Comparison of purse-string suture versus over-the-scope clip for gastric endoscopic full-thickness closure: traction and leak pressure testing in ex vivo porcine model.

BACKGROUND: The recently developed endoscopic full-thickness resection technique requires reliable closure. The main closure methods are the purse-string suture (PSS) technique and over-the-scope clip (OTSC) technique; however, basic data on the closure strength of each technique are lacking. This study was performed to compare the closure strengths of these two methods in an ex vivo porcine model. METHODS: In the traction test, a virtual 5-cm full-thickness closure line was closed by the following six methods three times each: conventional hemoclips, mucosal PSS, seromuscular PSS, mucosal OTSC, seromuscular OTSC, and surgical suture. The primary endpoint was the tension at the starting point of dehiscence, measured in Newtons (N) by an automatic traction machine. In the leak test, a 15-mm gastric full-thickness defect was closed by PSS or OTSC six times each, and the closed stomach was then pressurized in a water container. The primary endpoint was the leak pressure when air bubbles appeared. The secondary endpoints were the procedure time and presence of complete inverted closure. RESULTS: The mean tension was 2.16, 3.68, 5.15, 18.30, 19.30, and 62.40 N for conventional hemoclips, mucosal PSS, seromuscular PSS, mucosal OTSC, seromuscular OTSC, and surgical suture, respectively. Complete inverted closure was observed for seromuscular PSS, seromuscular OTSC, and surgical suture. The mean leak pressure was 13.7 and 24.8 mmHg in the PSS and OTSC group, respectively (P < 0.01). The mean procedure time was 541 and 169 s in the PSS and OTSC group, respectively (P < 0.01). Complete inverted closure was observed in OTSC alone. CONCLUSION: The OTSC, which allows complete inverted closure, showed greater closure strength than PSS. Considering the size limitation suitable for single OTSC, a therapeutic strategy for closing the larger size is further warranted.

[A case of pancreatic cancer with clusters of invasive micropapillary carcinoma markedly reduced by chemotherapy].

A man in his 60s was hospitalized with multiple cerebral infarctions and referred for Trousseau's syndrome. Computerized tomography confirmed a 60-mm mass in the pancreatic head and swollen lymph nodes around the abdominal aorta. Fine needle aspiration cytology of the pancreatic lesion and laparoscopic para-aortic lymph node biopsy revealed adenocarcinoma, including clusters of invasive micropapillary carcinoma (IMPC). Chemotherapy (gemcitabine and nab-paclitaxel) markedly decreased the primary and metastatic lesions, and no recurrence was clinically detected 24 months later. To the best of our knowledge, reports of pancreatic IMPCs are rare. Our case was the seventeenth case of pancreatic cancer with IMPC. In this case, chemotherapy was markedly effective.

Clinical predictors of histologic type of gastric cancer.

BACKGROUND AND AIMS: Gastric cancer is classified into differentiated and undifferentiated types according to the degree of glandular differentiation. Undifferentiated-type early gastric cancer (EGC) carries a higher risk of lymph-node metastasis than differentiated type, and therefore the indication criteria for endoscopic resection differ. This study aimed to clarify the ability of clinical predictors to distinguish between differentiated-type and undifferentiated-type EGCs. METHODS: This was a post hoc study of a multicenter prospective trial carried out in 5 Japanese hospitals, including 343 patients with cT1 EGC of ≥10 mm. According to the protocol, age, sex, and endoscopic findings of cancer (diameter, location, macroscopic type, and invasion depth) were evaluated, and the final diagnosis was confirmed from resected specimens. We evaluated the associations between these clinical factors and the histologic type of cancer and calculated the ability of the factors to diagnose differentiated-type EGC. The diagnostic ability of forceps biopsy was also calculated as a reference. RESULTS: Multivariate analysis identified older age (≥72 years), male sex, larger tumor size (>30 mm), elevated type, and shallower invasion depth (cT1a) as independent significant predictors for differentiated-type EGC, with elevated type showing the highest positive likelihood ratio. The sensitivity, specificity, accuracy, and positive and negative likelihood ratios of elevated type for differentiated-type EGC were 24%, 99%, 38%, 15.7, and 0.77, respectively, compared with 96%, 86%, 95%, 7.0, and 0.04 for forceps biopsy. CONCLUSIONS: Endoscopic elevated type is a significant predictor for differentiated-type EGC and may exclude undifferentiated-type EGC without the need for forceps biopsy.

