Asymmetrical circumferential distribution of esophagogastric junctional lesions: anatomical and physiological considerations

Esophageal submucosal hematoma during transnasal endoscopy: A rare case report

Esophageal submucosal hematoma is a rare, often incidental complication of therapeutic endoscopic procedures marked by disrupted blood vessels beneath the esophageal mucosa, forming a hematoma. We report the unique case of a severely thin and alcoholic 38-year-old woman with a history of reflux esophagitis who developed an esophageal submucosal hematoma during an unsedated transnasal endoscopy for health check-up. During the procedure, the patient experienced strong vomiting reflexes and vomited blood, leading to the initial suspicion of either Mallory-Weiss syndrome or epistaxis. However, subsequent sedated endoscopy revealed an esophageal submucosal tumor-like lesion and a mucosal laceration with blood clots, prompting a dual diagnosis of esophageal submucosal hematoma and Mallory-Weiss syndrome. The bleeding was not severe enough to require hemostatic intervention. The patient opted for conservative treatment with vonoprazan, which resulted in the improvement and healing of the hematoma within 28 days. This is the first report of an esophageal submucosal hematoma during transnasal endoscopy and emphasizes the importance of including an esophageal submucosal hematoma and Mallory-Weiss syndrome in the differential diagnosis of hematemesis encountered in similar scenarios. Factors such as severe thinness, daily alcohol consumption, and reflux esophagitis may have possibly contributed to the development of the esophageal submucosal hematoma in this patient.

Endoscopic features of esophageal adenocarcinoma derived from short-segment versus long-segment Barrett's esophagus

BACKGROUND AND AIM

The study aims to clarify the endoscopic features and clinicopathological differences in superficial Barret's esophageal adenocarcinoma (s-BEA) derived from short-segment Barrett's esophagus (SSBE) and long-segment Barrett's esophagus (LSBE).

METHODS

We reviewed data of 130 patients (141 lesions) with pathologically confirmed s-BEA (SSBE: 95 patients and 95 lesions; LSBE: 35 patients and 46 lesions). We analyzed endoscopic and clinicopathological features of s-BEA in patients with SSBE and LSBE.

RESULTS

The distribution of lesions according to macroscopic findings were as follows (s-BEA in SSBE vs LSBE): flat type (0-IIb), 3.2% (3/95) vs 32.6% (15/46) (P < 0.001); accompanied type 0-IIb, 2.1% (2/95) vs 21.7% (10/46) (P < 0.001); and complex type (0-I + IIb, 0-IIa + IIc, etc.), 30.5% (29/95) vs 50.0% (23/46) (P = 0.025). Complex-type s-BEAs had high incidences of T1b invasions and poorly differentiated components (simple type: 22.5% [20/89] and 18.0% [16/89]; complex type: 59.6% [31/52] and 44.2% [23/52], P < 0.001 and P = 0.002, respectively). In SSBE, 72.6% (69/95) of lesions were located at the right anterior wall (P = 0.01). All flat-type or depressed-type lesions derived from SSBE were identified as reddish areas, whereas only 65.2% (15/23) from LSBE were identified as reddish areas (P < 0.001).

CONCLUSIONS

In LSBE, flat-type, accompanied-type 0-IIb, and complex-type lesions were significantly more prevalent. Furthermore, complex-type s-BEAs tended to have T1b invasions and poorly differentiated components. S-BEAs in LSBE should be more carefully evaluated on endoscopic appearance including flat-type and complex-type lesions than in SSBE.

Circumferential distribution and clinical characteristics of esophageal cancer in lower esophagus: differences related to histological subtype

BACKGROUND

Esophageal adenocarcinoma (EAC) is frequently found on the right-anterior wall of the distal esophagus in short-segment Barrett's esophagus (SSBE) patients. However, the endoscopic characteristics of EAC in cases with long-segment BE (LSBE) and squamous cell carcinoma (ESCC) in the lower esophagus remain to be fully evaluated. Here, we determined the circumferential distribution and clinical characteristics of esophageal cancer occurring in the lower esophagus based on histological subtype.

METHODS

We retrospectively reviewed the medical records of 150 patients with esophageal cancer (ESCC, n = 100; EAC, n = 50) diagnosed at our hospital or a related facility between January 2002 and June 2017, including information regarding endoscopic findings, etiology, and clinical parameters.

