A diverticulum is a sac or pouch arising from a tubular organ, such as the esophagus. This article focuses on diverticula of the esophagus. As is common practice, Zenker diverticulum, a type of diverticulum that arises from the posterior hypopharynx, is also discussed in this article.
Esophageal diverticula are classified by location in the esophagus. Upper (pharyngoesophageal, Killian-Jamieson, or Zenker), middle, or lower (epiphrenic). Besides anatomical location, several other ways to classify diverticula of the esophagus and hypopharynx exist. Congenital diverticula are diverticula that are present at birth, while acquired diverticula develop later in life. Diverticula of the esophageal body can sometimes be difficult to classify as congenital or acquired.[1]
Diverticula also may be classified on the basis of histopathology. True diverticula contain all layers of the intestinal tract wall. False diverticula, also known as pseudodiverticula, occur when herniation of mucosa and submucosa through a defect in the muscular wall occurs (eg, Zenker diverticulum). A special type of pseudodiverticula, believed to represent dilated excretory ducts of esophageal submucosal glands, is observed in the condition esophageal intramural pseudodiverticulosis.
Finally, acquired diverticula of the esophagus and hypopharynx also may be classified according to their pathogenesis as pulsion diverticula or traction diverticula. Pulsion diverticula form as a result of high intraluminal pressures against weaknesses in the GI tract wall. Zenker diverticulum occurs due to increased pressure in the oropharynx during swallowing against a closed upper esophageal sphincter. An epiphrenic diverticulum occurs from increased pressure during esophageal propulsive contractions against a closed lower esophageal sphincter.[2] In contrast, traction diverticula occur as a consequence of pulling forces on the outside of the esophagus from an adjacent inflammatory process (eg, involvement of inflamed mediastinal lymph nodes in tuberculosis or histoplasmosis).
A Zenker diverticulum, which is seen in the images below, is formed by the herniation of mucosa through an area of weakness in the posterior wall of the hypopharynx (the Killian triangle).
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Barium esophagram, anteroposterior view, demonstrating a bilobed Zenker diverticulum.
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Zenker diverticulum, lateral view.
Sometimes Zenker diverticula are called pharyngoesophageal diverticula because of their close proximity to the cervical esophagus; however, this is somewhat of a misnomer because the diverticula actually arise from the hypopharynx rather than from the esophagus. Of the diverticula discussed in this article, Zenker diverticula are the most common type to cause symptoms.
Zenker diverticula are an acquired pulsion-type of diverticula that probably develop because of the aging process. They form in the posterior hypopharynx at a point where a defect in the muscular wall, between the inferior pharyngeal constrictor muscle and the cricopharyngeal sphincter (Killian triangle), usually exists.
Zenker diverticula are believed to occur because of an outflow obstruction caused when loss of coordination of the buccal squirt (ie, swallowing movement of the tongue posteriorly with contraction of the oropharyngeal muscles) and opening of the cricopharyngeus (ie, the upper esophageal sphincter) occurs. The noncompliant cricopharyngeus muscle becomes fibrotic over time.
Killian-Jamieson diverticula originate in the anterolateral wall just below the cricopharyngeus (Killian-Jamieson space).[3]
Oropharyngeal dysphagia, usually to solids and to liquids, is the most common symptom. Retention of food material and secretions in the diverticulum, particularly when diverticula are large, can result in regurgitation of undigested food, halitosis, cough, and even aspiration pneumonia. The patient may note food on the pillow upon awakening in the morning. With very large diverticula, a mass in the neck occasionally can be detected. Cancer rarely has been reported in association with Zenker diverticula.
Esophageal diverticula
Diverticula of the esophageal body are relatively rare. They primarily occur in the middle and distal esophagus (see the image below).
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Esophagram demonstrating a dilated tortuous esophagus and a large midesophageal diverticulum.
Diverticula that occur in the distal esophagus, in the lower 6-10 cm, are termed epiphrenic diverticula (see the image below).
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Barium esophagram demonstrating an epiphrenic diverticulum.
Diverticula of the mid and distal esophagus may have various etiologies. For instance, some diverticula in the mid esophagus are congenital in origin; others are of the traction variety. With the latter, diverticula develop by traction from contiguous mediastinal inflammation and adenopathy, eg, pulmonary tuberculosis and histoplasmosis. The diverticula that develop by traction and adenopathy usually are asymptomatic.
