| disease | Esophageal Diverticulum |
| alias | Oesophageal Pouch |
Esophageal diverticulum refers to an epithelial-covered blind pouch connected to the esophageal lumen. There are three common locations: ① Pharyngoesophageal diverticulum; occurs at the junction of the pharynx and esophagus, and is a pulsion-type diverticulum; ② Parabronchial diverticulum; occurs in the middle segment of the esophagus, also known as mid-esophageal diverticulum, and is a traction-type diverticulum; ③ Epiphrenic diverticulum; occurs in the upper part of the lower esophagus near the diaphragm, and is also a pulsion-type diverticulum. Pharyngoesophageal diverticula are the most common, followed by epiphrenic diverticula, with parabronchial diverticula being the least common. Whether esophageal diverticula produce symptoms is related to the size of the diverticulum, the location of the opening, and whether food and secretions are retained. Most symptoms are mild and atypical.
bubble_chart Etiology
The anatomical basis of pharyngoesophageal diverticulum is a defect located posteriorly and centrally between the oblique fibers of the inferior constrictor muscle of the pharynx and the transverse fibers of the cricopharyngeus muscle, more pronounced slightly to the left, hence diverticula often occur on the left side.
Pharyngoesophageal diverticula are usually not caused by a single factor, but often due to dyskinesia, achalasia, or other motility disorders of the cricopharyngeus and esophageal muscles, leading to mucosal herniation and the formation of diverticula on the aforementioned anatomical basis.
Pharyngoesophageal diverticula are commonly seen in adults over 50 years of age, more frequently in males than in females.
Very rarely, pharyngoesophageal diverticula may undergo malignant transformation, possibly due to long-term stimulation by food and secretions. Habitual compression of the diverticulum by patients to facilitate its emptying may also be a contributing factor to malignancy. If irregular inner walls of the diverticulum are observed during barium swallow radiography, malignancy should be highly suspected, and further examination is required.Epiphrenic diverticula are also of the pulsion type, with the diverticulum wall consisting only of the mucosal and submucosal layers, rarely containing muscle fibers. Most literature reports that the majority of epiphrenic diverticula are associated with esophageal motility disorders, hiatal hernia, and esophageal reflux. Esophageal reflux often causes esophageal muscular rigidity and spasms, increasing intraluminal pressure and leading to pulsion diverticula.
Mid-esophageal diverticula can be either pulsion or traction types, with the majority being traction diverticula. The causes and manifestations of mid-esophageal pulsion diverticula are completely similar to those of epiphrenic diverticula, while traction diverticula are caused by scar traction due to inflammation of peribronchial lymph nodes or subcutaneous nodes. They possess the full thickness of the esophageal wall, including the mucosa, submucosa, and muscle layers, with a wide neck and narrow base resembling a tent. Traction diverticula mostly occur on the anterior and right lateral walls of the esophagus at the tracheal bifurcation. Some authors believe that some mid-esophageal diverticula unrelated to esophageal motility abnormalities are congenital enteric cysts or esophageal duplications.
The pathological changes are due to the dilation of the submucosal gland ducts of the esophagus, with the lesions confined to the submucosal layer and not involving the esophageal muscle layer. The dilated gland ducts are cystic, surrounded by chronic inflammation, and may form small abscesses. Inflammatory changes and squamous metaplasia of the gland ducts can lead to stenosis or complete obstruction of the lumen, causing proximal dilation and the formation of pseudodiverticula. Due to chronic inflammation, fibrosis of the esophageal submucosa results in thickening and rigidity of the esophageal wall and narrowing of the lumen. Pseudodiverticula can involve the entire length of the esophagus but are more commonly found in the upper esophagus, consistent with the distribution of esophageal submucosal glands. Many patients with pseudodiverticula also have diabetes.
bubble_chart Clinical Manifestations
Clinical manifestations of pharyngeal esophageal diverticulum: In the early stage, only a small part of the mucous membrane protrudes to form a diverticulum, with a large opening and a right-angle connection to the pharyngeal esophageal cavity. Food is not easily retained, and there may be no symptoms or only mild symptoms. Occasionally, when food sticks to the diverticulum wall, it may cause throat irritation symptoms such as itching, which disappear after coughing or drinking water to dislodge the food residue.
