DIVERTICULA

DIVERTICULA

For all practical purposes the original classification by Zenker of esophageal diverticula still holds true. It explains the difference between them on etiological, rather than pathological grounds. There are pulsion diverticula and traction di­verticula. A pulsion diverticulum is a hernia of the mucous membrane which protrudes through a weak area in the esophageal wall and is, almost invariably, located just proximal to a point of sphincteric action. The two sites where this occurs are at the pharyngoesophageal junction proximal to the cricopharyngeus muscle and in the epiphrenic portion of the esophagus just above the lower mus­culature which possesses a pseudosphincteric action. The proximal one is com­monly called Zenker’s diverticulum and the lower one, epiphrenic diverticulum.

DIVERTICULUM – tutorial of surgery

A traction diverticulum comprises the full thickness of the esophageal wall and is caused by a pulling outward laterally of the esophagus by inflamed hilar lymph nodes, often tuberculous, at the level of the major bronchi. These traction diverticula, because of their transverse position, do not produce the clinical picture presented by pulsion diverticula which become dependent in position with con­sequent retention of food. Operation is therefore rarely indicated for traction diverticula. Occasional transitory dysphagia is about the only symptom associated with these outpouchings (Fig. 1).

PHARYNGOESOPHAGEAL (ZENKER’S) DIVERTICULUM

By far the most frequently observed esophageal diverticulum is that oc­curring at the pharyngoesophageal junction just proximal to the cricopharyngeus muscle, commonly called Zenker’s diverticulum. Probably due to increase in intra­luminal pressure caused by contraction of the cricopharyngeus, a protrusion of mucous membrane occurs in the diamond-shaped weak area of the esophagus posteriorly between the lower edge of the oblique muscle fibers of the inferior constrictor of the pharynx and the upper edge of the cricopharyngeus (Fig. 2). With continuation of the contracting mechanism, the sac gradually enlarges and begins to descend downward, resting in the space between the posterior esophageal wall and the prevertebral fascia. The mouth of the sac, as it enlarges, assumes a transverse direction, making it almost continuous with the lumen of the pharynx. This is the reason why swallowed food readily enters the diverticulum (Fig. 3).

In patients with long-standing symptoms, these sacs may reach considerable size. I have seen diverticula in this location which descended through the superior thoracic aperture as far as the level of the aortic arch, with transverse measure­ments three or four times greater than that of the esophagus itself. Nowadays it is rare to see diverticula of such dimensions because patients seek relief at an earlier stage of the disease than was the case 20 or more years ago.

The symptoms vary with the size of the sac and run the gamut of discomfort in the throat, choking spells, intermittent dysphagia, excess salivation, and embar­rassing gurgling noises when swallowing liquids (due to admixture with air). In the large ones, loss of weight occurs because most of the food enters the sac rather than the esophagus and is regurgitated by the patient. The diagnosis can be made clinically by a simple test. The patient is asked to drink three or four ounces of water. If undue gurgling is heard as he swallows the liquid, apply pressure on the left side of the neck just below the cricoid cartilage against the vertebral column; this will cause the expulsion of water from the diverticulum into the patient’s pharynx.

Fig. 1. X-ray of the esophagus showing a traction diverticulum of the middle third of the esophagus.

Fig. 2. Posterior view of the esophagus indicating the site of emergence of a Zenker’s diverticulum between the lower edge of the inferior constrictor of the pharynx and the cricopharyngeus muscle.

Increasing Food Flow        Major Food Flow Main Direction of Food Flow Into Diverticulum        Into Diverticulum

Fig. 3. Diagrammatic representation of the development of a Zenker’s diverticulum showing the gradual formation of a transverse position of the neck of the sac which favors the major flow of food into the diverticulum.

 

Further diagnostic investigation should always include roentgen examination while swallowing a barium mixture. The x-ray films taken from various angles will indicate the size of the sac, the location and size of its mouth, the direction of the lower end of the sac with respect to the midline, and any distortion or displacement of the esophagus itself (Figs. 4, 5).

Fig. 4. Typical roentgenogram of a Zenker’s diverticulum of moderate size.

I have never seen any justification for subjecting a patient with a Zenker’s diverticulum to esophagoscopy. The danger of instrumental perforation is great and nothing is really gained by the examination. It certainly is not indicated at the time of operation, a practice in vogue some years ago as a method of helping the surgeon to locate the sac.

Fig. 5. A large Zenker’s diverticulum extending into the superior mediastinum.

Other than the perisaeeular inflammation that may occur from decomposition of retained food, there are two complications that deserve mention. The occurrence of recurrent attacks of pulmonary infection due to aspiration of sac contents into the trachea is the more frequent complication. Recently, I saw an elderly woman who entered the hospital with high fever and roentgen evidence of extensive pulmonary infiltration. She had a large Zenker’s diverticulum of long standing, which caused persistent regurgitation, distressing cough, and considerable weight loss. In spite of intravenous feeding, interdiction of swallowing, and the liberal use of anti­biotics, there was no lowering of the fever or improvement in the pulmonary infection. Somewhat reluctantly, I removed the diverticulum, following which there was a dramatic lowering of the fever and a rapid resolution of the pulmonary infection. An uneventful convalescence followed. It is important to remember this clinical sequence.

Another, much less common, complication is the occurrence of carcinoma in the sac. I reported one such instance recently. This patient had a diverticulum for over 20 years which he regularly emptied after each meal by vigorously com­pressing the sac against the vertebral column. The appearance of blood finally sent him to a surgeon. Whether or not this repeated trauma over so many years was a factor in the development of cancer is a moot question (Annals of Surgery, Vol. 154, August 1961) (Fig. 6).

 

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