Evaluating false-positive detection in a computer-aided detection system for colonoscopy.

BACKGROUND AND AIM: Computer-aided detection (CADe) systems can efficiently detect polyps during colonoscopy. However, false-positive (FP) activation is a major limitation of CADe. We aimed to compare the rate and causes of FP using CADe before and after an update designed to reduce FP. METHODS: We analyzed CADe-assisted colonoscopy videos recorded between July 2022 and October 2022. The number and causes of FPs and excessive time spent by the endoscopist on FP (ET) were compared pre- and post-update using 1:1 propensity score matching. RESULTS: During the study period, 191 colonoscopy videos (94 and 97 in the pre- and post-update groups, respectively) were recorded. Propensity score matching resulted in 146 videos (73 in each group). The mean number of FPs and median ET per colonoscopy were significantly lower in the post-update group than those in the pre-update group (4.2 ± 3.7 vs 18.1 ± 11.1; P < 0.001 and 0 vs 16 s; P < 0.001, respectively). Mucosal tags, bubbles, and folds had the strongest association with decreased FP post-update (pre-update vs post-update: 4.3 ± 3.6 vs 0.4 ± 0.8, 0.32 ± 0.70 vs 0.04 ± 0.20, and 8.6 ± 6.7 vs 1.6 ± 1.7, respectively). There was no significant decrease in the true positive rate (post-update vs pre-update: 95.0% vs 99.2%; P = 0.09) or the adenoma detection rate (post-update vs pre-update: 52.1% vs 49.3%; P = 0.87). CONCLUSIONS: The updated CADe can reduce FP without impairing polyp detection. A reduction in FP may help relieve the burden on endoscopists.

Clinical outcomes and learning curve of Tip-in endoscopic mucosal resection for 15-25 mm colorectal neoplasms among non-experts.

BACKGROUND AND AIM: Tip-in endoscopic mucosal resection (EMR) has a high en bloc resection rate for large colorectal neoplasms. However, non-experts' performance in Tip-in EMR has not been investigated. We investigated whether Tip-in EMR can be achieved effectively and safely even by non-experts. METHODS: This retrospective study included consecutive patients who underwent Tip-in EMR for 15-25 mm colorectal nonpedunculated neoplasms at a Japanese tertiary cancer center between January 2014 and December 2020. Baseline characteristics, treatment outcomes, learning curve of non-experts, and risk factors of failing self-achieved en bloc resection were analyzed. RESULTS: A total of 597 lesions were analyzed (438 by experts and 159 by non-experts). The self-achieved en bloc resection (69.8% vs 88.6%, P < 0.001) and self-achieved R0 resection (58.3% vs 76.5%, P < 0.001) rates were significantly lower in non-experts with <10 cases of experience than in experts, but not in non-experts with >10 cases. Adverse event (P = 0.165) and local recurrence (P = 0.892) rates were not significantly different between experts and non-experts. Risk factors of failing self-achieved en bloc resection were non-polypoid morphology (OR 3.4, 95% CI 1.6-7.3, P = 0.001), lesions with an underlying semilunar fold (OR 3.6, 95% CI 1.6-7.3, P < 0.001), positive non-lifting sign (OR 3.1, 95% CI 1.2-8.0, P = 0.023), and non-experts with an experience of ≤10 cases (OR 3.6, 95% CI 2.1-6.3, P < 0.001). CONCLUSION: The clinical outcomes of Tip-in EMR for 15-25 mm lesions performed by non-experts were favorable.

A novel low-power pure-cut hot snare polypectomy for 10-14 mm colorectal adenomas: An ex vivo and a clinical prospective feasibility study (SHARP trial).