If the diverticulum gradually enlarges, the accumulation of food and secretions increases, sometimes spontaneously refluxing into the oral cavity, occasionally causing aspiration. During this period, patients may hear noises in the pharynx due to the movement of air and food in and out of the diverticulum.
If aspiration occurs, complications such as pneumonia, atelectasis, or lung abscess may develop. Complications like bleeding and perforation are less common.
Clinical manifestations of epiphrenic diverticulum: Most patients with small epiphrenic diverticula may have no symptoms or only mild symptoms. Diverticula associated with motor dysfunction may present with various symptoms, such as grade I dyspepsia, retrosternal pain, upper abdominal discomfort and pain, fetid mouth odor, regurgitation, and gurgling sounds in the chest. Large epiphrenic diverticula compressing the esophagus can cause dysphagia, and reflux can lead to aspiration.
Clinical manifestations of mid-esophageal diverticulum: Most traction diverticula are small with a wide neck and narrow base, facilitating drainage and reducing the likelihood of food retention. Therefore, they are generally asymptomatic and often discovered incidentally during health check-ups or imaging studies, remaining unchanged for many years. Symptoms such as dysphagia and pain only occur when the esophagus is displaced or narrowed due to traction, or when the diverticulum becomes inflamed. If the diverticulum becomes inflamed, ulcerated, or necrotic and perforates, it can cause complications such as bleeding, mediastinal abscess, and bronchial fistula, along with corresponding symptoms and signs.
Clinical manifestations of pseudodiverticulum of the esophagus: Patients often complain of grade I dysphagia, with symptoms occurring intermittently or progressing slowly. Esophageal pseudodiverticula are more common in patients aged 50 to 60, with a higher incidence in males than in females.
Diagnosis and Diagnostic Criteria of Esophageal Diverticulum: Clinical physical examination reveals few positive signs. In some patients, after swallowing a few mouthfuls of air, repeated compression at the anterior border of the sternocleidomastoid muscle at the level of the cricopharyngeus muscle can produce a gurgling sound.
The primary diagnostic method is X-ray examination. Occasionally, a fluid level is seen on a plain film. Barium swallow can reveal a diverticulum behind the esophagus (Figure 1). If the diverticulum is large and significantly compresses the esophagus, barium can be seen entering the diverticulum, followed by a stream of barium flowing from the diverticulum opening into the lower esophagus. Repeated changes in body position during the contrast study facilitate the filling and emptying of the diverticulum, making it easier to detect small diverticula and observe whether the mucosal lining of the diverticulum is smooth, thereby excluding early malignant changes.
Figure 1: Barium contrast image of esophageal diverticulum
Endoscopy carries certain risks and is not routinely performed. It is only conducted when malignancy is suspected or when other anomalies, such as esophageal webs or strictures, are present. Before endoscopy, the patient is instructed to swallow a black silk thread as a conduction exercise line for the endoscope, which increases the safety of the examination. If the thread is not visible or appears tangled at the endoscope tip, it indicates that the endoscope has entered the diverticulum.
Diagnosis and Diagnostic Criteria of Epiphrenic Diverticulum: Epiphrenic diverticulum is often confirmed by chest X-ray. A plain chest film may sometimes show a diverticulum cavity with a fluid level. Barium swallow reveals the diverticulum a few centimeters above the diaphragm, usually protruding to the right, but it can also protrude to the left or anteriorly. Diverticula in the subdiaphragmatic abdominal esophagus are extremely rare. Diverticula can coexist with hiatal hernia, and multiple views are necessary during contrast studies to avoid misdiagnosis or missed diagnosis of fistula disease.
Endoscopy carries certain risks and is only performed when malignancy or associated anomalies are suspected.
Mid-esophageal diverticula are also diagnosed by X-ray. During barium swallow, supine or head-down positions are used, and the body is rotated left and right to clearly outline the diverticulum. Because the openings of mid-esophageal diverticula are relatively large, contrast medium easily flows out of the diverticulum and does not remain inside.
