Carbon dioxide laser versus stapler-assisted endoscopic Zenker's diverticulotomy: a systematic review and meta-analysis

Surgical Nonresponders in Zenker Diverticulum and Lower Esophageal Pathology (POUCH Collaborative)

OBJECTIVE

To identify characteristics of patients who have poor improvement in symptoms following surgical management of Zenker Diverticulum (ZD).

METHODS

Prospective, multicenter cohort study of all individuals enrolled in the Prospective OUtcomes of Cricopharyngeus Hypertonicity (POUCH) Collaborative who underwent surgical repair of ZD between August 2017 and January 2024. Patient demographics, esophagrams, and the 10-item Eating Assessment Tool (EAT-10) pre- and post-procedure were obtained from a REDCap database. t-tests, Wilcoxon rank sum tests, Chi-square or Fisher's exact tests were used to compare the characteristics. Patients with <50% improvement in their EAT-10 scores were deemed surgical nonresponders (SNRs). Those with ≥50% improvement in their EAT-10 scores were deemed surgical responders (SRs).

RESULTS

A total of 184 patients were prospectively followed after undergoing either open or endoscopic surgical management. Twenty-two patients (12%) were deemed SNRs. Preoperative presence of a hiatal hernia was statistically significant characteristic between the SNRs (63.6%) and SRs (32.1%) (p = 0.004). Size of the ZD and history of previous ZD surgery was not a significant characteristic. The length of stay and complication rate were not statistically different between the groups.

CONCLUSION

Coexistent esophageal pathology may lead to poor symptomatic improvement following ZD surgery. Preoperative workup of other esophageal disorders is recommended to detect likely SNRs. For SNRs, further esophageal workup may be necessary to evaluate for other esophageal causes related to poor symptomatic improvement following ZD surgery.

LEVEL OF EVIDENCE

Level 3 Laryngoscope, 2024.

Cricopharyngeus muscle dysfunction: a poorly defined disorder from diagnosis to treatment

PURPOSE

Cricopharyngeus muscle dysfunction (CPMD) is a common clinical occurrence with very few clear diagnostic criteria and multiple pathways for treatment. Incidence of CPMD is not known, but some data suggest around 25% of people with dysphagia experience some degree of CPMD, which negatively impacts swallowing safety and efficiency. Workup and treatment of CPMD can require multidisciplinary collaboration across laryngologists, speech-language pathologists with training in dysphagia management, and gastroenterologists. The purpose of this paper is to review what is known about CPMD and identify areas of future research in CPMD diagnosis and treatment.

METHODS

An overview of CPMD, relative treatments and disorders, and a discussion of future areas of research needed to improve clinical care of CPMD.

RESULTS

Details regarding historical background, pathophysiology and treatment practiced for CPMD are included.

CONCLUSION

In summary, CPMD is a poorly defined disease due to a lack of understanding of its pathophysiology and the lack of consensus diagnostic criteria. Well-designed, prospective clinical trials are necessary to develop a better understanding of clinical incidence of CPMD, impact of the disorder on oropharyngeal swallowing, and how to approach treatment of the disorder surgically or in conjunction with therapy directed by a specialized speech-language pathologist.

Surgical Outcomes in Zenker Diverticula: A Multicenter, Prospective, Longitudinal Study

OBJECTIVE

To compare improvement in patient-reported outcomes (PROM) in persons undergoing endoscopic and open surgical management of Zenker diverticula (ZD).

METHODOLOGY

Prospective, multicenter cohort study of all individuals enrolled in the Prospective OUtcomes of Cricopharyngeus Hypertonicity (POUCH) Collaborative who underwent surgery for ZD. Patient survey, radiography reports, and the 10-item Eating Assessment Tool (EAT-10) pre- and post-procedure were abstracted from a REDCap database, which summarized means, medians, percentages, and frequencies of. Outcome based on operative intervention (endoscopic vs. open) was compared using t-test, Wilcoxon rank sum test or chi-square test, as appropriate.

