Mechanisms protecting against gastro-oesophageal reflux: a review

Atkinson, Michael

doi:10.1136/gut.3.1.1

Cited by 28 publications

(10 citation statements)

References 88 publications

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“…It has long been proposed that an acute angle of insertion between the oesophagus and the proximal stomach (‘angle of His’ in surgical studies) may contribute to reflux protection . However, the data used to support this view was acquired in anatomic preparations or using invasive methodology such as endoscopy that disturbs normal physiology .…”

Section: Introductionmentioning

confidence: 99%

Effects of baclofen on the functional anatomy of the oesophago-gastric junction and proximal stomach in healthy volunteers and patients with GERD assessed by magnetic resonance imaging and high-resolution manometry: a randomised controlled double-blind st

Curcic

Schwizer

Kaufman

et al. 2014

Aliment Pharmacol Ther

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Summary Background The mechanism of reflux protection may involve a ‘flap valve’ at the oesophago‐gastric junction (OGJ). Aim To assess the effects of baclofen, a gamma‐aminobutyric acid receptor type‐B (GABA‐B) agonist known to suppress reflux events, on the ‘functional anatomy’ of the OGJ and proximal stomach after a large test meal. Methods Twelve healthy volunteers (HVs) and 12 patients with gastro‐oesophageal reflux disease (GERD); with erosive oesophagitis or pathological oesophageal acid exposure completed a randomised, double‐blind, cross‐over study. On 2 test days participants received 40‐mg baclofen or placebo before ingestion of a large test meal. OGJ structure and function were assessed by high‐resolution manometry (HRM) and magnetic resonance imaging (MRI) using validated methods. Measurements of the oesophago‐gastric angle were derived from three‐dimensional models reconstructed from anatomic MRI images. Cine‐MRI and HRM identified postprandial reflux events. Mixed model analysis and Wilcoxon rank signed tests assessed differences between participant groups and treatment conditions. Results In both HVs and GERD patients, baclofen reduced the frequency of postprandial reflux events. The oesophago‐gastric insertion angle in GERD patients was reduced (−4.1 ± 1.8, P = 0.025), but was unchanged in healthy controls. In both study groups, baclofen augmented lower oesophageal sphincter (LES) pressure (HVs: +7.3 ± 1.8 mmHg, P < 0.0001, GERD: +4.50 ± 1.49 mmHg, P < 0.003) and increased LES length (HVs: +0.48 ± 0.11 cm, P < 0.0003, GERD: +0.35 ± 0.06 cm, P < 0.0001). Conclusions Baclofen inhibits transient LES relaxations and augments LES pressure and length. Additionally, baclofen has effects on the ‘functional anatomy’ of the OGJ and proximal stomach in GERD patients, which may suppress reflux by means of a ‘flap valve’ mechanism.

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Section: Introductionmentioning

confidence: 99%

Effects of baclofen on the functional anatomy of the oesophago-gastric junction and proximal stomach in healthy volunteers and patients with GERD assessed by magnetic resonance imaging and high-resolution manometry: a randomised controlled double-blind st

Curcic

Schwizer

Kaufman

et al. 2014

Aliment Pharmacol Ther

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“…The explanation of the upward shift offered above becomes untenable if the data plotted against the beginning of the high pressure zone are taken into consideration. The high pressure zone is thought to denote the lower oesophageal sphincter (Atkinson, 1962;Code, Creamer, Schlegel, Olsen, Donoghue, and Andersen, 1958) and the transition zone, the mucosal oesophagogastric junction (Meckeler and Ingelfinger, 1967). When a hiatus hernia moves up into the chest, theoretically the mucosal oesophagogastric junction and the lower oesophageal sphincter should move in parallel.…”

Section: Discussionmentioning

confidence: 99%

Transmural potential difference in patients with hiatus hernia and oesophageal ulcer.

