Esophageal strictures can be congenital or acquired and are associated with dilatation and hypertrophy of the esophagus above the stricture site. It is very rare clinically, most often develops at an early age and often requires surgical treatment. Clinical attention should be paid to differentiate it from secondary esophageal strictures.
Etiological analysis
X-ray analysis
The disease is the result of excessive hyperplasia of the trachea, the base of the esophageal septum or the mesodermal component of the lateral crest of the esophagus during the embryonic development of the esophagus, which mostly occurs below the tracheal bifurcation. Zhang Zhongwei, Department of Thoracic Surgery, Nankai Hospital, Tianjin, China
Common causes of acquired stenosis.
1.Esophageal mucosal epithelium is destroyed by inflammation or chemical corrosion and formed scar stenosis after repair;
2.Esophageal tumors such as esophageal cancer blocking the lumen of the esophagus to varying degrees;
3.Esophageal peripheral tissue lesions such as lung and mediastinal tumors, aneurysms, goiter, etc. are caused by external compression of the esophagus.
Due to the structural characteristics of the esophagus itself and the influence of neighboring organs, the esophagus shows three stenoses.
The first stricture is at the junction of the pharynx and esophagus, 15 cm from the central incisor;
The second stenosis is at the level of the fork of the trachea, where the left main bronchus crosses anteriorly, corresponding to the sternal angle or the level of the 4th and 5th thoracic intervertebral discs, 25 cm from the central incisors;
The third stenosis is at the level of the esophagus through the diaphragmatic esophageal foramen, which corresponds to the level of the 10th thoracic vertebra and is 37-40 cm from the central incisor.
The two ends of the esophagus, the first and third stenoses, are often closed, the former preventing air from entering the esophagus through the pharynx during inspiration and the latter preventing the reflux of gastric contents into the esophagus. The second stenosis is caused by the compression of the adjacent aortic arch and the left main bronchus, which does not affect the passage of food and has no physiological significance.
Auxiliary examinations
1.Barium esophagogram can be divided into two types according to the imaging characteristics of barium meal angiography.
(1) Long segment type: The stricture occurs in the middle and lower part of the esophagus and is about several centimeters long. The edges of the stricture are not smooth, and the esophagus above the strictured segment is dilated, and the barium travels slowly and retroperistalsis is visible (Figure 2). The clinical symptoms of this type appear earlier and are similar to reflux esophagitis, which is difficult to distinguish on X-ray.
(2) Short segment type: It often occurs at the junction of the middle and lower esophagus, and the stenotic segment is about a few millimeters to 1 cm long with smooth margins and regular mucosa. The esophagus above the stenosis is mildly dilated, the barium can still travel down, and the esophagus in the distal part of the stenosis has normal morphology. Sometimes foreign bodies or food masses are easily retained above the stricture. The stenotic segment cannot be dilated. This disease is often combined with aspiration pneumonia, barium meal examination should be routine chest X-ray.
Esophagoscopic pediatric microscopy can provide the main objective basis for the nature of the stricture.
3.Esophageal manometry.
Differential distinction
X-ray examination is the main basis for the diagnosis of this disease, and its images need to be differentiated from the following diseases.
1. cardia incontinentia stenosis is located in the cardia, with intermittent opening, and barium may enter the stomach in a jet. Congenital esophageal stricture is a persistent stricture with no signs of open jets, but the barium can pass continuously. Usually the dilatation of esophagus above the stricture is not as obvious as cardia dystrophy.
2, Acquired reflux esophagitis stenotic segment of the esophagus is not smooth, uneven, with mucosal destruction or niche shadow, and sometimes esophageal hiatal hernia is seen. During the follow-up observation, the degree of stenosis may worsen and become longer. Clinical symptoms also worsen.
Treatment options
1.Surgical methods
(1) Esophageal dilatation esophageal dilatation is an effective treatment method, and in recent years, the balloon expansion has replaced the rigid expansion strips. It is suitable for the treatment of thin membranous webbing.
(2) Resection of membranous webbing If the membranous webbing is thick and tough and dilatation is ineffective, the esophagus can be incised, the annular mucosa removed, and the esophageal mucosa anastomosed together. Successful endoscopic resection of congenital webbing has also been reported. Postoperative dilation is continued if necessary.
