In the surgical literature, hiatal hernias are divided into three or four types (Fig. 1A, 1B, 1C, 1D). The intrathoracic stomach may be found in paraesophageal hiatal hernias (types 2–4) [4]. The paraesophageal hiatal hernia (types 2–4) is an uncommon disorder, representing approximately 5% of all hernias occurring through the esophageal hiatus. An intrathoracic stomach results from a paraesophageal hiatal hernia in which a substantial portion of the stomach has herniated into the chest (Fig. 2A, 2B, 2C).

As the stomach herniates into the chest, it also rotates (Fig. 2A, 2B, 2C). The most common rotation is an anterior organoaxial rotation. In an organoaxial rotation, the stomach rotates along its longitudinal axis. The more mobile, greater curvature moves first in the anterior and then in the cephalad direction (Fig. 2B and 3A, 3B). As the herniation progresses, the more distal parts of the stomach and even the pylorus become involved in the rotation and intrathoracic displacement. Much less frequently, the organoaxial rotation may be in a posterior direction (Fig. 9A, 9B, 9C, 9D).

The stomach can rotate along an axis that is 90° to the longitudinal axis. Such rotation is called a mesenteroaxial rotation (Figs. 2C and 4A, 4B, 4C, 4D, 4E, 4F). This rotation may lead to an upside-down stomach. Mesenteroaxial rotation of an intrathoracic stomach is less common than organoaxial rotation. Mesenteroaxial rotation is more frequently seen in patients with progression of a type 2 paraesophageal hiatal hernia.

The term “gastric volvulus” is reserved for cases in which the abnormal rotation has led to strangulation and obstruction [5].

Symptoms of a paraesophageal hernia vary significantly from the more common sliding hiatal hernia. Patients with a small paraesophageal hernia are usually asymptomatic. True dysphagia is usually not a presenting symptom, and symptoms of reflux esophagitis are uncommon. As the disease progresses, food and air may distend the herniated gastric segment. This distention causes discomfort and chest pain that is usually most marked after a meal [6]. Belching and retching may lessen and relieve this discomfort. These symptoms may mimic angina and myocardial infarction. With a large herniation, respiratory symptoms may be prominent, especially postprandially. This is brought about by compression of the lung and, in the mediastinum, by the filled intrathoracic stomach [4, 7]. Anemia from occult bleeding gastric ulcerations in the herniated stomach may be a presenting clinical feature [7]. Other serious gastric complications are less common and include volvulus, gangrene, perforation, and recurrent pneumonia [6, 8].

Hiatal hernias are frequently incidentally noted on conventional radiography or CT performed for other reasons. Although a single fluid level on a radiograph with the patient in the upright position merely indicates the presence of a hiatal hernia, the presence of an intrathoracic stomach with organoaxial or mesenteroaxial rotation can be suggested if a retrocardiac “double fluid level” sign is seen [9] (Fig. 9A, 9B, 9C, 9D). Multiplanar reconstruction of CT images may aid in characterizing the herniation. No convincing data exist as to how to work up incidentally noted hiatal hernias. However, images from an upper gastrointestinal barium series best display the anatomy and are usually required if surgical intervention is considered.

Esophagoscopy plays only a minor part in the diagnosis of paraesophageal hernia [4]. Esophageal shortening may be suggested by the presence of strictures in patients with chronic inflammation such as Barrett's esophagus. However, in the absence of such findings, esophageal shortening is difficult to predict.

The most serious complication of paraesophageal hernia is when the low-grade obstruction progresses to incarceration and strangulation of the stomach. This develops when the rotation of the herniated stomach leads to volvulus or when the distended fundus prolapses into the abdomen (Fig. 10A, 10B, 10C, 10D). With further gastric distention, several obstruction points develop. Thus, one may encounter obstruction of the esophagus, the mid portion of the stomach, and the duodenum, all at the level of the diaphragmatic hiatus. An abdominal radiograph will show the enormously dilated gastric fundus, and the dilated antrum can be detected on a radiograph of the chest. If this closed loop is not promptly treated, it will progress to strangulation of the stomach [6]. Patients with such obstruction are in severe distress and will present with chest pain and retching but will be unable to vomit, and it may not be possible to pass a nasogastric tube. This constellation of symptoms is known as Borchardt's triad [10]. The presence of a retrocardiac double fluid level sign usually indicates the presence of an intrathoracic stomach with chronic volvulus but does not indicate the presence of obstruction.

The treatment of a symptomatic patient with an intrathoracic stomach is usually surgery. If obstruction occurs, emergent surgery is indicated. Because of the high morbidity and mortality rates that accompany complications, some surgeons advocate elective surgery for asymptomatic patients if no other medical disorders or contraindications are present [8, 10]. Operative approaches may be either through the abdomen or by a thoracotomy. The open laparotomy approach has long been the standard, but more recently the laparoscopic repair of these hernias has been refined and increasingly used [10]. The general principles of repair include reduction of the hernia into the abdomen, excision of the hernia sac, closure of the large diaphragmatic hiatus, and gastropexy. The results of elective repair of paraesophageal hernias or intrathoracic stomach are generally good, with low morbidity and mortality rates [7, 10].

Paraesophageal hernias are a common finding in diagnostic imaging studies; yet the recognition of such hernias is important because morbidity and even mortality may be avoided if the symptomatic patient is directed to surgery before life-threatening complications occur.

Address correspondence to S. Abbara.