Delineation of the extent of early gastric cancer by magnifying narrow-band imaging and chromoendoscopy: a multicenter randomized controlled trial.

BACKGROUND: Accurate delineation of tumor margins is necessary for curative resection of early gastric cancer (EGC). The objective of this multicenter, randomized, controlled study was to compare the accuracy with which magnifying narrow-band imaging (M-NBI) and indigo carmine chromoendoscopy delineate EGC margins. METHODS: Patients with EGC ≥ 10 mm undergoing endoscopic or surgical resection were enrolled. The oral-side margins of the lesions were first evaluated with conventional white-light endoscopy in both groups and then delineated by either chromoendoscopy or M-NBI. Biopsies were taken from noncancerous and cancerous mucosa, each at 5 mm from the margin. Accurate delineation was judged to have been achieved when the histological findings in all biopsy samples were consistent with endoscopic diagnoses. The primary end point was the difference in rate of accurate delineation between the two techniques. RESULTS: Data on 343 patients were analyzed. The accurate delineation rate (95 % confidence interval) was 85.7 % (80.4 - 91.0) in the chromoendoscopy group (n = 168), and 88.0 % (83.2 - 92.8) in the M-NBI group (n = 175; P = 0.63). Lower third tumor location (odds ratio [OR] 2.9; P = 0.01), nonflat macroscopic type (OR 4.4; P < 0.01), and high diagnostic confidence (OR 3.6; P < 0.001) were associated with accurate delineation, whereas use of M-NBI was not (OR 1.2; P = 0.39). Even after adjustment for identified confounders, the difference in accurate delineation between the groups was not significant (OR 1.0; P = 0.82). CONCLUSIONS: M-NBI does not offer superior delineation of EGC margins compared with chromoendoscopy; the two methods appear to be clinically equivalent.

Characteristic findings of high-grade cervical intraepithelial neoplasia or more on magnifying endoscopy with narrow band imaging.

BACKGROUND: Colposcopy, which is a standard modality for diagnosing cervical intraepithelial neoplasia (CIN), can have limited accuracy owing to poor visibility. Flexible magnifying endoscopy with narrow band imaging (ME-NBI) has excellent diagnostic accuracy for early gastrointestinal neoplasms and is expected to be highly useful for CIN diagnosis. This study aimed to determine the characteristic findings and evaluate the diagnostic ability of ME-NBI for lesions ≥ CIN 3. METHODS: A well-designed prospective diagnostic case series conducted at multiple tertiary-care centers. A total of 24 patients who underwent cervical conization with a preoperative diagnosis of high-grade squamous cell intraepithelial lesions (HSILs) or lesions ≥ CIN 3 were enrolled. Prior to conization, still images and video of ME-NBI were captured to investigate the cervical lesions. The images were reviewed based on histological examination of the resected specimens. RESULTS: The NBI-ME images revealed the following abnormal findings: (1) light white epithelium (l-WE), (2) heavy white epithelium (h-WE), and (3) atypical intra-epithelial papillary capillary loop (IPCL). Pathological examination of the resected specimens confirmed cervical lesions ≥ CIN 3 in 21 patients. The ME-NBI findings were classified into four groups: l-WE, l-WE with atypical IPCL, h-WE, and h-WE with atypical IPCL, at rates of 0, 23.8, 9.5, and 66.7%, respectively. Additionally, all 3 patients with micro-invasive carcinoma showed a strong irregularity of IPCLs. CONCLUSION: The lesions ≥ CIN 3 demonstrated characteristic ME-NBI findings of h-WE alone, or l-/h-WE with atypical micro-vessels. This study indicates that ME-NBI may have novel value for CIN diagnosis.

Extending magnifying NBI diagnosis of intestinal metaplasia in the stomach: the white opaque substance marker.

