Artificial Intelligence System to Determine Risk of T1 Colorectal Cancer Metastasis to Lymph Node.

BACKGROUND & AIMS: In accordance with guidelines, most patients with T1 colorectal cancers (CRC) undergo surgical resection with lymph node dissection, despite the low incidence (∼10%) of metastasis to lymph nodes. To reduce unnecessary surgical resections, we used artificial intelligence to build a model to identify T1 colorectal tumors at risk for metastasis to lymph node and validated the model in a separate set of patients. METHODS: We collected data from 3134 patients with T1 CRC treated at 6 hospitals in Japan from April 1997 through September 2017 (training cohort). We developed a machine-learning artificial neural network (ANN) using data on patients' age and sex, as well as tumor size, location, morphology, lymphatic and vascular invasion, and histologic grade. We then conducted the external validation on the ANN model using independent 939 patients at another hospital during the same period (validation cohort). We calculated areas under the receiver operator characteristics curves (AUCs) for the ability of the model and US guidelines to identify patients with lymph node metastases. RESULTS: Lymph node metastases were found in 319 (10.2%) of 3134 patients in the training cohort and 79 (8.4%) of /939 patients in the validation cohort. In the validation cohort, the ANN model identified patients with lymph node metastases with an AUC of 0.83, whereas the guidelines identified patients with lymph node metastases with an AUC of 0.73 (P < .001). When the analysis was limited to patients with initial endoscopic resection (n = 517), the ANN model identified patients with lymph node metastases with an AUC of 0.84 and the guidelines identified these patients with an AUC of 0.77 (P = .005). CONCLUSIONS: The ANN model outperformed guidelines in identifying patients with T1 CRCs who had lymph node metastases. This model might be used to determine which patients require additional surgery after endoscopic resection of T1 CRCs. UMIN Clinical Trials Registry no: UMIN000038609.

Utility of autologous fibrin glue and polyglycolic acid sheet for preventing delayed bleeding associated with antithrombotic therapy after gastric ESD.

Background and study aims Delayed bleeding is one of the most serious adverse events of gastric endoscopic submucosal dissection (ESD), especially in patients taking antithrombotic therapy. This study aimed to evaluate the utility and safety of a shielding method with autologous fibrin glue and polyglycolic acid (PGA) sheets for patients undergoing gastric ESD who are receiving antithrombotic therapy. Patients and methods One hundred twenty-three patients who were treated with gastric ESD while receiving antithrombotic therapy between December 2014 and September 2017 were enrolled in this study. Patients who received the shielding method were classified into the shielding group. Others were classified into the conventional group. Various clinico-pathological factors were retrospectively compared between the two groups. Results The shielding group consisted of 38 patients, and the conventional group consisted of the remaining 85 patients. In the shielding group, the rate of continuation of antithrombotic therapy was significantly higher (68.4 % vs 41.2 %). Incidence of delayed bleeding was lower in the shielding group (2.6 %, 1/38) than in the conventional group (14.1 %, 12/85). In the propensity score-adjusted logistic regression analysis, the delayed bleeding rate in the shielding group tended to be lower than in the conventional group ( P  = 0.070). Allogeneic transfusion was performed in eight patients (8/85, 9.4 %) in the conventional group and none in the shielding group ( P  = 0.047). No adverse event associated with endoscopic shielding were observed in the shielding group. Conclusions This study suggests that a shielding method with autologous fibrin glue and PGA sheet effectively prevents delayed bleeding after gastric ESD in patients receiving antithrombotic therapy.

Comparison of 3D endoscopy and conventional 2D endoscopy in gastric endoscopic submucosal dissection: an ex vivo animal study.