RESULTS

Of the 100 patients with ESCC, 28 lesions were located in the lower esophagus, though characteristic circumferential distribution was not seen regardless of location. Those showed a greater frequency of smoking and drinking habit and gastric mucosal atrophy as compared to patients with EAC. Consistent with the previous reports, EAC in SSBE (n = 41) was frequently located on the right-anterior wall. Likewise, EAC at the esophagogastric junction (EGJ) in LSBE was frequently located on the right-anterior wall, while EAC distant from the EGJ showed no characteristic circumferential distribution.

CONCLUSION

Our results showed no circumferential predilection for ESCC in the lower esophagus, suggesting that development of this type of lesion may be less affected by gastroesophageal reflux. In addition, EAC at the EGJ was frequently found on the right-anterior wall irrespective of BE length.

Mallory-Weiss Tear After Cardiopulmonary Resuscitation in a Patient Suffering From Acute Myocardial Infarction

A report of a 79 year old male patient suffering from acute myocardial infarction with Mallory-Weiss tear after successful cardiopulmonary resuscitation(CPR) by emergency medical technician in the swimming pool is presented. Successful percutaneous coronary intervention(PCI) was done after appropriate transfusion. The patient survived and discharged without major complications after admitting 11days in the hospital. Importance of CPR in AMI patient is reiterated as complication such as Mallory-Weiss tear may arise.

Eosinophilic esophagitis in Japan: Focus on response to acid suppressive therapy

Eosinophilic esophagitis (EoE) is a chronic inflammatory condition characterized by esophageal dysfunction and dense eosinophilic infiltration of esophageal epithelium. According to clinical consensus and guidelines published in 2011, esophageal eosinophilia was classified into two entities based on response to proton pump inhibitor (PPI) administration: EoE and PPI-responsive esophageal eosinophilia (PPI-REE). We have performed a series of investigations to determine whether EoE is actually different from PPI-REE. Consistent with Western reports, more than half of our examined patients with symptomatic esophageal eosinophilia suggestive of EoE achieved histological remission with single PPI therapy. Furthermore, our comparisons of clinical, endoscopic, and histopathological findings between patients with EoE and those with PPI-REE revealed nearly no differences between them. We also compared gene expression profiles in mucosal biopsy specimens between those groups and found that microarray findings obtained from PPI-REE patients substantially overlapped with those from EoE patients, suggesting that both represent the same condition or are variations of a single disease. In addition, we have noted that more than half of EoE patients who show resistance to a PPI therapy respond to vonoprazan, a novel potassium-competitive acid blocker that has been shown to provide more potent and sustained suppression of gastric acid secretion than PPIs. Our results indicate that PPI-REE may constitute a subtype of EoE. Based on novel evidence including results obtained in our studies, the most recently updated guidelines have included responders to PPI therapy within the spectrum of EoE, abandoning the term PPI-REE.

Mucosal breaks show same circumferential distribution in majority of patients with recurrent reflux esophagitis

Background and study aims Esophageal mucosal breaks in patients with reflux esophagitis (RE) have a unique circumferential distribution. However, the specific location of mucosal breaks during recurrence of RE remains unclear. We investigated the circumferential distribution of mucosal breaks in patients with recurrent RE and compared their location to that noted at the initial diagnosis. Patients and methods We retrospectively enrolled patients with recurrent RE with Los Angeles (LA) grade A-C who were treated at our University Hospital between July 1996 and June 2014. The circumferential distribution of esophageal mucosal breaks was evaluated at the time of the initial diagnosis and again at the time of recurrence. Information regarding clinical parameters, including proton pump inhibitor administration, presence of hiatal hernia, and mucosal atrophy, was also reviewed. Results A total of 114 patients with recurrent RE were examined during the study period, with a mean duration to recurrence after initial diagnosis of 39.4 months. The majority (72.8 %) had the same LA grade at recurrence. In addition, recurrent mucosal breaks in 96 (84.2 %) patients were observed to have occurred in the same circumferential location as at the initial diagnosis, while those in 18 (15.8 %) were observed in a different location. When recurrent lesions had a different location, the LA grade also tended to be different (P = 0.02). Conclusions We found that most patients with recurrent RE developed lesions in the same circumferential location as noted for the initial lesions. Those in different locations at recurrence were associated with a change in LA grade.