RESULTS

One hundred and forty-seven persons were prospectively followed. The mean age (SD) of the cohort was 68.7 (11.0). Overall, 66% of patients reported 100% improvement in EAT-10; 81% of patients had greater than 75% improvement; and 88% had greater than 50% improvement. Endoscopic was used for n = 109 patients, and open surgical intervention was used for n = 38. The median [interquartile range, IQR] EAT-10 percent improvement for endoscopic treatment was 93.3% [72, 100], and open was 100% [92.3, 100] (p = 0.05). The incidence of intraoperative complications was 3.7% for endoscopic and 7.9% for open surgical management. The median [IQR] in follow-up was 86 and 97.5 days, respectively.

CONCLUSION

Both endoscopic and open surgical management of ZD provide significant improvement in patient-reported outcomes. The data suggest that open diverticulectomy may provide a modest advantage in symptomatic improvement compared to endoscopic management. The data suggest that the postoperative complication rate is higher in the open surgical group.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:97-102, 2024.

Endoluminal treatment for Zenker's diverticulum - a population-based observational study

BACKGROUND

Zenker's diverticulum is a false diverticulum arising in the oesophago-pharyngeal junction. It may cause symptoms like dysphagia and regurgitation. In Central Norway, treatment is centralized to St. Olavs hospital, either as an endoscopic stapled oesophago-diverticulostomy procedure at the Department of Gastrointestinal Surgery or as laser diverticulostomy at the Department of Ear, Nose and Throat Surgery, depending on diverticulum size.

METHODS

Retrospective, population-based, study from 2001-2020 on patients treated for Zenker's diverticulum, at the time with a rigid endoscopic approach. Patients were identified through the in-hospital register for operations. The two treatment groups were compared on relevant pre-, intra-, and postoperative variables by review of the individual patient records.

RESULTS

78 consecutive patients, 36 at Dept. of Ear, Nose and Throat Surgery and 42 at Dept. of Gastrointestinal Surgery, were treated with a total of 104 interventions. Crude incidence for a surgery-demanding Zenker's diverticulum was 0.57 per 100 000 per year. The Dept. of Ear, Nose and Throat Surgery administered significantly less often prophylactic antibiotics than the Dept. of Gastrointestinal Surgery (p < 0.001), administered more frequently intraoperative dexamethasone (p < 0.001), and had significantly more postoperative infections (19.6% vs 3.4%, p = 0.01). No procedure-related mortality was registered. Although no standardized follow-up took place, at a median of 119 months elapsed, observed clinical recurrence was 35% for the endostapler treatment and 51% for the laser treatment procedure.

CONCLUSION

Both rigid endoscopic stapled oesophago-diverticulostomy and laser diverticulostomy are safe treatments for Zenker's diverticulum, however with a substantial risk of recurrence.

Objective Fluoroscopic Outcomes After Endoscopic Staple Versus Laser Zenker's Diverticulotomy

OBJECTIVE

Endoscopic Zenker's diverticulotomy (EZD) is typically performed via stapling (endoscopic staple diverticulotomy; ESD) or CO2 laser (endoscopic laser diverticulotomy; ELD). Conflicting reports exist on which approach provides optimal outcomes. This investigation compared objective fluoroscopic data between ESD and ELD.

METHODS

A retrospective review of all patients undergoing primary EZD at a tertiary center between January 1, 2014 and January 10, 2022 was performed. Patients undergoing ESD and ELD were matched by preoperative diverticulum size. Primary outcome measures were postoperative diverticulum size and change in diverticulum size from pre- to postoperative swallowing fluoroscopy. Secondary outcome measures were the Eating Assessment Tool (EAT-10) score, penetration aspiration scale (PAS), pharyngeal constriction ratio (PCR), and pharyngoesophageal segment opening (PESo).

RESULTS

Thirteen matched pairs with complete fluoroscopic data were identified. The mean (±SD) age of the cohort was 74.0 (±8.5) years. There were no age or gender differences between groups (p > 0.05). The mean pre-operative ZD size was 1.98 (±0.69) cm for ESD and 1.97 (±0.72) cm for ELD; the mean postoperative size was 0.84 (±0.62) cm for ESD and 0.34 (±0.27) cm for ELD (p < 0.05). Mean diverticulum size improved by 1.14 (±0.59) cm after ESD and 1.62 (±0.59) cm after ELD (p < 0.05). There were no significant differences in postoperative EAT-10, PAS, PCR, or PESo between groups.

CONCLUSION

The data suggest that endoscopic laser Zenker's diverticulotomy results in a greater improvement in diverticulum size than endoscopic staple diverticulotomy. The data did not suggest a difference in postoperative dysphagia symptom scores or other objective fluoroscopic parameters between staple and laser diverticulotomy.