BACKGROUND AND AIM: Hot snare polypectomy using blend or coagulation current is widely used; however, it causes deeper tissue heat injury, leading to adverse events. We hypothesized that hot polypectomy using low-power pure cut current (PureCut, effect 1 10 W) could reduce deeper tissue heat injury. We conducted animal experiments to evaluate the deeper tissue heat injury and conducted a prospective clinical study to examine its cutting ability. METHODS: In a porcine rectum, hot polypectomy using Blend current (EndoCut, effect 3 40 W) and low-power pure cut current was performed. The deepest part of heat destruction and thickness of the non-burned submucosal layer were evaluated histologically. Based on the results, we performed low-power pure cut current hot polypectomy for 10-14 mm adenoma. The primary endpoint was complete resection defined as one-piece resection with negative for adenoma in quadrant biopsies from the defect margin. RESULTS: In experiments, all low-power pure-cut resections were limited within the submucosal layer whereas blend current resections coagulated the muscular layer in 13% (3/23). The remaining submucosal layer was thicker in low-power pure cut current than in blend current resections. In the clinical study, low-power pure-cut hot polypectomy removed all 100 enrolled polyps. For 98 pathologically neoplastic polyps, complete resection was achieved in 84 (85.7%, 95% confidence interval, 77-92%). The lower limit of the 95% confidence interval was not more than 15% below the pre-defined threshold of 86.6%. No severe adverse events occurred. CONCLUSIONS: A novel low-power pure-cut hot polypectomy may be feasible for adenoma measuring 10-14 mm. (UMIN000037678).

Endoscopic causes and characteristics of missed gastric cancers after endoscopic submucosal dissection.

BACKGROUND AND AIMS: Because endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) preserves the entire stomach, missed gastric cancers (MGCs) are often found in the remaining gastric mucosa. However, the endoscopic causes of MGCs remain unclear. Therefore, we aimed to elucidate the endoscopic causes and characteristics of MGCs after ESD. METHODS: From January 2009 to December 2018, all patients undergoing ESD for initially detected EGC were enrolled. According to a review of EGD images before ESD, we identified the endoscopic causes (perceptual, exposure, sampling errors, and inadequate preparation) and characteristics of MGC in each endoscopic cause. RESULTS: Of 2208 patients who underwent ESD for initial EGC, 82 patients (3.7%) had 100 MGCs. The breakdown of endoscopic causes of MGCs was as follows: 69 (69%) perceptual errors, 23 (23%) exposure errors, 7 (7%) sampling errors, and 1 (1%) inadequate preparation. Logistic regression analysis showed that the risk factors for perceptual error were male sex (odds ratio [OR], 2.45; 95% confidence interval [CI], 1.16-5.18), isochromatic coloration (OR, 3.17; 95% CI, 1.47-6.84), greater curvature (OR, 2.31; 95% CI, 1.121-4.40), and lesion size ≤12 mm (OR, 1.74; 95% CI, 1.07-2.84). The sites of exposure errors were around the incisura angularis (11 [48%]), posterior wall of the gastric body (6 [26%]), and antrum (5 [21%]). CONCLUSIONS: We identified MGCs in 4 categories and clarified their characteristics. Quality improvements in EGD observation, with attention to the risks of perceptual and site of exposure errors, can potentially prevent missing EGCs.

Clinical outcomes of endoscopic submucosal dissection for superficial circumferential esophageal squamous cell carcinoma.

BACKGROUND AND AIMS: Our aim was to elucidate the clinical outcomes of endoscopic submucosal dissection (ESD) for superficial circumferential esophageal squamous cell carcinoma (cESCC). METHODS: Consecutive patients who underwent ESD for cESCC between 2009 and 2020 were retrospectively reviewed. Short-term outcomes were en-bloc resection, R0 resection, procedure time, and adverse events, whereas long-term outcomes were overall survival (OS), disease-specific survival (DSS), cumulative recurrence rate (CRR), and clinical course. RESULTS: Fifty-two patients with 52 cESCCs (median tumor length, 5.0 cm; interquartile range [IQR], 4.0-6.3) were evaluated. The en-bloc resection and R0 resection rates were 100% (95% confidence interval [CI], 94.4-100) and 69.2% (95% CI, 54.9-81.3), respectively. The median procedure time was 112 minutes (IQR, 87-162). Intraoperative perforations and delayed bleeding occurred in 4 (7.7%) and 1 (1.9%) patients, respectively. Among the 42 patients who underwent ESD alone, 36 (85.7%) experienced esophageal strictures. Within a median follow-up of 49.1 months (IQR, 25.7-74.7), the 4-year OS, DSS, and CRR were 86.2% (95% CI, 71.6-93.6), 95.5% (95% CI, 83.1-98.9), and 11.5% (95% CI, 4.1-23.1), respectively. There was no significant difference in the OS between patients with low-risk cESCC (pT1a, negative lymphovascular invasion, and negative vertical margin) and high-risk lesions, regardless of undergoing additional treatment (P = .93). In 31 patients with low-risk cESCC who were treated with ESD alone, the 4-year OS, DSS, and CRR were 93.2%, 100%, and 0%, respectively. CONCLUSIONS: ESD is a highly curative treatment for cESCC with favorable long-term outcomes, especially in low-risk patients. Stricture-prevention techniques should be improved to optimize the benefits of ESD for cESCC.

