Hiatus hernia overview

# Overview
A hiatus hernia  is the protrusion (or herniation) of the upper part of the stomach into the thorax through a tear or weakness in the diaphragm. Hiatus hernia may be classified into four subtypes: type I: Sliding hernia and type II, III, IV: paraesophageal hernias (rolling hernias). It is understood that hiatus hernia is the result of either decreased elastin of phrenoesophageal membrane due to aging that increases the risk of developing hiatal hernia. Pressure gradient between intra-abdominal and intra-thoracic pressure leads to the esophagogastric junction being displaced into normal hiatus. A rise in intraabdominal pressure and lower thoracic pressure can cause hernia. Esophageal shortening, pulls the junction into the hiatus. This physiological shortening occurs as a normal response to swallowing. The LES is shorter and weaker in large hiatus hernia and have severe reflux symptoms and trauma. Paraesophageal hernia are less common and have lesser incidence of GERD. Hiatus hernia may be caused by older age, trauma, congenital defects, increase in the abdominal pressure, obesity, and smoking. Hiatus hernia presents as gastroesophageal reflux disease (GERD) with dysphagia and must be differentiated from other causes of dysphagia. Hiatus hernias affect around 1 to 20% of the population. If left untreated, patients with a hiatus hernia may progress to develop strangulation, esophageal adenocarcinoma, and gastric volvulus. Prognosis is generally excellent and recovery after surgery in a large hernia is approximately 90%. The disease is well controlled with medical therapy but not cured. The symptoms include acid reflux, and pain, similar to heartburn, in the chest and upper stomach. In most patients, hiatus hernias cause no symptoms. Sometimes patients experience heartburn and regurgitation, when stomach acid refluxes back into the esophagus. Physical examination of patients with hiatus hernia is usually normal and unhelpful in the diagnosis. On chest radiographs, a paraesophageal hernia may appear as a soft-tissue-opacity lesion posterior to the heart near the esophageal hiatus. CT helps verify migration of the stomach cranially through the hiatus. Sagittal and coronal reformatted images often help demonstrate the hernia and the hiatal defect. Barium swallow may be helpful in the diagnosis of a hiatus hernia. Findings on a barium swallow suggestive hiatus hernia include anatomy and size of a hernia, the orientation of the stomach location of the gastroesophageal junction. In majority of cases, patients experience no discomfort and no treatment is required. However, when a hiatal hernia is large, it is likely to cause esophageal stricture which results in discomfort. Symptomatic patients benefit from not lying down immediately after meals and also benefit by elevating the head of their beds. If stress has been identified as the major risk factor, stress reduction techniques may be practiced, or if overweight, weight loss may be indicated. Certain medications causes lower esophageal sphincter (or LES to relax those medications should be avoided. Anti-acid drugs like proton pump inhibitors and H2 receptor blockers can be used to decrease the acid secretion. Surgery is the mainstay of treatment for patients with a symptoms or complications. Paraesophageal hernias can be repaired transabdominally or transthoracically. Laparoscopic approach is preferred for most patients. A Nissen-fundoplication is usually done with the surgery. A fixation of the stomach to the abdominal wall (anterior gastropexy) can be used to reduce the risk of gastric reherniation into the thoracic cavity. Complications include pneumonia, pulmonary embolism, heart failure, postoperative leak, and recurrence.

# Historical Perspective
In 1846, Henry Ingersoll Bowditch was first to described hiatus hernia following postmortem examination. In the recent treatment strategies laparoscopic fundoplication have indicated very relatively low complication when compare to other techniques, quick recovery, and relatively good long term effects.

# Classification
Hiatus hernia may be broadly classified into sliding hernia and paraesophageal hernias. Sliding hernia is also called type I hernia and paraesophageal hernia is divided into three subtypes including type II, type III and type IV.

# Pathophysiology
It is understood that hiatus hernia is the result of either decreased elastin of phrenoesophageal membrane due to aging or imbalance in pressure gradient between intra-abdominal pressure and intra-thoracic pressure leading to the esophagogastric junction being displaced into normal hiatus. A rise in intra-abdominal pressure and lower thoracic pressure can cause hernia. Occasionally, esophageal shortening pulls the junction into the hiatus. This physiological shortening may occur as a normal response to swallowing. The LES is shorter and weaker in large hiatus hernia and have severe reflux symptoms and trauma. Paraesophageal hernia are less common and have lower incidence of gastroesophageal reflux disease.

# Causes
The cause of hiatus hernia has not been identified clearly. Hiatus hernia is defined as the herniation of contents of the abdominal cavity via the esophageal hiatus of the diaphragm due to weakening of the muscles around esophagus. Hiatus hernia may be caused by older age, trauma, congenital defects, increase in the abdominal pressure, obesity, and smoking.

# Differentiating Hereditary pancreatitis from Other Diseases
Hiatus hernia presents as gastroesophageal reflux disease (GERD) with dysphagia and must be differentiated from other causes of dysphagia.

