Red dichromatic imaging and linked color imaging as reliable image-enhanced endoscopic procedures for detecting the distal end of the palisade vessels in the columnar metaplastic mucosa of the gastroesophageal junction zone.

BACKGROUND: There is a consensus that identifying the distal end of the palisade vessels (DEPV) is important for diagnosing gastroesophageal junction (GEJ). However, optimum observation methods have not been established. This study investigated the use of effective image-enhanced endoscopy (IEE) for DEPV detection. METHODS: One hundred endoscopic images in 20 cases of columnar metaplastic mucosa of the GEJ recorded with white-light imaging (Olympus-WLI and Fujifilm-WLI) and IEEs (narrow-band imaging; RDI1/2/3, red dichromatic imaging; texture and color enhancement imaging 1/2; blue-laser imaging; and LCI, linked color imaging) from two manufacturers were extracted and evaluated by 10 evaluators. Up to 24 radial straight lines from the center of the lumen were placed on the image, and the evaluators placed markings according to confidence level (high, low, and not detectable) at the DEPV locations. The detectability and reproducibility at the rate of the confidence level and coefficient of variance of markings among the evaluator were analyzed. RESULTS: In total, 15,180 markings were obtained. In terms of detectability, RDI1 (49.4%), RDI2 (53.0%), RDI3 (54.1%), TXI2 (49.7%), and LCI (34.6%) had a significantly higher rate of high confidence among the IEEs in each manufacturer. By contrast, Olympus-WLI (40.6%), Fujifilm-WLI (17.6%), narrow-band imaging (15.9%), and blue laser imaging (9.8%) presented with a significantly lower rates of high confidence. Regarding reproducibility, RDI3 and LCI had the lowest coefficient of variance for each manufacturer. CONCLUSIONS: RDI and LCI could be reliable modalities for detecting DEPVs in the columnar metaplastic mucosa of the GEJ zone.

Outcomes of Hemospray therapy in the treatment of intraprocedural upper gastrointestinal bleeding post-endoscopic therapy.

INTRODUCTION: With increasing advances in minimally invasive endoscopic therapies and endoscopic resection techniques for luminal disease, there is an increased risk of post-procedure bleeding. This can contribute to significant burden on patient's quality of life and health resources when reintervention is required. Hemospray (Cook Medical, North Carolina, USA) is a novel haemostatic powder licensed for gastrointestinal bleeding. The aim of this single-arm, prospective, non-randomised multicentre international study is to look at outcomes in patients with upper gastrointestinal bleeds following elective endoscopic therapy treated with Hemospray to achieve haemostasis. METHODS: Data was prospectively collected on the use of Hemospray from 16 centres (January 2016-November 2019). Hemospray was used during the presence of progressive intraprocedural bleeding post-endoscopic therapy as a monotherapy, dual therapy with standard haemostatic techniques or rescue therapy once standard methods had failed. Haemostasis was defined as the cessation of bleeding within 5 min of the application of Hemospray. Re-bleeding was defined as a sustained drop in haemoglobin (>2 g/l), haematemesis or melaena with haemodynamic instability after the index endoscopy. RESULTS: A total of 73 patients were analysed with bleeding post-endoscopic therapy. The median Blatchford score at baseline was five (interquartile range 0-9). The median Rockall score was six (interquartile range 5-7). Immediate haemostasis following the application of Hemospray was achieved in 73/73 (100%) of patients. Two out of 57 (4%) had a re-bleed post-Hemospray, one was following oesophageal endoscopic mucosal resection and the other post-duodenal endoscopic mucosal resection. Both patients had a repeat endoscopy and therapy within 24 h. Re-bleeding data was missing for 16 patients, and mortality data was missing for 14 patients. There were no adverse events recorded in association with the use of Hemospray. CONCLUSION: Hemospray is safe and effective in achieving immediate haemostasis following uncontrolled and progressive intraprocedural blood loss post-endoscopic therapy, with a low re-bleed rate.

The sub-classification of type B2 vessels according to the magnifying endoscopic classification of the Japan Esophageal Society.