Diagnostic performance of endoscopy for subsquamous extension of superficial adenocarcinoma of the esophagogastric junction.

OBJECTIVES: Extension of adenocarcinoma of the esophagogastric junction under the squamous epithelium may lead to errors when determining lateral margins. However, the characteristics of subsquamous extension are unclear. Herein, we evaluated the prevalence and characteristics of subsquamous extension of adenocarcinoma of the esophagogastric junction and the diagnostic performance of endoscopy for this condition. METHODS: Eighty-nine consecutive patients with superficial adenocarcinoma of the esophagogastric junction who underwent endoscopic or surgical resection at a tertiary cancer center between January 2010 and December 2017 were retrospectively evaluated. Endoscopic subsquamous extension was defined as a submucosal tumor-like elevation covered by squamous epithelium and/or a brownish area with abnormal microvessels on the squamous epithelium observed using narrow-band imaging. The diagnostic performance of endoscopy for subsquamous extension was evaluated using histological subsquamous extension as gold standard. RESULTS: Thirty-nine patients (44%) had histological subsquamous extension. Proton pump inhibitor use was significantly associated with histological subsquamous extension [odds ratio: 4.65; 95% confidence interval (CI): 1.77-12.2]. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of endoscopic subsquamous extension were 56% (95% CI: 40-72%), 96% (86-99%), 92% (73-99%), 74% (62-84%) and 79% (69-87%), respectively. The median length difference between histological and endoscopic subsquamous extension was 2 mm (range: -6 to 9 mm). CONCLUSIONS: The sensitivity of endoscopic diagnosis of subsquamous extension was unsatisfactory. The endoscopic length of subsquamous extension tended to be underestimated. An oral safety margin of one centimeter is reasonable during endoscopic resection of adenocarcinoma of the esophagogastric junction.IMPACT STATEMENT This study will contribute significantly to the literature because this is the first study to determine the difference between the lengths of subsquamous extension detected endoscopically and histologically. This study determines the prevalence of subsquamous extension and identifies characteristics associated with subsquamous extension. An understanding of the risk of subsquamous extension is important when choosing a treatment strategy and planning the resection margins in patients with adenocarcinoma of the esophagogastric junction. This study provides patients with subsquamous extension characteristics and suggests a method for accurately diagnosing this condition.

Complete endoscopic removal rate of detected colorectal polyps in a real world out-patient practical setting.

OBJECTIVES: Colonoscopy with adenomatous polypectomy reduces the incidence and mortality of colorectal cancer. We introduced a strategy of removing all neoplastic polyps in single-session out-patient colonoscopy using cold polypectomy. We aimed to investigate the achievement of single-session complete removal rate of detected colorectal polyps in clinical practice. MATERIALS AND METHODS: This retrospective study included colonoscopy-scheduled 40-79-year-old outpatients, with at least one colorectal neoplasm, between January 2015 and December 2016. Exclusion criteria were: colorectal neoplasms 21 mm or larger in size; pre-examination for colorectal surgery or endoscopic submucosal dissection; colonoscopy performed by health check program; ongoing antithrombotic treatment; inflammatory bowel disease; familial adenomatous polyposis. We defined 'clean colon' as the removal of all detected neoplastic polyps in a single-session colonoscopy. We evaluated clean colon rate, factors relating to clean colon failure and complications. RESULTS: We evaluated 2527 patients (mean age 68 years; 799 women) with 8203 colorectal polyps (7675 adenomas, 423 serrated lesions, 105 Tis and T1 cancers). In 1-4 mm polyps, cold snare polypectomy (CSP; 51.8%) and cold forceps polypectomy (CFP; 45.8%) were applied. Clean colon rates were 95.1% per patient and 97.1% per lesion. The significant factors denoting clean colon failure were inadequate bowel preparation, ≥5 lesions, and the most advanced estimated histology of adenocarcinoma, on multivariate analyses. Post-polypectomy bleeding requiring endoscopic hemostasis occurred in five patients (0.2%) who had undergone endoscopic mucosal resection (EMR) or hot snare polypectomy (HSP). Perforation occurred in one patient (0.04%) with EMR. CONCLUSIONS: The clean colon rates were satisfactory in single-session out-patient colonoscopy using cold polypectomy.

