scholarly journals Pressure morphology of the relaxed lower esophageal sphincter: the formation and collapse of the phrenic ampulla

2012 ◽  
Vol 302 (3) ◽  
pp. G389-G396 ◽  
Author(s):  
Monika A. Kwiatek ◽  
Frédéric Nicodème ◽  
John E. Pandolfino ◽  
Peter J. Kahrilas

This study aimed to apply novel high-resolution manometry with eight-sector radial pressure resolution (3D-HRM technology) to resolve the deglutitive pressure morphology at the esophagogastric junction (EGJ) before, during, and after bolus transit. A hybrid HRM assembly, including a 9-cm-long 3D-HRM array, was used to record EGJ pressure morphology in 15 normal subjects. Concurrent videofluoroscopy was used to relate bolus movement to pressure morphology and EGJ anatomy, aided by an endoclip marking the squamocolumnar junction (SCJ). The contractile deceleration point (CDP) marked the time at which luminal clearance slowed to 1.1 cm/s and the location (4 cm proximal to the elevated SCJ) at which peristalsis terminated. The phrenic ampulla spanned from the CDP to the SCJ. The subsequent radial and axial collapse of the ampulla coincided with the reconstitution of the effaced and elongated lower esophageal sphincter (LES). Following ampullary emptying, the stretched LES (maximum length 4.0 cm) progressively collapsed to its baseline length of 1.9 cm ( P < 0.001). The phrenic ampulla is a transient structure comprised of the stretched, effaced, and axially displaced LES that serves as a “yield zone” to facilitate bolus transfer to the stomach. During ampullary emptying, the LES circular muscle contracts, and longitudinal muscle shortens while that of the adjacent esophagus reelongates. The likely LES elongation with the formation of the ampulla and shortening to its native length after ampullary emptying suggest that reduction in the resting tone of the longitudinal muscle within the LES segment is a previously unrecognized component of LES relaxation.

1991 ◽  
Vol 261 (6) ◽  
pp. G974-G980 ◽  
Author(s):  
S. S. Harrington ◽  
W. J. Dodds ◽  
R. K. Mittal

The aim of this study was to characterize lower esophageal sphincter (LES) longitudinal muscle contraction during changes in LES pressure in opossums. LES pressure was used as a marker of LES circular muscle contraction. Longitudinal muscle contraction was measured by strain gauge transducers. For precise placement of the strain gauge on the LES, the high-pressure zone was identified using a manometric-laser illumination technique. Measurements were made during 1) spontaneous LES pressure fluctuations, 2) LES pressure changes induced by pharmacological agents, and 3) LES relaxation induced by vagal nerve stimulation. These studies show that 1) spontaneous LES pressure fluctuations correlated with spontaneous changes in LES longitudinal muscle contraction; 2) pharmacologically induced contraction and relaxation of LES pressure correlated with contraction and relaxation of LES longitudinal muscle, respectively; 3) a close temporal relationship existed between changes in LES longitudinal muscle contraction and LES pressure that occurred spontaneously or were induced pharmacologically; and 4) vagal stimulation caused LES longitudinal muscle contraction and LES pressure relaxation. We propose that LES longitudinal muscle may play a role in the modulation of intraluminal LES pressure.


2001 ◽  
Vol 281 (2) ◽  
pp. G533-G543 ◽  
Author(s):  
Y. F. Wang ◽  
E. E. Daniel

In the canine gastrointestinal tract, the roles that gap junctions play in pacemaking and neurotransmission are unclear. Using antibodies to connexin (Cx)43, Cx45, and Cx40, we determined the distribution of these connexins. Cx43 was present in all locations where structural gap junctions occur. Cx40 was also widely distributed in the circular muscle of the lower esophageal sphincter (LES), stomach, and ileum. Cx45 was sparsely distributed in circular muscle of the LES. In the interstitial cells of Cajal (ICC) networks of myenteric plexus, in the deep muscular and submuscular plexuses, sparse Cx45 and Cx40 immunoreactivity was present. In colon, immunoreactivity was found only in the myenteric and submuscular plexus and nearby circular muscle cells. No immunoreactivity was found in sites lacking structural gap junctions (longitudinal muscle, inner circular muscle of the intestine, and most circular muscle of the colon). Studies of colocalization of connexins suggested that in the ICC networks, some colocalization of Cx43 with Cx40 and/or Cx45 occurred. Thus gap junctions in canine intestine may be heterotypic or heteromeric and have different conductance properties in different regions based on different connexin compositions.


2015 ◽  
Vol 309 (5) ◽  
pp. G360-G367 ◽  
Author(s):  
Nirali Patel ◽  
Yanfen Jiang ◽  
Ravinder K. Mittal ◽  
Tae Ho Kim ◽  
Melissa Ledgerwood ◽  
...  