Background and aims Intestinal metaplasia (IM) of the stomach is associated with an increased risk of differentiated gastric cancer. While it is important to diagnose IM endoscopically, it can be difficult to observe by white-light endoscopy. In magnifying endoscopy with narrow-band imaging (M-NBI) of the stomach, a light-blue crest (LBC) is widely known to be a useful marker in the endoscopic diagnosis of IM. However, IM that exhibits only white opaque substance (WOS) without an LBC can also occur. The aim of this study was to elucidate whether the presence of WOS on M-NBI of the stomach could serve as a marker of IM in the same way that an LBC does. Methods The subjects were 40 consecutive patients who underwent M-NBI between July and December 2014. The primary endpoint in this study was to evaluate the diagnostic performance of M-NBI for histologically observed IM in WOS- and LBC-positive mucosa. Results The sensitivity and specificity of WOS for histologically diagnosed IM were 50.0 % (95 % confidence interval [CI] 40.0 % - 50.0 %) and 100.0 % (95 %CI 85.0 % - 100.0 %), respectively. Meanwhile, the sensitivity and specificity of LBC were 62.5 % (95 %CI 51.1 % - 65.9 %) and 93.8 % (95 %CI 76.7 % - 98.9 %), respectively. The sensitivity and specificity of WOS and/or LBC (WOS positive and LBC positive, WOS positive and LBC negative, or WOS negative and LBC positive) for histologically diagnosed IM were 87.5 % (95 %CI 76.9 % - 90.9 %) and 93.8 % (95 %CI 77.9 % - 98.9 %), respectively. Conclusions LBC and WOS are both useful markers for endoscopic diagnosis of IM. Combining both markers improves the sensitivity.Clinical trial number: UMINCTR000014453.

Evaluation of an e-learning system for diagnosis of gastric lesions using magnifying narrow-band imaging: a multicenter randomized controlled study.

Background and study aim Magnifying narrow-band imaging (M-NBI) is useful for the accurate diagnosis of early gastric cancer (EGC). However, acquiring skill at M-NBI diagnosis takes substantial effort. An Internet-based e-learning system to teach endoscopic diagnosis of EGC using M-NBI has been developed. This study evaluated its effectiveness. Participants and methods This study was designed as a multicenter randomized controlled trial. We recruited endoscopists as participants from all over Japan. After completing Test 1, which consisted of M-NBI images of 40 gastric lesions, participants were randomly assigned to the e-learning or non-e-learning groups. Only the e-learning group was allowed to access the e-learning system. After the e-learning period, both groups received Test 2. The analysis set was participants who scored < 80 % accuracy on Test 1. The primary end point was the difference in accuracy between Test 1 and Test 2 for the two groups. Results A total of 395 participants from 77 institutions completed Test 1 (198 in the e-learning group and 197 in the non-e-learning group). After the e-learning period, all 395 completed Test 2. The analysis sets were e-learning group: n = 184; and non-e-learning group: n = 184. The mean Test 1 score was 59.9 % for the e-learning group and 61.7 % for the non-e-learning group. The change in accuracy in Test 2 was significantly higher in the e-learning group than in the non-e-learning group (7.4 points vs. 0.14 points, respectively; P < 0.001). Conclusion This study clearly demonstrated the efficacy of the e-learning system in improving practitioners' capabilities to diagnose EGC using M-NBI.Trial registered at University Hospital Medical Information Network Clinical Trials Registry (UMIN000008569).

Basic principles and practice of gastric cancer screening using high-definition white-light gastroscopy: Eyes can only see what the brain knows.

Endoscopic diagnosis of gastrointestinal tumors consists of the following processes: (i) detection; (ii) differential diagnosis; and (iii) quantitative diagnosis (size and depth) of a lesion. Although detection is the first step to make a diagnosis of the tumor, the lesion can be overlooked if an endoscopist has no knowledge of what an early-stage 'superficial lesion' looks like. In recent years, image-enhanced endoscopy has become common, but white-light endoscopy (WLI) is still the first step for detection and characterization of lesions in general clinical practice. Settings and practice of routine esophagogastroduodenoscopy (EGD) such as use of antispasmodics, number of endoscopic images taken, and observational procedure are customarily decided in each facility in each country and are not well standardized. Therefore, in the present article, we attempted to outline currently available evidence and actual Japanese practice on gastric cancer screening using WLI, and provide tips for detecting EGC during routine EGD which could become the basis of future research.

Highest power magnification with narrow-band imaging is useful for improving diagnostic performance for endoscopic delineation of early gastric cancers.

