Esophageal hiatal hernia (hiatus hernia) is a condition in which an intra-abdominal organ (mainly the stomach) enters the thoracic cavity through a diaphragmatic esophageal hiatus. Esophageal hiatal hernia is a type of diaphragmatic hernia and is the most common type of diaphragmatic hernia, accounting for more than 90% of cases. Patients with esophageal hiatal hernia can be asymptomatic or mildly symptomatic, and the severity of symptoms is independent of the size of the hernia sac and the severity of esophageal inflammation. It is important to distinguish between hiatal hernia and reflux esophagitis, which can exist simultaneously or separately.
Disease etiology
1, congenital factors of esophageal dysplasia.
2, structure of the esophageal fissure site such as muscles with atrophy or weakened muscle tone.
3, Acquired factors of long-term increased abdominal pressure, such as pregnancy, ascites, chronic cough, habitual constipation, etc. can cause the body of the stomach to herniate above the diaphragm and form an esophageal hiatal hernia.
4. Post-surgical hiatal hernia, such as surgery on the upper part of the stomach or the cardia, which destroys the normal structure can also cause hernia.
5. Traumatic hiatal hernia.
The etiology of esophageal hiatal hernia is still controversial. A few patients with the onset of the disease in early childhood have congenital developmental disorders, forming a large esophageal hiatal hole and weak tissues around the hole; in recent years, it is believed that acquired factors are the main ones, related to obesity and chronic intra-abdominal pressure elevation.
The physiological role of the esophagogastric junction is still not well understood. When the esophagogastric junction is functional, it has an active flap, and liquids or solids are swallowed into the stomach, but do not reflux, and only when burping or vomiting can a small amount of reflux occur.
The factors that ensure this normal function are.
(i) the clamping effect of the diaphragm on the esophagus;
(2) the action of the mucosal folds at the esophagogastric junction;
(3) The esophagus is anatomically connected to the fundus of the stomach at an acute angle;
④The intra-abdominal esophageal segment is involved in the valvular action of the lower esophagus;
⑤ The role of the internal sphincter in the physiological high pressure area of the lower esophagus.
Most people believe that the 5th of the above factors is the main factor in preventing reflux, which is supported by the normal anatomical relationships in the vicinity. The prevention of gastric reflux is governed by the vagus nerve, and this effect disappears after removal of the vagus nerve. When the pressure in the stomach increases, gastric juice tends to flow back into the esophagus.
The squamous epithelial cells of the esophageal mucosa are not resistant to gastric acid, and long-term erosion by refluxed gastric acid can cause reflux esophagitis, with mucosal edema and congestion in mild cases and superficial ulcers in heavy cases, with patchy distribution or fusion, submucosal tissue edema, mucosal damage and pseudomembrane coverage, and easy bleeding.
Inflammation can penetrate into the muscular layer and fibrous epithelium, and even involve the mediastinum, thickening the tissue, becoming brittle, and enlarging the nearby lymph nodes. In the later stages, the esophageal wall becomes fibrotic, scarred and narrowed, and the esophagus becomes shorter. In some cases, the diaphragmatic esophagus membrane may be found to be stretched below the aortic arch up to the level of the 9th thoracic vertebra.
The severity of reflux esophagitis can vary depending on the following factors: the amount of gastric juice returned, the acidity of the reflux, the length of time present and individual differences in resistance. Most of the pathological changes in reflux esophagitis are reversible, and repair of mucosal lesions is possible after correction of esophageal hiatal hernia.
Pathophysiology
According to all locations of the esophagogastric junction, there are four main types of esophageal hiatal hernia in terms of morphology as follows.
1. Sliding esophageal hiatal hernia (reducible hiatal hernia): the most common clinical condition. The muscle tone of the esophageal hiatus is weakened, the mouth of the esophageal hiatus is enlarged, the diaphragmatic esophageal ligament and the diaphragmatic gastric ligament, which play a fixed role in the cardia, are relaxed, so that the range of motion of the cardia and the bottom of the stomach is increased, and the cardia and the bottom of the stomach protrude into the intrathoracic mediastinum through the enlarged esophageal hiatus when the abdominal pressure is increased.
2. Para-esophageal hernia: It is less common, accounting for only 5%-20% of hiatal hernias, and manifests as a part of the stomach (gastric body or gastric sinus) entering the thoracic cavity through the widened and relaxed foramen in the left front of the esophagus. It is sometimes accompanied by herniation of the large gastrocolic omentum. However, the esophagogastric junction is located below the diaphragm and remains at an acute angle, so gastroesophageal reflux rarely occurs. If the herniated part is large, including the fundus and upper part of the gastric body (giant hiatal hernia), the gastric axis is twisted and turned over, and serious consequences such as ulcer bleeding, entrapment, strangulation and perforation can occur.
