Esophageal diverticula are unusual but interesting abnormalities that can develop in any part of the esophagus. The most common esophageal diverticulum occurs in the cervical region and is known as a Zenker diverticulum. An esophageal diverticulum may also occur in the midesophagus near the pulmonary hilum or as an epiphrenic diverticulum near the gastroesophageal junction. There are two categories of esophageal diverticula—pulsion and traction. Each has a distinct etiology. Pulsion diverticula are the most common type in the United States and develop as a consequence of a motility abnormality in the esophagus distal to the site of the diverticulum.1 They are false diverticula because they are not composed of the entire wall of the esophagus, but instead the mucosa herniates or protrudes through the muscle layers (Fig. 30-1).
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.
The other type, traction diverticula, develop secondary to inflamed mediastinal lymph nodes and represent a true diverticulum since all layers of the esophageal wall are involved. The prevalence of all types of diverticula increases with age.
Pulsion diverticula are the most common type of diverticulum, and the most common pulsion diverticulum is a Zenker diverticulum. These develop in the cervical region secondary to repetitive pharyngeal pressure on boluses of food that are held up by a dysfunctional cricopharyngeus muscle.2 Over time, this pressure causes a posterior herniation of the esophageal mucosa through Killian dehiscence, a weak point at the junction of the inferior constrictor and cricopharyngeus muscles. Epiphrenic diverticula are also pulsion diverticula. These develop secondary to a motility disorder in the distal esophagus, most commonly at the gastroesophageal junction and most commonly achalasia.3 Radiographically, pulsion diverticula typically have a wide neck and a rounded contour, and they retain contrast material on a barium swallow (Fig. 30-2). Symptoms associated with pulsion diverticula are often initially related to the underlying motility abnormality, but as the size of the diverticulum increases the symptoms may become more attributable to the pouch itself. Thus, while dysphagia is often the primary initial symptom, as the pouch enlarges, regurgitation may become more prominent. It is not unusual for these symptoms to lead to a misdiagnosis of gastroesophageal reflux disease before the diverticulum itself is identified (Fig. 30-3). However, careful questioning will usually elicit the key information that the regurgitated material tastes bland, not bitter, since the regurgitated food or fluid was trapped in the pouch and never made it to the stomach. Other symptoms attributable to a diverticulum are halitosis, cough, and aspiration of debris retained within the pouch. The larger and more proximal the pouch, the more troublesome these ...