Mesentericoaxial Gastric volvulus with eventration of left hemidiaphragm

Gastric volvulus is abnormal rotation of the stomach of more than 180 degrees, creating closed loop obstruction.

Classification:

• on the axis of rotation (organo-axial, mesentero-axial or combined)
• on chronology (acute or chronic)
• extent (total or partial)
• direction (anterior or posterior)
• aetiology (secondary or idiopathic).

Secondary volvulus can be associated with paraesophageal hiatal hernias, eventration, trauma, and paralysis from phrenic nerve injury, gastric ulcer / neoplasm, extrinsic pressure from enlarged adjacent organs / masses, and abdominal adhesions.

Plain X-rays are the first imaging modality in a suspected case. Traditionally acute gastric volvulus was diagnosed on chest X-ray showing retrocardiac air bubble or large air-fluid level in the chest.

Upper GI series is the examination of choice for the diagnosis which shows the abnormal orientation of the stomach. It may show only a paraesophageal hernia or eventration of the diaphragm during a symptom-free interval.

There are ultrasound features described for diagnosis of gastric volvulus for eg the peanut sign in a case of chronic gastric volvulus. It consist s of a constricted segment of stomach with 2 dilated segments located above and below the constricted part.

The CT appearance of gastric volvulus is variable. The extent of diaphragmatic herniation, points of torsion, and final position of stomach determine the appearance.

The multiaxial reconstructions afforded by helical CT may be preferred to the images obtained with barium study, particularly in the acutely ill patient who is unable to tolerate a fluoroscopic examination.

Acute gastric volvulus is rare but needs to be diagnosed quickly to avoid life-threatening complications like ischaemic necrosis, haemorrhage and gangrene.