Esophageal axial shortening is caused by longitudinal muscle (LM) contraction, but circular muscle (CM) may also contribute to axial shortening because of its spiral morphology. The goal of our study was to show patterns of contraction of CM and LM layers during peristalsis and transient lower esophageal sphincter (LES) relaxation (TLESR). In rats, esophageal and LES morphology was assessed by histology and immunohistochemistry, and function with the use of piezo-electric crystals and manometry. Electrical stimulation of the vagus nerve was used to induce esophageal contractions. In 18 healthy subjects, manometry and high frequency intraluminal ultrasound imaging during swallow-induced esophageal contractions and TLESR were evaluated. CM and LM thicknesses were measured (40 swallows and 30 TLESRs) as markers of axial shortening, before and at peak contraction, as well as during TLESRs. Animal studies revealed muscular connections between the LM and CM layers of the LES but not in the esophagus. During vagal stimulated esophageal contraction there was relative movement between the LM and CM. Human studies show that LM-to-CM (LM/CM) thickness ratio at baseline was 1. At the peak of swallow-induced contraction LM/CM ratio decreased significantly (<1), whereas the reverse was the case during TLESR (>2). The pattern of contraction of CM and LM suggests sliding of the two muscles. Furthermore, the sliding patterns are in the opposite direction during peristalsis and TLESR.


2012 ◽  
Vol 302 (5) ◽  
pp. G542-G547 ◽  
Author(s):  
Eric Leslie ◽  
Valmik Bhargava ◽  
Ravinder K. Mittal

A subthreshold pharyngeal stimulus induces lower esophageal sphincter (LES) relaxation and inhibits progression of ongoing peristaltic contraction in the esophagus. Recent studies show that longitudinal muscle contraction of the esophagus may play a role in LES relaxation. Our goal was to determine whether a subthreshold pharyngeal stimulus induces contraction of the longitudinal muscle of the esophagus and to determine the nature of this contraction. Studies were conducted in 16 healthy subjects. High resolution manometry (HRM) recorded pressures, and high frequency intraluminal ultrasound (HFIUS) images recorded longitudinal muscle contraction at various locations in the esophagus. Subthreshold pharyngeal stimulation was induced by injection of minute amounts of water in the pharynx. A subthreshold pharyngeal stimulus induced strong contraction and caudal descent of the upper esophageal sphincter (UES) along with relaxation of the LES. HFIUS identified longitudinal muscle contraction of the proximal (3–5 cm below the UES) but not the distal esophagus. Pharyngeal stimulus, following a dry swallow, blocked the progression of dry swallow-induced peristalsis; this was also associated with UES contraction and descent along with the contraction of longitudinal muscle of the proximal esophagus. We identify a unique pattern of longitudinal muscle contraction of the proximal esophagus in response to subthreshold pharyngeal stimulus, which we propose may be responsible for relaxation of the distal esophagus and LES through the stretch sensitive activation of myenteric inhibitory motor neurons.


2020 ◽  
Vol 33 (Supplement_1) ◽  
Author(s):  
D Razia ◽  
L Giulini ◽  
R Bremner ◽  
S Mittal

Abstract   Peristaltic disorders of the esophageal body have been categorized according to how they appear on high-resolution manometry. Abnormalities in peristalsis may lead to abnormal esophageal clearance and dysphagia. The aim of our retrospective analysis was to study bolus transit patterns on barium esophagogram in patients with various grades of esophageal body peristalsis as diagnosed by high-resolution manometry. Methods After Institutional Review Board approval, we queried an esophageal center database to identify patients with normal lower esophageal sphincter parameters. Patients with jackhammer esophagus, esophageal spasm, previous foregut surgery, hiatal hernia, and fragmented peristalsis were excluded. Remaining patients were divided into 11 groups based on their percentages of normal swallows out of 10 swallows (0%–100% swallows normal, DCI &gt; 450 mmHg.s.cm). All previously obtained video esophagograms were re-evaluated in blinded fashion. Bolus transit time through the esophagus was measured in upright and prone positions, using live time stamps at the entry and exit of the bolus. ANOVA and χ2 were used. Results In total, 146 patients were included in the analysis. 73 (50%) were men. Mean age and body mass index were 58.4 ± 14.7 years and 22.8 ± 10.4 kg/m2, respectively. Bolus transit time in prone-position swallows increased in tandem with increases in number of abnormal swallows (11.3 ± 3.7, 22 ± 15.5, 29.5 ± 24.3, 42.7 ± 39.5, 42.4 ± 46.9, 64 ± 70.8, 59.4 ± 34.6, 58.8 ± 37.9, 110 ± 66.6, 83.2 ± 49.6 and 105.6 ± 72.5 seconds, p &lt; 0.0001) but no difference was noted in upright-position bolus transit time (p = 0.317). There was a dropoff in level of significance at Group 5 (60% swallows normal) compared to Group 11 (absent contractility), after which there were no inter-group differences (Fig. 1). Conclusion Bolus transit time in prone-position swallows progressively increases as percentage of normal swallows decreases. Further work associated with symptoms to define a cutoff between normal and ineffective peristalsis would be useful.