# Epidemiology and Demographics
Hiatus hernias affect around 1 to 20% of the population. Out of this 9 % are symptomatic, depending on the ability of the lower esophageal sphincter (LES). Approximately 95% of these categorize under "sliding" hiatus hernias, in which the lower esophageal sphincter protrudes above the diaphragm along with the stomach, and only 5% is the "rolling" type (paraesophageal), in which the lower esophageal sphincter (LES) remains stationary but the stomach protrudes above the diaphragm. A hiatus hernia is more common in older people.

# Risk Factors
Common risk factors in the development of hiatus hernia include aging, obesity, trauma, scoliosis, and congenital defects.

# Screening
There is insufficient evidence to recommend routine screening for hiatus hernia.

# Natural History, Complications, and Prognosis
The symptoms of a hiatus hernia usually develop in the first decade of life in children and start with symptoms such as vomiting, heartburn, regurgitation, and dysphagia. If left untreated, patients with a hiatus hernia may progress to develop strangulation, esophageal adenocarcinoma, and gastric volvulus. Prognosis is generally excellent and recovery after surgery in a large hernia is approximately 90%. The disease is well controlled with medical therapy but not cured.

# Diagnosis

## Diagnostic Study of Choice
When a patient is suspected for having a sliding hiatus hernia and symptoms of gastroesophageal reflux disease (GERD) which includes regurgitation, heartburn, and dysphagia epigastric pain or fullness, nausea, or vomiting. High resolution manometry with esophageal pressure topography (EPT) is the most sensitive test for the diagnosis of hiatal hernia.

## History and Symptoms
The majority of patients with hiatus hernia are asymptomatic. However, some cases may develop gastroesophageal reflux disease which is associated with heart burn, regurgitation, and dysphagia.

## Physical Examination
Physical examination of patients with hiatus hernia is usually normal and unhelpful in the diagnosis. In some cases, hiatus hernia may develop gastroesophageal reflux disease (GERD). Patients with GERD usually appear ill due to the pain. Common physical examination include hoarseness of voice, laryngitis, otitis media, and lung wheezes.

## Electrocardiogram
There are no ECG findings associated with hiatus hernia.

## Chest X Ray
An x-ray may be helpful in the diagnosis of a hiatus hernia. Findings on an x-ray suggestive of a hiatus hernia include retrocardiac opacity with the air-fluid level.

## Echocardiography or Ultrasound
Ultrasound may be helpful in the diagnosis of a hiatus hernia. Findings on an ultrasound suggestive of a hiatus hernia include intra-abdominal esophagus measurement, gastroesophageal junction location, bowel diameter, and gastroesophageal angle.

## CT
Chest CT scan may be helpful in the diagnosis of a hiatus hernia. Findings on CT scan suggestive of a hiatus hernia include retrocardiac air-fluid level and organs within the hernia sac.

## MRI
MRI may be helpful in the diagnosis of a hiatus hernia. Findings on MRI suggestive of a hiatus hernia include contiguous high-signal lesion extending from retroperitoneum into the thorax.

## Other Imaging Findings
A hiatal hernia occurs when a part of the stomach protrudes into the thoracic cavity through the esophageal hiatus of the diaphragm. Approximately 99% of hiatal hernia are sliding, and the rest 1% are paraesophageal hernia. Barium swallow may be helpful in the diagnosis of a hiatus hernia. Findings on a barium swallow suggestive hiatus hernia include anatomy and size of a hernia, the orientation of the stomach location of the gastroesophageal junction.

## Other Diagnostic Studies
There are no other diagnostic studies associated with a hiatus hernia.

# Treatment

## Medical Therapy
In most cases, patients experience no discomfort and no treatment is required. However, when a hiatal hernia is large, it is likely to cause esophageal stricture which results in discomfort. Symptomatic patients benefit from not lying down immediately after meals and also benefit by elevating the head of their beds.  If stress has been idetified as the major riskfactor,  stress reduction techniques may be practiced, or if overweight, weight loss may be indicated. Certain medications causes  lower esophageal sphincter (or LES to relax those medications should be avoided.  Anti-acid drugs like proton pump inhibitors and H2 receptor blockers can be used to decrease the acid secretion.

## Surgery
Surgery is the mainstay of treatment for patients with a symptoms or complications. Paraesophageal hernias can be repaired transabdominally or transthoracically. Laparoscopic approach is preferred for most patients. A  Nissen-fundoplication is usually done with the surgery. Overall mortality and morbidity rates associated with laparoscopic paraesophageal hernia repair are low. A fixation of the stomach to the abdominal wall (anterior gastropexy) can be used to reduce the risk of gastric reherniation into the thoracic cavity. Complications include pneumonia, pulmonary embolism, heart failure, postoperative leak, and recurrence.

## Primary Prevention
There are no established measures for the primary prevention of hiatus hernia.

## Secondary Prevention
Effective measures for the secondary prevention of a hiatus hernia include preventing and treating gastroesophageal reflux disease(GERD) that includes lifestyle modifications, management of GERD by using proton pump inhibitors and surgery to prevent recurrence.