Metachronous primary gastric cancer after endoscopic resection in patients with esophageal squamous cell carcinoma.

BACKGROUND: This study aimed to evaluate the risk factors for developing metachronous primary Gastric Cancer (GC) after Endoscopic Resection (ER) for esophageal Squamous Cell Carcinoma (SCC). METHODS: We studied 283 patients with esophageal SCC who underwent ER. The study outcomes were as follows: (1) incidence of metachronous primary GC after ER; and (2) predictors for the development of metachronous primary GC after ER by the Cox proportional hazards model. RESULTS: The median follow-up was 43.1 months (1.81-79.1), and the 3-year cumulative incidence of metachronous primary GC was 6.5% (95%CI: 4.1-10.4). The incidence of metachronous primary GC during the follow-up period was 2.31 per 100 person-years. The frequencies of severe gastric atrophy and macrocytosis at the timing of ER were significantly higher in patients with than without metachronous primary GC (91.7% vs. 73.2%, p = 0.0422, 20.8% vs. 5.2%, p = 0.0046, respectively). Severe gastric atrophy was associated with the development of metachronous primary GC (sex-and-age adjusted hazard ratio (HR) [95%CI] = 4.12 [0.95-27.78], p = 0.0093). Macrocytosis was associated with the development of metachronous primary GC (sex-and-age adjusted HR = 4.76 [1.75-13.0], p = 0.0012) and found to be an independent predictor for metachronous primary GC by multivariate Cox proportional hazards analysis (HR [95%CI] = 4.35 [1.60-11.84], p = 0.004). CONCLUSIONS: Severe gastric atrophy and macrocytosis should be noted in the development of metachronous primary GC after ER for esophageal SCC. In particular, macrocytosis at the timing of ER was considered an important predictor. CLINICAL TRIALS REGISTRY NUMBER: UMIN000001676.

Local recurrence risk of esophageal squamous cell carcinoma due to intralesional damage during endoscopic submucosal dissection.

BACKGROUND AND AIM: It is unclear whether additional treatment should be considered given the recurrence risk after endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) when the vertical margin is positive or unclear (VM1/VMX) due to intralesional damage. This study aimed to elucidate the local recurrence risk of ESCC caused by intralesional damage during ESD. METHODS: Among consecutive patients with pT1a ESCCs initially treated by ESD at our institution between January 2006 and December 2018, ESCCs diagnosed as VM1/VMX were retrospectively reviewed. Exclusion criteria were piecemeal resection and any additional treatment after ESD. Intralesional damage included the following three types: a macroscopic hole inside the lesion, an incision from the lateral margin of the specimen into the lesion, and crushing injury or burn effect into the deepest area of the lesion without an obvious hole. The local recurrence rate after ESD was primarily analyzed. RESULTS: Of 1174 pT1a ESCCs initially treated using ESD, 22 lesions were histopathologically diagnosed as VM1/VMX due to intralesional damage (1.9%; 95% confidence interval [CI], 1.2-2.8%). At a median follow-up period of 60.0 (interquartile range, 15.0-84.0) months, no local recurrence was observed (0.0%; 95% CI, 0.0-13.3%) among 21 lesions finally evaluated. CONCLUSIONS: The impact of intralesional damage during ESD for ESCC on local recurrence might be negligible. Follow-up without additional treatment may be acceptable even if intralesional damage occurs and results in VM1/VMX after ESD for pT1a ESCCs.

Optimization of endoscopic ultrasound-guided tissue sample acquisition for commercially available comprehensive genome profiling.

BACKGROUND AND AIM: Optimal tumor samples are crucial for successful analysis using commercially available comprehensive genomic profiling (CACGP). However, samples acquired by endoscopic ultrasound-guided tissue acquisition (EUS-TA) are occasionally insufficient, and no consensus on the optimal number of needle passes required for CACGP exists. This study aimed to explore the optimal number of needle passes required for EUS-TA to procure an ideal sample fulfilling the prerequisite criteria of CACGPs. METHODS: Patients who underwent EUS-TA for solid masses between November 2019 and July 2021 were retrospectively studied. The correlation between the acquisition rate of an ideal sample and the number of needle passes mounted on a microscope slide was evaluated. Additionally, the factors predicting a successful analysis were investigated in patients scheduled for CACGP using EUS-TA-obtained samples during the same period. RESULTS: EUS-TAs using 22- and 19-gauge (G) needles were performed in 336 and 57 patients, respectively. There was a positive correlation between the acquisition rate and the number of passes using a 22-G needle (38.9%, 45.0%, 83.7%, and 100% for 1, 2, 3, and 4 passes, respectively), while no correlation was found with a 19-G needle (84.2%, 83.3%, and 85.0% for 1, 2, and 3 passes, respectively). The analysis success rate in patients with scheduled CACGP was significantly higher with ideal samples than with suboptimal samples (94.1% vs 55.0%, P < 0.01). CONCLUSIONS: The optimal estimated number of needle passes was 4 and 1-2 for 22- and 19-G needles, respectively.