Retention of undigested food in large diverticula occasionally results in regurgitation, nocturnal cough, and aspiration pneumonia.
Occasional epiphrenic diverticula occur in the setting of long-standing peptic esophagitis and strictures, and they rarely are symptomatic. Other rare causes of diverticula of the mid and distal esophagus include iatrogenic surgical injury to the esophagus and Ehlers-Danlos syndrome (weakness of collagen). Perhaps the most common causes of mid esophageal and epiphrenic diverticula are motility disorders of the esophageal body, including achalasia, diffuse esophageal spasm, and hypertensive lower esophageal sphincter.
Dysphagia is the most common symptom associated with mid esophageal and epiphrenic diverticula, although it usually is related more to the underlying motility disturbance than to the diverticulum per se. However, on occasion, the diverticulum may be responsible for the dysphagia, particularly if it is very large and filled with food or a bezoar. Regurgitation and aspiration may be related to large mid esophageal and epiphrenic diverticula; however, in patients with achalasia, regurgitation and aspiration are more likely to be related to poor esophageal emptying from the underlying motility disturbance (eg, hypertensive lower esophageal sphincter that fails to relax, absence of esophageal body peristalsis).
Esophageal intramural pseudodiverticulosis
Esophageal intramural pseudodiverticulosis, which is seen in the images below, is a very rare condition in which numerous 1- to 4-mm, saccular, flask-shaped outpouchings form in the wall of the esophagus. Pseudodiverticula can number from a few to a hundred or more. This condition can be segmental or diffuse. About 200 cases have been reported in the literature.
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Multiple, small, flask-shaped outpouchings characteristic of esophageal intramural pseudodiverticulosis.
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Esophageal intramural pseudodiverticulosis involving the entire length of the esophagus.
Pseudodiverticula are formed by dilatation of the esophageal submucosal glands that communicate with the esophageal lumen.
Esophageal intraluminal pseudodiverticulosis generally is believed to be an acquired condition. While the precise pathogenesis is uncertain, inflammation and stasis appear to be factors. One hypothesis states that blockage of intramural ducts by inflammatory debris results in dilation of the submucosal glands.
Most patients with esophageal intraluminal pseudodiverticulosis have underlying esophageal strictures or dysmotility of the esophageal body. Esophageal intraluminal pseudodiverticulosis also has been reported as a consequence of corrosive injury to the esophagus, although most patients have associated strictures.
Dysphagia is the most common symptom associated with esophageal intramural pseudodiverticulosis. In most cases, esophageal intraluminal pseudodiverticulosis is related to the associated esophageal stricture or dysmotility.
An isolated case report cited significant bleeding from a distal esophageal diverticulum. The authors speculated that the bleeding resulted from food stasis, bacterial overgrowth, or chronic inflammation.
Findings on physical examination often are normal in patients with symptomatic esophageal diverticula. However, many patients relate a history of dysphagia, chest pain, or regurgitation.
Although the physical examination findings are often normal, a large Zenker diverticulum may present as a neck mass on physical examination. Halitosis also may be present and is secondary to accumulated food debris or medicines within the diverticulum.
Signs and symptoms of aspiration pneumonia may accompany the presence of large symptomatic diverticula.
Most diverticula are caused by an underlying motility disorder of the esophagus. Structural lesions, including a noncompliant cricopharyngeus muscle (ie, Zenker diverticulum), incomplete or uncoordinated relaxation of the lower esophageal sphincter, or strictures, may play a role as well. An underlying inflammatory process within the mediastinum has been associated with mid esophageal diverticula.
Radiographic studies and upper GI endoscopy detect many esophageal diverticula incidentally because esophageal diverticula often are asymptomatic. On standard chest radiographs and CT scans, large diverticula of the esophagus and hypopharynx also may manifest as air-filled and/or fluid-filled structures communicating with the esophagus.
Barium radiography (ie, barium esophagography, barium swallow) generally is the diagnostic procedure of choice. In addition to being excellent at defining the structural appearance of diverticula, barium swallow also may provide clues to underlying motility disturbances that may be involved in diverticular formation. However, if the patient has dysphagia or odynophagia or has alarm symptoms, then upper endoscopy is indicated.
