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Ineffective esophageal motility and the vagus: current challenges and future prospects

View Article: PubMed Central - PubMed

ABSTRACT

Ineffective esophageal motility (IEM) is characterized by low to very low amplitude propulsive contractions in the distal esophagus, hence primarily affecting the smooth muscle part of the esophagus. IEM is often found in patients with dysphagia or heartburn and is commonly associated with gastroesophageal reflux disease. IEM is assumed to be associated with ineffective bolus transport; however, this can be verified using impedance measurements or evaluation of a barium coated marshmallow swallow. Furthermore, water swallows may not assess accurately the motor capabilities of the esophagus, since contraction amplitude is strongly determined by the size and consistency of the bolus. The “peristaltic reserve” of the esophagus can be evaluated by multiple rapid swallows that, after a period of diglutative inhibition, normally give a powerful peristaltic contraction suggestive of the integrity of neural orchestration and smooth muscle action. The amplitude of contraction is determined by a balance between intrinsic excitatory cholinergic, inhibitory nitrergic, as well as postinhibition rebound excitatory output to the musculature. This is strongly influenced by vagal efferent motor neurons and this in turn is influenced by vagal afferent neurons that send bolus information to the solitary nucleus where programmed activation of the vagal motor neurons to the smooth muscle esophagus is initiated. Solitary nucleus activity is influenced by sensory activity from a large number of organs and various areas of the brain, including the hypothalamus and the cerebral cortex. This allows interaction between swallowing activities and respiratory and cardiac activities and allows the influence of acute and chronic emotional states on swallowing behavior. Interstitial cells of Cajal are part of the sensory units of vagal afferents, the intramuscular arrays, and they provide pacemaker activity to the musculature that can generate peristalsis in the absence of innervation. This indicates that a low-amplitude esophageal contraction, observed as IEM, can be caused by a multitude of factors, and therefore many pathways can be potentially explored to restore normal esophageal peristalsis.

No MeSH data available.


Illustration of the relationship between videofluoroscopic, manometric, impedance, and topographic representations of esophageal peristalsis.Notes: (A) Schematic drawing of placement of a combined manometry/intraluminal impedance monitoring system with five manometric side holes (SHs) spaced 4 cm apart and a 6 cm sleeve sensor placed just distal to the last manometric port. (B) Concurrent videofluoroscopic, manometric, and multichannel intraluminal impedance recordings of a 5 mL Renografin swallow that was completely cleared by one peristaltic sequence. (C) Comparison of conventional manometry obtained with a sleeve assembly as depicted in (A) and high-fidelity manometry with recording sites at 1 cm intervals displayed topographically as an isocontour plot. The standard manometric recordings are superimposed on the isocontour plot at axial locations corresponding to the equivalent portion of the high-fidelity manometry it represents. Reprinted from Gastroenterology. Vol 128(1). Pandolfino JE, Kahrilas PJ, American GA. AGA technical review on the clinical use of esophageal manometry. Pages:209–224. Copyright 2005, with permission from Elsevier.77
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f2-ceg-9-291: Illustration of the relationship between videofluoroscopic, manometric, impedance, and topographic representations of esophageal peristalsis.Notes: (A) Schematic drawing of placement of a combined manometry/intraluminal impedance monitoring system with five manometric side holes (SHs) spaced 4 cm apart and a 6 cm sleeve sensor placed just distal to the last manometric port. (B) Concurrent videofluoroscopic, manometric, and multichannel intraluminal impedance recordings of a 5 mL Renografin swallow that was completely cleared by one peristaltic sequence. (C) Comparison of conventional manometry obtained with a sleeve assembly as depicted in (A) and high-fidelity manometry with recording sites at 1 cm intervals displayed topographically as an isocontour plot. The standard manometric recordings are superimposed on the isocontour plot at axial locations corresponding to the equivalent portion of the high-fidelity manometry it represents. Reprinted from Gastroenterology. Vol 128(1). Pandolfino JE, Kahrilas PJ, American GA. AGA technical review on the clinical use of esophageal manometry. Pages:209–224. Copyright 2005, with permission from Elsevier.77

Mentions: At rest, the esophagus is quiet and a stimulus is required to generate motility. A bolus in the oropharyngeal region activates the swallowing center in the brain that initiates sequential vagally mediated contractions in the striated and the smooth muscle esophagus (Figure 2). A swallowed bolus triggers many sensory factors giving vagal input to the solitary nucleus that evokes peristalsis via vagal dorsal motor neurons to the smooth muscle part. The nucleus ambiguous houses the pattern generator for the striated esophagus. The bolus to be swallowed has to have minimal features; otherwise, the sensory coding produces an uncertain evaluation by the solitary nucleus and an inefficient swallow may result.17,18 An occasionally failed swallow-induced esophageal peristalsis in all or part of the esophagus is common in humans, in particular, with dry swallows.


