Factors affecting nonfunctioning small pancreatic neuroendocrine neoplasms and proposed new treatment strategies.

BACKGROUND & AIMS: Despite previously reported treatment strategies for nonfunctioning small (≤20 mm) pancreatic neuroendocrine neoplasms (pNENs), uncertainties persist. We aimed to evaluate the surgically resected cases nonfunctioning small pNENs (NF-spNENs) in a large Japanese cohort to elucidate an optimal treatment strategy for NF-spNENs. METHODS: In this Japanese multicenter study, data were retrospectively collected from patients who underwent pancreatectomy between January 1996 and December 2019, were pathologically diagnosed with pNEN, and were treated according to the WHO 2019 classification. Overall, 1,490 patients met the eligibility criteria, and 1,014 were included in the analysis cohort. RESULTS: In the analysis cohort, 606 patients (59.8%) had NF-spNENs, with 82% classified as grade 1 (NET-G1) and 18% as grade 2 (NET-G2) or higher. The incidence of lymph node metastasis (N1) by grade was significantly higher in NET-G2 (G1: 3.1% vs. G2: 15.0%). Independent factors contributing to N1 were NET-G2 or higher and tumor diameter ≥15 mm. The predictive ability of tumor size for N1 was high. Independent factors contributing to recurrence included multiple lesions, NET-G2 or higher, tumor diameter ≥15 mm, and N1. However, the independent factor contributing to survival was tumor grade (NET-G2 or higher). The appropriate timing for surgical resection of NET-G1 and NET-G2 or higher was when tumors were >20 and >10 mm, respectively. For neoplasms with unknown preoperative grades, tumor size >15 mm was considered appropriate. CONCLUSIONS: NF-spNENs are heterogeneous with varying levels of malignancy. Therefore, treatment strategies based on tumor size alone can be unreliable; personalized treatment strategies that consider tumor grading are preferable.

Multicenter comparative study on the usefulness of the optimal electrosurgical unit setting in endoscopic papillectomy for ampullary neoplasms (with video).

BACKGROUND: Endoscopic papillectomy (EP) is less invasive than surgery but procedure-related adverse events (AEs) still frequently occur. This study compared the benefits of EP using a new optimal endoCUT setting on the VIO (Erbe) electrosurgical unit (VIO-EP) with those using the conventional electrosurgical unit setting (ICC-EP, Erbe). METHODS: This multicenter, retrospective, comparative cohort study included 57 patients who underwent VIO-EP and 91 who underwent ICC-EP. The primary outcome was occurrence of EP-related AEs. Secondary outcomes were pathological findings (the resection margins, the R0 resection, and residual lesions). RESULTS: Pancreatitis tended to be less common in the VIO-EP group (5.3% vs. 9.9%, p = .248). Evaluation of computed tomography images showed that pancreatitis was confined to the pancreatic head in 77.8% of cases in the ICC-EP group and in 33.3% of those in the VIO-EP group. After exclusion of cases of delayed bleeding, pancreatitis tended to be less common in the VIO-EP group; this finding was not statistically significant (2.3% vs. 8.2%, p = .184). In pathological findings, residual lesions were significantly less common in the VIO-EP group. CONCLUSIONS: The risks of pancreatitis and residual lesions after EP may be lower when the VIO electrosurgical unit is used with the optimal setting.

Gut microbiota and metabolites in patients with COVID-19 are altered by the type of SARS-CoV-2 variant.

