Dimensions and Circumferential Stress-Strain Relation in the Porcine Esophagus in Vitro Determined by Combined Impedance Planimetry and High-Frequency Ultrasound

Jingbo Zhao; Claus Jørgensen; Donghua Liao
May 2007
Digestive Diseases & Sciences;May2007, Vol. 52 Issue 5, p1338
Academic Journal
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 15920 and 33825 mm2, respectively. In the same pressure range, the wall thickness decreased from 1.930.08 to 1.440.08 mm. The slope of the stress-strain curve was 2.580.35 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.


Related Articles

  • Effect of different swallow time intervals on the nutcracker esophagus. Brito, Eliza Maria; Camacho-Lobato, Luciana; Paoletti, Vera; Gideon, Mathew; Katz, Philip O.; Castell, Donald O. // American Journal of Gastroenterology;Jan2003, Vol. 98 Issue 1, p40 

    : ObjectiveNutcracker esophagus (NE) is defined as the presence of peristaltic contractions in which the average distal esophageal amplitude is greater than 180 mm Hg. The underlying mechanism responsible for these abnormalities is not known. The aim of this study was to test the hypothesis that...

  • An unusual cause of acute upper oesophageal obstruction. Hobbs, C.G.L. // Postgraduate Medical Journal;Jun2003, Vol. 79 Issue 932, p354 

    Presents images from an 85-year-old man with an acute upper esophageal obstruction. Posteroanterior chest radiograph; Water soluble contrast swallow.

  • A Novel Approach to Identify the Thermal Mechanism in High- and Low- Frequency Focused Ultrasound Thermal Ablation Process. Hao-Li Liu; Yung-Yaw Chen; Wen-Shiang Chen; Tzu-Ching Shih; Jhao-Syong Chen; Win-Li Lin // AIP Conference Proceedings;2007, Vol. 911 Issue 1, p144 

    The purpose of this study is to propose a novel approach to identify the thermal mechanism during the high- and low- frequency focused ultrasound thermal ablation process, and to verify that the occurrence of the ultrasound-induced macroscopically visible bubbles exert another key effect in...

  • Acute dissection of the thoracic aorta. Banning, Adrian P.; Ruttley, Michael S.T. // BMJ: British Medical Journal (International Edition);1/14/95, Vol. 310 Issue 6972, p72 

    Editorial. Focuses on transoesophageal echocardiography. Advantages over other diagnostic imaging techniques; Changing attitude about aortic surgery.

  • Emergency Medicine Reports: Basic Emergency Ultrasound-guided Procedures.  // Emergency Medicine Reports;2/14/2011 Supplement, p1 

    Photographs of several basic emergency ultrasound-guided procedures including high frequency linear array transducer, ultrasound of an abscess pocket, and ultrasound of the needle tip inside the bladder for a suprapubic aspiration are presented.

  • Noninvasive Transdermal Insulin Delivery Using Piston-Shaped PZT Transducers: In vivo Rabbits Evaluation. Al-Bataineh, Osama M.; Lweesy, Khaldon; Fraiwan, Luay // Jordan Journal of Mechanical & Industrial Engineering;Mar2012, Vol. 6 Issue 1, p11 

    No abstract available.

  • Power density requirement of a 4 MHz micro-ultrasonic transducer for sonodynamic therapy. Tung Siu; Mu Chiao // Biomedical Microdevices;Feb2008, Vol. 10 Issue 1, p89 

    Abstract  In this paper, we propose the use of micro-ultrasonic transducers (MUTs) for a therapeutic application in combination with a cancer drug. In particular, sonodynamic enhancement of doxorubicin cytotoxicity was investigated in vitro using human prostate cancer cells...

  • Energy-Based Adaptive Focusing of waves: Application to Ultrasonic Transcranial Therapy. Herbert, E.; Pernot, M.; Montaldo, G.; Tanter, M.; Fink, M. // AIP Conference Proceedings;4/14/2009, Vol. 1113 Issue 1, p8 

    We propose a general concept of adaptive focusing through complex media based on the estimation or measurement of the wave energy density at the desired focal spot. As it does not require the knowledge of phase information, this technique has many potential applications in acoustics and optics...

  • Endocavitary Ultrasound Applicator for Hyperthermia Treatment of Cervical Cancer. Wootton, Jeffery; Xin Chen; Juang, Titania; Rieke, Viola; Hsu, I-Chow Joe; Diederich, Chris // AIP Conference Proceedings;4/14/2009, Vol. 1113 Issue 1, p392 

    An endocavitary ultrasound applicator has been developed for targeted heat delivery to the cervix. The device has multiple sectored tubular transducers for truly 3-D heating control (angular and along the length) and is integrated with an intracavitary HDR brachytherapy applicator for sequential...


Read the Article


Sign out of this library

Other Topics