Ineffective esophageal motility and the vagus: current challenges and future prospects
Illustration of the relationship between videofluoroscopic, manometric, impedance, and topographic representations of esophageal peristalsis.Notes: (A) Schematic drawing of placement of a combined manometry/intraluminal impedance monitoring system with five manometric side holes (SHs) spaced 4 cm apart and a 6 cm sleeve sensor placed just distal to the last manometric port. (B) Concurrent videofluoroscopic, manometric, and multichannel intraluminal impedance recordings of a 5 mL Renografin swallow that was completely cleared by one peristaltic sequence. (C) Comparison of conventional manometry obtained with a sleeve assembly as depicted in (A) and high-fidelity manometry with recording sites at 1 cm intervals displayed topographically as an isocontour plot. The standard manometric recordings are superimposed on the isocontour plot at axial locations corresponding to the equivalent portion of the high-fidelity manometry it represents. Reprinted from Gastroenterology. Vol 128(1). Pandolfino JE, Kahrilas PJ, American GA. AGA technical review on the clinical use of esophageal manometry. Pages:209–224. Copyright 2005, with permission from Elsevier.77
© Copyright Policy
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC5036831&req=5

f2-ceg-9-291: Illustration of the relationship between videofluoroscopic, manometric, impedance, and topographic representations of esophageal peristalsis.Notes: (A) Schematic drawing of placement of a combined manometry/intraluminal impedance monitoring system with five manometric side holes (SHs) spaced 4 cm apart and a 6 cm sleeve sensor placed just distal to the last manometric port. (B) Concurrent videofluoroscopic, manometric, and multichannel intraluminal impedance recordings of a 5 mL Renografin swallow that was completely cleared by one peristaltic sequence. (C) Comparison of conventional manometry obtained with a sleeve assembly as depicted in (A) and high-fidelity manometry with recording sites at 1 cm intervals displayed topographically as an isocontour plot. The standard manometric recordings are superimposed on the isocontour plot at axial locations corresponding to the equivalent portion of the high-fidelity manometry it represents. Reprinted from Gastroenterology. Vol 128(1). Pandolfino JE, Kahrilas PJ, American GA. AGA technical review on the clinical use of esophageal manometry. Pages:209–224. Copyright 2005, with permission from Elsevier.77
Mentions: At rest, the esophagus is quiet and a stimulus is required to generate motility. A bolus in the oropharyngeal region activates the swallowing center in the brain that initiates sequential vagally mediated contractions in the striated and the smooth muscle esophagus (Figure 2). A swallowed bolus triggers many sensory factors giving vagal input to the solitary nucleus that evokes peristalsis via vagal dorsal motor neurons to the smooth muscle part. The nucleus ambiguous houses the pattern generator for the striated esophagus. The bolus to be swallowed has to have minimal features; otherwise, the sensory coding produces an uncertain evaluation by the solitary nucleus and an inefficient swallow may result.17,18 An occasionally failed swallow-induced esophageal peristalsis in all or part of the esophagus is common in humans, in particular, with dry swallows.

View Article: PubMed Central - PubMed

ABSTRACT

Ineffective esophageal motility (IEM) is characterized by low to very low amplitude propulsive contractions in the distal esophagus, hence primarily affecting the smooth muscle part of the esophagus. IEM is often found in patients with dysphagia or heartburn and is commonly associated with gastroesophageal reflux disease. IEM is assumed to be associated with ineffective bolus transport; however, this can be verified using impedance measurements or evaluation of a barium coated marshmallow swallow. Furthermore, water swallows may not assess accurately the motor capabilities of the esophagus, since contraction amplitude is strongly determined by the size and consistency of the bolus. The “peristaltic reserve” of the esophagus can be evaluated by multiple rapid swallows that, after a period of diglutative inhibition, normally give a powerful peristaltic contraction suggestive of the integrity of neural orchestration and smooth muscle action. The amplitude of contraction is determined by a balance between intrinsic excitatory cholinergic, inhibitory nitrergic, as well as postinhibition rebound excitatory output to the musculature. This is strongly influenced by vagal efferent motor neurons and this in turn is influenced by vagal afferent neurons that send bolus information to the solitary nucleus where programmed activation of the vagal motor neurons to the smooth muscle esophagus is initiated. Solitary nucleus activity is influenced by sensory activity from a large number of organs and various areas of the brain, including the hypothalamus and the cerebral cortex. This allows interaction between swallowing activities and respiratory and cardiac activities and allows the influence of acute and chronic emotional states on swallowing behavior. Interstitial cells of Cajal are part of the sensory units of vagal afferents, the intramuscular arrays, and they provide pacemaker activity to the musculature that can generate peristalsis in the absence of innervation. This indicates that a low-amplitude esophageal contraction, observed as IEM, can be caused by a multitude of factors, and therefore many pathways can be potentially explored to restore normal esophageal peristalsis.

No MeSH data available.