(3) Partial esophagectomy is feasible for congenital esophageal strictures and fibromuscular hypertrophic strictures secondary to tracheal and bronchial tissue remnants. For stenosis <3 cm, end-to-end esophageal anastomosis can be given after partial resection of the stenosis, and care should be taken to protect the vagus nerve and pharyngeal nerve during surgery. For congenital esophageal strictures caused by long segments of fibromuscular hypertrophy, substitution of esophageal surgery can be performed if dilatation is ineffective. If the stricture is close to the gastroesophageal junction, a segmental resection followed by esophageal anastomosis and anti-reflux surgery can be recommended; the latter is commonly used to prevent reflux by modified hill gastric wall fixation and nissen fundoplication. collis gastroplasty has also been reported to be an effective treatment for esophageal shortening and postoperative gastroesophageal reflux.
2. The key to surgical positioning and route selection is to clarify the stenosis site and surgical route. The right transthoracic route is most commonly used, but the left transthoracic route is often helpful for mid-stenosis. If the lower end is narrowed, a transabdominal route is also possible. A balloon dilatation strip placed in the esophagus during surgery is helpful for correct positioning.
Complications
As food reflux occurs after breastfeeding or eating, the refluxed food and saliva can enter the trachea and cause aspiration bronchitis or pneumonia.
What causes esophageal stricture
(1) Injurious esophageal stricture;
The most common cause is a chemically corrosive injury caused by swallowing a corrosive agent (strong alkali or acid), which forms a scarring stricture after healing. In addition, esophageal foreign body (denture, sharp bone) or medical source (instrumentation or treatment, radiation irradiation treatment) injury is less common than the former, but it also occurs from time to time.
During the swallowing process, the corrosive agent causes burns of different distribution and depth to the mouth, pharynx, esophagus and stomach, but the pathological changes are mainly related to the concentration of the swallowed corrosive agent, the dose, the length of stay in contact with the esophagus and other factors. The degree of burns can vary from congestion and edema of the esophageal mucosa, epithelial detachment up to the deeper muscular layer, ulceration or even involvement of the whole esophagus, resulting in perforation. The scar-forming phase starts around 3 weeks after the injury and gradually worsens, reaching the most severe stage after several weeks to months.
The stenosis is usually stable and no longer changes 6 months after the injury. The extent of injury scar stenosis is either segmental or more extensive over the entire length of the esophagus. The esophageal tissue at the stenosis loses its normal layered structure and is replaced by thickened fibrous tissue, called a scarred sclerotomy. The lumen is highly narrowed, with varying degrees of dilatation and wall thickening at the oral end of the esophagus at the stenosis. Especially in stenosis after corrosive burns, the chronic inflammatory reaction causes tight adhesions between the esophagus and the surrounding tissues, making surgical separation difficult. Scarred esophageal strictures due to foreign body or medical injury are mostly limited to a particular segment and are mild. The stenosis can be complicated by carcinoma after a long period of time, so we should be vigilant and perform endoscopic slide and biopsy when necessary to exclude malignant changes.
(2) Stenosis caused by esophagitis (peptic, reflux);
The esophageal mucosa is often stimulated by acid and bile reflux, which can lead to mucosal ulceration, inflammation, and even the formation of granulation and scarring, and contraction causing stricture.
The formation of reflux esophagitis is determined by two factors.
(1) high number and amount of reflux of gastric and pancreatic-biliary juices into the esophagus;
(2) Reduced motor activity of the esophagus, which has a low function of rapidly emptying the reflux without and preventing its prolonged contact with the mucosa. This disorder often coexists with esophageal hiatal hernia or occurs after cardia surgery in which the physiological function of its sphincter is disrupted (e.g., after cardia angioplasty or esophagogastric anastomosis). The stricture mostly occurs in the lower esophagus, but may extend upward.
(3) Post-surgical esophageal stricture.
Different types of strictures can occur at the site of esophageal surgery. Some of them are caused by suture reaction or characteristic anastomosis technique, resulting in a large amount of local granulation tissue at the anastomosis and contracture formation of stenosis after fibrosis; some are caused by chronic inflammation existing at the time of esophageal surgery or postoperative complications of reflux esophagitis.