Continuing Education Activity

Epiphrenic diverticulum, also known as a pulsion diverticulum, is a rare type of esophageal diverticulum occurring in the distal 10 centimeters of the esophagus, most commonly 4 to 8 centimeters above the gastric cardia. These rare diverticula are diagnosed with a barium esophagram and can be managed both non-operatively and operatively, depending on the patient's symptoms and underlying disorders. This activity reviews the evaluation and management of epiphrenic diverticula and explains the role of the interprofessional team in evaluating and treating patients with this condition.

Objectives:

• Describe the etiology of epiphrenic diverticula.
• Describe diagnostic exam findings consistent with epiphrenic diverticula.
• Outline the management options available for epiphrenic diverticula.
• Review the importance of the interprofessional team in optimizing outcomes in patients with epiphrenic diverticula.

Introduction

Epiphrenic diverticulum, also known as a pulsion diverticulum, is a rare type of esophageal diverticulum occurring in the distal 10 centimeters (CM) of the esophagus most commonly 4cm to 8 cm above the gastric cardia.[1] These diverticula are made up of the mucosal and submucosal lining, herniating through a weakness in the muscularis layer of the esophagus, classifying them as false or pseudodiverticula.[2][3] This anatomical weakness in the muscularis layer is where nerves and blood vessels enter to supply the distal esophagus.[4]

Etiology

An increase in intraluminal esophageal pressure is the etiology of epiphrenic diverticula. Although this can be due to several mechanisms, the most common is associated with an underlying esophageal motility disorder. Achalasia, diffuse esophageal spasm, or hypertensive lower esophageal sphincter, which results in a functional obstruction, are some reasons.[4][5][6]

These diverticula can also arise from an iatrogenic cause, such as after a fundoplication, which leads to a mechanical obstruction, and increased intraluminal pressure.[5] It is essential to recognize the etiology of epiphrenic diverticula because it will determine the type of treatment necessary to decrease reoccurrence.

Epidemiology

Epiphrenic diverticula are a rare type of esophageal diverticula with a prevalence that varies across studies and countries, ranging from 0.015 to 2%. Males show a slightly higher incidence, with a peak age between the sixth and seventh decades of life.[4]

Cancer, specifically squamous cell carcinoma, is associated with epiphrenic diverticula. However, it is a rare event, occurring in about 0.6% of patients. These patients are more likely to be male (83%), have larger diverticula (>5 cm), and have an older age (mean 68 years old).[7]

History and Physical

Patients who develop an epiphrenic diverticulum can present in various situations and with different symptoms, depending on the size of the diverticulum as well as the underlying motility disorder. Those with a small diverticulum and no associated motility disorder may be asymptomatic, and the diverticulum is only discovered incidentally; however, patients with larger diverticulum or those who have a concomitant motility disorder can present with worsening symptoms of dysphagia and regurgitation (the two most common symptoms).

Other symptoms include chest pain, heartburn, nocturnal cough, and asthma. Worrisome symptoms include weight loss, aspiration pneumonia, hematemesis, melena, and odynophagia. They could signify a malignant transformation to esophageal carcinoma. As the diverticulum grows in size, complications can arise. These can be severe heartburn (secondary to stasis) or compression of neighboring structures (esophagus, lung, and heart).[1][6][8][9]

Evaluation

Anatomy of the diverticulum, as well as the commonly associated motility disorders, determine the type and range of diagnostic evaluation needed for epiphrenic diverticulum. It usually consists of barium swallow, esophagogastroduodenoscopy (EGD), and manometry. Esophagogram using barium contrast helps to define the anatomical characteristics of the diverticulum as well as surgical planning. Most commonly, these diverticula are noted on the right side (70%) and are single; however, up to 15% can be multiple.[8] Upper endoscopy helps to visualize the inner lining of the esophagus, evaluating for ulcers, esophagitis, carcinoma, or hiatal hernia. Manometry confirms the presence of a motility disorder. Each of these studies helps to determine the type of surgery to be performed.[4][6]

Treatment / Management

The approach to the treatment of epiphrenic diverticula is based on the underlying motility disorder that is commonly present. Not only must the diverticulum be addressed, usually with a diverticulectomy, but a myotomy, fundoplication, or hiatal hernia repair may also be necessary.