Introduction: Patients with COVID-19 have dysbiosis of the intestinal microbiota with altered metabolites in the stool. However, it remains unclear whether the differences among SARS-CoV-2 variants lead to differences in intestinal microbiota and metabolites. Thus, we compared the microbiome and metabolome changes for each SARS-CoV-2 variant in patients with COVID-19. Materials and methods: We conducted a multicenter observational study of patients with COVID-19 and performed fecal microbiome, metabolome, and calprotectin analyses and compared the results among the different SARS-CoV-2 variants. Results: Twenty-one patients with COVID-19 were enrolled and stratified according to the SARS-CoV-2 strain: six with the Alpha, 10 with the Delta, and five with the Omicron variant. Fecal microbiome analysis showed that α-diversity was reduced in the order of the Omicron, Delta, and Alpha variants (p = 0.07). Linear discriminant analysis revealed differences in the abundance of short-chain fatty acid-producing gut microbiota for each SARS-CoV-2 variant. Fecal metabolome analysis showed that the Omicron and Delta variants had markedly reduced propionic and lactic acid levels compared to the Alpha strain (p < 0.05). Conclusion: The intestinal microbiota of patients with COVID-19 varies depending on the SARS-CoV-2 variant. Dysbiosis of the intestinal microbiota due to differences in SARS-CoV-2 variants causes a decrease in intestinal short-chain fatty acids.

Downregulation of SMOC1 is associated with progression of colorectal traditional serrated adenomas.

BACKGROUND: Aberrant DNA methylation is prevalent in colorectal serrated lesions. We previously reported that the CpG island of SMOC1 is frequently methylated in traditional serrated adenomas (TSAs) and colorectal cancers (CRCs) but is rarely methylated in sessile serrated lesions (SSLs). In the present study, we aimed to further characterize the expression of SMOC1 in early colorectal lesions. METHODS: SMOC1 expression was analyzed immunohistochemically in a series of colorectal tumors (n = 199) and adjacent normal colonic tissues (n = 112). RESULTS: SMOC1 was abundantly expressed in normal colon and SSLs while it was significantly downregulated in TSAs, advanced adenomas and cancers. Mean immunohistochemistry scores were as follows: normal colon, 24.2; hyperplastic polyp (HP), 18.9; SSL, 23.8; SSL with dysplasia (SSLD)/SSL with early invasive cancer (EIC), 15.8; TSA, 5.4; TSA with high grade dysplasia (HGD)/EIC, 4.7; non-advanced adenoma, 21.4; advanced adenoma, 11.9; EIC, 10.9. Higher levels SMOC1 expression correlated positively with proximal colon locations and flat tumoral morphology, reflecting its abundant expression in SSLs. Among TSAs that contained both flat and protruding components, levels of SMOC1 expression were significantly lower in the protruding components. CONCLUSION: Our results suggest that reduced expression of SMOC1 is associated with progression of TSAs and conventional adenomas and that SMOC1 expression may be a biomarker for diagnosis of serrated lesions and risk prediction in colorectal tumors.

Noninvasive rapid urinary trypsinogen-2 dipstick test for early exclusion of post-endoscopic retrograde cholangiopancreatography pancreatitis within hours after endoscopic retrograde cholangiopancreatography: Clinical diagnosis and considerations.

Objective: Few reports have explored the application of urinary trypsinogen-2 measurement in the early diagnosis of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis, and none have demonstrated the benefits of noninvasive testing. This study aimed to evaluate the clinical application of the rapid urinary trypsinogen-2 dipstick test (Nipro, Japan) compared with serum amylase and lipase levels for the early diagnosis of post-ERCP pancreatitis (PEP). Methods: A total of 100 consecutive patients (54 men and 46 women) who were admitted and underwent ERCP at Tokyo Medical University Hospital from August 2021 to December 2021 were recruited. All patients underwent rapid urinary trypsinogen-2 measurement using the dipstick test before and after ERCP. Measurements were taken 24 h before ERCP for pre-ERCP and 1-4 h after ERCP for post-ERCP. Additionally, serum amylase and lipase levels were measured at 8:00 a.m. of the day after ERCP (at least 8 h after ERCP), and their diagnostic abilities for PEP were compared and evaluated. Results: PEP occurred in 5/100 patients (5%). The sensitivity, specificity, positive predictive value, and negative predictive value of the dipstick test for diagnosing PEP were 100%, 83.2%, 23.8%, and 100%, respectively. These results were comparable to the diagnostic performance of serum amylase and lipase levels at 8:00 a.m. on the day after ERCP (at least 8 h after ERCP). However, false positives must be considered. Conclusion: The dipstick test may be useful in clinical practice as a noninvasive screening test for the early prediction of PEP.

