Excerpt from Gastric Volvulus

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Background

Gastric volvulus (Latin volvere, to roll) is rotation of all or part of the stomach by more than 180º, which may lead to a closed-loop obstruction and possible strangulation.

Symptoms may range from mild abdominal pain and vomiting, when no or partial outlet obstruction is present, to severe pain and retching, when there is complete obstruction and ischemia.

For excellent patient education resources, visit eMedicine's Esophagus, Stomach, and Intestine Center. Also, see eMedicine's patient education articles Abdominal Pain in Adults and Barium Swallow .

Pathophysiology

Gastric volvulus is classified on the basis of its location in reference to the diaphragm and on the basis of the axis of rotation.

Subdiaphragmatic, or primary, volvulus accounts for approximately one third of cases, and it is not associated with diaphragmatic defects.

Supradiaphragmatic, or secondary, volvulus accounts for approximately two thirds of cases, and it is associated with diaphragmatic defects. Predisposing factors occur with this type of volvulus in more than 50% of cases and include paraesophageal hiatal hernias, diaphragmatic eventration, diaphragmatic trauma, diaphragmatic paralysis from phrenic nerve injury, gastric ulcer or neoplasm, extrinsic pressure from enlarged adjacent organs or masses, and abdominal adhesions.

Gastric volvulus is also classified on the basis of its axis of rotation. In the more common, organoaxial volvulus (59% of cases), the stomach rotates on its longitudinal axis. This axis is defined as the line connecting the cardia and pylorus. The greater curvature moves from an inferior to a superior position. Compared with the other types of gastric volvulus, organoaxial volvulus is more commonly associated with strangulation. Because of the rich vascular supply of the stomach, strangulation occurs in only 5-28% of cases.

In mesenteroaxial volvulus (29% of cases), the stomach rotates about a vertical axis passing through the middle of the greater and lesser curvatures. The pylorus moves anteriorly and superiorly, whereas the greater curvature remains inferior. Mesenteroaxial volvulus is more often seen in young children and is associated with ligamentous laxity but not with diaphragmatic defects.

In both of these classifications, the configuration of the stomach may be characterized as upside down. The remaining cases demonstrate features of organoaxial and mesenteroaxial volvulus (2%), or they are unclassified (10%).

Mortality/Morbidity

The mortality rate for acute gastric volvulus is reportedly 42-56%. The mortality rate for chronic gastric volvulus is 10-13%.

Reported complications include the following:

• Ulceration
• Perforation
• Hemorrhage
• Pancreatic necrosis
• Omental avulsion
• Splenic rupture

Race

No racial predilection is reported.

Sex

Generally, the prevalence rates are considered equal in males and females. However, at least 1 study shows a female predilection.

Age

Gastric volvulus occurs in persons of any age, although the incidence peaks in those aged 40-50 years. Approximately 20% of cases occur in infants younger than 1 year.

Anatomy

The primary and secondary forms of gastric volvulus are associated with laxity of the supporting structures of the stomach. The gastrophrenic, gastrohepatic, gastrosplenic, and gastrocolic ligaments hold the stomach in place at the esophageal hiatus and pylorus. These ligaments allow significant gastric mobility but normally never permit more than 180º of rotation. Typically, laxity increases with age, and it may be more common in females than in males. In neonates, these ligaments may be absent or abnormally loose, resulting in volvulus. In the older child, gastric distention with air or fluid as a result of pyloric hypertrophy, pyloric stenosis, or air swallowing may cause ligamentous laxity and volvulus.

Clinical Details

The signs and symptoms of gastric volvulus depend on the condition's type (primary or secondary) and chronicity, as well as the degree of obstruction.

Chronic volvulus may be detected incidentally on plain chest radiographs or on upper gastrointestinal (GI) series. Symptoms and signs include the following:

• Vague, intermittent abdominal pain
• Chest pain in secondary cases
• Early satiety
• Upper abdominal fullness
• Dysphagia
• Dyspnea
• Obstructive jaundice
• Bowel sounds in the chest

Acute cases represent a surgical emergency. Typical symptoms and signs are described by noting the Borchardt triad:

• Severe upper abdominal pain and distention
• Violent retching with an inability to vomit
• Inability to pass a nasogastric tube into the stomach

Preferred Examination

The definitive diagnosis of gastric volvulus resides with the radiologist. Typically, the first examination to be performed in the patient with symptoms referable to the chest and/or abdomen is a plain radiograph. Although this is a good examination to start with, the most definitive study is the upper GI barium study.

Limitations of Techniques

Plain radiography may demonstrate findings that are indistinguishable from those that are produced by other causes of gastric atony or obstruction. However, the modality is useful for excluding other causes of the patient's symptoms, such as pneumoperitoneum or pneumothorax.

Barium study is highly sensitive and specific. However, the diagnosis may be missed in cases of intermittent torsion.

Fiberoptic endoscopy has a limited role in the diagnosis of gastric volvulus because the twist precludes passage of the endoscope.

Laboratory studies are generally unrewarding, although levels of amylase and alkaline phosphatase may be increased.

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