Barium swallow is a useful study in patients who are symptomatic and have mid esophageal and epiphrenic diverticula. Diagnosis of esophageal intramural pseudodiverticulosis is made best using barium radiography. Diagnosis of Zenker diverticulum is made best using barium swallow, which should include lateral views of the pharyngoesophageal junction. It also can be made using careful upper endoscopy by an experienced endoscopist.
Some reports have described Killian-Jamieson diverticula being detected on ultrasonography of the thyroid gland.[4] Because of the proximity of the upper esophagus to the thyroid gland, pharyngoesophageal diverticula may mimic thyroid nodules on thyroid ultrasonography.[5] A Zenker diverticulum reportedly can be distinguished from a thyroid nodule on ultrasound by the sign of air in the diverticulum.[6]
Esophageal manometry can be helpful to evaluate lower esophageal sphincter pressure, lower esophageal sphincter relaxation, and esophageal body function in symptomatic patients if achalasia or another esophageal motility disorder is suspected or if surgery is being considered. It can also demonstrate the incoordination between the buccal squirt and relaxation of the cricopharyngeus, although special manometric techniques are usually required. In patients with dysphagia, esophageal manometry is helpful to better define underlying motility disorders.
High-resolution manometry (HRM) is a variant of the conventional manometry in which multiple recording sites are used, thus creating a “map” of the esophageal contractions. This technology allows detection of segmental peristaltic defects, detecting motor defects in a higher number of patients with epiphrenic diverticula. One recent study reported finding motor abnormalities in nine people with epiphrenic diverticula.[7]
Perform esophagogastroduodenoscopy to rule out structural conditions of the esophagus, such as strictures or neoplasms, that have been associated with esophageal diverticula.
Flexible endoscopy is a useful study in patients who are symptomatic and have mid esophageal and epiphrenic diverticula.[8, 9, 10, 11] Endoscopy is unnecessary in a patient with Zenker diverticula if the diagnosis has been made using barium radiograph. If flexible upper GI endoscopy is needed in a patient with a known Zenker diverticulum, it should be performed with caution, with the endoscope being passed under direct visualization to minimize the risk of perforation.
Asymptomatic and minimally symptomatic esophageal body diverticula do not require treatment.
In many patients with mid esophageal and epiphrenic diverticula, dysphagia is related to underlying dysmotility; thus, treatment should be directed to the motility disorder when feasible. For instance, achalasia can be treated with pneumatic dilation, botulinum toxin injection into the lower esophageal sphincter, or surgical Heller esophagomyotomy.
Treatment of esophageal intramural pseudodiverticulosis is directed toward underlying strictures or dysmotility.
Treatment of Zenker diverticulum traditionally has been surgical, although the specific operation used still is controversial. Surgical options include diverticulectomy with cricopharyngeal myotomy, diverticular suspension (diverticulopexy) with cricopharyngeal myotomy, and cricopharyngeal myotomy alone.
Diverticulectomy
Consider diverticulectomy when esophageal body diverticula are believed to be the cause of aspiration. An abdominal laparoscopic approach may be feasible for some patients with epiphrenic diverticula. Case reports of endoscopic treatment of giant midesophageal diverticula have been reported. However, patients who are being considered for diverticulectomy should first undergo careful study with barium swallow, flexible endoscopy, and esophageal manometry. Treatment directed at an underlying esophageal motility disorder, such as achalasia, cannot be ignored.
Diverticulectomy usually is not performed by itself, because it does not correct the defect in cricopharyngeal function that usually contributes to the formation of a Zenker diverticulum. While the transcervical approach has been used traditionally, the transoral route using a rigid esophagoscope also may be used.
Good results have been obtained by performing a diverticulotomy using a flexible endoscope and needle-knife papillotome to cut the common wall between the diverticulum and the oropharynx as well as the cricopharyngeus while the patient is consciously sedated. Data suggest that this technique offers good results with a relatively high success rate, but it should be performed in large centers with surgeons who are experienced with this technique. In some variations of this technique, the diverticulum is stapled.[12]
Other procedures
Other novel techniques are being developed. Flexible endoscopic diverticulotomy approaches have been explored using various techniques, including argon plasma coagulation, monopolar coagulation forceps, and needle-knife incision.[9, 10, 13, 14] These techniques typically use a cap or hood attached to the endoscope. The goal of these techniques is the division of the septum between the diverticulum and the esophagus, thus performing a cricopharyngeal myotomy.
