Zenker's Diverticulum (Pharyngeal Pouch)

What is Zenker's diverticulum?

When you swallow, throat muscles push food down while the cricopharyngeus muscle (upper esophageal sphincter) relaxes to let it through. In Zenker's diverticulum, this muscle becomes stiff and does not open fully. The repeated high pressure pushes the lining of the throat out through a naturally weak triangular area just above the muscle, called Killian's triangle.

Over years, the pouch slowly enlarges. Food and liquid enter it instead of passing down the esophagus, sit there and later spill back into the throat.

It is a "false" or pulsion diverticulum: only the inner lining pushes out, not the full muscle wall. Related but less common pouches are the Killian-Jamieson diverticulum, which forms slightly lower and to the side, and the epiphrenic diverticulum, near the bottom of the esophagus.

Symptoms

• Difficulty swallowing (oropharyngeal dysphagia), usually gradual
• Regurgitation of undigested food, sometimes hours after eating or when bending over or lying down
• Gurgling in the throat when swallowing
• Bad breath from food decaying in the pouch
• Coughing, choking or throat clearing after meals or at night
• A feeling of a lump in the throat
• Pills seeming to get stuck or reappearing
• Hoarse voice
• Weight loss in larger pouches
• A soft swelling on the left side of the neck in some people

Causes and risk factors

• Age: most patients are 60 to 80
• Stiffening and reduced relaxation of the cricopharyngeus muscle, a form of cricopharyngeal dysfunction
• Possibly reflux, though the link is debated
• More common in people of northern European descent and in men

Complications

• Aspiration pneumonia from regurgitated material entering the lungs, the most serious complication
• Malnutrition and dehydration
• Pills getting trapped, reducing their effect
• Perforation of the pouch during endoscopy or passing a feeding tube, which is why the condition should be known before such procedures
• Cancer within the pouch: rare, well under 1 to 2% of cases

Diagnosis

• Barium swallow (esophagram): the key test. You swallow contrast liquid while X-rays are taken, showing the pouch, its size and how it fills and empties.
• Upper endoscopy: may be done to examine the pouch lining and rule out cancer, with care to avoid entering the pouch by accident.
• Videofluoroscopic swallow study or manometry in selected cases to assess muscle function.
• CT scan occasionally, when the diagnosis is unclear.

Many other conditions cause swallowing problems, including achalasia, strictures, stroke and esophageal cancer, so new difficulty swallowing in an older adult always needs testing.

Treatment

Small pouches with few symptoms can be watched. Treatment is advised when symptoms affect eating, cause aspiration or weight loss. All approaches divide the cricopharyngeus muscle, which removes the cause, and deal with the pouch.

Endoscopic treatment (through the mouth)

• Flexible endoscopic septotomy: a gastroenterologist uses a flexible scope to cut the wall (septum) between the pouch and the esophagus, including the cricopharyngeus muscle, joining them into one channel.
• Z-POEM (peroral endoscopic myotomy): a newer technique that tunnels under the lining to cut the muscle completely.
• Rigid endoscopic stapling or laser (ENT approach): a surgeon staples or lasers the wall through a rigid scope under general anesthesia.

These are quicker, avoid a neck incision and usually allow eating within a day or two. Recurrence is somewhat more common than after open surgery, but procedures can be repeated.

Open surgery

Through a cut on the left side of the neck, the surgeon divides the cricopharyngeus muscle (cricopharyngeal myotomy) and removes the pouch (diverticulectomy), suspends it, or inverts it. Open surgery suits large pouches or very small ones that endoscopic tools cannot reach. Results are durable, with longer recovery and a small risk of nerve injury causing hoarseness.

Recovery

Most people return to a soft diet within days and a normal diet within 1 to 2 weeks. Swallowing, regurgitation and cough improve in the large majority after treatment.

Living with Zenker's diverticulum

Before treatment, some measures reduce symptoms:

• Eat slowly, take small bites and chew well
• Choose soft, moist foods
• Drink water after meals to rinse the pouch
• Massage or press gently on the neck, or turn the head, if this helps empty the pouch
• Raise the head of the bed and avoid lying down soon after eating
• Ask whether pills can be taken in liquid form

Frequently asked questions

What are the symptoms of Zenker's diverticulum?

Common symptoms are trouble swallowing, food coming back up undigested, gurgling in the throat, bad breath, coughing or choking after meals, a lump-in-the-throat feeling and weight loss. Symptoms often worsen slowly over years as the pouch enlarges.

What causes Zenker's diverticulum?

It is caused by the upper esophageal sphincter muscle not relaxing properly during swallowing. The increased pressure pushes the throat lining out through a weak spot just above that muscle, forming a pouch. Aging is the main risk factor, and most people are diagnosed after age 60.

How is Zenker's diverticulum diagnosed?

The main test is a barium swallow, an X-ray taken while you swallow a contrast liquid, which clearly shows the pouch. Endoscopy may be used to look at the lining and plan treatment. Tell any doctor doing endoscopy that you have the pouch, as instruments can enter it accidentally.

Can Zenker's diverticulum go away on its own?

No. The pouch does not shrink by itself, and it usually slowly grows over time. Small pouches with mild symptoms can be monitored. Bothersome or growing pouches are treated with an endoscopic procedure or surgery that cuts the tight muscle and opens or removes the pouch.

Is Zenker's diverticulum dangerous?

It is not usually life-threatening, but it can cause serious problems. The biggest risk is aspiration pneumonia from regurgitated food entering the lungs. It can also cause malnutrition and weight loss. Cancer in the pouch is rare. Treatment greatly reduces these risks.