What is an Intrathoracic Stomach?
An intrathoracic stomach is a condition where the stomach, or a significant portion of it (typically >75%), herniates upward through the diaphragm into the thoracic cavity, most commonly through an enlarged hiatus or diaphragmatic defect. 1, 2
Anatomic Definition
- The term specifically refers to herniation of abdominal organs, particularly the stomach, into the thoracic cavity through a diaphragmatic defect 3
- This is typically defined as greater than 75% of the stomach being displaced into the chest on imaging studies 2
- The condition represents an advanced form of diaphragmatic hernia where the stomach becomes the predominant herniated organ 3, 1
Mechanisms of Development
The intrathoracic stomach develops through two primary pathways:
- Type IV paraesophageal hernia: Progressive enlargement of the hiatus allows the stomach to migrate upward alongside the esophagus 1, 4
- Traumatic or iatrogenic diaphragmatic defects: Can occur after blunt trauma, penetrating injury, or surgical procedures (nephrectomy, esophagogastrectomy, splenopancreatectomy, gynecologic surgery) 3, 5
Clinical Presentation
Patients with intrathoracic stomach are symptomatic in approximately 95% of cases, with predominantly obstructive symptoms rather than reflux: 1
- Postprandial pain occurs in 59% of patients 1
- Vomiting in 31% 1
- Dysphagia in 30% 1
- Gastroesophageal reflux symptoms are present in only 16% of cases 1
- Dyspnea (86%) and abdominal pain (17%) are common when associated with traumatic diaphragmatic hernias 3, 6
- Anemia develops in 21% of patients, with occasional melena from chronic gastric bleeding 1
Life-Threatening Complications
The most critical complication is acute gastric volvulus with potential strangulation and necrosis: 1, 5
- Gastric volvulus occurs when the intrathoracic stomach undergoes organoaxial torsion within the chest 5
- Strangulation can lead to gastric necrosis, perforation, severe peritonitis, sepsis, and multi-organ failure 3
- Emergency presentation with suspected strangulation carries significant mortality risk if untreated 3, 1
- However, actual gastric strangulation requiring emergency surgery is relatively rare, occurring in approximately 12.5% of acute presentations 1, 4
Diagnostic Imaging Findings
Chest X-ray demonstrates characteristic findings: 3, 6, 7, 5
- Abnormal bowel gas pattern in the thoracic cavity 3
- Air-fluid level in the lower lung fields 3, 5
- Elevated gastric bubble within the chest 5
CT scan with contrast is the gold standard for diagnosis: 3, 6
- Shows the distended stomach located in the hemithorax through a diaphragmatic defect 5
- Demonstrates diaphragmatic discontinuity and the "collar sign" 6
- CT has 14-82% sensitivity and 87% specificity for diaphragmatic hernias 6
Important Clinical Distinctions
The intrathoracic stomach must be distinguished from related conditions: 7