Endoscopic papillectomy could be rewarding to patients with early stage duodenal ampullary carcinoma?

BACKGROUND/PURPOSE: There is currently no consensus on the use of endoscopic papillectomy (EP) for early stage duodenal ampullary adenocarcinoma. This study aimed to evaluate the feasibility of EP for patients with early stage duodenal ampullary adenocarcinoma. METHODS: Patients who underwent EP for ampullary adenocarcinomas were investigated. Complete and clinical complete resection rates were evaluated. Clinical complete resection was defined as either complete resection or resection with positive or unknown margins but no cancer in the surgically resected specimen, or no recurrence on endoscopy after at least a 1-year follow-up. RESULTS: Adenocarcinoma developed in 30 patients (carcinoma in situ [Tis]: 21, mucosal tumors [T1a(M)]: 4, tumors in the sphincter of Oddi [T1a(OD)]: 5). The complete resection rate was 60.0% (18/30) (Tis: 66.7% [14/21], T1a[M]: 50.0% [2/4], and T1a[OD]: 40.0% [2/5]). The mean follow-up period was 46.8 months. The recurrence rate for all patients was 6.7% (2/30). The clinical complete resection rates of adenocarcinoma were 89.2% (25/28); rates for Tis, T1a(M), and T1a(OD) were 89.4% (17/19), 100% (4/4), and 80% (4/5), respectively. CONCLUSIONS: EP may potentially achieve clinical complete resection of early stage (Tis and T1a) duodenal ampullary adenocarcinomas.

IgG4-related pancreatobiliary diseases could be associated with onset of pancreatobiliary cancer: A multicenter cohort study.

BACKGROUND: The risk and prognosis of pancreatobiliary cancer and in patients with autoimmune pancreatitis (AIP) and IgG4-related sclerosing cholangitis (IgG4-SC) remain unclear. Therefore, we retrospectively investigated the risk of pancreatobiliary cancer and prognosis in patients with AIP and IgG4-SC. METHODS: Patients with AIP and IgG4-SC at seven centers between 1998 and 2022 were investigated. The following data were evaluated: (1) the number of cancers diagnosed and standardized incidence ratio (SIR) for pancreatobiliary and other cancers during the observational period and (2) prognosis after diagnosis of AIP and IgG4-SC using standardized mortality ratio (SMR). RESULTS: This study included 201 patients with AIP and IgG4-SC. The mean follow-up period was 5.7 years. Seven cases of pancreatic cancer were diagnosed, and the SIR was 8.11 (95% confidence interval [CI]: 7.29-9.13). Three cases of bile duct cancer were diagnosed, and the SIR was 6.89 (95% CI: 6.20-7.75). The SMR after the diagnosis of AIP and IgG4-SC in cases that developed pancreatobiliary cancer were 4.03 (95% CI: 2.83-6.99). CONCLUSIONS: Patients with autoimmune pancreatitis and IgG4-SC were associated with a high risk of pancreatic and bile duct cancer. Patients with AIP and IgG4-SC have a worse prognosis when they develop pancreatobiliary cancer.

Braided-type stent versus laser-cut-type stent for patients with unresectable distal malignant biliary obstruction: a randomized controlled trial.