Increased efforts to a laparoscopic approach to repair both epiphrenic diverticula and Zenker diverticula have been explored. The literature supports open surgery and a laparoscopic approach as appropriate methods of repair.[15] The laparoscopic technique uses stapler closure, and multiple case reports cite wound leakage from stapler failure as a complication. With complication rates as high as 20%, a skilled surgeon with experience in this procedure is beneficial. Benefits of the laparoscopic approach include decreased morbidity because of no thoracotomy wounds and chest tubes and a less invasive approach.
A study of 229 endoscopic diverticulotomies (in 189 patients), conducted by Kos et al, indicated that better results can be achieved using a combination of CO2 laser and Acuspot in the endoscopic procedure than by employing endoscopic diverticulotomy with electrocautery or with a carbon dioxide (CO2) laser alone.[9] The investigators reported the following postsurgical results:
Endoscopy with CO2 laser: Dysphagia was absent following 78.4% of procedures; repeat surgery was required following 19.6% of procedures
Endoscopy with electrocautery: Dysphagia was absent bsent following 72% of procedures; repeat surgery was required following 24.3% of procedures
Endoscopy with CO2 laser and Acuspot: Dysphagia was absent following 84.6% of procedures; repeat surgery was required following 13% of procedures
Several reports in the literature lately describe surgical treatment of esophageal diverticula. One recent publication analyzed a single surgeon’s experience with endoscopic CO2 laser and stapler repair of Zenker diverticulum by comparing dysphagia and regurgitation outcomes in 148 patients. This report concluded that endoscopic CO2 laser and staple methods are effective in treating Zenker diverticulum. The laser can have greater efficacy and result in lower recurrence rates.[16]
Most of the reports involve treatment of Zenker diverticula and discuss open versus endoscopic methods.[17, 18, 19, 20] None was a controlled study. They were series reports or retrospective reviews. There is no consensus of which method is the best.
Consult a gastroenterologist for patients who have symptoms associated with esophageal diverticula or who have esophageal motility disorders, such as achalasia.
Consult a general or thoracic surgeon (with experience) after gastroenterological evaluation for patients who have significant symptoms associated with Zenker diverticulum, achalasia, or diverticula.
Clinical Context:
Botulinum toxin type A is produced by Clostridium botulinum and is responsible for botulism in humans. Botulinum toxin type A produces denervation of affected muscle tissue by irreversibly binding to presynaptic nerve endings and inhibiting the release of acetylcholine.
When endoscopically injected into the lower esophageal sphincter (LES), interference with cholinergic transmission of the myenteric plexus leads to smooth muscle relaxation with a subsequent fall of the LES resting pressure. This drug has been used in other fields of medicine to treat spastic torticollis and blepharospasm.
Complications may include recurrent aspiration pneumonia, which has been associated with large symptomatic esophageal diverticula and Zenker diverticula, and, rarely, carcinoma that develops within a diverticulum.
Jack Bragg, DO, Associate Professor, Department of Clinical Medicine, University of Missouri School of Medicine
Disclosure: Nothing to disclose.
Coauthor(s)
John B Marshall, MD, Professor, Department of Internal Medicine, Division of Gastroenterology, University of Missouri School of Medicine
Disclosure: Nothing to disclose.
Specialty Editors
Francisco Talavera, PharmD, PhD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
Chief Editor
Julian Katz, MD, Clinical Professor of Medicine, Drexel University College of Medicine
Disclosure: Nothing to disclose.
Additional Contributors
Maurice A Cerulli, MD, FACP, FACG, FASGE, AGAF, Associate Professor of Clinical Medicine, Albert Einstein College of Medicine of Yeshiva University; Associate Professor of Clinical Medicine, Hofstra Medical School
Disclosure: Nothing to disclose.
Acknowledgements
Simmy Bank, MD Chair, Professor, Department of Internal Medicine, Division of Gastroenterology, Long Island Jewish Hospital, Albert Einstein College of Medicine
Disclosure: Nothing to disclose.
Christopher (Kit) Bartalos, DO Fellow, Department of Gastroenterology, University of Missouri at Columbia
Disclosure: Nothing to disclose.
Rodney A Perez, MD Medical Director, The Endoscopy Center, Asheville Gastroenterology Associates; Consulting Staff, Department of Gastroenterology, Mission St Joseph's Hospital
Rodney A Perez, MD is a member of the following medical societies: American Gastroenterological Association
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