BACKGROUND AND OBJECTIVES: Conventional endoscopy provides two-dimensional (2D) information without depth information. This study compared three-dimensional (3D) endoscopy and 2D endoscopy using an endoscopic submucosal dissection (ESD) training model to evaluate the utility of 3D endoscopy. METHODS: Porcine stomach specimens (7 × 7 cm) were prepared from commercially available resected porcine stomachs and a 10-mm hypothetical lesion was marked at the center of each specimen. Specimens were individually placed in an ESD training model, and subjected to either 2D or 3D ESD. En bloc resection rate, perforation rate, incision time, dissection time, and levels of five eyestrain symptoms (fatigue, pain, blurred vision, head-heaviness, and headache; 100-mm visual analog scale) were compared between the 2D and 3D procedures. In a crossover design, 8 endoscopists each performed two 2D and two 3D procedures. RESULTS: All 32 lesions were resected en block, but perforation occurred in one 2D procedure. Incision time was significantly shorter in 3D ESD than in 2D ESD (102.8 ± 42.1 s vs. 135.8 ± 65.7 s, p < 0.05). Dissection time was also significantly shorter in 3D ESD than in 2D ESD (366.3 ± 187.6 s vs. 517.8 ± 282.3 s, p < 0.05). Differences in levels of all symptoms except blurred vision between before and after ESD were larger in 3D ESD than in 2D ESD. CONCLUSIONS: Incision time and dissection time were significantly shorter in 3D ESD compared with 2D ESD, but eyestrain was increased. Depth information from 3D images appears to facilitate rapid and stable ESD maneuvers.

Operational effectiveness of three-dimensional flexible endoscopy: an ex vivo study using a new model.

BACKGROUND AND OBJECTIVES: Two-dimensional (2D) images lack depth information and thus provide probabilistic recognition that do not completely match the actual three-dimensional (3D) information. Here, we investigated the operability of 3D endoscopes. METHODS: A 3D operation model was developed by passing 20 silk threads through upper and lower plates at 2-mm intervals in front and back rows separated by 1 mm. We evaluated accuracy and time of operating an electrosurgical knife. A successful operation was defined as pulling only a front-row thread; an unsuccessful operation was defined as pulling no thread (miss) or simultaneously pulling front- and back-row threads. Endoscopists (four experts, six trainees) repeated the operation under 2D and 3D conditions until individually accumulating 10 successful attempts under each condition. RESULTS: Operation accuracy was significantly higher for 3D compared with 2D in all endoscopists (88.5% vs. 61.3%; p < 0.01) and in both experience groups (trainees: 84.5% vs. 61.2%; experts: 95.2% vs. 61.5%; both p < 0.01). Operation time was significantly shorter for 3D compared with 2D in all endoscopists (12.5 ± 4.1 s vs. 14.8 ± 4.7 s; p < 0.01) and in both experience groups (trainees: 12.8 ± 4.2 s vs. 15.2 ± 4.9 s; experts: 12.1 ± 4.0 s vs. 14.3 ± 4.3 s; both p < 0.01). DISCUSSION: Compared with 2D endoscopy, 3D endoscopy significantly improved operation accuracy and shortened operation time, suggesting that 3D endoscopy enables accurate operation by depth information, aiding spatial recognition.

Esophageal Motility after Extensive Circumferential Endoscopic Submucosal Dissection for Superficial Esophageal Cancer.

BACKGROUND/AIMS: Endoscopic submucosal dissection (ESD) for superficial esophageal cancer is sometimes extensive, and in our experience, patients not infrequently present with dysphagia after ESD even in the absence of esophageal stricture. The aim of this study was to evaluate esophageal motility using high-resolution manometry (HRM) in patients with and without dysphagia after extensive circumferential ESD. METHODS: HRM was performed in a total of 52 patients who had undergone ESD for superficial esophageal cancer and a mucosal defect after ESD exceeded more than two-thirds of the esophageal circumference. The frequency and type of esophageal dysmotility and the relationship between esophageal motility and dysphagia were evaluated. RESULTS: Esophageal dysmotility was observed in 13 patients (25%): jackhammer esophagus in 4, esophagogastric junction outflow obstruction in 4, absent contractility in 2, and distal esophageal spasm, ineffective esophageal motility, and fragmented peristalsis in 1 patient each. Of the 22 patients with dysphagia after ESD, 9 (41%) had esophageal dysmotility. Of the 30 patients without dysphagia after ESD, 4 (13%) had esophageal dysmotility. The relationship between dysmotility and dysphagia was significant (p = 0.025). CONCLUSIONS: Esophageal dysmotility exists in approximately one-quarter of patients after extensive circumferential ESD, which is associated with dysphagia in the absence of esophageal stricture.

