A Zenker’s diverticulum (ZD) is an abnormal, pouch-like structure that forms in the throat where the lower part of the pharynx meets the upper esophagus. It is also known as a pharyngoesophageal diverticulum or pharyngeal pouch. This relatively rare condition most often affects older adults, particularly those in their seventh or eighth decade of life. The pouch is considered a “false” diverticulum because it involves only the inner lining (mucosa and submucosa) of the digestive tract wall, rather than all layers.
How the Diverticulum Forms
The development of the diverticulum is tied to a specific area of weakness in the throat musculature called Killian’s triangle. This triangular space is located on the back wall of the pharynx, just above the cricopharyngeal muscle, which acts as the upper esophageal sphincter (UES). Normally, this muscle relaxes quickly during swallowing to allow food to pass smoothly into the esophagus.
In individuals who develop ZD, the cricopharyngeal muscle fails to relax completely or remains uncoordinated. This dysfunction causes the pressure inside the lower pharynx to spike when a person swallows food. This increased pressure forces the inner lining of the throat to push outward through the path of least resistance, which is Killian’s triangle.
This mechanism is known as a “pulsion” diverticulum, where excessive internal pressure pushes the tissue layers out. Over time, the resulting pouch grows, often hanging down and collecting food particles and saliva. This anatomical change can worsen the swallowing problem, as the growing pouch may press on the esophagus itself.
Recognizing the Signs and Symptoms
The most common symptom of Zenker’s diverticulum is dysphagia, or difficulty swallowing. Patients often feel as though food is getting stuck in their throat or have a sensation of a lump near the neck. As the pouch fills with food, it can cause the regurgitation of undigested food and liquids, sometimes hours after a meal.
Retention of food within the pouch can lead to other uncomfortable symptoms, most notably halitosis, or bad breath, due to the decaying food. A chronic cough or the unintended aspiration of food or liquid into the windpipe can also occur, particularly at night, raising the risk of recurrent lung infections. The inability to eat comfortably and chronic regurgitation may eventually lead to unintended weight loss.
Identifying the Condition
Physicians rely on objective testing to confirm the diagnosis of Zenker’s diverticulum, with the Barium Swallow being the most common and effective test. During this procedure, the patient swallows a liquid containing barium sulfate, a contrast agent that coats the inside of the digestive tract. A series of X-ray images, often recorded as a video, are taken as the patient swallows.
The barium clearly outlines the digestive path, making the abnormal pouch visible as it fills with the contrast agent. This test confirms the presence of the diverticulum and shows its size and exact location relative to the esophagus. Endoscopy, which uses a flexible tube with a camera, may also be used to examine the lining of the pouch and rule out other issues like cancer. However, inserting the tube near the pouch requires caution due to a slight risk of perforation.
Managing and Treating Zenker’s Diverticulum
Treatment for Zenker’s diverticulum is reserved for patients experiencing noticeable or disruptive symptoms. The goal of intervention is to relieve high pressure and eliminate food retention by addressing the underlying muscle dysfunction. This is achieved by dividing the cricopharyngeal muscle, a procedure called a myotomy, which allows food to pass more easily into the esophagus.
Endoscopic repair has become the preferred approach for many patients due to its minimally invasive nature. This procedure involves passing instruments through the mouth to cut the muscular wall between the pouch and the esophagus, effectively turning the two structures into one common channel. Endoscopic techniques, which often use specialized staplers or lasers, result in shorter hospital stays, quicker recovery, and an earlier return to eating.
Open surgical repair, which involves an external incision in the neck, is a more traditional method used for very large diverticula or when endoscopic repair is not feasible. This approach often includes both the cricopharyngeal myotomy and the removal of the pouch itself, known as a diverticulectomy. While open surgery offers a strong success rate, it is more invasive and carries a higher risk of complications compared to the endoscopic approach. The decision between methods depends on the pouch size, the patient’s overall health, and the surgeon’s expertise.