Three-Dimensional Vessel Segmentation in Whole-Tissue and Whole-Block Imaging Using a Deep Neural Network: Proof-of-Concept Study.

In the field of pathology, micro-computed tomography (micro-CT) has become an attractive imaging modality because it enables full analysis of the three-dimensional characteristics of a tissue sample or organ in a noninvasive manner. However, because of the complexity of the three-dimensional information, understanding would be improved by development of analytical methods and software such as those implemented for clinical CT. As the accurate identification of tissue components is critical for this purpose, we have developed a deep neural network (DNN) to analyze whole-tissue images (WTIs) and whole-block images (WBIs) of neoplastic cancer tissue using micro-CT. The aim of this study was to segment vessels from WTIs and WBIs in a volumetric segmentation method using DNN. To accelerate the segmentation process while retaining accuracy, a convolutional block in DNN was improved by introducing a residual inception block. Three colorectal tissue samples were collected and one WTI and 70 WBIs were acquired by a micro-CT scanner. The implemented segmentation method was then tested on the WTI and WBIs. As a proof-of-concept study, our method successfully segmented the vessels on all WTI and WBIs of the colorectal tissue sample. In addition, despite the large size of the images for analysis, all segmentation processes were completed in 10 minutes.

Tip-in EMR as an alternative to endoscopic submucosal dissection for 20- to 30-mm nonpedunculated colorectal neoplasms.

BACKGROUND AND AIMS: Tip-in EMR, which includes anchoring the snare tip, has recently shown a favorable en-bloc and R0 resection rate for colorectal neoplasms. Thus, Tip-in EMR may be an alternative to endoscopic submucosal dissection (ESD). We aimed to compare clinical outcomes between Tip-in EMR and ESD for large colorectal neoplasms. METHODS: This retrospective study evaluated consecutive patients who underwent Tip-in EMR or ESD for 20- to 30-mm nonpedunculated colorectal neoplasms at a Japanese tertiary cancer center between January 2014 and December 2019. Baseline characteristics, treatment results, and long-term outcomes were analyzed using 1:1 propensity score matching. RESULTS: Seven hundred nine lesions were evaluated. The Tip-in EMR group included 1 lesion with a nonlifting sign but no lesions with fold convergence. After propensity score matching, each group included 140 lesions. The ESD group showed significantly higher en-bloc resection rates (99.3% vs 85.0%) and R0 resection rates (90.7% vs 62.9%). Procedure time was significantly shorter in the Tip-in EMR group (8 minutes vs 60 minutes). The Tip-in EMR and ESD groups did not differ significantly with respect to local recurrence rate (2.1% vs 0%). CONCLUSIONS: Tip-in EMR is comparable with ESD with respect to the local recurrence rate but has a shorter procedure time, despite the lower en-bloc and R0 resection rates for 20- to 30-mm nonpedunculated colorectal neoplasms without fold convergence or nonlifting sign. Thus, Tip-in EMR could be a feasible alternative to ESD in these lesions.

Biliary obstruction and pancreatitis after duodenal stent placement in the descending duodenum: a retrospective study.