Indications for surgery are not based on size but instead on symptoms such as worsening dysphagia, regurgitation, food retention, or complications such as aspiration pneumonia, perforation, and cancer. Asymptomatic patients with epiphrenic diverticulum can be managed non-operatively. The surgical approach can be either open or laparoscopic/robotic with a trend toward minimally invasive due to its decreased pain, length of stay, and mortality.[2] 

Open approaches can be via laparotomy or left thoracotomy, or a combined thoracoabdominal approach. Minimally invasive procedures can be transhiatal or transthoracic, depending on the distance of the diverticulum from the lower esophageal sphincter. This also includes robotic-assisted devices such as the Da Vinci Surgical System robot, which may offer better visualization than the traditional laparoscopic/thoracoscopic approach.[9] Use of routine myotomy is commonly employed due to the high association of an underlying motility disorder. Without this procedure, diverticular recurrence rates can approach 20%, with leak rates approaching 24%.[2][4]

The extent of the subdiverticular myotomy is more critical than the proximal length to encompass the area of obstruction. This is performed between 90-180 degrees from the diverticulectomy site to avoid a leak.[8] A myotomy is usually then followed by a partial fundoplication in order to limit postoperative reflux, which has been noted to occur in 48% of patients versus 9.5% after a Dor fundoplication.[6]

Differential Diagnosis

Epiphrenic diverticula can present in numerous ways, as mentioned earlier. Because of this fact, the differential diagnosis can be vast. Symptoms of dysphagia and regurgitation can be present in other esophageal diverticula, such as Zenker and traction diverticula. A barium esophagram will help to differentiate these diverticula depending on their anatomical location. These symptoms are also present in many esophageal motility disorders, which may or may not be the underlying cause of the diverticulum. Performing manometric studies will help to determine the type of management. Other differentials to consider are acid reflux, hiatal hernia, benign tumors, and esophageal cancer, all of which can be differentiated based on the standard work-up that includes esophagogram, esophagogastroduodenoscopy (EGD), and manometry.

Prognosis

Patients with an epiphrenic diverticulum who are asymptomatic are managed with non-operative treatments. These patients develop complications or symptoms less than 10% of the time.[2] The resolution of symptoms after surgical management in epiphrenic diverticulum approaches 90% in some studies, especially when diverticulectomy is combined with myotomy.[2][10]

Complications

Complications of epiphrenic diverticula can arise from both the disease process as well as the treatment process.

Complications can be due to the size of the diverticulum leading to regurgitation, stasis of food, and aspiration. Other complications are due to inflammatory and malignant changes within the diverticulum. These include ulceration, focal adhesions, abscesses, fistulas, bleeding, perforation, and malignant degeneration.[4] These complications are exceedingly rare, but that does not relieve the need for a thorough evaluation before the management of the diverticulum. 

Postoperative complications include esophageal leak, dysphagia, and acid reflux. The risks can be reduced with an understanding of the pathophysiology behind the diverticulum and proper surgical technique. Combining a myotomy with a diverticulectomy minimizes the risk of suture line leak from 35 to 15%.[4] Acid reflux can also be decreased with the addition of a partial fundoplication, especially with underlying achalasia, which has an approximately 50 to 60% risk of reflux without a myotomy.[8]

Deterrence and Patient Education

In order to effectively manage an epiphrenic diverticulum, patients must be aware of the signs and symptoms associated with the disease process. Not only patients must know them, but they also should understand red flags that may allude to more worrisome pathology such as perforation or malignancy. Asymptomatic patients should relay the presence of the diverticulum to health care workers and be on the lookout for possible symptoms. Blind esophageal intubation should be avoided to help prevent an iatrogenic injury such as perforation of the diverticulum.[1]

Enhancing Healthcare Team Outcomes

Epiphrenic diverticula is a complex disorder that requires input from an interprofessional team of healthcare individuals. Because of its myriad of symptoms, these diverticula can be approached in a medical or surgical direction. Therefore, it requires several specialties, from general practitioners to gastroenterologists to general/thoracic surgeons. Strong communication between specialties can help diagnose patients with epiphrenic diverticulum, as well as to rule out other differentials or to rule in underlying pathologies (motility disorders).

Treatment strategies center around a thorough workup that includes esophagograms, EGDs, and manometry, but a physicians' clinical perspective is ultimately combining all the data for an accurate diagnosis. The general practitioner can guarantee that epiphrenic diverticula are diagnosed before major complications by coordinating gastroenterology with surgery early on in the dysphagia workup.