Diverticulum is a medical term that refers to an abnormal, pouch-like structure. Diverticula can form in nearly all areas of the digestive tract.

When a pouch forms at the junction of the pharynx and the esophagus, it is called Zenker’s diverticulum. The pharynx is located at the back of your throat, behind your nasal cavity and mouth.

Zenker’s diverticulum typically appears in the hypopharynx. This is the bottommost part of the pharynx, where it joins the tube (esophagus) that leads to the stomach. Zenker’s diverticulum usually appears in an area known as Killian’s triangle.

Zenker’s diverticulum is rare, affecting between 0.01 and 0.11 percent of the population. It tends to occur in middle-aged and older adults, especially people in their 70s and 80s. Zenker’s diverticulum is rare among people under 40. It affects men more often than women.

It’s also referred to as pharyngoesophageal diverticulum, hypopharyngeal diverticulum, or pharyngeal pouch.


There are several different systems for classifying Zenker’s diverticulum:

Lahey systemBrombart and Monges systemMorton and Bartley systemvan Overbeek and Groote system
Stage 1small, round protrusionthorn-like diverticulum
2–3 millimeter (mm)
longitudinal axis
<2 centimeters (cm)1 vertebral body
Stage 2pear-shapedclub-like diverticulum
7–8 mm longitudinal axis
2-4 cm1–3 vertebral bodies
Stage 3shaped like a gloved fingerbag-shaped diverticulum
pointing downward
>1 cm in length
>4 cm>3 vertebral bodies
Stage 4no stage 4esophageal compressionno stage 4no stage 4

Difficulty swallowing, also known as dysphagia, is the most common symptom of Zenker’s diverticulum. It appears in an estimated 80 to 90 percent of people with Zenker’s diverticulum.

Other signs and symptoms of Zenker’s diverticulum include:

If left untreated, symptoms of Zenker’s diverticulum can worsen over time.

Swallowing is a complex process that requires coordination of the muscles in the mouth, pharynx, and esophagus.

When you swallow, a circular muscle called the upper esophageal sphincter opens to allow chewed food matter to pass. After you swallow, the upper esophageal sphincter closes to prevent inhaled air from entering the esophagus.

The formation of Zenker’s diverticulum is related to upper esophageal sphincter dysfunction.

When the upper esophageal sphincter doesn’t open all the way, it puts pressure on an area of the pharynx wall. This excess pressure gradually pushes the tissue outward, causing it to form the diverticulum.

Gastroesophageal reflux disease (GERD) and age-related changes in tissue composition and muscle tone are also thought to play a role in this process.

Talk to your doctor if you or someone you care for is experiencing symptoms of Zenker’s diverticulum.

Zenker’s diverticulum is diagnosed using a test called a barium swallow. A barium swallow is a special X-ray that highlights the inside of your mouth, pharynx, and esophagus. A barium swallow fluoroscopy allows your doctor to see how you swallow in motion.

Sometimes, other conditions are present alongside Zenker’s diverticulum. Your doctor might suggest additional tests to detect or rule out other conditions.

An upper endoscopy is a procedure that involves using a thin, camera-equipped scope to look at the throat and esophagus. Esophageal manometry is a test that measures pressure inside the esophagus.

Mild cases of Zenker’s diverticulum may not require immediate treatment. Depending on your symptoms and the size of the diverticulum, your doctor might suggest a “wait and see” approach.

Changing your eating habits can sometimes help improve symptoms. Try eating smaller quantities of food in a single sitting, chewing thoroughly, and drinking between bites.

Moderate to severe cases of Zenker’s diverticulum usually require surgery. There are a few surgical options. Your doctor can help you understand which option is best for you.

Endoscopic procedures

During an endoscopy, a surgeon inserts a thin, tube-like instrument called an endoscope into your mouth. The endoscope is equipped with a light and a camera. It can be used to make an incision in the wall that separates the diverticulum from the lining of the esophagus.

Endoscopies for Zenker’s diverticulum can be rigid or flexible. A rigid endoscopy uses an unbendable endoscope and requires general anesthesia. Rigid endoscopies require significant neck extension.

Because of the risk of complications, this procedure is not recommended for people who have:

  • a small diverticulum
  • a high body mass index
  • difficulty extending their neck

A flexible endoscopy uses a bendable endoscope and can be performed without general anesthetic. It’s the least invasive surgical option available for treating Zenker’s diverticulum. It’s usually an outpatient procedure that carries a low risk of complications.

Though flexible endoscopies can ease symptoms of Zenker’s diverticulum, recurrence rates can be high. Multiple flexible endoscopy procedures may be used to address recurring symptoms.

Open surgery

When an endoscopy isn’t possible or the diverticulum is large, open surgery is the next option. Surgery for Zenker’s diverticulum is done under general anesthetic.

The surgeon will make a small incision in your neck in order to perform a diverticulectomy. This involves separating the diverticulum from your esophageal wall. In other cases, the surgeon performs a diverticulopexy or a diverticular inversion. These procedures involve changing the position of the diverticulum and sewing it in place.

Open surgery has a high success rate, with symptoms unlikely to reappear in the long term. However, it requires a hospital stay of several days and sometimes, a return to the hospital to remove stitches.

You might need to use a feeding tube for a week or more following the procedure. Your doctor might suggest following a special diet while you heal.

If left untreated, Zenker’s diverticulum can increase in size, making your symptoms worse. Over time, severe symptoms such as difficulty swallowing and regurgitation can make it difficult to stay healthy. You might experience malnutrition.

Aspiration is a symptom of Zenker’s diverticulum. It occurs when you inhale food or other matter into the lungs instead of swallowing it into the esophagus. Complications of aspiration include aspiration pneumonia, an infection that occurs when food, saliva, or other matter get trapped in your lungs.

Other rare complications of Zenker’s diverticulum include:

Approximately 10 to 30 percent of people who undergo open surgery for Zenker’s diverticulum experience complications. Possible complications include:

  • pneumonia
  • mediastinitis
  • nerve damage (palsy)
  • hemorrhage (bleeding)
  • fistula formation
  • infection
  • stenosis

Speak to your doctor about the risks of open surgery for Zenker’s diverticulum.

Zenker’s diverticulum is a rare condition that typically affects older adults. It occurs when a pouch of tissue forms where the pharynx meets the esophagus.

Mild forms of Zenker’s diverticulum may not require treatment. Treatment for moderate to severe forms of Zenker’s diverticulum typically involves surgery.

The long-term outlook for Zenker’s diverticulum is good. With treatment, most people experience an improvement in symptoms.

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