Pharyngeal Pouch or Zenker's Diverticulum

Introduction:

The pharyngeal pouch or sac is formed in the pharynx. It is a very uncommon condition and affects mostly elderly people. It is also referred to as Zenker's diverticulum. The pouch or sac developed in the pharynx can aggravate from a small size to a larger size, resulting in worsening symptoms. The condition is mostly the result of fibrosis of the cricopharyngeus muscle (located at the upper end of the esophagus). The cricopharyngeal muscles usually relax during swallowing. The swallowing mechanism gets disrupted due to the tightening or hardening of the cricopharyngeus muscle because of fibrosis.

What Is the Incidence of Pharyngeal Pouch Formation?

• The pharyngeal pouch or Zenker's diverticulum is seen most commonly among elderly patients in the age group of 70 to 80 years old.

• A pharyngeal pouch is very uncommon in people below 45 years.

What Are the Causes of Zenker's Diverticulum or Pharyngeal Pouch?

The cause of Zenker's diverticulum is not yet known; however, it is supposed to be caused by the weaker point of muscle located in the hypopharynx, which is called Killian's dehiscence area or Killian's triangle. The fibrosis of these muscles results in stiffening of the muscle, thereby disrupting the normal function of swallowing.

What Are the Signs and Symptoms of Pharyngeal Pouch Formation?

Patients are asymptomatic if the sac or pouch formed is small. As the pharyngeal pouch enlarges, patients present with the following symptoms:

• The deposit of food within the pouch results in pressure on the esophagus.

• Dysphagia (difficulty in swallowing).

• Loss of appetite results in weight loss.

• Vomiting and choking feeling due to the presence of liquid and food particles in the pouch.

• Recurrent chest infections.

• Acid reflux or regurgitation due to indigestion.

• Infection.

• Coughing sensation.

• The sensation of the presence of a foreign body in the throat.

• Aspiration pneumonia.

• Halitosis (bad breath).

• A lump in the neck.

• Obstruction in the airway.

• Change of voice.

How to Diagnose Zenker's Diverticulum or Pharyngeal Pouch?

Various methods for diagnosing pharyngeal pouch are:

• Clinical Examination and History: A thorough history of the patients should be recorded for the presenting signs and symptoms. Signs and symptoms like choking sensations, halitosis, acid reflux due to indigestion, and recurrent chest infection should be recorded carefully. A complete physical examination of the patient should be done to evaluate any lump or soft tissue mass in the neck.

• Fluoroscopy: A barium swallow test followed by a computed tomographic scan or chest X-ray helps diagnose the pharyngeal pouch easily. It helps to detect patients with aspiration pneumonia. The pharyngeal pouch is usually observed between C5 to C6 levels of vertebrae.

• Endoscopic Examination: A flexible fiberoptic (tube with an attached camera) endoscope is used to examine the esophagus completely for the presence of a sac or pouch.

What Is the Treatment for the Formation of a Pharyngeal Pouch?

The pharyngeal pouch can be managed by:

• Endoscopic Management: The endoscopic approach for treating the pharyngeal sac is comparatively simpler with reduced risk than the open surgical approach. The surgery is usually performed under general anesthesia. In this method, a tube is introduced into the food pipe through the mouth to approach the pouch. After reaching the pharyngeal pouch, a specialized stapler is used to cut the fibrotic walls to release the tension of the cricopharyngeus muscle. This technique is called endoscopic pharyngeal sac stapling.

• Endoscopic Laser Cricopharyngeal Myotomy: A carbon dioxide (CO2) laser is used in this surgical procedure to remove as well as release the fibrotic bands of the cricopharyngeus muscles and divide the pouch. The patient is monitored for a few days, and Ryle's feeding tube is given. A postoperative radiograph is taken to check for the healing of the esophagus.

• Open Surgical Approach: In an open surgical procedure, a horizontal incision is given in the neck along the cricoid cartilage along with an anterior border of the sternocleidomastoid muscle. The pharyngeal sac is identified using the endoscope, and it is excised or inverted based on the size of the pharyngeal sac. Excision (cutting by a surgical blade) is usually preferred for the larger pouch. The cut given is then closed with suture (stitches), and the patient is kept on observation for a few days.

What Are the Advantages and Drawbacks of the Endoscopic Approach for Pharyngeal Pouch Removal?

The advantages and disadvantages associated with the endoscopic surgical approach are:

Advantages:

• It is comparatively simpler and carries less risk than the open surgical approach.

• Faster procedure.

• No outer cuts are used.

Drawbacks:

• Recurrence of the pharyngeal sac can occur.

• Greater complication rates.

• In the case of larger pharyngeal pouches, it is sometimes difficult to perform the procedure.

What Are the Advantages and Drawbacks of the Open Surgical Approach for Pharyngeal Pouch Removal?

The advantages and disadvantages associated with the open surgical approach are:

Advantages:

• Multiple pouches can be treated by this method.

• The risk of recurrence is very low with an open surgical approach.

Disadvantages:

• Need an external cut in the neck for performing surgery.

• Scar formation is seen.

What Are the Complications Associated With Pharyngeal Pouch Surgery?

Various complications that may occur after surgery are:

• Recurrent Laryngeal Nerve Palsy: There is a risk of recurrent laryngeal nerve palsy associated with the surgery. Injury to recurrent laryngeal nerves can result in hoarseness of voice.

• Salivary Fistula: The risk of salivary leak increases after endoscopic surgery.

• Hematoma: The risk of hematoma formation is associated with the surgery.

• Recurrence: Pharyngeal pouch can recur after the surgery. The risk of recurrence is more with an endoscopic approach as compared to the open surgical approach.

Conclusion:

A pharyngeal pouch or Zenker's diverticulum is a rare infection involving the food pipe. It affects mostly the elderly age group and can cause mild to severe dysphagia. In addition, it affects the cricopharyngeal muscle resulting in fibrosis of the muscle. Early diagnosis and management of the pharyngeal sac are crucial to prevent associated symptoms like gastric regurgitation, recurrent chest infection, and aspiration pneumonia. Any delay in the management can result in enlargement of the pharyngeal pouch, which can exert pressure on the windpipe and can also cause respiratory obstruction.