Recognition accuracy of tumor extent using a prototype 3D endoscope for superficial gastric tumor: an ex vivo crossover study.

BACKGROUND AND STUDY AIMS: Many studies have shown the utility of rigid three-dimensional (3 D) endoscopes in surgery, but few have reported the utility of flexible 3 D endoscopes. This ex vivo study was intended to investigate whether a newly developed 3 D endoscope (GIF-Y0083; Olympus) improves diagnostic accuracy for superficial gastric tumor. METHODS: Twelve observers comprising experts, trainees, and novices (4 each) evaluated 2 D and 3 D images of 20 specimens resected by gastric ESD. Evaluation items were diagnostic accuracy of tumor extent and degree of confidence in assessing (a) tumor extent, (b) morphology, and (c) comprehensive recognition. The 2 D and 3 D endoscopy data were compared in a crossover analysis. RESULTS: Overall, diagnostic accuracy was significantly higher with 3 D images (88.1 %) than with 2 D images (84.2 %) ( P  < 0.01). Comparison by skill level showed that 3 D images significantly improved diagnostic accuracy among novices but not among experts or trainees. Comparison by morphology showed that diagnostic accuracy did not differ significantly for type IIa/IIb lesions but improved significantly for type IIc lesions among trainees and novices. Overall, 3 D images significantly increased the degree of confidence in the assessment of all three items (a - c). Comparison by skill level showed similar results, and comparison by morphology showed that regardless of skill level, the degree of confidence in assessing all items (a - c) increased significantly only when examining type IIc lesions. CONCLUSION: Compared with 2 D images, 3 D images significantly improved both diagnostic accuracy of tumor extent and degree of confidence for diagnosing superficial gastric tumor. The utility of the 3 D endoscope was apparent among trainees and novices and for the diagnosis of type IIc lesions.

Characterization of Helicobacter pylori-Naïve Early Gastric Cancers.

AIM: Helicobacter pylori-naïve gastric cancers(GCs) have not been well documented. We aimed to characterize early H. pylori-naïve GCs. SUBJECTS AND METHODS: Of 666 patients with GC resected by endoscopic submucosal dissection, H. pylori-naïve patients were extracted according to the definition: no H. pylori eradication history, negative for serum H. pylori-antibody and current H. pylori-infection tests, and no gastric atrophy by pepsinogen (PG) test, endoscopy, and histology. RESULTS: It was found that 16 GCs were H. pylori-naïve, and classified into undifferentiated and differentiated type adenocarcinoma. All 9 undifferentiated type GCs were pale, depressed, mucosal pure signet ring cell adenocarcinoma except one of them and 7 differentiated type GCs were classified into 3 fundic gland type GCs and 4 foveolar type GCs. All fundic gland type GCs positive for PG-1 were cardia small submucosal tumor (SMT)-like protrusions with dilated vessels on the surface. All 4 foveolar type GCs were composed of dysplastic clear cells resembling foveolar epithelium, negative for PG-1 but positive for mucin 6 (MUC6) and MUC5AC. Endoscopically, all were laterally spreading elevations with papillary or villous surface. CONCLUSIONS: H. pylori-naïve GCs were infrequent at 2.5%, and classified into 3 types: a small pale depression of signet ring cell adenocarcinoma, a small SMT-like protrusion of fundic gland type GC, and a large laterally spreading elevation of foveolar type GC.

Feasibility of Autologous Fibrin Glue and Polyglycolic Acid Sheets to Prevent Delayed Bleeding after Endoscopic Submucosal Dissection of Gastric Neoplasms in Patients Receiving Antithrombotic Therapy.

