Columnar Metaplasia in the Esophageal Remnant After Esophagectomy: A Common Occurrence and a Valuable Insight Into the Development of Barrett Esophagus. Ann Surg. 2016;264:1016-1021. [PMID: 26756755 DOI: 10.1097/sla.0000000000001591]

Single-center experience in implementation of endoscopic surveillance protocol after esophagectomy

Esophageal cancer has a notably high recurrence rate with a paucity of robust evidence in defining the optimal surveillance strategy. The surveillance protocol at our institution comprises of annual esophagogastroduodenoscopy (OGD) from years 1 to 5 postoperatively. This study aims to evaluate the implementation of the endoscopic surveillance at our center and ascertain the value of endoscopy in detecting local recurrence after esophagectomy. A retrospective cohort review of all patients (320 patients) who underwent esophagectomy between 2013 and 2018 was conducted. The local esophageal cancer database and corresponding OGD reports were accessed to obtain data on demographics, operation details, local recurrence, and endoscopy performed. 1086 OGDs were performed between 2014 and 2020, broadly categorized to surveillance and symptomatic OGDs; 555 and 531, respectively. Surveillance OGDs detected four asymptomatic local recurrences, of which only one was treated with curative intent. Symptomatic OGDs resulted in a higher yield for the detection of local recurrence compared with surveillance endoscopy; 5% versus 0.7%, with overall median time-to-recurrence of 11.5 months (95% confidence interval 9-17). Of local recurrences, 85.7% occurred within the first 2 years postoperatively. The proportion of endoscopic findings differed between intensive and ad hoc surveillance cohorts for strictures, esophagitis, Barrett's esophagus, and sloughing. Thirteen patients were diagnosed with histologically confirmed Barrett's with no subsequent local recurrences. Surveillance endoscopy had a low positive yield rate with subsequent minimal survival benefits. Therefore, it is prudent to consider an alternative protocol that focuses on the period with the highest risk of recurrence and symptom presentation.

Mechanisms and pathophysiology of Barrett oesophagus

Barrett oesophagus, in which a metaplastic columnar mucosa that can predispose individuals to cancer development lines a portion of the distal oesophagus, is the only known precursor of oesophageal adenocarcinoma, the incidence of which has increased profoundly over the past several decades. Most evidence suggests that Barrett oesophagus develops from progenitor cells at the oesophagogastric junction that proliferate and undergo epithelial-mesenchymal transition as part of a wound-healing process that replaces oesophageal squamous epithelium damaged by gastroesophageal reflux disease (GERD). GERD also seems to induce reprogramming of key transcription factors in the progenitor cells, resulting in the development of the specialized intestinal metaplasia that is characteristic of Barrett oesophagus, probably through an intermediate step of metaplasia to cardiac mucosa. Genome-wide association studies suggest that patients with GERD who develop Barrett oesophagus might have an inherited predisposition to oesophageal metaplasia and that there is a shared genetic susceptibility to Barrett oesophagus and to several of its risk factors (such as GERD, obesity and cigarette smoking). In this Review, we discuss the mechanisms, pathophysiology, genetic predisposition and cells of origin of Barrett oesophagus, and opine on the clinical implications and future research directions.

Intestinal Metaplasia in the Esophageal Remnant Is Rare After Ivor Lewis Esophagectomy

BACKGROUND

Most patients undergoing esophagectomy will experience intermittent reflux of gastric and biliary content into the remnant esophagus postoperatively. The incidence of new or recurrent intestinal metaplasia following chemoradiation and surgery has not been well-described. Furthermore, post-resection guidelines do not exist regarding surveillance for metaplasia in the esophageal remnant.

METHODS

Patients undergoing Ivor Lewis esophagectomy after concurrent chemoradiation for a diagnosis of esophageal adenocarcinoma from 2006 to 2018 were identified. Pathology records were reviewed for the presence of intestinal metaplasia on pretreatment biopsies, surgical specimen, or post-resection biopsies.

RESULTS

In total, 619 patients met inclusion criteria, including 267 (43%) who had intestinal metaplasia noted either prior to or at the time of esophagectomy. The median duration of metaplastic disease prior to resection was 4.4 months. During a median follow-up time of 28 months (interquartile range, 12-60), intestinal metaplasia was noted in the remnant esophagus in 12 (2%) patients, 7 of whom had a prior history of metaplasia. Local recurrence of adenocarcinoma was also uncommon, and occurred in 37/577 (6%) of patients with complete resections, with similar event rates among those with and without a prior history of metaplasia (14/249 [6%] vs. 23/328 [7%], p = 0.614).

CONCLUSIONS

Our findings suggest that despite several factors predisposing to mucosal damage following esophagectomy, occurrence of new intestinal metaplasia after trimodality therapy in our patient population appears to be rare, even among patient with a previous history of this pathologic finding, which may have significant implications for surveillance and cost-savings after resection.

