Endoscopic Treatment of Zenker Diverticulum

G&H What is Zenker diverticulum, and why does it require treatment?

AR Zenker diverticulum is a rare, benign condition that significantly affects patients' quality of life because it reduces the ability to swallow food (both liquids and solids). In this disease, a large sac develops in the upper part of the esophagus, just below the cricopharynx, due to cricopharyngeal muscle spasms. Zenker diverticulum is found most commonly in older patients.

G&H What are the most common treatment options for Zenker diverticulum?

AR Traditionally, treatment for Zenker diverticulum has consisted of open surgery. However, open surgery is complicated by significant rates of morbidity and mortality, particularly because most patients with the disease are elderly and have several comorbidities. More recently, a new technique has been developed that allows endoscopists to treat Zenker diverticulum with fexible endoscopy. This approach consists of cutting the septum between the diverticulum and the esophageal lumen, as the septum contains part of the cricopharyngeal mask. Cutting the septum achieves 2 goals. The first is to create a common room between the sac of the diverticulum and the esophagus, so that food can pass more easily into the esophagus. By cutting the septum, there is no longer an obstacle blocking the food from reaching the esophageal lumen. The second goal is to reduce the local pressure of the cricopharyngeal muscle. When the septum is cut, so is the muscle, which significantly reduces the muscular spasms that originally caused the diverticulum. Attaining these goals results in significant reduction or complete disappearance of dysphagia symptoms in patients with Zenker diverticulum. The majority of patients who undergo endoscopic treatment no longer experience symptoms following the procedure.

G&H What are the benefits of endoscopic management of this condition over traditional approaches?

AR The traditional treatment approaches consist of open surgery or rigid endoscopic treatment with a laryngoscope. Both of these treatments are associated with a number of disadvantages, particularly because they require general anesthesia and tracheal intubation. In addition, they are more invasive than flexible endoscopy. The rates of complications and mortality with traditional treatments are substantial, particularly compared to flexible endoscopic treatment. Moreover, flexible endoscopic treatment is associated with a shorter hospital stay (normally 2 days) and reduced patient discomfort. Patients are also able to resume oral food intake the day after endoscopic treatment. Thus, the overall benefit of treating Zenker diverticulum with endoscopic treatment is very high.

G&H Is endoscopy becoming more frequently used for treatment of Zenker diverticulum?

AR Due to its high risks of perforation and damage, treatment of Zenker diverticulum is considered to be very dangerous, particularly by “pure” gastroenterologists who Endoscopic Treatment of Zenker Diverticulum Alessandro Repici, MD Director, Digestive Endoscopy Unit Istituto Clinico Humanitas Milan, Italy do not have a background in advanced therapeutic endoscopy. These gastroenterologists may even consider the condition to be a contraindication to upper gastrointestinal endoscopy, which is usually considered an extremely safe procedure, and may thus refer these patients directly to surgical treatment. However, over the last several years, as more and more data are demonstrating that flexible endoscopy can provide very effective noninvasive treatment for these patients, even the more skeptical of gas-troenterologists are starting to become more comfortable with this treatment option. In our hospital, for example, we are seeing more and more patients with Zenker diverticulum referred by gastroenterologists to the endoscopy department for treatment.

G&H Have different devices or techniques been examined for performing endoscopic management of Zenker diverticulum?

AR Originally, endoscopic treatment of Zenker diverticulum was performed with a needle knife. Over the following several years, some researchers reported a number of technique modifications such as the use of argon plasma coagulation or hot-biopsy forceps. My colleagues and I recently conducted a study to evaluate the hook knife—a device normally used in endoscopic submucosal resection—in patients with Zenker diverticulum. We selected this device because it is the only one currently available that allows us to pull tissue upward while cutting. This step is very important when making the incision between the diverticulum and septum because, in the traditional surgical technique, the cut was made from the top down, which made it very difficult to see the end of the muscle to avoid perforating it. We proposed that inverting the direction of the cut—pulling the tissue up with a hook knife—would enable a more complete cut with a lower risk of complications.

G&H Could you discuss the design and results of your study?

AR Our study was comprised of 32 consecutive patients (23 male; mean age, 74.8 years) with dysphagia secondary to Zenker diverticulum. The clinical outcome was assessed by assigning a dysphagia symptom score from 0 (no symptoms) to 4 (the inability to swallow saliva).

Our results, which were recently published in Endoscopy, were very satisfying, as more than 30 patients safely completed the treatment. In 2 cases, pneumomediastinum was diagnosed without a clear perforation, which was easily treated conservatively, with the patient able to eat within several days following the intervention and discharged 5 days after treatment. In the rest of the patients, there were no complications. At 1-month follow-up, the mean dysphagia score improved significantly, with 87.5% of patients being asymptomatic and 4 patients having dysphagia that was milder than before the treatment. Three of these 4 patients underwent a successful endoscopic re-treatment with complete relief of dysphagia; 1 patient was not re-treated because of advanced age (92 years). During the follow-up period, 2 patients developed a recurrence of dysphagia. The overall success rate was 90.6%. This rate of technical and clinical success is slightly higher than that of traditional techniques, demonstrating that using this type of device and inverting the direction of the cut results in a better incision and reduced complications.

G&H What conclusions did you draw from your study?

AR First, we were able to confirm that flexible endoscopy is a noninvasive and viable treatment method for treating patients with Zenker diverticulum, including those who are very old and have comorbidities, and that the procedure is possible with just mild sedation (ie, without general anesthesia, tracheal intubation, or an operating room). Second, we were able to conclude that a hook knife is a very safe and effective alternative to the traditionally used endoscopic technique. If the hook knife demonstrates efficacy and safety in a larger series, it may become the most useful tool for performing this type of endoscopic procedure.

G&H Has there been any examination of patient satisfaction with endoscopic myotomy for this condition?

AR Because we have not examined patient satisfaction in a scientific manner, we cannot provide exact data on this issue. However, we can offer observations based upon patients who have been treated in our hospital, which is the largest private hospital in Milan, Italy and has a high volume of endoscopic procedures and a long tradition of operative endoscopy. More than 75 Zenker diverticulum patients have been treated in our hospital in the last 5 years, which is a large number of patients considering that the condition is very rare. Based upon our experiences, it appears that patient satisfaction with endoscopic treatment of Zenker diverticulum is very high; patients particularly like the noninvasive nature of the treatment, the short hospital stay, and the high rates of dysphagia resolution. Long-term follow-up showed that a small subgroup of patients developed a recurrence of their symptoms, but in these patients, endoscopic treatment can usually be re-applied, making repeatability of the treatment another advantage. We have re-treated patients who present with recurrent symptoms and have found flexible endoscopy to still be very effective.

G&H What training is necessary to perform endoscopic treatment in these patients safely and effectively?

AR Endoscopic treatment for Zenker diverticulum is very challenging and requires endoscopists to work in the upper esophagus, an area with which they are not very familiar and that has a high risk of mediastinitis. Thus, this procedure requires special training, which is not easy to attain because this condition is rare. In addition, most of these cases involve very elderly patients with comorbidities that complicate treatment. With such challenging cases, it is diffcult to allow fellows to perform the procedure. These procedures should ideally be performed by endoscopists with a very high level of expertise in therapeutic endoscopy and not individuals still in training.

G&H What are the next steps in research for this emerging treatment?

AR Our next step will be to retrospectively compare the results of all patients treated in our institution, either by surgical methods (both open surgery and rigid endoscopy) or flexible endoscopy. We hope to demonstrate that flexible endoscopy can afford the same technical and clinical results with a lower complication rate and reduced hospital stay.