BACKGROUND: Metallic stents placed in the descending duodenum can cause compression of the major duodenal papilla, resulting in biliary obstruction and pancreatitis. These are notable early adverse events of duodenal stent placement; however, they have been rarely examined. This study aimed to assess the incidence of and risk factors for biliary obstruction and/or pancreatitis after duodenal stent placement in the descending duodenum. METHODS: We retrospectively reviewed data of consecutive patients who underwent metallic stent placement in the descending duodenum for malignant gastric outlet obstruction at a tertiary referral cancer center between April 2014 and December 2019. Risk factors for biliary obstruction and/or pancreatitis were analyzed using a logistic regression model. RESULTS: Sixty-five patients were included. Biliary obstruction and/or pancreatitis occurred in 12 patients (18%): 8 with biliary obstruction, 2 with pancreatitis, and 2 with both biliary obstruction and pancreatitis. Multivariate analysis indicated that female sex (odds ratio: 9.2, 95% confidence interval: 1.4-58.6, P = 0.02), absence of biliary stents (odds ratio: 12.9, 95% confidence interval: 1.8-90.2, P = 0.01), and tumor invasion to the major duodenal papilla (odds ratio: 25.8, 95% confidence interval: 2.0-340.0, P = 0.01) were significant independent risk factors for biliary obstruction and/or pancreatitis. CONCLUSIONS: The incidence of biliary obstruction and/or pancreatitis after duodenal stent placement in the descending duodenum was non-negligible. Female sex, absence of biliary stents, and tumor invasion to the major duodenal papilla were the primary risk factors. Risk stratification can allow endoscopists to better identify patients at significant risk and permit detailed informed consent.

Predicting the depth of superficial adenocarcinoma of the esophagogastric junction.

BACKGROUND AND AIM: Preoperative determination of the invasion depth of superficial adenocarcinoma of the esophagogastric junction is important for appropriate endoscopic or surgical resection. There are no objective criteria regarding this; therefore, we investigated the factors associated with the invasion depth of superficial adenocarcinoma of the esophagogastric junction. METHODS: This retrospective study evaluated patients with superficial adenocarcinoma of the esophagogastric junction who had undergone endoscopic or surgical resection at a Japanese tertiary cancer center between April 2004 and December 2017. We analyzed endoscopic features of intramucosal to slight submucosal (M-SM1; < 500 µm) and deep submucosal (SM2; ≥ 500 µm) adenocarcinoma of the esophagogastric junction and extracted significant factors associated with and assessed the diagnostic performance of endoscopic features for SM2 lesion. RESULTS: A total of 106 cases were included in this study. Multivariate analysis indicated that depressed or protruded type (odds ratio [OR], 11.1), lesion size ≥ 15 mm (OR, 3.11), uneven surface (OR, 6.31), and subsquamous extension (OR, 5.41) were significantly associated with SM2 adenocarcinomas of the esophagogastric junction. When the macroscopic type was depressed or protruded, high sensitivity (97%) but fair specificity (46%) were observed for SM2 adenocarcinoma of the esophagogastric junction, whereas uneven surface and subsquamous extension showed high specificity (96% and 87%) but fair sensitivity (36% and 46%). CONCLUSIONS: Depressed or protruded type, lesion size ≥ 15 mm, uneven surface, and subsquamous extension were significantly associated with the invasion depth of superficial adenocarcinoma of the esophagogastric junction. These endoscopic features are useful in determining the treatment method preoperatively.

Cold snare polypectomy for superficial non-ampullary duodenal epithelial tumor: a prospective clinical trial (pilot study).

BACKGOUND: Cold snare polypectomy (CSP) can minimize the risk of adverse events and has become a standard treatment for small colorectal polyps. CSP might also be suitable for small superficial non-ampullary duodenal epithelial tumors (SNADETs). This study aimed to evaluate the safety of CSP for SNADETs. METHODS: The major indication criteria were as follows: (1) endoscopically diagnosed SNADET, (2) ≤ 10 mm, and (3) a single primary lesion. CSP was performed using an electrosurgical snare without electrocautery. Follow-up endoscopy and scar biopsy were performed 3 months after CSP. The primary endpoint was the delayed adverse events rate. RESULTS: In total, 21 patients were enrolled. Two and 19 lesions were located in the duodenal bulb and 2nd portion, respectively; the median lesion size was 8 mm. CSP was attempted for all lesions; three lesions could not be resected without electrocautery and were removed by conventional endoscopic mucosal resection (EMR). The rate of spurting bleeding after CSP was 0%. The median procedure time was 12 min, the median resected specimen size was 12 mm, and the rate of en bloc resection was 81% (17/21). No adverse events were observed intraoperatively, with no delayed adverse events after CSP. Histopathology revealed 15 adenomas, 4 cancers (intramucosal), and 2 non-neoplastic lesions. The horizontal margins were negative/positive/undetermined in 9, 1, and 11 cases, respectively. All vertical margins were negative. Only one recurrence was detected by follow-up endoscopy 3 months after CSP. CONCLUSIONS: CSP can be performed safely for small SNADETs. CLINICAL TRIAL REGISTRATION: This trial was registered with the University Hospital Medical Information Network Clinical Trials Registry ( http://www.umin.ac.jp/ctr/index.htm ), and the registration number is UMIN000019157.