BACKGROUND/AIMS: Delayed bleeding is one of the most serious complications following gastric endoscopic submucosal dissection (ESD) under antithrombotic therapy. As a safety measure, for patients receiving antithrombotic therapy, we covered the ESD ulcer with autologous fibrin glue (prepared using autologous blood) alone or with polyglycolic acid (PGA) sheets. METHODS: From July 2014 to November 2015, 20 patients with gastric neoplasms who were receiving antithrombotic therapy were enrolled in this study. After ESD, the ESD ulcers were covered with autologous fibrin glue alone or with PGA sheets. We prospectively evaluated the feasibility of this safety measure. RESULTS: In total, 22 lesions in 20 patients were resected en bloc by ESD. The mean specimen size and tumor size were 31.5 ± 9.5 mm and 14.0 ± 8.8 mm, respectively. There were no cases of delayed bleeding or adverse events in this study. Attachment of autologous fibrin glue was observed in 81.8% (18/22) and 68.2% (15/22) of lesions at endoscopy performed 1 day and 7 days after ESD, respectively. CONCLUSION: No patient in this study had delayed bleeding or adverse events. This suggests that this measure may facilitate the safety of gastric ESD in patients receiving antithrombotic therapy. This trial is registered with UMIN000019386.

Clinicopathological features of superficial non-ampurally duodenal epithelial tumor; gastric phenotype of histology correlates to higher malignant potency.

BACKGROUND: Superficial non-ampullary duodenal epithelial tumors (SNADETs) are relatively rare, but they are now being detected more frequently due to advances in endoscopic technology. Nevertheless, the pathological nature of SNADETs remains unclear and a management strategy for these tumors has not been established. METHODS: To elucidate the clinicopathological features, we conducted a retrospective analysis of 138 endoscopically resected SNADETs. Lesions were classified into two groups by histological grade according to the Vienna classification: category 3 (71 lesions, 51.4%) and category 4/5 (67 lesions, 48.6%). RESULTS: Compared with category 3 lesions, category 4/5 lesions were significantly more common in elderly patients (p < 0.001) and had a significantly larger tumor diameter (p = 0.001). Immunohistochemical analysis showed that category 4/5 lesions expressed MUC5AC (p = 0.002), MUC6 (p < 0.001), and p53 (p = 0.003) significantly more frequently and expressed CD10 (p = 0.002) and CDX2 (p = 0.029) significantly less frequently. Multivariate regression analysis showed that advanced age (p < 0.001), MUC6 expression (p = 0.001), and p53 expression (p = 0.004) were independent risk factors for a classification of category 4/5. In addition, advanced age (p = 0.010) and MUC5AC expression (p = 0.011) were identified as risk factors for lesions classified as category 4.2 (noninvasive carcinoma) or higher. All category 5 lesions expressed MUC5AC. CONCLUSIONS: The gastric phenotype of MUC5AC and MUC6 may be linked to the malignant potential of SNADETs.

Utility of Endoscopic Examination in the Diagnosis of Acute Graft-versus-Host Disease in the Lower Gastrointestinal Tract.

BACKGROUND AND AIMS: We retrospectively investigated the incidence of acute graft-versus-host disease (GVHD) in the lower gastrointestinal (GI) tract and the diagnostic accuracy of endoscopy. METHODS: Of 1231 patients who underwent allogeneic hematopoietic stem cell transplantation between January 2005 and December 2014, 186 of whom underwent colonoscopy and biopsy and had no cytomegalovirus infection. The endoscopic findings and histologic diagnosis from these 186 patients were retrospectively analyzed. RESULTS: Based on the histopathological findings, 171 patients were diagnosed with GVHD, accounting for 13.9% of all transplant recipients. Useful endoscopic findings for the diagnosis of GVHD were atrophy of the ileocecal valve and villous atrophy in the terminal ileum and tortoise shell-like mucosae, edema, and low vascular permeability in the colon. Even when no mucosal abnormality was observed, the incidence of GVHD was 78.9% in the terminal ileum and 75.0% in the colon. Furthermore, patients with mucosal exfoliation, although infrequent, were all diagnosed with grade 3/4 GVHD. CONCLUSIONS: It is important to perform endoscopy proactively for the early diagnosis of GVHD, and biopsy should be performed even when no abnormality is observed. In addition, because patients with mucosal exfoliation are extremely likely to have grade 3/4 GVHD, early treatment should be initiated.