Gastrointestinal function testing model using a new laryngopharyngeal pH probe (Restech) in patients after Ivor-Lewis esophagectomy

BACKGROUND

There is no established correlation between 24-h esophageal pH-metry (Eso-pH) and the new laryngopharyngeal pH-monitoring system (Restech) as only small case series exist. Eso-pH was not designed to detect laryngopharyngeal reflux (LPR) and Restech may detect LPR better. We have previously published a dataset using the two techniques in a large patient collective with gastroesophageal reflux disease. Anatomically, patients after esophagectomy were reported to represent an ideal human reflux model as no reflux barrier exists.

AIM

To use a human reflux model to examine our previously published correlation in these patients.

METHODS

Patients after Ivor Lewis esophagectomy underwent our routine follow-up program with surveillance endoscopies, computed tomography scans and further exams following surgery. Only patients with a complete check-up program and reflux symptoms were offered inclusion into this prospective study and evaluated using Restech and simultaneous Eso-pH. Subsequently, the relationship between the two techniques was evaluated

RESULTS

A total of 43 patients from May 2016 - November 2018 were included. All patients presented with mainly typical reflux symptoms such as heartburn (74%), regurgitation (84%), chest pain (58%), and dysphagia (47%). Extraesophageal symptoms such as cough, hoarseness, asthma symptoms, and globus sensation were also present. Esophageal 24-hour pH-metry was abnormal in 88% of patients with a mean DeMeester Score of 229.45 [range 26.4-319.5]. Restech evaluation was abnormal in 61% of cases in this highly selective patient cohort. All patients with abnormal supine LPR were also abnormal for supine esophageal reflux measured by conventional Eso-pH.

CONCLUSION

Patients following esophagectomy and reconstruction with gastric interposition can ideally serve as a human reflux model. Interestingly, laryngopharyngeal reflux phases occur mainly in the upright position. In this human volume-reflux model, results of simultaneous esophageal and laryngopharyngeal (Restech) pH-metry showed 100% correlation as being explicable by one of our reflux scenarios.

Histologic Study of the Esophagogastric Junction of Organ Donors Reveals Novel Glandular Structures in Normal Esophageal and Gastric Mucosae

INTRODUCTION

Whether cardiac mucosa at the esophagogastric junction is normal or metaplastic is controversial. Studies attempting to resolve this issue have been limited by the use of superficial pinch biopsies, abnormal esophagi resected typically because of cancer, or autopsy specimens in which tissue autolysis in the stomach obscures histologic findings.

METHODS

We performed histologic and immunohistochemical studies of the freshly fixed esophagus and stomach resected from 7 heart-beating, deceased organ donors with no history of esophageal or gastric disease and with minimal or no histologic evidence of esophagitis and gastritis.

RESULTS

All subjects had cardiac mucosa, consisting of a mixture of mucous and oxyntic glands with surface foveolar epithelium, at the esophagogastric junction. All also had unique structures we termed compact mucous glands (CMG), which were histologically and immunohistochemically identical to the mucous glands of cardiac mucosa, under esophageal squamous epithelium and, hitherto undescribed, in uninflamed oxyntic mucosa throughout the gastric fundus.

DISCUSSION

These findings support cardiac mucosa as a normal anatomic structure and do not support the hypothesis that cardiac mucosa is always metaplastic. However, they do support our novel hypothesis that in the setting of reflux esophagitis, reflux-induced damage to squamous epithelium exposes underlying CMG (which are likely more resistant to acid-peptic damage than squamous epithelium), and proliferation of these CMG as part of a wound-healing process to repair the acid-peptic damage could result in their expansion to the mucosal surface to be recognized as cardiac mucosa of a columnar-lined esophagus.

Reflux Following Esophagectomy for Esophageal Cancer

Gastroesophageal reflux is a common problem after gastroesophageal resection and reconstruction, despite the routine prescription of proton pump inhibitors (PPIs). Resection of the lower esophageal sphincter and excision of the vagus nerve are generally thought to be the main factors that interfere with gastric motor function. However, physiological studies of reflux symptoms after esophagectomy are still lacking. Gastroesophageal reflux occurs frequently after esophagectomy, but there is no known effective method to prevent it. Therefore, in order to manage gastroesophageal reflux after esophagectomy, strict lifestyle modifications and gastric acid suppression treatment such as PPIs are needed, and further clinical studies are required.

Pathogenesis and Cells of Origin of Barrett's Esophagus

In patients with Barrett's esophagus (BE), metaplastic columnar mucosa containing epithelial cells with gastric and intestinal features replaces esophageal squamous mucosa damaged by gastroesophageal reflux disease. This condition is estimated to affect 5.6% of adults in the United States, and is a major risk factor for esophageal adenocarcinoma. Despite the prevalence and importance of BE, its pathogenesis is incompletely understood and there are disagreements over the cells of origin. We review mechanisms of BE pathogenesis, including transdifferentiation and transcommitment, and discuss potential cells of origin, including basal cells of the squamous epithelium, cells of esophageal submucosal glands and their ducts, cells of the proximal stomach, and specialized populations of cells at the esophagogastric junction (residual embryonic cells and transitional basal cells). We discuss the concept of metaplasia as a wound-healing response, and how cardiac mucosa might be the precursor of the intestinal metaplasia of BE. Finally, we discuss shortcomings in current diagnostic criteria for BE that have important clinical implications.