Specific locations of linear furrows in patients with esophageal eosinophilia

BACKGROUND AND AIM

Linear furrows are the most frequently found endoscopic abnormality in patients with esophageal eosinophilia (EE); however, the precise endoscopic features remain to be fully elucidated. Here, we aimed to clarify the endoscopic features of EE, essential for the diagnosis of eosinophilic esophagitis (EoE), by focusing on the specific locations of linear furrows in a Japanese population.

METHODS

We enrolled 70 cases with EE (≥15 eosinophils/high-power field) who were diagnosed at our hospital and related facilities. Information regarding endoscopic findings and clinical parameters was retrospectively reviewed. Next, the position of linear furrows in relation to esophageal longitudinal folds (ridge or valley) was evaluated in each case and compared with the position of mucosal breaks in patients with reflux esophagitis. Finally, the relationship between linear furrows and eosinophilic infiltration was evaluated.

RESULTS

Of the 70 EE patients, 63 (90%) had linear furrows. Those occurred in a radial pattern and were widespread throughout the lower to upper esophagus, and exclusively found in esophageal longitudinal mucosal fold valleys, not on ridges, which was different from the position of mucosal breaks in patients with reflux esophagitis. Increased eosinophilic infiltration was significantly more frequent in linear furrows in the valleys (93%) as compared to mucosa on adjacent ridges (60%) (P < 0.05).

CONCLUSION

Investigation of these endoscopic characteristics, especially by focusing on linear furrows in esophageal mucosal fold valleys, may provide important clues for more accurate diagnosis of EoE.

Correlation of the location of superficial Barrett's esophageal adenocarcinoma (s-BEA) with the direction of gastroesophageal reflux

BACKGROUND

Superficial Barrett's esophageal adenocarcinoma (s-BEA) in Barrett's esophagus frequently occurs in the right wall of the esophagus. Our aim was to examine the correlation between the location of s-BEA and the direction of acid and non-acid reflux in patients with Barrett's esophagus.

PATIENTS AND METHODS

We performed 24-h pH monitoring in 33 s-BEA patients using a pH catheter with eight sensors. One sensor was located at the 6 o'clock position in the lower esophagus and sensors 1 - 8 were arranged counterclockwise at the same level. The catheter was positioned at the same level as the s-BEA. We measured the maximal total duration of acid (MTD-A) and non-acid (MTD-NA) reflux. When the direction of MTD-A and MTD-NA coincided with the location of the s-BEA, the case was defined as coincidental and we calculated the rate of coincidence, and the probability of the rate of coincidence was estimated with 95 % confidence intervals (95 %CI).

RESULTS

Among the 33 cases of s-BEA examined, the rate of coincidence of both MTD-A and MTD-NA was 24/33 (72.7 %) (95 %CI 0.54 - 0.87). The rate of coincidence of either MTD-A or MTD-NA was 30/33 (90.9 %) (95 %CI 0.76 - 0.98).

CONCLUSIONS

Our study revealed that the location of s-BEA mostly corresponds to the direction of MTD-A or MTD-NA. Accurate observation of the distribution of acid or non-acid reflux by pH monitoring would aid early detection of s-BEA by endoscopy.

Localization of specialized intestinal metaplasia and the molecular alterations in Barrett esophagus in a Japanese population: an analysis of biopsy samples based on the "Seattle" biopsy protocol

It remains unclear why Barrett esophagus (BE)-associated adenocarcinoma (EAC) frequently occurs in the 0 to 3 o'clock area of the BE. The aims of this study were to clarify the localization of specialized intestinal metaplasia (SIM) as a precancerous lesion and of molecular alterations among different locations using 4-quadrant biopsies based on the "Seattle" protocol. We prospectively evaluated microsatellite instability; methylation status at the APC, CDKN2A, hMLH1, RUNX3, and MGMT genes; the immunoreactivity of the monoclonal antibody Das-1 for the colonic phenotype; and Ki-67 staining in 10 early EACs and 128 biopsy samples from 32 BE patients. Among the molecular changes, only APC gene hypermethylation was an independent predictive marker of EAC (odds ratio, 24.4; P = .01). SIM was more frequently identified in the 0 to 3 o'clock quadrant than in the 6 to 9 o'clock quadrant (P = .08). The Ki-67 index was higher in SIM than in the columnar-lined epithelium (CLE) without goblet cells (P < .0001) and in both SIM and CLE with Das-1 reactivity than in those without (P = .04 and P = .06, respectively). Furthermore, the index was relatively higher in the 0 to 3 o'clock quadrant than in the 6 to 9 o'clock quadrant in cases with Das-1 reactivity. RUNX3 methylation was more frequently found in SIM than in CLE (P = .04), whereas the incidence of the other biomarkers did not show a significant difference between the 0 to 3 o'clock and 6 to 9 o'clock areas, nor between SIM and CLE. SIM with Das-1 reactivity, but not molecular alterations, in the 0 to 3 o'clock quadrant may have higher proliferative activity compared to the other areas of the BE.