Feasibility Study of the Three-Dimensional Flexible Endoscope in Endoscopic Submucosal Dissection: An ex vivo Animal Study.

BACKGROUND/AIM: Clinical application of 3-dimensional (3D) technology for flexible endoscopes has not been reported. We developed a 3D flexible endoscope and conducted a feasibility study of endoscopic submucosal dissection (ESD) in porcine stomach. METHODS: Four endoscopists used a 3D flexible endoscope to perform a total of 8 ESD procedures on resected porcine stomachs. We assessed the en bloc resection rate, perforation rate, and mechanical issues that arise during ESD. A visual analog scale (0, 2D superior; 100, 3D superior) was used to evaluate the depth perception, sense of security of the procedure, and eyestrain of 3D visualization. RESULTS: En bloc resection was achieved in all cases and there were no cases of perforation or mechanical issues. Depth perception and sense of security were rated 85.5 ± 12.4 and 70.7 ± 9.7 respectively (mean ± SDs). Eyestrain was rated high for 3D visualization (mean ± SDs, 12.6 ± 8.6). CONCLUSIONS: ESD using a 3D flexible endoscope was technically feasible. The endoscopists reported good depth perception and a high sense of security when using 3D visualization but also noted strong eyestrain.

Endoscopic Submucosal Dissection and Endoscopic Mucosal Resection for Non-Ampullary Superficial Duodenal Tumor.

BACKGROUND: Endoscopic submucosal resection (ESD) and endoscopic mucosal resection (EMR) are well established as curable and safety procedures for treating superficial tumors of the stomach, esophagus and colon. However, a majority of endoscopic resection strategies for non-ampullary superficial duodenal tumors (NASDTs) remains undefined. The aim of this study was to clarify which was the right method for NASDT treatment - EMR or ESD. SUMMARY: We analyzed 129 consecutive endoscopic resection (74 ESD and 55 EMR) procedures performed with NADSTs and divided the ESD group into 49 large ESD groups (more than 20 mm in diameter) and 25 small ESD groups (less than 20 mm in diameter). With respect to the technical outcomes of EMR/ESD for small size NASDTs, EMR was safer than ESD, but its nature of curability was inferior to that of ESD. The rates of complication such as perforation or delayed bleeding were significantly higher in both ESD groups than in the EMR group. However, the prophylactic endoscopic closure of large mucosal defects after ESD was useful for resolving those complications. The limitations of our study were involvement of a single-center, limited sample size, short follow-up duration and the retrospective design, which may have introduced selection bias. However, the present findings suggest that adequate endoscopic treatment strategy for NASDTs can lead to favorable outcomes and an excellent prognosis. Key Message: It is necessary to select EMR or ESD adequately for R0 resection of small NASDTs, according to their size and location. For large NASDTs, duodenal ESD with essential management is feasible and useful as a therapeutic procedure.

Postoperative bleeding after gastric endoscopic submucosal dissection in patients receiving antithrombotic therapy.

BACKGROUND AND AIMS: It is controversial whether antithrombotic therapy increases the risk of bleeding after endoscopic submucosal dissection (ESD). The aim of this study was to evaluate the effects of antithrombotic therapy on gastric ESD. METHODS: Patients who underwent gastric ESD at Toranomon Hospital between April 2005 and July 2014 were enrolled. The risk of post-ESD bleeding was evaluated by multivariate logistic regression analysis. RESULTS: Of 1781 patients enrolled, 253 were taking an antithrombotic; 186 discontinued taking a single antithrombotic (n = 150) or multiple antithrombotics (n = 36) before ESD, whereas 15 continued taking a single antiplatelet agent and another 52 switched to heparin alternative therapy during the peri-ESD period. Post-ESD bleeding occurred in 101 patients (5.7 %): 68 patients (3.8 %) who did not take an antithrombotic, 11 patients (7.3 %) who discontinued taking a single antithrombotic, six patients (16.7 %) who discontinued taking multiple antithrombotics, one patient (6.7 %) who continued taking a single antiplatelet agent, and 15 patients (28.8 %) who switched to heparin therapy. In multivariate analysis, heparin alternative therapy [odds ratio (OR) 10.04, 95 % confidence interval (CI) 4.35-23.16], discontinuation of the use of multiple antithrombotics before ESD (OR 5.44, 95 % CI 2.00-14.79), tumor location in the lower third of the stomach (OR 2.17, 95 % CI: 1.32-3.58), and a long procedure time (100 min or greater; OR 2.00, 95 % CI 1.25-3.20) were independent risk factors for post-ESD bleeding. Among 52 subjects who switched to heparin therapy, one developed acute renal infarction and one developed cerebral bleeding. CONCLUSIONS: Because heparin alternative therapy significantly increases the risk of post-ESD bleeding and may not decrease the risk of thromboembolic events, other options should be considered for patients receiving anticoagulation therapy.