Early Tumor Shrinkage and Depth of Response as Predictors of Survival for Advanced Biliary Tract Cancer: An Exploratory Analysis of JCOG1113.

BACKGROUND: Recent studies suggest that early tumor shrinkage (ETS) and depth of response (DpR) reflect outcomes of chemotherapy in various cancers. This study evaluated the association of ETS and DpR with clinical outcomes using data from JCOG1113, which demonstrated the non-inferiority of gemcitabine plus S-1 (GS) to gemcitabine plus cisplatin (GC) for chemotherapy-naïve advanced biliary tract cancer. MATERIAL AND METHODS: In total, 354 (289 with measurable target lesions) patients enrolled in JCOG1113 were divided into ETS-unachieved and ETS-achieved groups (≥20% tumor reduction at week 6) and DpR-low and DpR-high groups (≥40% maximum shrinkage) until 12 weeks after enrollment. The impact of ETS and DpR on survival outcome was evaluated using the multivariable Cox proportional hazard model. RESULTS: The proportions of patients in the ETS-achieved and DpR-high groups were similar between the 2 treatment arms. The hazard ratios (HRs) of progression-free survival (PFS) and overall survival (OS) for the ETS-achieved group were 0.70 (95% confidence interval (CI), 0.52-0.93) and 0.60 (95%CI, 0.44-0.81), respectively. The HRs of PFS and OS for the DpR-high group were 0.67 (95%CI, 0.48-0.94) and 0.64 (95%CI, 0.46-0.90), respectively. In the subpopulation treatment effect pattern plot analysis, most patients in the ETS-achieved group in the GC arm did not experience disease progression after 12 weeks from the landmark. CONCLUSION: As on-treatment markers, ETS and DpR were effective tools. ETS was clinically useful, because it can be used to evaluate the outcomes of treatment early at a specific time.

ERCP using balloon-assisted endoscopes versus EUS-guided treatment for common bile duct stones in Roux-en-Y gastrectomy.

BACKGROUND AND AIMS: We compared ERCP using a balloon-assisted endoscope (BE-ERCP) with EUS-guided antegrade treatment (EUS-AG) for removal of common bile duct (CBD) stones in patients with Roux-en-Y (R-Y) gastrectomy. METHODS: Consecutive patients who had previous R-Y gastrectomy undergoing BE-ERCP or EUS-AG for CBD stones in 16 centers were retrospectively analyzed. RESULTS: BE-ERCP and EUS-AG were performed in 588 and 59 patients, respectively. Baseline characteristics were similar, except for CBD diameter and angle. The technical success rate was 83.7% versus 83.1% (P = .956), complete stone removal rate was 78.1% versus 67.8% (P = .102), and early adverse event rate was 10.2% versus 18.6% (P = .076) in BE-ERCP and EUS-AG, respectively. The mean number of endoscopic sessions was smaller in BE-ERCP (1.5 ± .8 vs 1.9 ± 1.0 sessions, P = .01), whereas the median total treatment time was longer (90 vs 61.5 minutes, P = .001). Among patients with biliary access, the complete stone removal rate was significantly higher in BE-ERCP (93.3% vs 81.6%, P = .009). Negative predictive factors were CBD diameter ≥15 mm (odds ratio [OR], .41) and an angle of CBD <90 degrees (OR, .39) in BE-ERCP and a stone size ≥10 mm (OR, .07) and an angle of CBD <90 degrees (OR, .07) in EUS-AG. The 1-year recurrence rate was 8.3% in both groups. CONCLUSIONS: Effectiveness and safety of BE-ERCP and EUS-AG were comparable in CBD stone removal for patients after R-Y gastrectomy, but complete stone removal after technical success was superior in BE-ERCP.

Feasibility of Surveillance for Mucinous Cystic Neoplasm of the Pancreas: A Multi-Institutional Retrospective Study of 328 Patients by the Japanese Pancreatic Society.