Endoscopy is of little help for small, shallow mid-esophageal diverticula and is only performed when malignant transformation is suspected.
Diagnosis and Diagnostic Criteria of Pseudodiverticulum: Pseudodiverticula are not visible on X-ray. Barium swallow reveals multiple long-necked flask-shaped or small button-shaped sacs within the esophageal lumen, ranging from 1 to 5 mm in size, scattered or localized. In areas of significant esophageal narrowing, pseudodiverticula are more numerous, suggesting that esophageal stricture is related to inflammation around the pseudodiverticula.
Endoscopy shows chronic inflammatory changes in the esophagus. The openings of pseudodiverticula are seen in only a very small number of patients, and biopsy is also difficult to confirm the diagnosis.
Many patients with pseudodiverticula often have Candida infections, which may be secondary, especially in diabetic patients.
bubble_chart Treatment Measures
The condition of pharyngeal esophageal diverticulum is mostly progressive, and non-surgical conservative treatments are ineffective. Therefore, once the diagnosis is confirmed, elective surgery should be scheduled as soon as possible before complications arise.
1. Preoperative preparation Generally, no special preoperative preparation is needed. Very few patients may require intravenous fluid therapy to correct malnutrition. If there are complications, they should be actively treated. Surgery can be performed once the condition is under control, without unnecessary delay. Surgery eliminates the disease cause of complications, allowing for a complete cure.
A liquid diet should be followed 48 hours before surgery, and the patient should change positions as much as possible to empty the residual contents in the diverticulum. If a nasogastric tube can be placed into the diverticulum under fluoroscopy before surgery and the retained contents can be repeatedly washed and suctioned, it helps prevent aspiration during anesthesia induction. The gastric tube retained in the diverticulum aids in locating and dissecting the diverticulum during surgery, facilitating the surgical procedure.
2. Anesthesia Endotracheal intubation and general anesthesia are used to control respiration and prevent aspiration, making the surgical procedure easier.
3. Surgical method Pharyngeal esophageal diverticula are mostly located posterior to the midline and slightly to the left. The surgery usually adopts a left cervical approach, but the decision must be based on preoperative imaging. If the diverticulum is biased to the right, a right cervical approach should be chosen.
In the supine position, the head is turned to the healthy side. An incision is made along the anterior border of the sternocleidomastoid muscle, from the level of the hyoid bone to 1 cm above the clavicle. The platysma is cut, and the sternocleidomastoid muscle and surrounding tissues and muscles are separated anterior to the trachea and retracted laterally to expose the omohyoid muscle, which is either removed or retracted. Removal is more beneficial for exposing the diverticulum. The carotid pulse is retracted laterally, and the inferior thyroid artery and middle thyroid vein are cut. The thyroid is retracted towards the midline, taking care to protect the recurrent laryngeal nerve in the tracheoesophageal groove. The diverticulum wall is carefully identified, and the gastric tube within the diverticulum can be palpated by hand. The anesthesiologist can also slowly inject air into the diverticulum through the gastric tube to make the diverticulum bulge, facilitating identification. The diverticulum sac is grasped and lifted with a rat-tooth forceps, and the neck of the diverticulum is dissected along the sac wall. Below the neck of the diverticulum is the upper edge of the cricopharyngeus muscle, and above it is the lower edge of the inferior pharyngeal constrictor muscle. The transverse fibers of the cricopharyngeus muscle and the esophageal muscle layer are cut along the midline from top to bottom for about 3 cm, and the esophageal mucosa and muscle layer at the neck of the diverticulum are separated to the left and right up to half the circumference of the esophagus, allowing the mucosa to bulge and no further treatment is needed. If the diverticulum is very large, it should be excised. The gastric tube originally in the diverticulum is advanced into the esophageal lumen. The neck of the diverticulum is clamped with a vascular clamp parallel to the longitudinal axis of the esophagus, and the diverticulum wall is excised. The esophageal mucosa is sutured, with the knots tied inside the lumen. Care must be taken not to excise too much to avoid causing esophageal stenosis. A drainage strip is placed, and the neck incision is sutured layer by layer.