Diagnostic ability of magnification endoscope with narrow-band imaging in screening esophagogastroduodenoscopy.

OBJECTIVES: Magnifying endoscopy with narrow-band imaging (M-NBI) is useful for the optical diagnosis of gastrointestinal neoplasms. However, the utility of M-NBI in screening esophagogastroduodenoscopy (EGD) is unclear. We aimed to evaluate the diagnostic ability of the magnification endoscope (ME) in screening EGD for a population with a low prevalence of upper gastrointestinal cancers. METHODS: Overall, 4887 asymptomatic examinees without a history of laryngopharyngeal and/or upper gastrointestinal neoplasms who underwent opportunistic screening EGD between April 2011 and December 2017 were enrolled in this retrospective study. The examinees were categorized into two groups depending on whether screening EGD was performed using ME (ME group) or not (non-ME group). Using a propensity score-matched analysis, the diagnostic ability of EGD was compared between the two groups. RESULTS: In total, 1482 examinees (30%) were allocated to the ME group and 3405 (70%) to the non-ME group. Thirty-five epithelial neoplasms were detected in 30 examinees (0.6%). The groups were matched for baseline characteristics (1481 pairs). Both groups showed no significant difference in the epithelial neoplasm detection rate (0.8% vs. 0.3%; P = 0.14). The biopsy rate was significantly lower in the ME group than in the non-ME group (12% vs. 15%; P = 0.003). The positive predictive value (PPV) for biopsy was significantly higher in the ME group than in the non-ME group (6.6% vs. 2.8%; P = 0.048). CONCLUSIONS: Using an ME for screening EGD in an apparently healthy, asymptomatic population could reduce unnecessary biopsies by improving PPV for biopsy without decreasing the epithelial neoplasm detection rate.

Endoscopic submucosal dissection versus surgery in elderly patients with early gastric cancer of relative indication for endoscopic resection.

OBJECTIVES: Surgery is recommended for early gastric cancer (EGC) beyond the endoscopic resection (ER)-indication for the risk of lymph node metastasis; however, ER may be chosen as a "relative ER-indication" considering age and comorbidities. This study aimed to compare outcomes of endoscopic submucosal dissection (ESD) only and surgery (primary surgery and additional surgery after non-curative ESD) among elderly patients with relative ER-indication EGC and to further assess prognostic factors. METHODS: Outcomes of ESD and surgery (417 cases; 114 ESD, 303 surgery) in elderly patients (≥75 years) with relative ER-indication EGC were retrospectively analyzed. Prognostic factors were also examined. RESULTS: During the observation period (median; ESD, 34 months; surgery, 61 months), 29% of ESD and 35% of surgery patients died, including 4% and 5% from gastric cancer (GC), respectively. ESD showed lower overall survival (OS) than surgery (P = 0.027) but comparable disease-free survival (P = 0.916). OS-associated factors were age and prognostic nutritional index (PNI) in males (age ≥79, hazard ratio [HR] 2.21, P = 0.001; PNI <45, HR 2.06, P = 0.031) and age in females (age ≥82, HR 4.06, P = 0.004). Treatment was not a prognostic factor in either subgroup. Pathological category ≥pT1b2 (submucosal invasion ≥500 µm) and lymphovascular invasion (LVI) were significantly associated with GC death (mortality: ≥pT1b2, 7.7%, P = 0.002; LVI, 10.1%, P < 0.001). CONCLUSIONS: In elderly patients with relative ER-indication EGC, ESD may have comparable long-term efficacy to surgery, and treatment selection had a minor contribution to OS. For patients with poor preoperative prognostic factors, diagnostic ESD may be performed first, followed by additional surgery based on pathological results.

Pivotal trial of a biodegradable stent for patients with refractory benign esophageal stricture.