1989 ◽  
Vol 256 (3) ◽  
pp. G589-G597 ◽  
Author(s):  
H. P. Parkman ◽  
J. C. Reynolds ◽  
C. P. Ogorek ◽  
K. M. Kicsak

The purpose of this study was to determine the anatomic and physiological interactions between neuropeptide Y (NPY) and adrenergic transmitters at the feline lower esophageal sphincter (LES). Intraluminal pressures of the esophagus, LES, and gastric fundus were recorded in anesthetized cats. In a separate group of cats, gastroesophageal junctions were removed after locating the LES manometrically. Adjacent sections were stained with antibodies for NPY and tyrosine hydroxylase (TH). Indirect immunofluorescence revealed staining of TH- and NPY-like immunoreactive (LI) nerves in the circular muscle of the LES. Staining was also present for NPY-LI in longitudinal muscle, muscularis mucosa, periarterial nerves, and nerves and cell bodies of the myenteric plexus of the LES. In vivo, NPY produced a biphasic effect at the LES with an initial contraction (lasting approximately 30 s) followed by a relaxation (lasting approximately 3 min). NPY at the dose giving 50% of the maximum response (10(-6) g/kg) induced a contraction of 14.8 +/- 5.0 mmHg (P less than 0.05) followed by a decrease of basal LES pressure from 29.2 +/- 4.7 to 19.4 +/- 2.9 mmHg (P less than 0.01). Propranolol and phentolamine had no influence on either effect of NPY.(ABSTRACT TRUNCATED AT 250 WORDS)


1997 ◽  
Vol 272 (6) ◽  
pp. G1509-G1517 ◽  
Author(s):  
J. Liu ◽  
V. K. Parashar ◽  
R. K. Mittal

Lower esophageal sphincter (LES) pressure shows axial and circumferential asymmetry, the reasons for which are not clear. Our aim was to determine whether the muscle thickness and shape of the LES were the reasons for the axial and circumferential asymmetry in the LES pressure. High-frequency, catheter-based intraluminal ultrasonography was performed to obtain images of the human LES and esophagus. Station pull-through manometry was performed to record the axial and circumferential asymmetry of LES pressure. Circular and longitudinal muscle were thicker in the LES compared with in the esophagus. There was a close correlation between the axial asymmetry in LES pressure and circular muscle thickness. The thickness of LES muscle increased and decreased with an increase and decrease in the LES pressure, respectively. The circumferential asymmetry in resting LES pressure was related to the noncircular shape of the LES. A swallow-induced LES relaxation was followed by its contraction. During the contraction phase, the LES and esophagus showed relative symmetry in pressure and shape. We conclude that the axial asymmetry of LES pressure is explained by its muscle thickness. On the other hand, circumferential asymmetry is related to the noncircular shape of the LES.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kazumasa Muta ◽  
Eikichi Ihara ◽  
Shohei Hamada ◽  
Hiroko Ikeda ◽  
Masafumi Wada ◽  
...  

AbstractThe preparatory accommodation response of lower esophageal sphincter (LES) before swallowing is one of the mechanisms involved in LES relaxation during wet swallows, however, the physiological and/or pathological roles of LES accommodation remain to be determined in humans. To address this problem, we conducted a prospective observational study of 38 patients with normal high-resolution manometry (HRM) and 23 patients with idiopathic esophagogastric junction outflow obstruction (EGJOO) to assess dry and wet swallows. The LES accommodation measurement was proposed for practical use in evaluating the LES accommodation response. Although swallow-induced LES relaxation was observed in both dry and wet swallows, LES accommodation (6.4, 3.1–11.1 mmHg) was only observed in wet swallows. The extent of LES accommodation was impaired in idiopathic EGJOO (0.6, − 0.6–6 mmHg), and the LES accommodation measurement of patients with idiopathic EGJOO (36.8, 29.5–44.3 mmHg) was significantly higher in comparison to those with normal HRM (23.8, 18–28.6 mmHg). Successful LES relaxation in wet swallowing can be achieved by LES accommodation in combination with swallow-induced LES relaxation. Impaired LES accommodation is characteristic of idiopathic EGJOO. In addition to the IRP value, the LES accommodation measurement may be useful for evaluating the LES relaxation function in clinical practice.


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