Recognition Accuracy Using 3D Endoscopic Images for Superficial Gastrointestinal Cancer: A Crossover Study.

Aim. To determine whether 3D endoscopic images improved recognition accuracy for superficial gastrointestinal cancer compared with 2D images. Methods. We created an image catalog using 2D and 3D images of 20 specimens resected by endoscopic submucosal dissection. The twelve participants were allocated into two groups. Group 1 evaluated only 2D images at first, group 2 evaluated 3D images, and, after an interval of 2 weeks, group 1 next evaluated 3D and group 2 evaluated 2D images. The evaluation items were as follows: (1) diagnostic accuracy of the tumor extent and (2) confidence levels in assessing (a) tumor extent, (b) morphology, (c) microsurface structure, and (d) comprehensive recognition. Results. The use of 3D images resulted in an improvement in diagnostic accuracy in both group 1 (2D: 76.9%, 3D: 78.6%) and group 2 (2D: 79.9%, 3D: 83.6%), with no statistically significant difference. The confidence levels were higher for all items ((a) to (d)) when 3D images were used. With respect to experience, the degree of the improvement showed the following trend: novices > trainees > experts. Conclusions. By conversion into 3D images, there was a significant improvement in the diagnostic confidence level for superficial tumors, and the improvement was greater in individuals with lower endoscopic expertise.

Clinicopathological Outcomes of Patients with Early Gastric Cancer after Non-Curative Endoscopic Submucosal Dissection.

BACKGROUND: Endoscopic submucosal dissection (ESD) was developed to resect early gastric cancer (EGC), which could not be resected by conventional endoscopic mucosal resection, and the indications for ESD are expanding to include more types of EGCs. Favorable long-term outcomes of ESD for EGCs that meet the expanded curability criteria have been reported. However, the outcomes of non-curative ESD are not known in detail. SUMMARY: We analyzed the outcomes of 165 EGCs in 165 patients after non-curative ESD, as well as the clinical course. Of these patients, 109 underwent additional surgical resection (group S) and 56 patients were followed up without additional surgery (group F). The complete resection rate was 90.7% (39/43) for intramucosal cancer (M), 97.3% (36/37) for minimally submucosal invasive cancer (SM1), and 74.1% (63/85) for deep submucosal invasive cancer (SM2). The lymph node metastasis rate was 0% for M, 5.4% for SM1, and 10.6% for SM2 cancers. Regarding long-term survival, although the number of patients who died of another disease was significantly higher in group F than in group S, there was no significant difference in overall survival between the groups. KEY MESSAGE: The resectability of ESD for ECGs with an invasion depth of M to SM1 after non-curative ESD was excellent, and lesions without lymphovascular invasion did not metastasize or recur, resulting in a favorable prognosis. Our data may help in deciding whether additional surgery should be performed for borderline lesions after non-curative ESD. Furthermore, we suggest the possibility of further expanding the indications for ESD.

Conventional White Light Endoscopic Features of Small Superficial Barrett's Esophageal Adenocarcinoma.

