Pharyngeal pouch

What is a pharyngeal pouch?

A pharyngeal pouch, also called Zenker's diverticulum, is a small pocket that can form between your throat and the top of your food pipe (oesophagus). It happens when the lining of your throat bulges outward through a naturally weak point in the surrounding muscle.

What are the symptoms of a pharyngeal pouch?

A very small pouch may cause no symptoms, or only an occasional feeling of food sticking in your throat. As a pouch grows larger, it can collect food and put pressure on the entrance to your food pipe, causing:

• difficulty swallowing, with food feeling like it is sticking just below your Adam's apple
• regurgitation of undigested food, sometimes minutes to hours after eating, especially when lying flat
• a gurgling noise in your throat when you eat
• a chronic cough, or choking sensation, if food or liquid spills into your windpipe
• chest infections that keep coming back
• bad breath or a hoarse voice
• weight loss, if swallowing problems reduce how much you can eat.

An obvious lump in the neck and pain are possible but rare.

What causes a pharyngeal pouch, and who is at risk?

The exact cause is not fully understood, but a pharyngeal pouch tends to form where the muscle wall of the throat is naturally weaker. To swallow normally, the muscles lower in your throat need to relax and let food pass through to your food pipe. If they do not relax enough, or move in an uncoordinated way, pressure builds up and can push the lining of your throat through this weak point. Severe acid reflux can also cause muscle spasm that contributes to swallowing problems.

A pharyngeal pouch can occasionally be present from birth, but it is far more commonly acquired with age, typically from around 50 years old onwards, and most often affects people aged 70 and older. It is uncommon overall, affecting an estimated 1 person in 100,000 each year, and is more common in men than women, affecting roughly three men for every two women.

Are there different types of pharyngeal pouch?

Pharyngeal pouches vary mainly by size and the symptoms they cause. A small pouch may not need any treatment, while a larger pouch is more likely to collect food, causing swallowing problems, regurgitation and chest infections.

Rarely, abnormal cells can develop within a pharyngeal pouch, which is thought to affect around 1 in 200 people who have one. Your surgeon may take this into account when examining or treating your pouch.

How is a pharyngeal pouch diagnosed?

The main test is a barium swallow, sometimes called videofluoroscopy. This involves swallowing a liquid contrast (dye) while X-rays are taken, which shows the pouch and allows its size to be assessed. An upper endoscopy, using a thin tube with a camera, can also be used to look at your throat and food pipe directly.

If your symptoms are mild, your GP may monitor you before referring you to an ear, nose and throat (ENT) specialist if they get worse. Your specialist may also run further tests to rule out other causes of any weight loss.

How is a pharyngeal pouch treated?

Non-surgical treatment

If your pouch is small and not causing significant symptoms, or you are not well enough for surgery, it may simply be monitored, sometimes alongside changes to your diet. Other non-surgical options for smaller pouches include:

• Botox (botulinum toxin) injections into the tight throat muscle, to help manage symptoms
• balloon dilatation, where a small balloon is used to stretch the muscle
• surgical dilatation (stretching) of the throat under general anaesthetic, which relieves symptoms temporarily but carries a small risk of tearing the throat.

The downside of managing a pouch without surgery is that swallowing problems can continue or slowly worsen over time, which may lead to malnutrition, and techniques such as Botox or balloon dilatation are more likely to need repeating than surgery.

Surgical treatment

Surgery aims to open the pouch into the food pipe so food no longer collects there. The two main approaches are:

• endoscopic stapling (sometimes called Dohlman's procedure), where a rigid tube is passed through your mouth to reach the pouch, and a stapling device cuts and seals the wall between the pouch and your food pipe, also releasing the tight muscle. This is the most common and least risky approach, and many patients go home the same day or after one night
• an endoscopic laser technique, where a laser divides the muscle instead of, or alongside, stapling. This usually needs a longer hospital stay of two to five days, with feeding through a tube while the area heals
• open surgery (sometimes called cricothyromyotomy or diverticulotomy with myotomy), through a cut in the neck, to remove or reposition the pouch and release the tight muscle. This is used if the endoscopic approach is not possible, for example if the pouch is too large or your mouth or neck cannot accommodate the endoscope, and needs a longer hospital stay of around five to seven days.

After endoscopic surgery, you can usually start drinking water within about six hours, and move on to soft food and then a normal diet over the following days. Most people need one to two weeks off work. Some hospitals arrange a follow-up appointment around three months later, while others will not routinely see you again unless problems continue.

When should I see a doctor?

See your GP if you have ongoing difficulty swallowing, food sticking in your throat, unexplained regurgitation of food, or a gurgling noise when you eat.

After surgery, report a racing pulse, a high temperature and chest pain to your medical team immediately. These can be signs of mediastinitis, a rare but serious infection in the chest, and need urgent attention.