BACKGROUND AND AIMS: Fully covered self-expandable metallic stents (SEMSs) are laser-cut (L) or braided (B); however, it remains unclear which approach is more effective for distal malignant biliary obstruction (DMBO). This study compared the clinical outcomes of using L-type and B-type stents because we believe that recurrent biliary obstruction (RBO) is less likely to occur with L-type stents. METHODS: Patients diagnosed with unresectable DMBO were randomly assigned to groups L and B in a stratified block fashion, and outcomes were compared. The primary outcome was the rate of RBO within 1 year; secondary outcomes were adverse events, clinical success rate, time to RBO (TRBO), and overall survival. RESULTS: Of the 60 enrolled participants, 56 (group L, n = 27; group B, n = 29) were included. The rates of RBO within 1 year were 44.4% and 17.2% in groups L and B, respectively (odds ratio, 2.57; 95% confidence interval [CI], 1.045-6.353). Early adverse events, which improved with conservative treatment, included pancreatitis (n = 4) in group L and pancreatitis (n = 3) and cholecystitis (n = 1) in group B (P = .913). The median TRBO (220 days [95% CI, 56-272] vs 418 days [95% CI, 232-454]) was significantly longer in group B than in group L (log-rank test, P = .0118). The median overall survival (group L, 158 days; group B, 204 days) after stenting was not significantly different between groups (P = .8544). CONCLUSIONS: In the setting of DMBO, B-type stents are associated with less recurrent obstruction than L-type stents, although there was no difference in safety. (UMIN Clinical Trials Registry number: UMIN000027239.).

Pre-emptive hydration with lactated Ringer's solution could reduce the incidence of post-endoscopic retrograde cholangiopancreatography pancreatitis in at-risk patients: Propensity score-matched analysis.

BACKGROUND/PURPOSE: This study aimed to investigate the efficacy of intensive fluid-loading therapy post-endoscopic retrograde cholangiopancreatography (ERCP) for the prevention of post-ERCP pancreatitis (PEP) in at-risk patients. METHODS: In this retrospective study, data of 1200 patients at risk for PEP were investigated. After propensity score matching, 404 patients were included in the normal (n = 202) and hydration (n = 202) groups. On the day of ERCP, patients in both groups were infused with 2000 ml/24 h of fluid before ERCP. Meanwhile, the hydration group received an additional 1000 ml/10 h of lactated Ringer's solution postoperatively. RESULTS: The incidence of PEP was lower in the hydration group (12.4%) than in the normal group (24.3%) (odds ratio [OR]: 0.44; 95% CI: 0.26-0.75, p = .003). The incidence of severe PEP was 2.0% and 6.9% in the hydration and normal groups (OR: 0.27; 95% CI: 0.09-0.84, p = .027), respectively. The incidence of fatal PEP was 0% and 2.0% in the hydration and normal groups (OR: N.A.: p = .123), respectively. CONCLUSIONS: Post-ERCP hydration may be an effective method of preventing PEP, including severe PEP, in at-risk patients.

Effectiveness and Prognostic Factors of Everolimus in Patients with Pancreatic Neuroendocrine Neoplasms.

Objective The effectiveness of everolimus for the management of pancreatic neuroendocrine neoplasms (PNENs), including the G3/NEC types, remains unclear. We therefore investigated the effectiveness of the drug for the management of PNENs. Methods We analyzed the progression-free survival (PFS) and overall survival (OS) associated with everolimus and factors influencing the PFS and OS. Results One hundred patients were evaluated. The PFS associated with the G1/G2 types tended to be significantly longer than that associated with the G3/NEC types [hazard ratio (HR), 0.45; p=0.005]. A multivariate analysis showed that the significant factors influencing the PFS were age (<65 years old; HR, 0.44; p=0.002), grade (G1/G2; HR, 0.42; p=0.006), everolimus treatment line (≤2nd; HR, 0.55; p=0.031), and presence of treatment with metformin (yes; HR, 0.29; p=0.044). The median OS was 63.8 months. In the multivariate analysis, the significant factors influencing the OS were grade (G1/G2; HR, 0.21; p<0.001), volume of liver metastasis (≤25%; HR, 0.27; p<0.001), everolimus treatment line (≤2nd; HR, 0.27; p<0.001), and presence of primary tumor resection (yes; HR, 0.33; p=0.005). Conclusion The effectiveness of everolimus in the management of G3/NEC types and prognoses tended to be poorer than those associated with the G1/G2 types. Everolimus combined with metformin and early-line treatment with everolimus may be effective for managing advanced PNENs.

Request for biliary drainage for IgG4-SC could be waived before steroid administration?