OBJECTIVE: We aimed to elucidate the feasibility of surveillance of patients with mucinous cystic neoplasm (MCN). METHODS: We performed a retrospective, multi-institutional study of 328 patients who underwent surgery for MCN at 18 Japanese institutions. Patients with MCN were divided into an immediate surgery group and a surveillance group, which underwent surgery after surveillance. RESULTS: The median surveillance period until surgery in the surveillance group was 27 months (range, 7-165 months). Compared with the immediate surgery group, the surveillance group showed smaller tumor diameter (46 vs 50 mm, P = 0.01), more frequent laparoscopic approach (58% vs 37%, P < 0.01), and less frequent malignancy (7% vs 15%, P = 0.03). The new appearance of mural nodules and elevation of serum tumor markers were associated with malignancy in the surveillance group. Two patients in the surveillance group experienced postoperative recurrence, although there was no significant difference in recurrence or disease-free survival between the two groups. In the surveillance group, the 1-, 5-, and 10-year cumulative incidence rates of malignant MCN were 0.8%, 5.6%, and 36.5%, respectively. CONCLUSION: As the risk of progression to malignant MCNs increases over the long term, MCNs should be resected rather than subjected to unnecessary surveillance.

Postprocedure serum amylase or lipase levels predict postendoscopic retrograde cholangiopancreatography pancreatitis: Meta-analysis of diagnostic test accuracy studies and utility assessment.

OBJECTIVES: We aimed to clarify the clinical utility of measuring serum pancreatic enzymes after endoscopic retrograde cholangiopancreatography (ERCP) for the purpose of predicting post-ERCP pancreatitis (PEP) by a meta-analysis of diagnostic test accuracy studies. METHODS: Studies on the prediction accuracy of PEP by serum amylase or lipase measured at 2, 3, and 4 h after ERCP were collected. A literature search was performed in PubMed and the Cochrane Library database for studies published between January 1980 and March 2023. The quality of individual studies was evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2. Data were analyzed using Meta-DiSc 2.0 software. RESULTS: We searched the databases and identified 20 observational studies (12,313 participants). PEPs were defined according to criteria by Cotton or modified Cotton, revised Atlanta criteria, or the Japanese criteria. Meta-analysis of eight studies (4389 participants) showed a pooled sensitivity of 71.1% (95% confidence interval [CI] 56.1-82.5) and pooled specificity of 91.2% (95% CI 85.9-94.6) for the serum amylase cut-off value at 3 times the upper limit of normal (ULN). Another meta-analysis of five studies (1970 participants) showed a pooled sensitivity of 85.8% (95% CI 61.9-95.7) and pooled specificity of 85.3% (95% CI 81.9-88.1) for the serum lipase cut-off value at 3 times ULN. CONCLUSION: Despite a high risk of bias due to various reference standards, this updated meta-analysis and the utility assessment by a decision tree showed the utility of serum amylase or lipase levels more than 3 times ULN measured 2-4 h after ERCP for predicting PEP.

Risk factors for early and late cholecystitis after covered metal stent placement for distal biliary obstruction.

BACKGROUND: Cholecystitis is a major adverse event after self-expandable metallic stent placement for distal biliary obstruction (DBO). Covered self-expandable metallic stent (CSEMS) is being increasingly used, but few studies have investigated risk factors for cholecystitis limited to CSEMS. The present study aimed to identify risk factors for cholecystitis after CSEMS. METHODS: Patients who underwent initial CSEMS placement for DBO between November 2014 and September 2021 were enrolled and followed-up until death, recurrent biliary obstruction, cholecystitis, or until March 2022. Cholecystitis within 30 days of CSEMS was defined as early cholecystitis and after 30 days as late cholecystitis. RESULTS: Cholecystitis occurred in 51 of 339 patients (15%) after CSEMS. Forty-one patients (80.4%) had early cholecystitis, and 10 (19.6%) had late cholecystitis. Multivariate logistic regression analysis revealed that the maximum diameter of the common bile duct (CBD) (per 1 mm increase) (odds ratio [OR]: 0.87; 95% confidence interval [CI]: 0.76-1.00; p = .044), gallbladder stones (OR: 3.63; 95% CI: 1.62-8.10; p = .002), and tumor involvement in the cystic duct (CD) (OR: 4.87; 95% CI: 2.16-11.00; p < .001) were significant independent risk factors associated with early cholecystitis. No significant risk factors were identified for late cholecystitis. CONCLUSIONS: A smaller CBD diameter, gallbladder stones, and tumor involvement in the CD were identified as risk factors for early cholecystitis development after CSEMS.

