Disclosure Zenker diverticulum is rare, occurs in elderly populations, and results in a classic presentation of symptoms. The condition has severe complications, including aspiration and pneumonia, and is managed by surgical repair. This article discusses the presentation and management of this classic disease process. History of the Procedure: In 1877, Friedrich Albert von Zenker, professor of pathology at Erlangen University in Germany, described the pulsion diverticulum that bears his name. His series included 5 personal cases and 22 cases collected from the literature. In the beginning of the 20th century, Killian identified the origin of the diverticulum between the cricopharyngeus muscle and the inferior pharyngeal constrictor muscles. Wheeler first successfully resected this pharyngoesophageal diverticulum in 1886. Problem: The esophageal mucosa herniates posteriorly between the cricopharyngeus muscle and the inferior pharyngeal constrictor muscles; therefore, Zenker is a false diverticulum. This diverticulum carries with it a high frequency of food elements retained within its pouch. These food elements and secretions lead to halitosis, regurgitation, aspiration, and dysphagia. Frequency: International: European prevalence parallels that of the United States, but the disease is rarely reported in the Middle East and Far East. Etiology: The etiology is incompletely understood; and, since Zenker diverticulum is unique to humans, experimental modeling is not possible. It is thought that patients with Zenker diverticulum have improperly timed relaxation of the cricopharyngeus muscle during swallowing. Over time, the increased pressure causes herniation of the esophageal mucosa posteriorly, between the inferior pharyngeal constrictor and the cricopharyngeus muscle. Whether these patients have an anatomical predisposition to diverticulum formation is unknown. Pathophysiology: Abnormal muscle activity in the cricopharyngeus results in a discoordination of the swallowing mechanism that causes increased pressure on the mucosa of the pharynx. This results in the slow, progressive distention of the mucosa. The weakest area is posterior, the location of the pulsion diverticulum formation. Esophageal manometry has been used to elucidate the pathophysiology of the upper esophagus, which is responsible for the diverticular formation. However, upper esophageal manometry is technically difficult to perform. Results are confounded by the asymmetry of the upper esophageal sphincter. Pressures can be very high, but they last for only a fraction of a second, resulting in difficulty obtaining equipment sensitive enough to demonstrate these pressures accurately. To further confound the problem, the process of obtaining measurements stimulates the swallowing reflex, resulting in the catheter being displaced and the data lost. Because of these limitations, very few studies have been performed to describe the manometric aspects of Zenker diverticulum. Manometry is certainly not useful in routine patient evaluation. The studies that have been performed show upper esophageal sphincter pressures that can be either normal or decreased. Some patients have abnormal premature relaxation and contractions of the upper esophageal sphincter, while others have pharyngeal contractions against a closed sphincter. Clinical: Patients present with upper esophageal dysphagia, regurgitation of undigested food, aspiration, noisy deglutition, halitosis, and changes in voice. Mild-to-moderate weight loss is frequent. Aspiration and pneumonia are potentially serious complications. Although the diverticulum can reach sizes of 15 cm or more, it is rarely palpable. Squamous cell carcinoma has been found in the diverticulum in less than 0.5% of specimens. Coexistent hiatal hernia, esophageal spasm, achalasia, and esophagogastroduodenal ulceration are common.
Indications for repair are broad. The diverticulum can frequently be the etiology for aspiration and pneumonia. For this reason, it should be repaired in patients capable of tolerating the operative procedure. Nonoperative management may be undertaken in patients with small diverticula (<1 cm) or in those with medical comorbidities precluding surgery.