BACKGROUND: Superficial Barrett's esophageal adenocarcinoma (BEA) arising from short-segment Barrett's esophagus (SSBE) is visualized as a reddish lesion located on the right or anterior side wall of the esophagogastric mucosal junction (EGJ) and showing an elevated macroscopic appearance under conventional white light endoscopy (WLE). However, because the form and color are variable, misdiagnosis as reflux esophagitis or SSBE is frequent under WLE. The aim of this study is to clarify conventional WLE features of small superficial BEA. SUMMARY: We retrospectively analyzed 30 lesions ≤20 mm in diameter in 30 patients who underwent endoscopic mucosal resection or endoscopic submucosal dissection at Toranomon Hospital between 2002 and 2014. Mean age of patients with small superficial BEA arising from SSBE was 64.3 ± 11.2 years, and mean tumor size was 12.0 ± 4.8 mm. Small superficial BEA fell into the following 4 categories based on WLE features: EGJ polyp type, 43.3% (13 of 30 lesions); triangular SSBE type, 43.3% (13 of 30 lesions); cardiac erosion type, 10.0% (3 of 30 lesions); and unclassified or mixed type, 3.4% (1 of 30 lesions). EGJ polyp-type tumors were located on the right or anterior side wall of the EGJ, and no tumors showed invasion to the submucosal layer. On the other hand, triangular SSBE-type tumors were located anywhere in the EGJ, and 38.5% showed submucosal invasion (5 of 13 lesions). KEY MESSAGES: We consider this classification significantly contributes to the detection of small superficial BEA arising from SSBE under WLE.

Adenocarcinoma of the cervical esophagus arising from ectopic gastric mucosa: report of two cases and review of the literature.

Esophageal adenocarcinoma arising from ectopic gastric mucosa (EGM) is extremely rare. We describe here two Japanese patients with adenocarcinoma of the cervical esophagus arising from EGM. Case 1 is a 62-year-old man who had slightly red EGM in the cervical esophagus on upper gastrointestinal endoscopy (UGE). Because the biopsy showed atypical glands that were suspicious for adenocarcinoma, endoscopic submucosal dissection was performed. Histopathological examination revealed that the lesion was a well-differentiated adenocarcinoma (pT1a MM). Lymphovascular invasion was absent, and the margins were free from carcinoma. Case 2 is a 57-year-old man who had an elevated lesion with a bleeding tendency in an area of EGM in the cervical esophagus on UGE. Adenocarcinoma was diagnosed in the biopsy. Because of the presence of enlarged lymph nodes (#106recL), preoperative chemoradiotherapy was performed to reduce the size of the adenocarcinoma and lymph nodes prior to resection of the cervical esophagus and reconstruction with free jejunal grafts. Histopathological examination revealed moderately differentiated adenocarcinoma (0-I, pT2N1M0, pStage II). In both cases, adenocarcinoma was surrounded by EGM, which led to the diagnosis of EGM-derived esophageal adenocarcinoma. Here, we report its immunohistochemical characteristics in the present cases and discuss the histogenesis.

Ex vivo comparison study of smart Shooter®, a new endoscopic device for safe and speedy treatment.

BACKGROUND: In many endoscopic procedures, the operative view can be compromised when manipulating the treatment device because the endoscopists must release their hand from the endoscope. We have developed a new device called the Smart Shooter® (SS) for simultaneous manipulation of the endoscope and treatment device, and evaluated the utility of the SS compared with the conventional method. METHODS: The SS is a semirigid, loop-shaped channel extender that enables endoscopists to manipulate the treatment device with the thumb of the right hand while holding the endoscope with the same hand. We conducted a comparative study of gastric endoscopic submucosal dissection (ESD) and esophageal injection sclerotherapy (EIS) in a porcine model to compare the utility of the SS method with the conventional method. RESULTS: In gastric ESD, all lesions were resected en bloc with no perforation. The mean operative time was significantly shorter with the SS method than with the conventional method (287.5 ± 155.4 vs. 403.5 ± 215.6 s, p = 0.04). In esophageal EIS, 4 paravenous injections were given with the SS method and 5 were given using the conventional method. Similarly, the mean operative time was significantly shorter with the SS method than with the conventional method (19.0 ± 7.8 vs. 23.8 ± 10.0 s, p = 0.04). CONCLUSION: Use of the SS enabled a shorter operative time for gastric ESD and esophageal EIS with no adverse events. The present results suggest that the SS can contribute to safe and speedy endoscopic treatment.

