Esophageal diverticula are unusual but interesting abnormalities that can develop in any part of the esophagus. Most commonly they are found in the cervical esophagus, and in this location they are known as Zenker's diverticula. Esophageal diverticula also may be found in the midesophageal area near the pulmonary hilum and in the epiphrenic region in the distal esophagus.
There are two types of esophageal diverticula–pulsion and traction. Each has a distinct etiology. The pulsion type is the most common form in the United States. A pulsion diverticulum develops as a consequence of a motility abnormality in the esophagus distal to the site of the diverticulum.1 The most common pulsion diverticulum is the Zenker's variety, and it occurs secondary to repetitive pharyngeal pressure on boluses of food that are delayed by a dysfunctional cricopharyngeus muscle.2 Over time, this pressure causes a herniation of the esophageal mucosa through a weak point, called Killian's dehiscence. This point is located superior to the cricopharyngeus muscle at its junction with the inferior constrictor muscle. Pulsion diverticula are not composed of the entire wall of the esophagus and therefore are considered false diverticula (Fig. 25-1). Radiographically, they tend to have a wide neck and rounded contour, and typically they retain contrast material on a barium swallow (Fig. 25-2).
A. The epiphrenic esophageal diverticulum depicted in the intraoperative photograph is of the pulsion variety. Pulsion diverticula (B) are not covered by the muscle layers of the esophageal wall and thus are considered false diverticula.
Barium swallow of a patient with a large epiphrenic diverticulum.
Traction diverticula, on the other hand, are caused by granulomatous inflammation of mediastinal lymph nodes. The inflamed nodes attach to the esophagus. With subsequent contraction, the nodes pull on the esophagus, creating a conical outpouching. Traction diverticula are considered true diverticula because the entire wall of the esophagus is involved in the defect. In contrast to pulsion diverticula, traction diverticula tend to have a pointed tip that empties well on barium swallow (Fig. 25-3). Traction diverticula are found most commonly in areas where tuberculosis or histoplasmosis is endemic. The prevalence of all types of diverticula increases with age.
A. Barium swallow of a patient with a midesophageal traction diverticulum. Note the calcified nodes in hilum. B. Illustration of a true diverticulum showing involvement of the complete esophageal wall.
Symptoms associated with pulsion diverticula are often initially related ...