Circumferential distribution and location of Mallory-Weiss tears: recent trends

BACKGROUND AND STUDY AIMS

Mallory-Weiss tears (MWTs) are not only a common cause of acute nonvariceal gastrointestinal bleeding but also an iatrogenic adverse event related to endoscopic procedures. However, changes in the clinical characteristics and endoscopic features of MWTs over the past decade have not been reported. The aim of this study was to investigate recent trends in the etiology and endoscopic features of MWTs.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of patients with a diagnosis of MWT at our university hospital between August 2003 and September 2013. The information regarding etiology, clinical parameters, endoscopic findings, therapeutic interventions, and outcome was reviewed.

RESULTS

A total of 190 patients with MWTs were evaluated. More than half (n = 100) of the cases occurred during endoscopic procedures; cases related to alcohol consumption were less frequent (n = 13). MWTs were most frequently located in the lesser curvature of the stomach and right lateral wall (2 - to 4-o'clock position) of the esophagus, irrespective of the cause. The condition of more than 90 % of the patients (n = 179) was improved by conservative or endoscopic treatment, whereas 11 patients (5.8 %) required blood transfusion. Risk factors for blood transfusion were a longer laceration (odds ratio [OR] 2.3) and a location extending from the esophagus to the stomach (OR 5.3).

CONCLUSIONS

MWTs were frequently found on the right lateral wall (2 - to 4-o'clock position) of the esophagus aligned with the lesser curvature of the stomach, irrespective of etiology. Longer lacerations extending from the esophagus to the gastric cardia were associated with an elevated risk for bleeding and requirement for blood transfusion.

Pathophysiology of Barrett's esophagus-associated neoplasia: circumferential spatial predilection

The prevalence rates of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC) arising from BE show striking geographic patterns as they are much more common in Western as compared with Asian countries. However, recent epidemiological studies indicate that the number of patients with BE and EAC are gradually increasing in Asia including Japan, corresponding to the increase in prevalence of gastroesophageal reflux disease (GERD). Because the prognosis of patients with advanced-stage EAC remains poor, early detection of neoplastic lesion in those with BE has led to recent interest in effective treatment. Several promising studies have revealed that early neoplasia in BE is mainly located in the right anterior wall of the distal esophagus. Interestingly, this endoscopic characteristic has been found in both Western and Japanese populations. Potential pathophysiologic explanations underlying the circumferential distribution of neoplasia in BE include a nonuniform asymmetric distribution of esophageal acid exposure, with a tendency toward mucosal acid-related injury on the right side of the esophageal wall in patients with GERD, and the functional structure of the lower esophageal sphincter. Findings of the present study should improve lesion detection and aid in developing a target biopsy protocol for surveillance of BE.

Relationship between esophageal cardiac glands and gastroesophageal reflux disease

OBJECTIVE

The role of esophageal cardiac glands has not been fully determined. This study was performed to clarify the protective role of esophageal cardiac glands against the development of gastroesophageal reflux disease (GERD).

METHODS

The subjects included 2,656 Japanese individuals who visited our institution for a detailed medical checkup. GERD symptoms were assessed using the Japanese version of the Carlsson-Dent self-administered questionnaire (QUEST) and an upper gastrointestinal endoscopy examination in each subject. The presence of reflux esophagitis, size of diaphragmatic hiatus, degree of gastric mucosal atrophy and existence of visible esophageal cardiac glands in the distal esophagus, based on the detection of yellowish elevated areas, were determined using endoscopy.

