A hiatal hernia occurs when a portion of the stomach prolapses through the diaphragmatic esophageal hiatus. Most hiatal hernias are asymptomatic and are discovered incidentally, but rarely, a life-threatening complication may present acutely. The image below depicts a paraesophageal hiatal hernia.
Most people with hiatal hernias are asymptomatic. In a minority of individuals, hiatal hernias may predispose to reflux or worsen existing reflux.
Complications of hiatal hernia may include the following:
The physical examination usually is unhelpful. Certain conditions may predispose to the development of hiatal hernia, including the following:
Diaphragmatic hernias may be congenital or acquired. Acquired hiatal hernias are divided further into nontraumatic (more common) and traumatic hernias. Nontraumatically acquired hernias are divided yet further into 2 types: (1) sliding hiatal hernia and (2) paraesophageal hiatal hernia (a mixed variety is also possible).
See Presentation for more detail.
The typical reason for evaluation is the presence of symptoms of gastroesophageal reflux disease (GERD) or a chest radiograph suggesting a paraesophageal hernia.
A barium upper gastrointestinal series may yield the following findings:
A barium study also helps distinguish a sliding from a paraesophageal hernia.
Upper GI endoscopy may be performed for the following purposes:
See Workup for more detail.
When symptoms are due to GERD, treatment goals include the following:
In the majority of patients, these goals are achieved by means of a combination of the following:
If iron-deficiency anemia occurs, it usually responds well to proton-pump inhibitor (PPI) therapy.
Surgical treatment involves removing the hernia sac and closing the abnormally wide esophageal hiatus. It is necessary only in the very few patients who have complications of GERD despite aggressive PPI treatment. Potential surgical candidates include the following:
The 3 major types of surgical procedures that may be considered are as follows:
A hiatal hernia occurs when a portion of the stomach prolapses through the diaphragmatic esophageal hiatus. Although the existence of hiatal hernia has been described in earlier medical literature, it has come under scrutiny only in the last century or so because of its association with gastroesophageal reflux disease (GERD) and its complications. There is also an association between obesity and the presence of hiatal hernia. By far, most hiatal hernias are asymptomatic and are discovered incidentally. On rare occasion, a life-threatening complication, such as gastric volvulus or strangulation, may present acutely.
The esophagus passes through the diaphragmatic hiatus in the crural part of the diaphragm to reach the stomach. The diaphragmatic hiatus itself is approximately 2 cm in length and chiefly consists of musculotendinous slips of the right and left diaphragmatic crura arising from either side of the spine and passing around the esophagus before inserting into the central tendon of the diaphragm. The size of the hiatus is not fixed, but narrows whenever intra-abdominal pressure rises, such as when lifting weights or coughing. 
The lower esophageal sphincter (LES) is an area of smooth muscle approximately 2.5-4.5 cm in length. The upper part of the sphincter normally lies within the diaphragmatic hiatus, while the lower section normally is intra-abdominal. At this level, the visceral peritoneum and the phrenoesophageal ligament cover the esophagus. The phrenoesophageal ligament is a fibrous layer of connective tissue arising from the crura, and it maintains the LES within the abdominal cavity. The A-ring is an indentation sometimes seen on barium studies, and it marks the upper part of the LES. Just below this is a slightly dilated part of the esophagus, forming the vestibule. A second ring, the B-ring, may be seen just distal to the vestibule, and it approximates the Z-line or squamocolumnar junction. The presence of a B-ring confirms the diagnosis of a hiatal hernia. Occasionally, the B-ring also is called the Schatzki ring.
Any sudden increase in intra-abdominal pressure also acts on the portion of the LES below the diaphragm to increase the sphincter pressure. An acute angle, the angle of His, is formed between the cardia of the stomach and the distal esophagus and functions as a flap at the gastroesophageal junction and helps prevent reflux of gastric contents into the esophagus (see the image below).
The gastroesophageal junction acts as a barrier to prevent reflux of contents from the stomach into the esophagus by a combination of mechanisms forming the antireflux barrier. The components of this barrier include the diaphragmatic crura, the LES baseline pressure and intra-abdominal segment, and the angle of His. The presence of a hiatal hernia compromises this reflux barrier not only in terms of reduced LES pressure but also reduced esophageal acid clearance. Patients with hiatal hernias also have longer transient LES relaxation episodes particularly at night time. These factors increase the esophageal mucosa acid contact time predisposing to esophagitis and related complications.