Beck¹,

Hernandez²

1969

Gut

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Recordings of transmural potential difference (PD) in the stomach have well established that the mucosal surface of this organ is negative in relation to the serosal surface (Rehm, 1946;Revelstad, Owen, and Magath, 1952). On the other hand, it had been noted that the oesophagus has a positive transmural potential difference (Helm, Schlegel, Code, and Summerskill, 1965). The potential difference transition zone from negative to positive values was shown to represent the mucosal transition from acid-bearing to columnar and from columnar to oesophageal mucosa (Meckeler and Ingelfinger, 1967). Utilizing an improved method of recording transmural potential difference (Hernandez and Beck, 1968), we reexamined the characteristics of the potential difference transition zone in normal individuals and in patients suffering from hiatus hernia. In addition, we explored the variations in potential difference which occur over lesions where the mucosal integrity of the oesophagus was destroyed by ulcerations. METHODS RECORDING OF POTENTIAL DIFFERENCE SIMULTANEOUSLYWITH OESOPHAGEAL PRESSURE MEASUREMENTS ('PULL-THROUGH METHOD') Oesophageal pressure and potential difference were measured by a technique previously described and evaluated (Hernandez and Beck, 1968), and measurements of pressure changes were based on the method of Winans and Harris (1967). The main features of the combined method are depicted in Figure 1.For both the pressure and the potential difference recording, Ringer's solution (Na+ = 147 m-equiv/l; K+ = 4 m-equiv/l; Ca++ 4.5 m-equiv/l and Cl-= 156 m-equiv/1 was infused at a rate of 0-382 ml/min. The 50 ml plastic syringes were filled through a three-way plastic stopcock (SC) and placed into a Harvard pump2 (HP) which slowly advanced the plungers. Three of the

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“…The distal portion (approximately 2 cm) of the oesophagus is thought to act as a valve. This portion of the oesophagus is within the abdominal cavity, and thus any increase in intra‐abdominal pressure will be transmitted equally to the stomach and the intra‐abdominal oesophagus 26, 27 . Thus, as long as the LOS maintains an intraluminal pressure increment greater than intragastric pressure, the reflux barrier is maintained. The phrenoesophageal ligament inserts circumferentially into the oesophageal musculature close to the squamo‐columnar junction, 16 and contributes to the competence of the GOJ 28, 29 .…”

Section: Oesophageal Anatomy and Physiology In Normal Subjectsmentioning

confidence: 99%

The role of the hiatus hernia in gastro‐oesophageal reflux disease

Gordon¹,

Kang²,

Neild³

et al. 2004

Aliment Pharmacol Ther

163

130

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A sliding hiatus hernia disrupts both the anatomy and physiology of the normal antireflux mechanism. It reduces lower oesophageal sphincter length and pressure, and impairs the augmenting effects of the diaphragmatic crus. It is associated with decreased oesophageal peristalsis, increases the cross-sectional area of the oesophago-gastric junction, and acts as a reservoir allowing reflux from the hernia sac into the oesophagus during swallowing. The overall effect is that of increased oesophageal acid exposure. The presence of a hiatus hernia is associated with symptoms of gastrooesophageal reflux, increased prevalence and severity of reflux oesophagitis, as well as Barrett's oesophagus and oesophageal adenocarcinoma. The efficacy of treatment with proton pump inhibitors is reduced. Our view on the significance of the sliding hiatus hernia in gastrooesophageal reflux disease has changed enormously in recent decades. It was initially thought that a hiatus hernia had to be present for reflux oesophagitis to occur. Subsequently, the hiatus hernia was considered an incidental finding of little consequence. We now appreciate that the hiatus hernia has major patho-physiological effects favouring gastro-oesophageal reflux and hence contributing to oesophageal mucosal injury, particularly in patients with severe gastro-oesophageal reflux disease.

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Mechanisms protecting against gastro-oesophageal reflux: a review

Cited by 28 publications

References 88 publications

Effects of baclofen on the functional anatomy of the oesophago-gastric junction and proximal stomach in healthy volunteers and patients with GERD assessed by magnetic resonance imaging and high-resolution manometry: a randomised controlled double-blind st

Effects of baclofen on the functional anatomy of the oesophago-gastric junction and proximal stomach in healthy volunteers and patients with GERD assessed by magnetic resonance imaging and high-resolution manometry: a randomised controlled double-blind st

Transmural potential difference in patients with hiatus hernia and oesophageal ulcer.

The role of the hiatus hernia in gastro‐oesophageal reflux disease

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