3. Mixed esophageal hiatal hernia: This type is the least common, accounting for about 5%, and refers to the co-existence of sliding esophageal hiatal hernia and paraesophageal hernia, often as a result of oversized diaphragmatic esophageal hiatus. It is characterized by a sliding of the gastroesophageal junction from the abdominal cavity into the posterior mediastinum, with the fundus of the stomach and even the main gastric body, the lesser curvature, moving upward with the enlargement of the hiatal foramen. Due to the enlargement of the hernia sac and the increasing contents of the hernia, the lung and heart can be compressed to produce different degrees of lung atrophy and heart displacement.
4. Short esophageal hiatal hernia: It is mainly due to shortening of the esophagus. It can be caused by long-term reflux esophagitis resulting in esophageal fibrosis, or after surgery, or due to congenital causes of esophageal shortening.
Clinical manifestations
Patients with hiatal hernia may be asymptomatic or have minimal symptoms, and the severity of symptoms is not related to the size of the hernia sac or the severity of esophageal inflammation. Patients with sliding hiatal hernia are often asymptomatic; if symptoms are present, they are often due to gastroesophageal reflux and, to a lesser extent, to the mechanical effects of the hernia. The clinical manifestations of paraesophageal hiatal hernia are mainly due to mechanical effects and can be tolerated by patients for many years; mixed hiatal hernia can be symptomatic in both aspects.
The symptoms are summarized in the following 3 areas.
1. Gastroesophageal reflux symptoms
The symptoms include burning sensation behind the sternum or under the glabella, retrograde sensation of gastric contents, epigastric fullness, belching, and pain. The nature of the pain is mostly burning or pins and needles, which can be radiated to the back, shoulders, neck and other places. The symptoms may be triggered and aggravated by lying down, eating sweet and acidic foods. This symptom is especially common in sliding type hiatal hernia.
2. Complication symptoms
(1) Bleeding: hiatal hernia can sometimes bleed, mainly due to esophagitis and herniorrhaphy, mostly as a chronic small amount of oozing blood, which can lead to anemia.
(2) Reflux esophageal stricture: In patients with reflux symptoms, organic stricture occurs in a few cases, resulting in dysphagia, painful swallowing, and vomiting after eating.
(3) Hernia sac impaction: usually seen in paraesophageal hernia. If a patient with hiatal hernia has sudden severe epigastric pain with vomiting, complete inability to swallow or simultaneous hemorrhage, it suggests acute intussusception.
3. Compression symptoms of hernia sac
When the hernia sac is large and compresses the heart, lungs and mediastinum, it can produce symptoms such as shortness of breath, palpitation, cough and cyanosis. When the esophagus is compressed, esophageal stagnation or difficulty in swallowing can be felt behind the sternum.
Diagnostic tests
Diagnosis: Because of the relative rarity of the disease and the absence of specific symptoms and signs, diagnosis is difficult. Suspected patients with gastroesophageal reflux symptoms, older age, obesity, and obvious correlation between symptoms and body position should be taken seriously, and some instrumental tests are needed to confirm the diagnosis.
Other auxiliary examinations.
1.X-ray is still the main method to diagnose esophageal hiatal hernia. In the case of reversible hiatal hernia (especially in mild cases), a negative examination cannot exclude the disease and should be repeated in highly suspicious clinical cases with special positions such as supine head down and foot up.
(1) Direct signs.
①Supradiaphragmatic hernia sac.
(2) Elevation and contraction of the lower esophageal sphincter ring (A ring).
(3) A coarse and tortuous gastric mucosal crease in the hernia sac.
④The appearance of the esophagogastric ring (B ring).
(5) A hernia sac (gastric sac) is seen on one side of the esophagus, while the esophagogastric junction remains under the diaphragmatic foramen.
(6) The mixed type may have a giant hernia sac or gastric axis torsion.
(2) Indirect signs.
① Widening of the diaphragmatic esophageal foramen (>4 cm).
(ii) Barium reflux into the supradiaphragmatic hernia sac.
(3) Concave ring at least 3cm away from the diaphragm and shortened esophagus.
2.Endoscopic examination The diagnostic rate of endoscopic examination for esophageal hiatal hernia is higher than before, and it can be supplemented with X-ray examination to assist the diagnosis.
(1) Elevation of the dentate line of the lower esophagus.
(2) Retained fluid in the lumen of the esophagus.
(3) Enlargement and/or relaxation of the cardia opening.
(4) Blurring of the His angle.
(5) The fundus of the stomach becomes linear.
(6) Diaphragmatic esophageal fissure is wide and flaccid.
3.Esophageal manometry examination In case of esophageal hiatal hernia, esophageal manometry may have abnormal patterns to assist in the diagnosis.
(1) Double pressure bands on lower esophageal sphincter (LES) manometry.
(2) Lower esophageal sphincter pressure (LESP) decreases below normal values.
The treatment of esophageal hiatal hernia is divided into conservative medical treatment and surgical treatment. Most patients do not need surgical treatment because conservative medical treatment is sufficient, and surgical treatment can choose between open surgery and minimally invasive laparoscopic surgery, which is more safe and reliable.