Volume (3-dimensional) space-time reconstruction of esophageal peristaltic contraction by using simultaneous US and manometry

Dai, Qing; Liu, Ji‐Bin; Brasseur, James G.; Thangada, Vinod K.; Thomas, Beje; Parkman, Henry P.; Miller, Larry S.

doi:10.1016/s0016-5107(03)02298-3

Cited by 10 publications

(8 citation statements)

References 12 publications

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“…They report results essentially equivalent to the thickness and pressure results in Figure 8, showing an increase and decrease in muscle thickness surrounding the pressure as in Figure 8. In a more recent study, Dai et al [21] showed that the time period of circular muscle contraction with bolus transport through the esophageal body, as inferred from the duration of the peristaltic pressure, is strongly correlated to the time period of longitudinal muscle contraction as inferred from LLS (r = 0.92), further confirming the integration of longitudinal and smooth muscle contraction in esophageal peristalsis.…”

Section: Related Observationsmentioning

confidence: 84%

Function of longitudinal бvs�� circular muscle fibers in esophageal peristalsis, deduced with mathematical modeling

Brasseur

Nicosia²,

Pal³

et al. 2007

WJG

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Section: Related Observationsmentioning

confidence: 84%

Function of longitudinal бvs�� circular muscle fibers in esophageal peristalsis, deduced with mathematical modeling

Brasseur

Nicosia²,

Pal³

et al. 2007

WJG

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“…The significance of this liquid layer will be discussed at length in RESULTS and DISCUSSION. A "base resting state" of the GES was defined using mean anatomical measurements from in vivo studies of the resting state in normal controls. The resting state thickness of the combined mucosal layers was approximated as 2 mm and was constant along the lumen (6,9,39,57). The axial variations in muscle wall thickness that were used in the model (see Fig.…”

Section: The Anatomical Modelmentioning

confidence: 99%

Liquid in the gastroesophageal segment promotes reflux, but compliance does not: a mathematical modeling study

Ghosh¹,

Kahrilas

Brasseur³

2008

American Journal of Physiology-Gastrointestinal and Liver Physi

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Ghosh SK, Kahrilas PJ, Brasseur JG. Liquid in the gastroesophageal segment promotes reflux, but compliance does not: a mathematical modeling study. Am J Physiol Gastrointest Liver Physiol 295: G920 -G933, 2008. First published August 21, 2008 doi:10.1152/ajpgi.90310.2008.-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. gastroesophageal reflux disease; lower esophageal sphincter; compliance; stiffness MUCH IS UNDERSTOOD ABOUT THE biomechanics underlying gastroesophageal reflux once refluxate flow into the esophagus has occurred, such as sphincter relaxation pressures (21), transsphincteric pressure gradient (46), hiatal distension (25), and the proximal extent of reflux (11). However, the mechanical differences that distinguish normal from chronic reflux are those that manifest at the time of opening and the initiation of reflux; these are less well understood. This lack of understanding of the initiation process is primarily because the initial opening process involves a level of mechanical subtlety in the balances among multiple forces and muscle deformations that are difficult to measure accurately in vivo due to rapid changes occurring over very short times with small changes in radial distention.The opening of the gastroesophageal segment (GES) and reflux result from dynamic adjustments in the subtle force balance that are initi...

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“…Phase 1 was the resting phase, which occurred before the bolus reached the ultrasound transducer ( fi g. 7,8 ). During phase 1, the circular and longitudinal smooth muscle appeared as thin circumferential hypoechoic bands separated by a thin hyperechoic intramuscular connective tissue.…”

Section: Esophageal Body and Peristaltic Contractionmentioning

confidence: 99%

“…Dai et al [8] developed a technique in which 3-dimensional (space-time) reconstructions were acquired during peristaltic contraction. Two-dimensional ultrasound images were reconstructed in 3-dimensional space-time plots with time as the X-axis variable.…”

Section: Esophageal Body and Peristaltic Contractionmentioning

confidence: 99%

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Use of Endoluminal Ultrasound to Evaluate Gastrointestinal Motility

Miller¹,

Dai²,

Korimilli³

et al. 2006

Dig Dis

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The use of high-frequency ultrasound transducers in the gastrointestinal tract (GI) has already yielded remarkable findings concerning the anatomy, physiology and pathophysiology of the GI tract and of various motility disorders. These transducers have made completely invisible portions of the GI tract (the longitudinal smooth muscle, muscles of the upper esophageal sphincter, components of the gastroesophageal junction high-pressure zone, and the muscle of the anal sphincter complex) accessible to investigation. Use of simultaneous ultrasound and manometry has allowed the exploration of the normal physiology of peristaltic contraction. The components of the high-pressure zone of the distal and proximal esophagus have been isolated and the movement of these components has been studied individually and as a group. Various esophageal motility disorders have been investigated including achalasia, scleroderma, Barrett’s esophagus and diffuse esophageal spasm. The possible etiology of the symptoms of esophageal chest pain and heartburn (sustained esophageal contractions of the longitudinal smooth muscle), have been studied. The possible underlying pathophysiology of GERD (the missing gastric clasp and sling fiber pressure profile) has been explored. Three-dimensional high-frequency ultrasound imaging has allowed the peristaltic contraction sequence to be viewed in a completely new and unique manner. The biomechanics of both esophageal contraction and the gastroesophageal junction high-pressure zone have been investigated and the mechanical advantage of esophageal shorting has been studied. The mechanism of action of standard surgical and newer endoscopic therapies for GERD has been defined. Future applications of this technology are limited only by our imagination.

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Volume (3-dimensional) space-time reconstruction of esophageal peristaltic contraction by using simultaneous US and manometry

Cited by 10 publications

References 12 publications

Function of longitudinal бvs�� circular muscle fibers in esophageal peristalsis, deduced with mathematical modeling

Function of longitudinal бvs�� circular muscle fibers in esophageal peristalsis, deduced with mathematical modeling

Liquid in the gastroesophageal segment promotes reflux, but compliance does not: a mathematical modeling study

Use of Endoluminal Ultrasound to Evaluate Gastrointestinal Motility

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