OBJECTIVES: Guidelines for magnified endoscopic diagnosis of esophageal squamous cell carcinoma (SCC) have been proposed by the Japan Esophageal Society. Type B1, B2, and B3 reflect increasing tumor invasion depths (within mucosal epithelium or into lamina propria mucosa [T1a-EP/LPM], into muscularis mucosa or superficial invasion into submucosa [T1a-MM/T1b-SM1], and into submucosa [T1b-SM2], respectively). The diagnostic accuracy of type B1 and B3 is high, but accuracy of type B2 is low. We aimed to improve the diagnostic accuracy of type B2. METHODS: We retrospectively reviewed 248 SCC lesions treated with endoscopic submucosal dissection between January 2012 and July 2018 and identified the B2 lesions. The maximum diameter of the area presenting B2 was measured and evaluated in relation to tumor invasion, for which receiver-operating characteristic (ROC) curves were generated. The optimal area size for distinguishing T1a-EP/LPM from T1a-MM or deeper invasion was determined. RESULTS: There were 78 lesions with B2, of which 26 (33%) were T1a-MM or T1b-SM1 SCCs. ROC curve analysis indicated that the optimal cut-off for the target area showing B2 was 4 mm. The invasion depth (EP/LPM: MM/SM1: SM2) of B2 observed in an area with a diameter <4 mm (B2-Narrow) and those with diameter ≥4 mm (B2-Broad) was 46:11:1 and 1:15:4, respectively. To predict T1a-MM or deeper invasion, B2-Broad had a sensitivity, specificity, positive predictive value, and negative predictive value of 61%, 98%, 95%, and 79%, respectively. CONCLUSION: The diagnostic accuracy of type B2 was improved by evaluating the area of type B2.

Color information from linked color imaging is associated with invasion depth and vascular diameter in superficial esophageal squamous cell carcinoma.

OBJECTIVES: Accurate diagnosis of invasion depth is important for reliable treatment of esophageal squamous cell carcinoma (ESCC), but it is limited to the muscularis mucosae to slight submucosal invasion (MM/SM1). The diagnostic accuracy of invasion depth is unsatisfactory and remains to be improved. We aimed to investigate the association between the color of the superficial ESCC and invasion depth using linked color imaging (LCI) under light-emitting diode (LED) light sources. METHODS: Lesions diagnosed as superficial ESCC were observed using white light imaging and then by LCI. The color values were calculated using Commission Internationale de l'Eclariage - L*a*b* color space, and the color difference was calculated according to invasion depth. The vascular diameters and vascular angles of the intrapapillary capillary loops were pathologically analyzed. Their correlation with mucosal color was also investigated by LCI. RESULTS: In all, 52 lesions from 48 patients were analyzed. On the basis of invasion depth, the color difference between the normal mucosa and the lesion was larger in the MM/SM1 or deeper group than in the epithelium and the lamina propria mucosa (EP/LPM) group using LCI (P = 0.025). The vascular diameter was positively correlated with the b* color value (correlation coefficient = 0.302, P = 0.033). CONCLUSION: Observation using LCI under LED light sources may improve the endoscopic diagnosis of the invasion depth of superficial ESCC. Further research is needed to validate its usefulness. (UMIN000024615).

Computer-assisted diagnosis of early esophageal squamous cell carcinoma using narrow-band imaging magnifying endoscopy.

BACKGROUND: We developed a computer-assisted diagnosis model to evaluate the feasibility of automated classification of intrapapillary capillary loops (IPCLs) to improve the detection of esophageal squamous cell carcinoma (ESCC). METHODS: We recruited patients who underwent magnifying endoscopy with narrow-band imaging for evaluation of a suspicious esophageal condition. Case images were evaluated to establish a gold standard IPCL classification according to the endoscopic diagnosis and histological findings. A double-labeling fully convolutional network (FCN) was developed for image segmentation. Diagnostic performance of the model was compared with that of endoscopists grouped according to years of experience (senior > 15 years; mid level 10 - 15 years; junior 5 - 10 years). RESULTS: Of the 1383 lesions in the study, the mean accuracies of IPCL classification were 92.0 %, 82.0 %, and 73.3 %, for the senior, mid level, and junior groups, respectively. The mean diagnostic accuracy of the model was 89.2 % and 93.0 % at the lesion and pixel levels, respectively. The interobserver agreement between the model and the gold standard was substantial (kappa value, 0.719). The accuracy of the model for inflammatory lesions (92.5 %) was superior to that of the mid level (88.1 %) and junior (86.3 %) groups (P < 0.001). For malignant lesions, the accuracy of the model (B1, 87.6 %; B2, 93.9 %) was significantly higher than that of the mid level (B1, 79.1 %; B2, 90.0 %) and junior (B1, 69.2 %; B2, 79.3 %) groups (P < 0.001). CONCLUSIONS: Double-labeling FCN automated IPCL recognition was feasible and could facilitate early detection of ESCC.

The microscopic anatomy of the esophagus including the individual layers, specialized tissues, and unique components and their responses to injury.