LEVEL OF EVIDENCES

Level 3 Laryngoscope, 133:3057-3060, 2023.

Comparing Open Versus Rigid Endoscopic and Flexible Endoscopic Techniques for the Treatment of Zenker's Diverticulum

OBJECTIVE

To describe the outcomes of patients undergoing open stapler versus transoral rigid and flexible endoscopic therapies for symptomatic Zenker's diverticulum.

STUDY DESIGN

Single institution retrospective review.

SETTING

Tertiary care academic hospital.

METHODS

We retrospectively evaluated the outcomes of 424 consecutive patients who underwent Zenker's diverticulotomy via an open stapler, rigid endoscopic CO2 laser, rigid endoscopic stapler, rigid endoscopic harmonic scalpel, or flexible endoscopic technique from January 2006 to December 2020.

RESULTS

A total of 424 patients (173 females, mean age 73.1 ± 11.2 years) from a single institution were included. A total of 142 patients (33%) underwent endoscopic laser treatment, 33 (8%) underwent endoscopic harmonic scalpel, 92 (22%) underwent endoscopic stapler, 70 (17%) underwent flexible endoscopic, and 87 (20%) underwent open stapler. All open and rigid endoscopic procedures and most of the flexible endoscopic procedures (65%) were performed under general anesthesia. The flexible endoscopic group had a higher percentage of procedure-related perforation, defined as subcutaneous emphysema or contrast leak on imaging (14.3%). The recurrence rates were higher in the harmonic stapler, flexible endoscopic, and endoscopic stapler groups at 18.2%, 17.1%, and 17.4%, respectively, and lower in the open group (1.1%). Length of hospital stay and return to oral intake were similar among groups.

CONCLUSION

The flexible endoscopic technique was associated with the highest rate of procedure-related perforation, while the endoscopic stapler had the lowest number of procedural complications. Recurrence rates were higher among the harmonic stapler, flexible endoscopic, and endoscopic stapler groups and lower in the endoscopic laser and open groups. Prospective comparative studies with long-term follow-up are needed.

Cap-Assisted Endoscopic Septotomy of Zenker's Diverticulum: Early and Long-Term Outcomes

INTRODUCTION

Multiple therapeutic modalities including surgery and rigid and flexible endoscopy have been adopted to manage Zenker's diverticulum (ZD). Minimally invasive flexible endoscopic septotomy (FES) techniques have been increasingly favored over the past 20 years; however, long-term data are still scanty. The aim of this study is to evaluate early and long-term outcomes of FES for naive ZD in a single-center setting.

METHODS

From 2010 to 2017, ZD patients treated with FES were included in a prospectively maintained database (NCT03948438). Those who had already been treated surgically or endoscopically were excluded from the analysis. The Dakkak and Bennett dysphagia scale was used to rate the dysphagia. Persistent complete or near-complete resolution of symptoms (Dakkak and Bennett 0 or 1) was defined as clinical success. Postprocedural adverse events were reported according to ASGE lexicon.

RESULTS

Overall, 256 consecutive patients were treated. Mean pouch size was 29.8 ± 11.3 mm. The procedure was successfully completed in all scheduled patients, with an early clinical success of 96.1%. Adverse events occurred in 3.5% (9/256) of patients. Eight of them were mild/moderate with no fatal events, whereas one patient required surgery. Recurrences occurred in 31.3% (80/256) of treated patients after a mean time of 9 ± 3 months and 95% of recurrences were treated by a second FES. At an average follow-up of 5.5 years, 95.3% of patients were asymptomatic after a mean number of 1.3 procedures.

DISCUSSION

FES is a safe and effective treatment modality for patients with ZD. Recurrence rate is significant; however, endoscopic reintervention is associated with long-term relief of dysphagia.

Foregut Diverticula

Diverticular disease can present anywhere along the gastrointestinal (GI) tract. It can result from various pathologies such as abnormal contraction within the GI tract or inflammation causing scar tissue and the resulting forces surrounding the GI tract. Its clinical presentation can vary from asymptomatic to severe symptoms, with significant decrease in quality of life. The treatment for various diverticula along the GI tract can also vary, depending on the severity of symptoms. This article describes diverticular disease occurring within the foregut, with emphasis on pathophysiology, clinical presentation, and treatment.