OBJECTIVE: Benign esophageal strictures (BES) cause dysphagia and decrease patients' quality of life. Although mechanical dilation is the standard of care for BES, in some patients, dysphagia is unrelieved despite repeated procedures. The biodegradable stent was developed to resolve refractory BES, with reported favorable outcomes, but it is unapproved in Japan. Thus, we evaluated the safety and efficacy of the biodegradable stent (BDS) for patients with refractory BES for regulatory approval. METHODS: This was a nonrandomized single-arm prospective trial conducted at eight institutions. We included patients with BES after ≥ 5 times of dilation or ≥ one time of radial incision and cutting whose dysphagia score (DS) was 2 or worse and an endoscope could not admit. The primary endpoint was the proportion of patients whose DS improvement of ≤ 1 was maintained at 3 months. RESULTS: Thirty patients (median age: 69 years, male/female: 27:3) were enrolled and treated; BDS placement failed in 1 patient. Fourteen patients maintained their DS improvement until 3 months after placement (proportion of DS improvement at 3 months 46.7% [95% CI: 28.3-65.7]), and the median dysphagia-free survival was 98 days [95% CI: 68-123]. Most adverse events could be managed conservatively; however, a patient with BES after chemoradiotherapy (CRT) developed an esophago-left atrium fistula and died approximately 4 months after stent placement. CONCLUSION: The BDS was effective for refractory BES and the safety was acceptable. However, the indication for this procedure in patients RECEIVING CRT for esophageal cancer should be carefully considered.

Tip-in Endoscopic Mucosal Resection for 15- to 25-mm Colorectal Adenomas: A Single-Center, Randomized Controlled Trial (STAR Trial).

INTRODUCTION: One-piece endoscopic mucosal resection (EMR) for lesions >15 mm is still unsatisfactory, and attempted 1-piece EMR for lesions >25 mm can increase perforation risk. Therefore, modifications to ensure 1-piece EMR of 15- to 25-mm lesions would be beneficial. The aim of this study was to investigate whether Tip-in EMR, which anchors the snare tip within the submucosal layer, increases en bloc resection for 15- to 25-mm colorectal lesions compared with EMR. METHODS: In this prospective randomized controlled trial, patients with nonpolypoid colorectal neoplasms of 15-25 mm in size were recruited and randomly assigned in a 1:1 ratio to undergo Tip-in EMR or standard EMR, stratified by age, sex, tumor size category, and tumor location. The primary endpoint was the odds ratio of en bloc resection adjusted by location and size category. Adverse events and procedure time were also evaluated. RESULTS: We analyzed 41 lesions in the Tip-in EMR group and 41 lesions in the EMR group. En bloc resection was achieved in 37 (90.2%) patients undergoing Tip-in EMR and 30 (73.1%) who had EMR. The adjusted odds ratio of en bloc resection in Tip-in EMR vs EMR was 3.46 (95% confidence interval: 1.06-13.6, P = 0.040). The Tip-in EMR and EMR groups did not differ significantly in adverse event rates (0% vs 4.8%) or median procedure times (7 vs 5 minutes). DISCUSSION: In this single-center randomized controlled trial, we found that Tip-in EMR significantly improved the en bloc resection rate for nonpolypoid lesions 15-25 mm in size, with no increase in adverse events or procedure time.

Comparison of five-phase computed tomography images of type 1 autoimmune pancreatitis and pancreatic cancer: Emphasis on cases with atypical images.

BACKGROUND/OBJECTIVES: International consensus diagnostic criteria (ICDC) include characteristic images of autoimmune pancreatitis (AIP); however, reports on atypical cases are increasing. The aims of this study were to compare CT findings between AIP and pancreatic cancer (PC), and to analyze type 1 AIPs showing atypical images. METHODS: Five-phase CT images were compared between 80 type 1-AIP lesions and 80 size- and location-matched PCs in the case-control study. Atypical AIPs were diagnosed based on the four ICDC items. RESULTS: ICDC items were recognized in most AIP lesions; pancreatic enlargement (87.7%), narrowing of the main pancreatic duct (98.8%), delayed enhancement (100%), and no marked upstream-duct dilation (97.5%). CT values of AIPs increased rapidly until the pancreatic phase and decreased afterward, while those of PCs gradually increased until the delayed phase (P < 0.0001). Atypical images were recognized in 14.8% of AIPs, commonly without pancreatic enlargement (18.5 mm) and sometimes mimicking intraductal neoplasms. The CT values and their ratios were different between atypical AIPs and size-matched PCs most significantly in the pancreatic phase, but similar in the delayed phase. CONCLUSIONS: Ordinary type 1 AIPs can be diagnosed with the ICDC, but atypical AIPs represented a small fraction. "Delayed enhancement" is characteristic to ordinary AIPs, however, "pancreatic-phase enhancement" is more diagnostic for atypical AIPs.