Archive for the 'Lower esophageal sphincter' Category

08 Jun

Evolving concepts of reflux: CAUSES FOR FAILURE OF THE GASTROESOPHAGEAL BARRIER Part 1

Transient losses of the barrier are most commonly seen in early reflux disease and are associated with gastric distention. The ingestion of air and food results in gastric distention, and the vectors produced by the gastric wall tension pull on the gastroesophageal junction. This causes the terminal esophagus to be ‘taken up’ into the stretched […]

07 Jun

Evolving concepts of reflux: SUMMARY

Almost all reflux episodes in normal subjects are precipitated by gastric distention. In patients, gastric distention from overeating and aerophagia is the cause of early GERD and remains an important but decreasing cause of reflux as the severity of the disease, reflected by the grade of esophagitis, worsens. The increased esophageal acid exposure in patients […]

05 Jun

Evolving concepts of reflux: CAUSES FOR FAILURE OF THE GASTROESOPHAGEAL BARRIER Part 4

Variations in the anatomy of the cardia, from a normal acute angle of His to the abnormal dome architecture of a sliding hiatal hernia, influences the ease with which the sphincter is shortened by gastric distention. Consequently, alteration in the geometry of the cardia facilitates the loss of barrier function. Greater gastric distention is necessary […]

04 Jun

Evolving concepts of reflux: CAUSES FOR FAILURE OF THE GASTROESOPHAGEAL BARRIER Part 3

For the clinician, the finding of a permanently defective barrier has several implications. Patients with this abnormality can be difficult to control with medical therapy. The damage is irreversible, and is commonly associated with reduced esophageal body contractility and abnormal wave progression. Under this condition, if reflux is not controlled, the progressive loss of effective […]

03 Jun

Evolving concepts of reflux: CAUSES FOR FAILURE OF THE GASTROESOPHAGEAL BARRIER Part 2

In advanced , permanent loss of sphincter length occurs from inflammatory injury that extends from the mucosa into the muscular layers of the distal esophagus. Fletcher et al showed that, in the fasting state, there is a persistent region of high acidity in the area of the gastroesophageal junction and that this region of acidity […]

29 May

Evolving concepts of reflux: PHYSIOLOGY OF THE GASTROESOPHAGEAL BARRIER Part 6

If a sphincter, in the fasting state, has abnormally low pressure, a short overall length or a minimal length exposure to the abdominal pressure environment, the result is a permanent loss of resistance and the unhampered reflux of gastric contents into the esophagus. This is known as a permanently defective sphincter and is identified by […]

28 May

Evolving concepts of reflux: PHYSIOLOGY OF THE GASTROESOPHAGEAL BARRIER Part 5

The observation that gastric distention results in shortening of the sphincter down to a critical length, so that the pressure dissipates, the lumen opens and reflux occurs, provides a mechanical explanation for ‘transient sphincter relaxation’ without invoking a neuromuscular reflex. If only the sphincter pressure and not its length is measured, as with a Dent […]

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