BACKGROUND AND STUDY AIMS: Magnifying endoscopy with narrow-band imaging (ME-NBI) is more reliable than chromoendoscopy (CE) for delineating the horizontal extent of early gastric cancers prior to endoscopic submucosal dissection (ESD). However, the added benefits of ME-NBI over CE in terms of the difference in magnification level have yet to be elucidated. The aim of this study was to investigate the improvement in diagnostic accuracy for tumor delineation obtained with different magnification levels of ME-NBI following CE. PATIENTS AND METHODS: This was a retrospective study, performed at a single tertiary referral center. A series of 158 consecutive patients with 161 early gastric cancers resected en bloc using ESD was included in the study. The margins of each lesion were examined in their entirety using CE, followed by low power optical magnifying endoscopy with narrow-band imaging (LM-NBI), and finally the highest power optical magnifying endoscopy with narrow-band imaging (HM-NBI). The primary endpoint was the added benefit, as measured using the successful delineation rate, for the delineation of gastric cancer margins using CE + LM-NBI vs CE, and for CE + LM-NBI + HM-NBI vs CE + LM-NBI. RESULTS: The successful delineation rates (95 % CI) using CE, CE + LM-NBI and CE + LM-NBI + HM-NBI were 72.7 % (68.5-79.9 %), 88.9 % (84.2-93.8 %), and 98.1 % (95.8-100 %). The diagnostic accuracy improved significantly for CE + LM-NBI compared with CE (P < 0.001), and for HM-NBI compared with LM-NBI (P < 0.001). CONCLUSIONS: HM-NBI is useful for improving diagnostic performance for endoscopic delineation of early gastric cancers, following CE and LM-NBI.

Diagnostic performance and limitations of magnifying narrow-band imaging in screening endoscopy of early gastric cancer: a prospective multicenter feasibility study.

BACKGROUND: Curative treatment of patients with gastric cancer requires reliable detection of early gastric cancer. Magnifying endoscopy with narrow-band imaging (M-NBI) is useful for the accurate preoperative diagnosis of early gastric cancer. However, the role of M-NBI in screening endoscopy has not been established. The aims of this study were to determine the feasibility and limitations of M-NBI in screening endoscopy. METHODS: We conducted a multicenter prospective uncontrolled trial of patients undergoing routine screening endoscopy patients. We determined the diagnostic accuracy, sensitivity and specificity of M-NBI according to the degree of certainty and need for biopsy, as assessed using the VS (vessel plus surface) classification system. We analyzed the endoscopic and histopathological characteristics of both false negative and false positive high confidence M-NBI diagnoses. We then developed a provisional diagnostic strategy based on the diagnostic performance and limitations identified in this study. RESULTS: A total of 1097 patients were enrolled in the study. We analyzed 371 detected lesions (20 cancers and 351 non-cancers). The accuracy, sensitivity and specificity of high confidence M-NBI diagnoses were 98.1, 85.7 and 99.4 %, respectively. The false negative case was a pale mucosal lesion with tissue diagnosis of signet-ring cell carcinoma. Exclusion of pale mucosal lesions increased the accuracy, sensitivity and specificity of high confidence M-NBI diagnoses to 99.4, 100 and 99.4 %, respectively. We therefore propose a practical strategy targeting non-pale mucosal lesions. CONCLUSIONS: With a refined strategy considering its limitations, M-NBI can act as an "optical biopsy" in screening endoscopies.

Interventional radiology using endoscopy: Blood supply route-targeted endoscopic injection sclerotherapy with multiple ligations for giant esophagogastric varices.

A case of high-risk giant esophagogastric varices was treated by blood supply route-targeted endoscopic injection sclerotherapy with multiple ligations (EISML). An endoscope was inserted in the left lower semi-lateral position under general anesthesia in the digital subtraction angiography room. The C-arm was rotated to obtain a frontal view for fluoroscopy. Before puncturing the esophageal varices, the balloon attached to the tip of the endoscope was inflated to block the variceal blood flow. At puncture, an intravascular injection was confirmed fluoroscopically, and a total of 18 m of 5% ethanolamine oleate with iopamidol was injected retrogradely at 5-minute intervals from the esophagogastric varices to the root of the left gastric vein, maintaining stagnation for 25 minutes. The variceal site of the injection was ligated immediately after the removal of the needle to prevent variceal bleeding. Multiple variceal ligations were added to stop the variceal blood flow. Contrast-enhanced CT 3 days after EISML showed the thrombus formation in esophagogastric varices and the left gastric vein. The blood supply route-targeted EISML can be a feasible procedure for giant esophagogastric varices.

Non-atrophic gastric mucosa is an independently associated factor for superficial non-ampullary duodenal epithelial tumors: a multicenter, matched, case-control study.