The esophagus, a straight tube that connects the pharynx to the stomach, has the complex architecture common to the rest of the gastrointestinal tract with special differences that relate to its function as a conduit of ingested substances. For instance, it has submucosal glands that are unique and have a specific protective function. It has a squamous lining that exists nowhere else in the gut except the anus and it has a different submucosal nerve plexus when compared to the stomach and intestines. All of the layers of the esophageal wall and the specialized structures including blood and lymphatic vessels and nerves have specific responses to injury. The esophagus also has unique features such as patches of gastric mucosa called inlet patches at the very proximal part and it has a special sphincter mechanism at the most distal aspect. This review covers the normal microscopic anatomy of the esophagus and the patterns of reaction to stress and injury of each layer and each special structure.

Oesophageal mucosal blood flow changes after thoracic endovascular stent graft implantation using a novel sensor probe.

OBJECTIVES: Secondary aorto-oesophageal fistula is a rare, lethal complication occurring after thoracic endovascular aneurysmal repair. The cause of secondary aorto-oesophageal fistula is unknown, but a reduction in local oesophageal mucosal blood flow (OMBF) may be a basis for such a devastating sequela. Our study aims to develop a novel blood flow sensor probe to detect changes in OMBF after thoracic stent graft implantation in an experimental swine model. METHODS: A novel laser Doppler flowmetry sensor probe incorporating an optical fibre sensor within a nasogastric tube was developed using microelectromechanical system technology. OMBF was measured at various levels using this sensor probe, to test its feasibility before and after thoracic endovascular stent graft implantation covering Th4-Th8 vertebral levels in 6 swine. RESULTS: In the middle oesophagus (Th5-Th7), where the aorta was covered with a stent graft, the measured OMBFs were significantly decreased after thoracic endovascular stent graft implantation than those of baseline (8.6 ± 2.7 vs 18.4 ± 7.9 ml/min/100 g, P < 0.0001), followed by a plateau period for at least 2 h after stent grafting (8.7 ± 3.3 ml/min/100 g, P < 0.0001 vs baseline). OMBFs in the upper (Th1-Th3) and lower (Th9-Th11) oesophagus, where the aorta was not covered with a stent graft, were unaffected by thoracic endovascular stent grafting. CONCLUSIONS: The novel laser Doppler flowmetry sensor probe was useful to monitor precise changes of OMBF in a swine model, demonstrating a significant reduction in OMBF after thoracic endovascular stent graft implantation.

Systematic assessment with I-SCAN magnification endoscopy and acetic acid improves dysplasia detection in patients with Barrett's esophagus.

Background and study aims Enhanced endoscopic imaging with chromoendoscopy may improve dysplasia recognition in patients undergoing assessment of Barrett's esophagus (BE). This may reduce the need for random biopsies to detect more dysplasia. The aim of this study was to assess the effect of magnification endoscopy with I-SCAN (Pentax, Tokyo, Japan) and acetic acid (ACA) on dysplasia detection in BE using a novel mucosal and vascular classification system. Methods BE segments and suspicious lesions were recorded with high definition white-light and magnification endoscopy enhanced using all I-SCAN modes in combination. We created a novel mucosal and vascular classification system based on similar previously validated classifications for narrow-band imaging (NBI). A total of 27 videos were rated before and after ACA application. Following validation, a further 20 patients had their full endoscopies recorded and analyzed to model use of the system to detect dysplasia in a routine clinical scenario. Results The accuracy of the I-SCAN classification system for BE dysplasia improved with I-SCAN magnification from 69 % to 79 % post-ACA (P = 0.01). In the routine clinical scenario model in 20 new patients, accuracy of dysplasia detection increased from 76 % using a "pull-through" alone to 83 % when ACA and magnification endoscopy were combined (P = 0.047). Overall interobserver agreement between experts for dysplasia detection was substantial (0.69). Conclusions A new I-SCAN classification system for BE was validated against similar systems for NBI with similar outcomes. When used in combination with magnification and ACA, the classification detected BE dysplasia in clinical practice with good accuracy.Trials registered at ISRCTN (58235785).

Usefulness of Non-magnifying Narrow Band Imaging in EVIS EXERA III Video Systems and High-Definition Endoscopes to Diagnose Dysplasia in Barrett's Esophagus Using the Barrett International NBI Group (BING) Classification.