Relevant Anatomy: Absolute contraindications to operative management of a Zenker diverticulum do not exist. Relative contraindications to surgery are few. In an asymptomatic patient with a small diverticulum (<1 cm) discovered incidentally, the surgeon may elect to follow the patient for the development of symptoms or enlargement of the diverticulum. The only other relative contraindication to operative treatment is the inability of the patient to tolerate the procedure; however, with the broad range of procedures available and the varying degrees of anesthesia required, surgery is rarely precluded in symptomatic patients. |
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Diagnostic Procedures:
Medical therapy: No medical treatment is currently known or practiced for symptomatic Zenker diverticulum. Surgical therapy: Small, asymptomatic diverticula require no specific therapy. For all others, surgical treatment is the preferred therapy. The 2 key elements of the successful surgical management of this disease are division of the cricopharyngeus muscle and elimination of the diverticular pouch as a reservoir of food and secretions. Preoperative details: The patient should receive routine preoperative evaluation for general anesthesia as guided by a thorough history and physical examination. No preoperative preparation is specific to addressing the Zenker diverticulum. Intraoperative details: Surgical approaches include (1) stapled or hand-sewn diverticulectomy with cricopharyngeal myotomy, (2) stapled or hand-sewn diverticulopexy with cricopharyngeal myotomy, and (3) endoscopic division of the diverticular wall with an endoscopic stapler. Historically, myotomy alone was performed, with a lower rate of relief of symptoms and more frequent complications. Myotomy alone is associated with persistent symptoms in up to 30% of patients. Recurrence requiring repeat surgery is necessary more frequently than with other procedures. Diverticulectomy with cricopharyngeal myotomy With a stapled or hand-sewn diverticulectomy and cricopharyngeal myotomy, the pouch neck is either oversewn or stapled, and the pouch is excised. The cricopharyngeus muscle is divided longitudinally no less than 5 cm. This is typically performed through a left neck incision and is primarily closed with a closed suction drain in place. Diverticulopexy with cricopharyngeal myotomy In the diverticulopexy with cricopharyngeal myotomy, the diverticulum is inverted and sutured to the prevertebral fascia, and the cricopharyngeus muscle is divided as above. The difference in this procedure is that the pouch is not excised. This procedure is more commonly advocated in the severely debilitated patient because there is no division of the esophagus, pharynx, or diverticulum, and there is no suture line. Endoscopic myotomy In the endoscopic myotomy, a double-bladed rigid endoscope is placed into the pharynx with one blade positioned in the esophagus and the other in the diverticulum. A reticulating endoscopic linear stapler is introduced into the pharynx with one jaw of the stapler in the pouch and one jaw in the esophagus. The stapler is locked across the common septum of the two and is fired. If necessary, this is repeated until the bottom of the pouch is reached. This results in an opening of the pouch and a division of the cricopharyngeus muscle. The pouch wall becomes incorporated as a wall of the esophagus. Postoperative details: Oral intake is prohibited until the fifth postoperative day. A Gastrografin swallow study is performed to exclude extravasation of contrast. If no leak is present, the diet is advanced as tolerated, and the patient is discharged. If a drain was placed, it is removed the day after oral intake resumes. Follow-up care: The patient is followed for wound healing and relief of symptoms. Long-term follow-up care is not routinely required.
In a review of over 900 patients with Zenker diverticulum who underwent diverticulectomy and cricopharyngeus myotomy from 1944-1978 at the Mayo Clinic, the overall uncomplicated success rate was 93%. Mortality in this series was 1.2%, and morbidity was similarly low, including vocal cord paralysis (3.0%), wound infection (1.2%), and wound infection with fistula (1.8%). Recurrence was listed as a delayed complication and occurred in 3.6% of the patients. In the Mayo Clinic report, complications were predicted by the patients' underlying medical problems or specific attributes of the diverticulum. Factors relating to the diverticulum that predicted complications included large size, perforation, recurrence, cancer (in the sac), and respiratory or nutritional complications related to the sac.
In 1983, Payne and King reported a series of 888 patients undergoing diverticulectomy. They reported morbidity of 6% and mortality of 1.2%. In 1998, Peracchia and associates reported a series of 95 patients undergoing endoscopically stapled division of the diverticular wall. These patients experienced 0% mortality and morbidity less than 3%. Recurrence rates ranged from 3-10%, depending on the method of repair. The patients, despite their typical presentation in advanced age and multiple concomitant medical problems, did very well. Successful, uncomplicated outcomes were reported in 93-100% of patients, depending on the study and surgical techniques. The key to effective surgical management of the disease is early recognition, division of the cricopharyngeus muscle, and removal of the diverticulum as a reservoir. If these issues are addressed, any of the listed procedures can be effective.
Use of a diverticuloscope and endoscopic stapler to divide the wall between the diverticulum and the esophagus is a promising technique. Although it was first described in 1917, recent advances in endoscopic staplers have made this technique feasible. Endoscopic staplers accomplish the surgical requirements of eliminating the reservoir and dividing the cricopharyngeus muscle. Average operative time is 25 minutes versus 60-90 minutes for open procedures. Additionally, no neck incision or drain is required. Early reports from Europe in a series of 60 patients show no morbidity or mortality, with results equivalent to those obtained from open procedures. These patients have shorter hospital stays and operative times, and they avoid the morbidity of an open incision. Larger series and comparative studies will bear out the long-term efficacy of this procedure, but it appears to be an excellent alternative to the well-established surgical procedures.
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