A case of mucinous adenocarcinoma in the setting of chronic colitis associated with intestinal spirochetosis and intestinal stricture.

Mucinous adenocarcinoma (MC) is a unique pathological type of colorectal cancer (CRC). The development of MC is often associated with intestinal inflammation and/or microsatellite instability (MSI). Moreover, MC has clinicopathological characteristics that render making the correct diagnosis difficult such as extramural progression. Meanwhile, intestinal spirochetosis (IS) is a condition in which colonic epithelial cells are colonized and/or infected by spirochetes. Intestinal inflammation due to IS occurs by the destruction of colonic microvilli and induces chronic diarrhea. Recently, it was reported that the prevalence of IS tended to be high in patients with sessile serrated adenomas/polyps, the precursor of MSI-high CRC including MC. This study presents a case of MC in the setting of intestinal inflammation due to IS and tries to clarify the cause of MC development by performing immunohistochemical stain of resected specimen for DNA mismatch repair (MMR) proteins. This patient is a 63-year-old man with no symptoms who had a positive fecal occult blood test. Subsequent endoscopic findings and biopsy results revealed intestinal stricture of the transverse colon and chronic infective colitis associated with IS. Metronidazole therapy was initiated but was not effective. Although follow-up colonoscopy was performed repeatedly, intestinal perforation occurred 20 months later. Subtotal colectomy and ileostomy were performed. Pathological examination of resected specimens revealed MC with normal expression of MMR proteins, including MLH1, MSH2, MSH6, and PMS2. The histopathological classification was Union for International Cancer Control (UICC) IIIB and adjuvant chemotherapy was initiated. This is an interesting case of MC developing in the setting of chronic colitis associated with IS. It seemed that the cause of MC development was not MSI but intestinal inflammation. Besides, endoscopic diagnosis of MC in this case was difficult because of the extramural progression and lack of obvious atypical colonic glands in biopsy specimens. This report provides evidence for an association between neoplasm and IS-induced intestinal inflammation. Moreover, we suggest that making the diagnosis of MC could be difficult because of its unique clinicopathological characteristics.

Endocytoscopy is a promising modality with high diagnostic accuracy for gastric cancer.

BACKGROUND AND STUDY AIM: Endocytoscopy (ECS) enables in vivo microscopic imaging, which allows analysis of mucosal structures at the cellular level; however, limited data are available on the validity of ECS in the stomach. The aim of this study was to evaluate the feasibility of ECS in the diagnosis of early gastric cancer. PATIENTS AND METHODS: Gastric lesions that were the targets of histopathological diagnosis by endoscopic submucosal dissection or biopsy specimen were prospectively enrolled and evaluated using a single charge-coupled device-integrated endocytoscope, following double staining with crystal violet and methylene blue. High grade ECS atypia was defined according to specific irregularities in gland structure and cell nuclei. The primary end point was the accuracy of ECS diagnosis for gastric cancer, using histopathological diagnosis as the gold standard. RESULTS: A total of 82 lesions were investigated, including 23 early gastric cancers, 10 gastric adenomas, and 49 non-neoplastic lesions. Ten lesions could not be clearly observed by ECS because of poor staining due to viscous mucus or plaque; thus, assessability rates with ECS were 88 % in total and 91 % for gastric cancer. High grade ECS atypia was observed in 86 % of assessable gastric cancers, but not in any cases of gastric adenomas or non-neoplastic lesions. The sensitivity, specificity, positive and negative predictive values of high grade ECS atypia as the criterion for the diagnosis of gastric cancer were 86 %, 100 %, 100 %, and 94 %, respectively. No serious complications occurred during or after the examinations. CONCLUSION: ECS is a clinically feasible modality to obtain in vivo histology, with high diagnostic accuracy in gastric cancer.