Early identification of esophageal squamous neoplasm by hyperspectral endoscopic imaging

Esophageal squamous neoplasm presents a spectrum of different diatheses. A precise assessment for individualized treatment depends on the accuracy of the initial diagnosis. Detection relies on comprehensive and accurate white-light, iodine staining, and narrow-band imaging endoscopy. These methods have limitations in addition to its invasive nature and the potential risks related to the method. These limitations include difficulties in precise tumor delineation to enable complete resection, inflammation and malignancy differentiation, and stage determination. The resolution of these problems depends on the surgeon's ability and experience with available technology for visualization and resection. We proposed a method for identifying early esophageal cancerous lesion by endoscopy and hyperspectral endoscopic imaging. Experimental result shows the characteristic spectrum of a normal esophagus, precancerous lesion, canceration, and intraepithelial papillary capillary loop can be identified through principal component score chart. The narrow-band imaging (NBI) image shows remarkable spectral characteristic distribution, and the sensitivity and specificity of the proposed method are higher than those of other methods by ~0.8 and ~0.88, respectively. The proposed method enables the accurate visualization of target organs, it may be useful to capsule endoscope and telemedicine, which requires highly precise images for diagnosis.

Cardiac Metaplasia: Follow, Treat, or Ignore?

Over the past two decades, evidence has accumulated to challenge the traditional view that cardiac mucosa, which is comprised exclusively of mucus glands, is the normal lining of the most proximal portion of the stomach (the gastric cardia). There is now considerable evidence to suggest that cardiac mucosa develops as a GERD-induced, squamous-to-columnar esophageal metaplasia in some, if not all, cases. Although cardiac mucosa lacks the goblet cells commonly required for a histologic diagnosis of intestinal metaplasia, cardiac mucosa has many molecular features of an intestinal-type mucosa, and appears to be the precursor of intestinal metaplasia with goblet cells. In apparently normal individuals, cardiac mucosa is commonly found in a narrow band, less than 3 mm in extent, on the columnar side of the squamo-columnar junction at the end of the esophagus. A greater extent of cardiac mucosa can be found in GERD patients, and the magnitude of that extent appears to be an index of GERD severity. Presently, the risk of adenocarcinoma imposed by cardiac mucosa is not clear, but appears to be far less than that of intestinal metaplasis with goblet cells. The British Society of Gastroenterology accepts an esophagus lined by cardiac mucosa as a "Barrett's esophagus". However, if one defines Barrett's esophagus as a metaplasia that predisposes to cancer, then only intestinal metaplasia clearly fulfills that criterion at this time. Well-designed, prospective studies are needed to establish the malignant potential of cardiac mucosa.

Endoscopic and histopathologic reflux-associated mucosal damage in the remnant esophagus following transthoracic esophagectomy for cancer-5-year long-term follow-up

Gastroesophageal reflux is a common problem following esophagectomy and reconstruction with gastric interposition. Despite a routine prescription of proton pump inhibitors, reflux-associated mucosal damage in the remnant esophagus is frequently observed. Purpose of this study is to evaluate mucosal damage in the esophageal remnant during long-term follow-up and to compare the prevalence of this damage between the subgroups of esophageal squamous cell and adenocarcinoma. All patients undergoing transthoracic Ivor-Lewis esophagectomy were prospectively entered in our IRB approved database. All patients underwent a routine check-up program with yearly surveillance endoscopies following esophagectomy. Only patients with a complete follow-up were included into this study. Endoscopic and histopathologic mucosal changes of the remnant esophagus were analyzed in close intervals. A total of 50 patients met the inclusion criteria, consisting of 31 adenocarcinomas (AC) and 19 squamous cell carcinomas (SCC). Mucosal damage was already seen 1 year after surgery in 20 patients macroscopically (43%) and in 21 patients microscopically (45%). At 5-year follow-up the prevalence for macroscopic and microscopic damage was 55% and 60%, respectively. The prevalence of mucosal damage was higher in AC patients than in SCC patients (1y-FU: 51% [AC] vs. 28% [SCC]; 5y-FU: 68% [AC] vs. 35% [SCC], P < 0.05). Newly acquired Barrett's esophagus was seen in 10 patients (20%) with two of those patients (20%) showing histopathologic proof of neoplasia. This study shows a high prevalence of reflux-associated mucosal damage in the remnant esophagus one year out of surgery and only a moderate increase in prevalence in the following years. Mucosal damage was more frequently seen in AC patients and the occurrence of de-novo Barrett's esophagus and de-novo neoplasia was high. Endoscopic surveillance with targeted biopsies seems to be an indispensable tool to follow patients after esophagectomy appropriately.