Comparison of Surgical Treatments for Zenker Diverticulum: A Systematic Review and Network Meta-analysis

Importance

Zenker diverticulum (ZD) can cause significant dysphagia, and symptoms can return or persist after surgery. This systematic review and network meta-analysis is the first to our knowledge to compare 3 common surgical techniques for ZD.

Objective

To compare the 3 most common surgical techniques-endoscopic laser-assisted diverticulotomy, endoscopic stapler-assisted diverticulotomy, and transcervical diverticulectomy with cricopharyngeal myotomy-in adult patients with ZD.

Data Sources

The published literature was searched using strategies designed by a medical librarian (search performed September 21, 2018). Strategies were established using a combination of controlled vocabulary terms and keywords and were executed in Ovid MEDLINE (1946 to September 21, 2018), Embase (1947 to September 21, 2018), Scopus (1823 to September 21, 2018), Cochrane Library, and ClinicalTrials.gov. Results were limited to English using database-supplied filters, which generated studies from 1997 to 2017.

Study Selection

Inclusion criteria were cohort studies or randomized clinical trials. Studies that included patients needing revision surgery or undergoing an alternative technique were excluded.

Data Extraction and Synthesis

The Preferred Reporting Items for Systematic Reviews and Meta-analyses-Network Meta-analyses (PRISMA-NMA) checklist was used to report the study findings. Two authors independently reviewed the studies.

Main Outcome and Measure

The primary outcome measure was the incidence of persistent or recurrent symptoms following surgery. The primary study outcome was planned before data collection began.

Results

The search generated 529 studies. After applying inclusion and exclusion criteria, 9 cohort studies remained, consisting of 903 patients treated with either laser-assisted diverticulotomy (n = 283), transcervical diverticulectomy (n = 150), or stapler-assisted diverticulotomy (n = 470). A network meta-analysis was performed. Between endoscopic laser-assisted diverticulotomy and open diverticulectomy, the open approach showed a statistically lower likelihood of persistent/recurrent symptoms following treatment (odds ratio [OR], 0.20; 95% CI, 0.04-0.91). Comparing laser-assisted diverticulotomy with the stapler-assisted technique, there was not a significant difference between the 2 techniques (OR, 0.83; 95% CI, 0.43-1.60). The consistency model for the network meta-analysis was supported (χ21 = 0.12; P = .73).

Conclusions and Relevance

This systematic review and meta-analysis compared 3 common techniques for treating ZD. The open approach showed a decreased likelihood of persistent or recurrent symptoms following surgery compared with the 2 other techniques.

Long-term success of flexible endoscopic septal division with the stag beetle knife for Zenker's diverticulum: a tertiary center study

OBJECTIVES

Flexible endoscopic septum division is an established treatment for Zenker's diverticulum (ZD); however, long-term outcome data are lacking. We aimed to evaluate the long-term efficacy of flexible endoscopic septal division (FESD) using the stag beetle knife for ZD and identify predictors of symptom recurrence.

METHODS

Patients undergoing the procedure between 2013 and 2018 were prospectively enrolled. Procedures were performed by a single operator. Symptom severity pre- and postprocedure was recorded using the dysphagia, regurgitation, and complications scale. Symptom recurrence was defined as a total score > 1 after the index procedure. Time-to-event analyses were performed using Kaplan-Meier plots, with multivariable analyses performed using Cox regression models.

RESULTS

Altogether, 65 patients (mean age 74.0 years, 60% male) were included. Previous stapling had been performed in 44.6% of patients. Over the mean posttreatment follow-up period of 19 months, 5.6% of the treatment naïve group and 34.5% of the recurrent group underwent repeated FESD (P = 0.003), with rates of symptom remission and improvement of 75.4% and 92.7%, respectively. Recurrence at 48 months was higher in patients with recurrent ZD (84.7%) than in treatment-naïve patients (10.7%). On multivariable analysis, recurrent disease (hazard ratio [HR] 20.8, P = 0.005) and younger age (HR 0.96/year, P = 0.047) were associated with symptom recurrence.

CONCLUSIONS

In patients with treatment-naïve ZD, flexible endoscopic septal division is safe and provides durable symptom remission. However, in patients with poststapling recurrence, the risk of recurrence is high and time-dependent.