RESULTS

Esophageal cardiac glands were observed in 355 cases (13.4%). Reflux esophagitis was significantly less frequent in the cases with esophageal cardiac glands than in those without. The esophageal cardiac glands were mainly located on the left-posterior side of the esophageal wall of the distal esophagus. A multiple regression analysis showed that the presence of esophageal cardiac glands was an independent factor for preventing reflux esophagitis. On the other hand, the existence of these glands did not correlate with the presence of GERD symptoms (QUEST score of 6 or more).

CONCLUSION

The presence of visible esophageal cardiac glands may have a protective role against the development of reflux esophagitis.

Evaluation of routine biopsies in endoscopic screening for esophagogastric junction cancer

AIM: To explore whether routine biopsies at the high incidence spot of esophagogastric junction (EGJ) cancer are justified in endoscopic screening.

METHODS: This was a multicenter population-based study conducted in eight high-risk areas in China. A total of 37396 participants underwent endoscopic examination. Biopsies were obtained from visible mucosal abnormalities or from normal-appearing mucosa at the high incidence spot of esophagogastric junction cancer when no abnormality was detected. Specimens showing high-grade intraepithelial neoplasia (HIN) or higher grade lesions were deemed as pathologically “positive”. The ratios of positive pathologic diagnosis between participants with abnormal and normal-appearing mucosa were compared using the Pearson χ² test. Odds ratios and 95% confidence intervals, adjusted for potential confounders, were calculated using logistic regression.

RESULTS: A total of 37520 individuals participated in this study and 37396 (99.7%) participants had full information and were suitable for analysis. During endoscopic examinations, 9.11% (3405/37396) participants were found to have visible mucosal lesions. Of the participants who had normal-appearing mucosa at the EGJ, only 0.28% (94/33991) were diagnosed with HIN or higher grade lesions, whereas 6.05% (206/3405) of participants with abnormalities at the EGJ had a positive pathologic result. After controlling for other variables, visible abnormal mucosa detected under endoscopy strongly predicted a positive pathologic result (OR = 32.51, 95%CI: 23.96-44.09). The proportion of participants with “positive” pathologic diagnoses increased as the total number of endoscopic examinations performed by the doctors increased (< 5000 cases vs 5000-10000 cases vs > 10000 cases, Z = -2.7207, P = 0.0065, Cochran Armiger trend test). The same trend was found between the proportion of participants with positive pathologic diagnoses and the total number of years the doctors performed endoscopy (< 5 years vs 5-10 years vs > 10 years, Z = -10.3222, P < 0.001, Cochran Armiger trend test).

CONCLUSION: Additional routine biopsies from the high incidence spot of EGJ cancer are of limited value and are unjustified.

Observations of Acid Reflux and Motor Function in Distal Esophagus Using Simultaneous Measurements of Intra-esophageal pH and Pressure in 8 Directions With Novel Sensor Catheter - A Feasibility Study

Background/Aims

Esophagogastric junctional lesions, such as mucosal breaks with Los Angeles grade A or B reflux esophagitis, lacerations in Mallory Weiss syndrome, and short segment Barrett's esophagus, are mainly found in the right anterior wall of the distal esophagus. Asymmetrical lower esophageal sphincter pressure and resting radial asymmetrical acid reflux may be causes of this asymmetrical distribution of reflux esophagitis and short segment Barrett's esophagus. We developed a novel pH and pressure catheter to investigate the asymmetrical distributions of pH and intra-esophageal pressure in the distal esophagus.

Methods

One healthy male volunteer was enrolled in this study. Acid reflux and motor function in distal esophagus was investigated using simultaneous measurements of intra-esophageal pH and pressure in 8 directions with novel sensor catheter.

Results

Thirty-six acid and weak acid reflux events were observed, of which 22 were circumferential refluxes with pH drops in all channels and 14 were partial refluxes with pH drops in some channels. Increase in transient circumferential intraesophageal pressure was observed just after 72.7% of the circumferential reflux and 42.9% of the partial reflux events.

Conclusions

Using a novel sensor catheter, 2 different types of acid reflux events were identified in the present study.

Radially asymmetric gastroesophageal acid reflux in the distal esophagus: examinations with novel pH sensor catheter equipped with 8 pH sensors

BACKGROUND

Esophageal mucosal breaks in patients with Los Angeles (LA) grade A or B esophagitis are mainly found in the right anterior wall of the distal esophagus. The aim of this study was to reveal radial acid exposure in the distal esophagus and determine whether radial asymmetry of acid exposure is a possible cause of radially asymmetric distribution of the lesions.

