title: Shear modulus of elasticity of the esophagus.
abstract: Experimental and diagnostic procedures like distension of a balloon catheter, bougie, and esophagogastroduodenoscopy can induce shear deformation in the esophageal wall. However, the shear modulus of the esophagus is yet unknown. The aim of this study was to determine the esophageal shear modulus and its dependence on the circumferential and longitudinal stresses and strains in the rat. The constitutive equation including the shear deformation based on a pseudo-strain-energy function was generated. Results were obtained using a new triaxial instrument to perform simultaneous torsion, inflation, and longitudinal stretching tests. The shear modulus varied with the inflation pressure and the longitudinal stretch ratio. The shear modulus at the longitudinal stretch ratio of 1.5 and between inflation pressures of 0 and 2.0 kPa ranged from 5.43 to 185.01 kPa. The mechanical constant of the esophagus showed that the esophageal wall was anisotropic with different stiffness in the circumferential, longitudinal, and the shear directions. The stiffness in the longitudinal direction was higher than in the circumferential direction (P < 0.001). This test can be extended for further mechanical remodeling experiments and for other tubular organs such as the small intestine or blood vessels.
authors.affiliation: Center of Excellence in Visceral Biomechanics and Pain, Aalborg Hospital and Center of Sensory-Motor Interaction, Aalborg University, Aalborg, Denmark.
authors.forename: Jian
authors.initials: J
authors.lastname: Yang
authors.forename: Donghua
authors.initials: D
authors.lastname: Liao
authors.forename: Jingbo
authors.initials: J
authors.lastname: Zhao
authors.forename: Hans
authors.initials: H
authors.lastname: Gregersen
mesh_terms: D000818:Animals; D016880:Anisotropy; D003198:Computer Simulation; D004548:Elasticity; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004947:Esophagus / Q000502:physiology*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D008954:Models, Biological; D010808:Physical Examination / Q000295:instrumentation / Q000379:methods*; D010812:Physical Stimulation / Q000295:instrumentation / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D033081:Shear Strength; D013314:Stress, Mechanical