tension gastrothorax

Tension gastrothorax describes a rare life-threatening condition caused by mediastinal shift due to a distended stomach herniating into the thorax through a diaphragmatic defect.

Clinical presentation

Presentation is generally with acute and severe respiratory failure, with clinical features such as dyspnea, chest pain, and tachycardia being common . Case reports commonly detail clinical progression into shock and cardiac arrest .

Pathology

Tension gastrothorax requires a left-sided diaphragmatic defect to exist, and thus occurs in two different patient populations:

The pathophysiology is thought to be due to an instance of significantly increased intra-abdominal pressure (e.g. blunt trauma, Valsalva maneuver, pregnancy) which results in herniation of the stomach through the left-sided diaphragmatic defect into the thorax . The exact mechanism of how or when this herniated stomach becomes rapidly filled with air is unclear, but potentially an abnormally positioned gastro-esophageal junction that prevents belching may be the trigger for the formation of a one-way valve and therefore resultant tension gastrothorax .

Similarly to a tension pneumothorax, this air collection can grow and expand until it exerts a positive mass effect on the mediastinum, eventually resulting in respiratory and cardiac arrest .

Radiographic features

Plain radiograph

Chest radiographs demonstrate a large air-filled lucent structure in the left hemithorax causing contralateral mediastinal shift . In differentiating it from a tension pneumothorax, the following are useful:

  • the left hemidiaphragm is poorly defined
  • there may be a fluid level in the left hemithorax
  • lack of a gastric bubble
CT/MRI

These cross-sectional modalities will allow the best visualization of the tension gastrothorax, but are rarely available in an emergency situation .

Treatment and prognosis

Prompt management with nasogastric tube insertion to decompress the stomach is necessary to prevent further clinical deterioration . The patient’s diaphragmatic defect should then be surgically repaired once stable .

History and etymology

The term 'gastrothorax' was first used in the literature by American emergency physician Gary Ordog and his colleagues in 1984 in the context of a tension gastrothorax occurring after trauma .