METHODS

We developed a novel pH sensor catheter using a polyvinyl chloride catheter equipped with 8 antimony pH sensors radially arrayed at the same level. Four healthy volunteers, 5 patients with non-erosive reflux disease (NERD), and 10 with LA grade A or B esophagitis were enrolled. The sensors were set 2 cm above the upper limit of the lower esophageal sphincter, and post-prandial gastroesophageal acid reflux was monitored for 3 h with the subjects in a sitting position.

RESULTS

We successfully examined radial acid exposure in the distal esophagus in all subjects using our novel pH sensor catheter. Radial variations of acid exposure in the distal esophagus were not observed in the healthy subjects. In contrast, the patients with NERD and those with reflux esophagitis had radial asymmetric acid exposure that was predominant on the right wall of the distal esophagus. In the majority of patients with reflux esophagitis, the directions of longer acid exposure coincided with the locations of mucosal breaks.

CONCLUSIONS

Radial acid exposure could be examined using our novel 8-channel pH sensor catheter. We found that the directions of longer acid exposure were associated with the locations of mucosal breaks.

Influence of Full-body Water Immersion on Esophageal Motor Function and Intragastric Pressure

Background/Aims

In Japan, it is customary to take a daily bath during which the body is immersed in water to the neck. During full-body immersion, hydrostatic pressure is thought to compress the chest and abdomen, which might influence esophageal motor function and intra-gastric pressure. However, whether water immersion has a significant influence on esophageal motor function or intragastric pressure has not been shown. The aim of this study was to clarify the influence of full-body water immersion on esophageal motor function and intragastric pressure.

Methods

Nine healthy male volunteers (mean age 40.1 ± 2.8 years) were enrolled in this study. Esophageal motor function and intragastric pressure were investigated using a high-resolution 36-channel manometry device.

Results

All subjects completed the study protocol. Intragastric pressure increased significantly from 4.2 ± 1.1 to 20.6 ± 1.4 mmHg with full-body water immersion, while the lower esophageal high pressure zone (LEHPZ) value also increased from 20.5 ± 2.2 to 40.4 ± 3.6 mmHg, with the latter being observed regardless of dietary condition. In addition, peak esophageal peristaltic pressure was higher when immersed as compared to standing out of water.

Conclusions

Esophageal motor function and intragastric pressure were altered by full-body water immersion. Furthermore, the pressure gradient between LEHPZ and intragastric pressures was maintained at a high level, and esophageal peristaltic pressure was elevated with immersion.

Endoscopic characteristics of short-segment Barrett's esophagus, focusing on squamous islands and mucosal folds

BACKGROUND AND AIM

Endoscopic definitions of Barrett's esophagus (BE) vary among countries, mainly because of the difficulty in diagnosing short-segment BE (SSBE) endoscopically. The aim of this study was to investigate whether the endoscopic identification of squamous islands and the specific position of columnar epithelium helps improve the diagnosis of SSBE.

METHODS

First, we prospectively enrolled 100 consecutive patients with SSBE and evaluated the number of identified squamous islands in the columnar epithelium with different modalities: white light (WL), narrow band imaging (NBI), and iodine chromoendoscopy. Second, in another group of 100 consecutive patients with tongue-like SSBE, the correlation of the location of Barrett's mucosa to the esophageal longitudinal folds (ridge or valley) was evaluated endoscopically.

RESULTS

It was possible to detect squamous islands in 48, 71, and 75 patients by WL, NBI, and iodine chromoendoscopy, respectively. The detection rate of squamous islands by NBI or iodine chromoendoscopy was significantly superior to that by WL. Tongue-like SSBEs were predominantly found on the ridge of mucosal folds (71%), similar to the location of mucosal breaks (84%).

CONCLUSIONS

Squamous islands in the columnar epithelium were efficiently observed by NBI or iodine chromoendoscopy. SSBE was found more frequently on the ridges but not in the valleys of esophageal longitudinal mucosal folds. NBI endoscopic observation focusing on columnar epithelium with squamous islands on the ridges of distal esophageal folds may improve endoscopic detection of SSBE.