P<0.05). Oxazolone-induced colitis increased the circumferences and wall cross-sectional area (P<0.01), the opening angle and residual strain at the serosa increased (P<0.01). Furthermore, the circumferential and longitudinal stiffness increased in the UC wall and was most pronounced in longitudinal direction. The opening angle and residual strain was linearly correlated to the wall thickness, area and inflammation degree. In conclusion, morphological and biomechanical changes of the colon occurred during the development of UC. The increased stiffness may contribute to the abnormal function in patients with UC.
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Affiliation(s)
- Jian Yang
- Mech-Sense, Aalborg Hospital Science and Innovation Centre (AHSIC), Aalborg Hospital, Sdr. Skovvej 15, DK 9000 Aalborg, Denmark
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Abstract
The gastrointestinal (GI) tract is the system of organs within multi-cellular animals that takes in food, digests it to extract energy and nutrients, and expels the remaining waste. The various patterns of GI tract function are generated by the integrated behaviour of multiple tissues and cell types. A thorough study of the GI tract requires understanding of the interactions between cells, tissues and gastrointestinal organs in health and disease. This depends on knowledge, not only of numerous cellular ionic current mechanisms and signal transduction pathways, but also of large scale GI tissue structures and the special distribution of the nervous network. A unique way of coping with this explosion in complexity is mathematical and computational modelling; providing a computational framework for the multilevel modelling and simulation of the human gastrointestinal anatomy and physiology. The aim of this review is to describe the current status of biomechanical modelling work of the GI tract in humans and animals, which can be further used to integrate the physiological, anatomical and medical knowledge of the GI system. Such modelling will aid research and ensure that medical professionals benefit, through the provision of relevant and precise information about the patient’s condition and GI remodelling in animal disease models. It will also improve the accuracy and efficiency of medical procedures, which could result in reduced cost for diagnosis and treatment.
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Zhao J, Jørgensen CS, Liao D, Gregersen H. Dimensions and circumferential stress-strain relation in the porcine esophagus in vitro determined by combined impedance planimetry and high-frequency ultrasound. Dig Dis Sci 2007; 52:1338-44. [PMID: 17356919 DOI: 10.1007/s10620-006-9238-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Accepted: 01/30/2006] [Indexed: 01/07/2023]
Abstract
The mechanical properties of the esophagus are important for its function because the esophagus is subjected to changes in wall stress and strains caused by the passage of boli and the action of peristalsis. Electrodes for impedance planimetry and an ultrasound transducer were placed on the probe inside a fluid-filled bag and used to study the circumferential stress and strain relation of the porcine esophagus in vitro. Impedance planimetry was used to determine the luminal cross-sectional area (CSA) and high-frequency ultrasound was used to determine the esophageal wall thickness during bag distension. Circumferential stress and strain were computed from steady-state values of pressure, CSA, and wall thickness. The incremental elastic modulus was obtained from the slope of the stress-strain curve and was plotted as a function of strain. The steady state pressure-CSA relation was nonlinear. At the lowest and highest luminal pressure load of 1 and 5 kPa, the steady state CSA was 159+/-20 and 338+/-25 mm(2), respectively. In the same pressure range, the wall thickness decreased from 1.93+/-0.08 to 1.44+/-0.08 mm. The slope of the stress-strain curve was 2.58+/-0.35 kPa. The circumferential stress and the incremental elastic modulus as function of the strain were exponential, that is, the tissue was soft at physiologic pressures and stiffer in the supraphysiologic pressure range. These biomechanical properties of the esophageal wall seem to prevent overstretch of the esophageal wall when luminal loading becomes supraphysiologic.
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Affiliation(s)
- Jingbo Zhao
- Center of Excellence in Visceral Biomechanics and Pain, Aalborg Hospital, Søndre Skovvej 15, DK-9000, Aalborg, Denmark
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Zhao J, Chen X, Yang J, Liao D, Gregersen H. Opening angle and residual strain in a three-layered model of pig oesophagus. J Biomech 2007; 40:3187-92. [PMID: 17517416 DOI: 10.1016/j.jbiomech.2007.04.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 04/02/2007] [Accepted: 04/02/2007] [Indexed: 01/19/2023]
Abstract
Studies of various biological tissues have shown that residual strains are important for tissue function. Since a force balance exists in whole wall thickness specimens cut radially, it is evident that layer separation is an important procedure in the understanding of the meaning of residual stresses and strains. The present study investigated the zero-stress state and residual strain distribution in a three-layer model of the pig oesophagus. The middle part of the oesophagus was obtained from six slaughterhouse pigs. Four 3-mm-wide rings were serially cut from each oesophagus. Two of them were used for separating the wall into mucosa-submucosa, inner and outer muscle layers. The remaining two rings were kept as intact rings. The inner and outer circumferences and wall thickness of different layers in intact and separated rings were measured from the digital images in the no-load state and zero-stress state. The opening angle was measured and the residual strain at the inner and outer surface of different layers and the intact wall were computed. Compared with intact sectors (62.8+/-9.8 degrees ), the opening angles were smaller in the inner muscle sectors (37.2+/-11.4 degrees , P<0.01), whereas the opening angles of mucosa-submucosa (63.9+/-6.8 degrees ) and outer muscle sectors (63.9+/-6.8 degrees ) did not differ (P>0.1). Referenced to the zero-stress state of the intact sectors, the inner and outer residual strains of the intact rings was -0.128+/-0.043 and outer residual strain was 0.308+/-0.032. Referenced to the "true" zero-stress state of separated three-layered sectors, the inner residual strain of intact rings were -0.223+/-0.021 (P<0.01) and 0.071+/-0.022 (P<0.01). Referenced to the "true" zero-stress state, the residual strain distribution of different layers in intact rings was shown that the inner surface residual strain was negative at mucosa-submucosa and inner muscle layers and was positive at outer muscle layer, whereas the outer surface residual strain was negative at the mucosa-submucosa layer and positive at the inner and outer muscle layers. For the separated different layered rings, the inner residual strain was negative and outer residual strain was positive; however, the absolute values did not differ (P>0.1). In conclusion, it is possible to microsurgically separate the oesophagus into three layers, i.e., mucosa-submucosa, inner muscle and outer muscle layers, the residual strain differ between the layers, and the residual strain distribution was more uniform after the layers were separated.
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Affiliation(s)
- Jingbo Zhao
- Center of Excellence in Visceral Biomechanics and Pain, Aalborg Hospital Science and Innovation Center, Room 404, Aalborg Hospital, Søndre Skovvej 15, DK 9000 Aalborg, Denmark.
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