BACKGROUND/AIMS: The etiology of superficial non-ampullary duodenal epithelial tumors (SNADETs) remains unclear. Recent studies have reported conflicting associations between duodenal tumor development and Helicobacter pylori infection or endoscopic gastric mucosal atrophy. As such, the present study aimed to clarify the relationship between SNADETs and H. pylori infection and/or endoscopic gastric mucosal atrophy. METHODS: This retrospective case-control study reviewed data from 177 consecutive patients with SNADETs who underwent endoscopic or surgical resection at seven institutions in Japan over a three-year period. The prevalence of endoscopic gastric mucosal atrophy and the status of H. pylori infection were compared in 531 sex- and age-matched controls selected from screening endoscopies at two of the seven participating institutions. RESULTS: For H. pylori infection, 85 of 177 (48.0%) patients exhibited SNADETs and 112 of 531 (21.1%) control patients were non-infected (p<0.001). Non-atrophic mucosa (C0 to C1) was observed in 96 of 177 (54.2%) patients with SNADETs and 112 of 531 (21.1%) control patients (p<0.001). Conditional logistic regression analysis revealed that non-atrophic gastric mucosa was an independent risk factor for SNADETs (odds ratio, 5.10; 95% confidence interval, 2.44-8.40; p<0.001). CONCLUSION: Non-atrophic gastric mucosa, regardless of H. pylori infection status, was a factor independently associated with SNADETs.

Outcomes of Endoscopic Intervention Using Over-the-Scope Clips for Anastomotic Leakage Involving Secondary Fistula after Gastrointestinal Surgery: A Japanese Multicenter Case Series.

BACKGROUND: The over-the-scope clip (OTSC) is a highly effective clipping device for refractory gastrointestinal disease. However, Japanese data from multicenter studies for anastomotic leakage (AL) involving a secondary fistula after gastrointestinal surgery are lacking. Therefore, this study evaluated the efficacy and safety of OTSC placement in Japanese patients with such conditions. METHODS: We retrospectively collected data from 28 consecutive patients from five institutions who underwent OTSC-mediated closure for AL between July 2017 and July 2020. RESULTS: The AL and fistula were located in the esophagus (3.6%, n = 1), stomach (10.7%, n = 3), small intestine (7.1%, n = 2), colon (25.0%, n = 7), and rectum (53.6%, n = 15). The technical success, clinical success, and complication rates were 92.9% (26/28), 71.4% (20/28), and 0% (0/28), respectively. An age of <65 years (85.7%), small intestinal AL (100%) and colonic AL (100%), defect size of <10 mm (82.4%), time to OTSC placement > 7 days (84.2%), and the use of simple suction (78.9%) and anchor forceps (80.0%) were associated with higher clinical success rates. CONCLUSION: OTSC placement is a useful therapeutic option for AL after gastrointestinal surgery.

Diagnosis of histological type of early gastric cancer by magnifying narrow-band imaging: A multicenter prospective study.

Objectives: Distinguishing undifferentiated-type from differentiated-type early gastric cancers (EGC) is crucial for determining the indication of endoscopic resection. We aimed to investigate the diagnostic performance of white-light endoscopy (WLE) and magnifying narrow-band imaging (M-NBI) for the histological type of EGC. Methods: In this multicenter prospective study, patients with histologically proven cT1 EGC, macroscopically depressed or flat type, size ≥5 mm, and without erosion/ulcer, were recruited. The diagnostic criterion of WLE for undifferentiated-type EGC was pale color. The M-NBI algorithm was created based on microsurface and microvascular patterns, and lesions with absent microsurface pattern and opened-loop microvascular patterns were diagnosed as undifferentiated-type. The center of the lesion was defined as the evaluation point and was initially evaluated by WLE, then by M-NBI, and a biopsy specimen was taken as a reference standard. The primary and key secondary endpoints were overall diagnostic accuracy and specificity, respectively. Results: In total, 167 lesions (122 differentiated-type and 45 undifferentiated-type EGCs) in 167 patients were analyzed. The overall accuracy, sensitivity, specificity, and positive likelihood ratio of WLE for undifferentiated-type cancer were 80%, 69%, 84%, and 4.4, respectively, and those of M-NBI were 82%, 53%, 93%, and 7.2, respectively. There was no significant difference in overall accuracy (p = 0.755), but specificity was significantly higher in M-NBI (p = 0.041). Conclusions: The use of M-NBI did not improve the accuracy of WLE for the diagnosis of depressed/flat undifferentiated-type EGCs but improved the specificity. It may reduce surgical overtreatment by preventing misdiagnosis of differentiated-type EGC as undifferentiated-type.