Mallory-Weiss syndrome is characterized by upper gastrointestinal bleeding secondary to longitudinal mucosal lacerations at the gastroesophageal junction or gastric cardia. The original description by Mallory and Weiss in 1929 involved patients with persistent retching and vomiting following an alcoholic binge. However, Mallory-Weiss syndrome may occur after any event that provokes a sudden rise in intragastric pressure or gastric prolapse into the esophagus.
A Mallory-Weiss tear (MWT) likely occurs as a result of a large, rapidly occurring, and transient transmural pressure gradient across the region of the gastroesophageal junction. Acute distension of the nondistensible lower esophagus can also produce a linear tear in this region.
With a rapid rise in intragastric pressure due to precipitating factors, such as retching or vomiting, the transmural pressure gradient increases dramatically across the hiatal hernia, which abuts a low intrathoracic pressure zone. If the shearing forces are high enough, a longitudinal laceration eventually occurs. Within the hernia, the tear is more likely to involve the lesser curvature of the gastric cardia, which is relatively immobile compared to the remainder of the stomach.
Another potential mechanism for MWTs is the violent prolapse or intussusception of the upper stomach into the esophagus, as can be witnessed during forceful retching at endoscopy.
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