4. Postoperative management Oral intake can be resumed on the second postoperative day. The drainage strip is removed 48 to 72 hours after surgery if there is not much drainage.
The main surgical complications are recurrent laryngeal nerve injury, which mostly resolves on its own. The next most common complication is leakage or fistula formation at the repair site, which usually heals with local wound care. If esophageal stenosis occurs, esophageal dilation can be performed.
Treatment of epiphrenic diverticulum: Symptomatic large diverticula, diverticula that gradually enlarge during follow-up, diverticula with retention signs, or diverticula associated with other anomalies such as hiatal hernia or achalasia should be surgically treated. Special attention should be paid to correcting associated anomalies during surgery to avoid complications or recurrence.
1. Preoperative preparation Basically the same as for pharyngeal esophageal diverticulum, but gastrointestinal preparation should be performed before surgery: oral metronidazole 0.4g, three times a day for three consecutive days. The night before surgery, after gastric lavage, oral streptomycin 1g is administered and an enema is given. These measures help prevent the occurrence of esophageal fistula.
2. Anesthesia The same as for pharyngeal esophageal diverticulum surgery, using endotracheal intubation and general anesthesia.
3. Surgical method Epiphrenic diverticulum is mostly approached through the left 7th rib bed, even though sometimes the diverticulum is located on the right side, as the left thoracic approach facilitates the surgical procedure.
After opening the chest, the lung is retracted forward, and the mediastinal pleura is incised to expose the esophagus, taking care to preserve the vagal plexus. Palpating the gastric tube within the diverticulum or asking the anesthesiologist to inject air through the gastric tube can help identify the diverticulum. If the diverticulum is located on the right side of the esophagus, the esophagus can be mobilized and rotated to facilitate exposure of the diverticulum. The diverticulum often herniates from a gap in the esophageal muscle layer. After identifying the interface between the circular muscle of the esophagus and the esophageal mucosa, the muscle layer is incised approximately 3 cm distally and 2 cm proximally to fully expose the neck of the diverticulum. If the diverticulum is large, it can be excised, with the mucosal and muscle layers incised separately, extending proximally to the level of the inferior pulmonary vein and distally to 1 cm above the gastric wall. The site of the myotomy of the cardia should be lateral to the suture repair of the diverticulum neck to reduce the risk of fistula. Routine closed thoracic drainage is performed.
4. Postoperative Management: Routine fasting after surgery, gastrointestinal decompression and intravenous fluid replacement. Stop gastrointestinal decompression after the return of borborygmus sounds, and resume oral intake the next day. Remove the thoracic drainage tube after good lung expansion and absence of thoracic drainage.
Treatment of Mid-Esophageal Diverticulum: Asymptomatic traction esophageal diverticula do not require treatment. Mild symptoms can be observed for years. Surgical treatment is only necessary when symptoms gradually worsen, the diverticulum gradually enlarges, or complications such as inflammation, perforation by foreign bodies, or bleeding occur.
During surgery, the disease cause leading to the traction diverticulum should be removed, and any coexisting esophageal motility disorders or obstructions, such as achalasia, diaphragmatic hernia, or hiatal hernia, should be corrected to prevent recurrence or complications.
Preoperative preparation and anesthesia are the same as for epiphrenic diverticulum surgery.
The surgery generally adopts a right thoracic approach. The mediastinal pleura is incised behind the hilum to identify the esophagus. Enlarged lymph nodes and tightly adherent fibrous tissue often surround the diverticulum, making the dissection of the diverticulum somewhat difficult. Carefully and patiently remove the enlarged lymph nodes, and take care not to injure the esophagus when incising the diverticulum. Suture in two layers: the mucous membrane and the muscle. Concurrent abscesses or fistulas should be excised and repaired together. The pleura, intercostal muscles, and pericardium can be used as reinforcing tissues.
Treatment of Pseudodiverticulum of the Esophagus: The goal of treatment is to alleviate symptoms and manage associated lesions. Surgery is generally not required. Esophageal dilation can relieve dysphagia, and antacid treatment can alleviate esophageal inflammation. However, the X-ray appearance of pseudodiverticula often remains unchanged, and they may occasionally disappear on their own.