BACKGROUND: Narrow band imaging (NBI) allows identification of abnormal areas of Barrett's esophagus (BE) and could facilitate targeted biopsies. AIMS: We evaluated the diagnostic accuracy for dysplasia prediction using non-magnifying NBI in Evis Exera III processors and high-definition endoscopes using the Barrett International NBI Group (BING) classification, as well as inter/intraobserver agreement for dysplasia prediction and mucosal/vascular patterns. METHODS: Eight observers (4 staff endoscopists and 4 trainee endoscopists) evaluated 100 images selected from an anonymized bank of 470 photographs using the BING classification. Observers were to assign their individual assessment of the mucosal and vascular pattern, and prediction for dysplasia. Accuracy for dysplasia prediction and intra/interobserver agreement was calculated. RESULTS: Dysplasia prediction had an accuracy of 81.1%, sensitivity of 48.4%, and a specificity of 91%. Positive predictive value and negative predictive value (NPV) were 61.4 and 85.5%, respectively. Dysplasia prediction done with a high degree of confidence (vs. low degree of confidence) had better diagnostic accuracy (85.8 vs. 70.7%). Interobserver concordance for dysplasia was weak: Κ = 0.40. Agreement for mucosal and vascular patterns was 0.39 and 0.30, respectively. Intraobserver concordance (assessed 6 months after initial test) for mucosal pattern, vascular pattern, and dysplasia prediction was moderate: Κ = 0.56, Κ = 0.47 and Κ = 0.60, respectively. CONCLUSIONS: Our results showed that NBI had a significant accuracy in BE assessment for dysplasia prediction, high specificity (>90%), and NPV (>85%), with suboptimal sensitivity. NBI could be a useful additional tool for BE inspection and targeted biopsies, but cannot avoid the need for biopsies following the Seattle protocol.

Pre-emptive endoscopic vacuum therapy for treatment of anastomotic ischemia after esophageal resections.

Background and study aims Endoscopic vacuum therapy (EVT) is a promising new approach for the treatment of anastomotic leakage in the gastrointestinal tract. Here, we present the first case series demonstrating successful use of EVT for the treatment of post-esophagectomy anastomotic ischemia prior to development of leakage. Patients and methods Between 2012 and 2015, intraluminal EVT was performed in eight patients with anastomotic ischemia following esophagectomy. The primary outcome measure was successful mucosal recovery. Secondary outcome measures were duration of treatment, number of sponge changes, septic course, and associated complications. Results Complete mucosal recovery was achieved in six patients (75 %) with different degrees of anastomotic ischemia. In two patients (25 %), small anastomotic leaks developed, which resolved by continuing the EVT treatment. Median duration of EVT treatment until mucosal recovery was 16 days (range 6 - 35), with a median of 5 sponge changes per patient (range 2 - 11). No EVT-associated complications were noted. Three patients developed anastomotic stenoses, which were treated by endoscopic dilation therapy. Conclusion This is the first case series to demonstrate that the early use of EVT potentially modulates clinical outcomes and infection parameters in patients with anastomotic ischemia following esophagectomy. Further studies are needed to define the indications and patients who are most likely to benefit from early EVT.

Temporal and spectral properties of esophageal mucosal blood perfusion: a comparison between normal subjects and nutcracker esophagus patients.

BACKGROUND: The mechanism of esophageal pain in patients with nutcracker esophagus (NE) and other esophageal motor disorders is not known. Our recent study shows that baseline esophageal mucosal perfusion, measured by laser Doppler perfusion monitoring, is lower in NE patients compared to controls. The goal of our current study was to perform a more detailed analysis of esophageal mucosal blood perfusion (EMBP) waveform of NE patients and controls to determine the optimal EMBP biomarkers that combined with suitable statistical learning models produce robust discrimination between the two groups. METHODS: Laser Doppler recordings of 10 normal subjects (mean age 43 ± 15 years, 8 males) and 10 patients (mean age 47 ± 5.5 years., 8 males) with NE were analyzed. Time and frequency domain features were extracted from the first twenty-minute recordings of the EMBP waveforms, statistically ranked according to four independent evaluation criterions, and analyzed using two statistical learning models, namely, logistic regression (LR) and support vector machines (SVM). KEY RESULTS: The top three ranked predictors between the two groups were the 0.5 and 0.75 perfusion quantile values followed by the surface of the EMBP power spectrum in the frequency domain. ROC curve ranking produced a cross-validated AUC (area under the curve) of 0.93 for SVM and 0.90 for LR. CONCLUSIONS & INFERENCES: We show that as a group NE patients have lower perfusion values compared to controls, however, there is an overlap between the two groups, suggesting that not all NE patients suffer from low mucosal perfusion levels.