Methodological Quality of Systematic Reviews and Meta-analyses Published in High-Impact Otolaryngology Journals

OBJECTIVE

To assess the methodological quality of intervention-focused systematic reviews (SRs) and meta-analyses (MAs) published in high-impact otolaryngology journals.

DATA SOURCES

Ovid Medline, Embase, and Cochrane Library.

REVIEW METHODS

A comprehensive search was performed for SR and MA citations from 2012 to 2017 in the 10 highest impact factor otolaryngology journals. Abstracts were screened to identify published manuscripts in which the authors indicated clearly that they were performing an SR or MA. Applying a modified typology of reviews, 4 reviewers characterized the review type as SR, MA, or another review type. A simplified version of the AMSTAR 2 (A MeaSurement Tool to Assess systematic Reviews 2) tool was used to assess the reporting and methodological quality of the SRs and MAs that were focused on interventions.

RESULTS

Search and abstract screening generated 499 manuscripts that identified themselves as performing an SR or MA. A substantial number (85/499, 17%) were review types other than SRs or MAs, including 34 (7%) that were literature reviews. In total, 236 SRs and MAs focused on interventions. Over 50% of these SRs and MAs had weaknesses in at least 3 of the 16 items in the AMSTAR 2, and over 40% had weaknesses in at least 2 of the 7 critical domains. Ninety-nine percent of SRs and MAs provided critically low confidence in the results of the reviews.

CONCLUSION

Intervention-focused SRs and MAs published in high-impact otolaryngology journals have important methodological limitations that diminish confidence in the results of these reviews.

Systemic inflammatory response after endoscopic surgery of Zenker's diverticulum

Zenker’s diverticulum can be treated with a carbon dioxide laser or linear stapling device. A retrospective study on patients undergoing elective surgery for Zenker`s diverticulum with carbon dioxide laser or stapler was performed to analyse possible differences in inflammatory responses during the postoperative period. Leucocyte counts and C-reactive protein levels in peripheral blood were measured before and on days 1, 2, 3 and 5 after the operation. Statistical analysis was performed using the Mann-Whitney U-test. Of 34 patients, 16 were treated by laser and 18 by stapler. Age, sex ratio and ASA grade did not differ between the groups. Postoperative leukocytosis was significantly milder in the stapler group compared with patients who were treated by carbon dioxide laser. The mean C-reactive protein (CRP) level on day 1, 2 and 3 after surgery was significantly higher in the CO₂ laser group than in the stapler group. Leukocyte counts recovered on day 3 after surgery in both groups while CRP levels did not decline to preoperative levels at day 5 after the operation in either group. No inflammatory complications such as mediastinitis or pneumonia occurred. In conclusion, the inflammatory response in the early period after carbon dioxide laser diverticulotomy of Zenker’s diverticulum is higher than after stapler-assisted surgery of Zenker’s diverticulum.

New and emerging techniques for endoscopic treatment of Zenker's diverticulum: State-of-the-art review

Zenker's diverticulum (ZD), or pharyngeal pouch, is an anatomical defect characterized by herniation of the posterior pharyngeal wall through Killian's dehiscence, and may result in dysphagia and regurgitation. Multiple therapeutic modalities including surgery, rigid and flexible endoscopy have been developed to manage ZD. Although surgical management with open and endoscopically assisted techniques have historically been the mainstay of ZD treatment, minimally invasive flexible endoscopic techniques, carried out under conscious sedation, are increasingly favored. Over the last two decades, the advent of new accessories and techniques have changed the landscape of endotherapy for ZD, with the current armamentarium including, but not limited to, endoscopic stapling, CO₂ laser, argon plasma coagulation, needle knife, bipolar forceps, hook knife, clutch cutter, stag beetle knife, and submucosal tunneling endoscopic septum division. We hereby review the latest evidence to support the endoscopic management of ZD.