The application of low echo reduction in endoscopic ultrasound-guided tissue acquisition for pancreatic mass lesions.

Toyonaga and colleagues demonstrate, with accompanying video, the use of low echo reduction, which is a novel endoscopic ultrasound function provided by a new endoscopic ultrasound processor that increases contrast without white-out. Low echo reduction might be useful in improving lesion boundaries and needle visibility during endoscopic ultrasound-guided tissue acquisition.

Tip-in endoscopic papillectomy for ampullary adenoma near diverticulum to minimize complications.

Toyonaga and colleagues present a novel "tip-in endoscopic papillectomy" approach for resecting ampullary tumors, aiming to minimize complications like perforation and residual tumor by adapting the colonic polyp endoscopic mucosal resection tip-in method. The technique is described with accompanying video in a case of ampullary tumor near a diverticulum.

Evidence-based clinical practice guidelines for cholelithiasis 2021.

The Japanese Society of Gastroenterology first published evidence-based clinical practice guidelines for cholelithiasis in 2010, followed by a revision in 2016. Currently, the revised third edition was published to reflect recent evidence on the diagnosis, treatment, and prognosis of cholelithiasis conforming to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system. Following this revision, the present English version of the guidelines was updated and published herein. The clinical questions (CQ) in the previous version were reviewed and rearranged into three newly divided categories: background questions (BQ) dealing with basic background knowledge, CQ, and future research questions (FRQ), which refer to issues that require further accumulation of evidence. Finally, 52 questions (29 BQs, 19 CQs, and 4 FRQs) were adopted to cover the epidemiology, pathogenesis, diagnosis, treatment, complications, and prognosis. Based on a literature search using MEDLINE, Cochrane Library, and Igaku Chuo Zasshi databases for the period between 1983 and August 2019, along with a manual search of new information reported over the past 5 years, the level of evidence was evaluated for each CQ. The strengths of recommendations were determined using the Delphi method by the committee members considering the body of evidence, including benefits and harms, patient preference, and cost-benefit balance. A comprehensive flowchart was prepared for the diagnosis and treatment of gallbladder stones, common bile duct stones, and intrahepatic stones, respectively. The current revised guidelines are expected to be of great assistance to gastroenterologists and general physicians in making decisions on contemporary clinical management for cholelithiasis patients.

A comparative study between computed tomography and endoscopic ultrasound in the detection of a mural nodule in intraductal papillary mucinous neoplasm -Multicenter observational study in Japan.

BACKGROUND/OBJECTIVES: The detection of malignancy is a major concern in the management of intraductal papillary mucinous neoplasm (IPMN). The height of the mural nodule (MN), estimated using endoscopic ultrasound (EUS) and computed tomography (CT), has been considered crucial for predicting malignant IPMN. Currently, whether surveillance using CT or EUS alone is sufficient for detecting MNs remains unclear. This study aimed to compare the ability of CT and EUS to detect MNs in IPMN. METHODS: This multicenter, retrospective observational study was conducted in 11 Japanese tertiary institutions. Patients who underwent surgical resection of IPMN with MN after CT and EUS examinations were eligible to participate. The MN detection rates between CT and EUS were examined. RESULTS: Two-hundred-and-forty patients who underwent preoperative EUS and CT had pathologically confirmed MNs. The MN detection rates of EUS and CT were 83% and 53%, respectively (p < 0.001). Additionally, the MN detection rate of EUS was significantly higher than that of CT regardless of morphological type (76% vs. 47% in branch-duct-type IPMN; 90% vs. 54% in mixed IPMN; 98% vs. 56% in main-duct-type IPMN; p < 0.001). Further, pathologically confirmed MNs ≥5 mm were more frequently observed on EUS than on CT (95% vs. 76%, p < 0.001). CONCLUSIONS: EUS was superior to CT for the detection of MN in IPMN. EUS surveillance is essential for the detection of MNs.