Cricopharyngeal myotomy with flexible endoscope for Zenker's diverticulum using hook knife and endoclips (with video describing an objective measurement of the cutting length)

Cricopharyngeal myotomy with flexible endoscope is a well-known and safe treatment for Zenker's diverticulum. We describe hereafter how we perform this flexible endotherapy. From January 2011 to January 2017, we treated 28 patients with this endotherapy. Our technique is described step-by-step in the paper: the main principle is to perform an endoscopic cut of the diverticular septum and cricopharyngeal muscle's fibers (see the video). We describe an objective measurement of the cutting length and depth of the myotomy. Technical success was achieved in all the patients. As to clinical success, 76.2% of patients showed a significant improvement and relevant disappearance of preoperative dysphagia. The present follow-up ranges from 6 months to 5 years. This flexible endoscopic technique can overcome some limitations of rigid endoscopic technique (i.e., upper teeth protrusion, inadequate jaw opening, or limited neck mobility). The main indication was based on clinical presentation and referred to the diverticular dimensions between 2 and 5 cm. Tips for the technique are described in the paper. This variant of cricopharyngeal myotomy with flexible endoscopy is feasible and effective for the treatment of Zenker's diverticulum in selected patients.

Long-term results using LigaSure™ 5 mm instrument for treatment of Zenker's diverticulum

The purpose of the present study was to evaluate the long-term results and patient's satisfaction of a new approach using the LigaSure™ 5 mm instrument for treatment of Zenker's diverticulum (ZD) and to compare with other long-term results using traditional treatment modalities. Between December 2011 and August 2013, a total of 23 patients with ZD underwent endoscopic surgery using the LigaSure™ technique in our department. A retrospective evaluation of the surgery was based on medical records and additionally a long-term follow-up was performed using a standardized questionnaire that was send to all patients. The questions dealt with complaints according to a visual analog scale (VAS) and were sent a minimum of one year after the surgery (mean time 22 months, range 12-32 month). The overall response rate was 91%. The mean age of the patients was 69 years (range 37-89 years). The patients reported nine for overall satisfaction on the VAS (range 0-10: 10 being very content and 0 very uncontent, 25 and 75% quartiles: 7 and 10) regarding the final outcome of their surgery, although several of the patients had continuous symptoms within the first postoperative year. Eight patients (38%) reported no symptoms at all. Our results suggest that endoscopic management of ZD with the LigaSure™ 5 mm instrument is a minimally invasive, fast and safe method with solid long-term outcome with relief of symptoms and patient satisfaction. This new operative instrument was not found inferior to traditional endoscopic techniques and is now the standard treatment method for ZD in our departments.

Pharyngeal pouch management: an historical review

BACKGROUND

Management of the pharyngeal pouch has evolved enormously since the first description by Ludlow in 1764 and the first case series by Zenker and Von Ziemssen in 1877. With the introduction of antibiotics, and the advancement of surgical technique with the advent of endoscopic surgery and lasers, current management is vastly different to that in the nineteenth century.

OBJECTIVES

This paper traces the history of pharyngeal pouch management, and discusses the various treatment options and opinions recorded during the nineteenth and twentieth centuries, comparing these with techniques popular today.

RESULTS AND CONCLUSION

Pharyngeal pouch surgery has been associated with significant morbidity, both because of the elderly age of patients typically affected by the condition and because of the surgery itself and potential post-operative complications encountered. The historical development of pharyngeal pouch management and the understanding of pharyngeal pouch pathophysiology are discussed.

A Tailored Approach to the Surgical Treatment of Zenker's Diverticula

The advent of endoscopic techniques has transformed the surgical therapy of Zenker's diverticula. Although the treatment paradigm has shifted to minimally invasive approaches with endoscopic stapling-assisted or laser-assisted repair, traditional transcervical procedures can still play a role in selected cases. The goal of this article is to illustrate our tailored approach to patients with Zenker's diverticula and illustrate our open surgical and endoscopic techniques. The discussion will also include the evidence-based rationale for our preoperative assessment and choice of technique.

Esophageal strictures and diverticula

Esophageal disease and dysfunction of the lower esophageal sphincter (LES) manifesting as gastroesophageal reflux disease (GERD) particularly, is the most common of all gastrointestinal conditions impacting patients on a day-to-day basis. LES dysfunction can lead to anatomic changes to the distal esophagus, with GERD-mediated changes being benign stricture or progression of GERD to Barrett's esophagus and even esophageal cancer, and LES hypertension impairing esophageal emptying with subsequent development of pulsion esophageal diverticulum. This article details the causes, clinical presentation, workup, and treatment of esophageal stricture and epiphrenic esophageal diverticulum. Other types of esophageal diverticula (Zenker's and midesophageal) are also covered.