BACKGROUND: In IgG4-related sclerosing cholangitis (IgG4-SC), the necessity of biliary drainage (BD) is unclear. In this study, we aimed to retrospectively investigate the improvement of liver damage and jaundice in cases of IgG4-SC with and without BD, before starting steroids. METHODS: A total of 52 patients with IgG4-SC were investigated in the study. The study endpoints were the normalization rate of alkaline phosphatase (ALP)/total bilirubin (T-Bil) after 8 weeks of steroids, with and without BD. RESULTS: Propensity score matching was performed based on ALP and T-Bil, and 28 patients were included. There were 14 patients each in the BD and non-BD groups. Before initiation of steroids, the mean ALP in the BD group and the non-BD group was 378/461 (P = .541); the mean T-Bil was 2.5/1.8 (P = .401). Eight weeks after initiation of steroids, ALP improvement rate in the BD group/non-BD group was 69.2%/61.5% (P = 1.000), and T-Bil improvement rate was 100%/100% (P = Ns). CONCLUSIONS: Steroids for IgG4-SC could prove effective in improving liver damage and jaundice, regardless of the presence or absence of BD. BD for IgG4-SC aimed to improve jaundice may not be necessary.

Utility of Fine-Gauge Balloon Catheter for EUS-Guided Hepaticogastrostomy.

BACKGROUND AND PURPOSE: During endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS), tract dilation is one of the most important steps, and the placement of conventional metal stents with 8.5 Fr delivery devices is difficult due to the large outer shape of the device. Fine-gauge balloon catheters have become popular because of their stricture penetration ability and ease of dilation. This study aimed to evaluate the utility of fine-gauge balloon catheters. PATIENTS AND METHODS: This retrospective study involved 38 patients who underwent conventional metal stent placement. The patients were classified into two groups: those who underwent dilation with a fine-gauge balloon catheter before initial metal stenting (balloon dilation group) and those who underwent bougie dilation only (non-balloon dilation group). We evaluated the stenting success rate after initial dilation and adverse events. RESULTS: Seventeen and twenty-one patients were included in the balloon dilation and non-balloon dilation groups, respectively. The stenting success rate after initial dilation was 100% (17/17) in the balloon dilation group and 71.4% (15/21) in the non-balloon dilation group (p = 0.024). As adverse events, peritonitis was observed in one case (4.8%) in the balloon dilation group, and in three cases (14.3%) in the non-balloon dilation group (p = 0.613). CONCLUSIONS: Dilation using a fine-gauge balloon catheter before conventional metal stent with 8.5 Fr delivery device placement is considered effective in EUS-HGS.

Franseen Needles May Be Promising for Improving the Sampling Adequacy of EUS-FNA for Subepithelial Lesions.

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is useful in diagnosing subepithelial lesions (SELs), and adequate tissue sampling is necessary to differentiate between benign and malignant diseases to determine therapeutic strategies. This study aimed to evaluate sampling adequacy and diagnostic performance of EUS-FNA for SELs with Franseen needles. This retrospective study enrolled 130 patients who underwent EUS-FNA with a 22-gauge needle for SELs from January 2010 to March 2021. We compared sampling adequacy and predictive factors influencing the sampling adequacy of EUS-FNA for SELs between Franseen and conventional needles. The sampling adequacy rates were 95.0% (38/40) with Franseen needles and 76.7% (69/90) with conventional needles (p = 0.011). The mean number of punctures with Franseen needles (2.80) was significantly less than that with conventional needles (3.42) (p < 0.001). In the multivariate analysis, the use of Franseen needles (p = 0.029; odds ratio [OR], 5.37; 95% confidence interval [CI], 1.18−23.36) was an independent factor influencing the sampling adequacy. Compared to conventional needles, the Franseen needle could play a vital role in accurately diagnosing SELs by yielding better sampling adequacy and reducing the number of passes.

Detection rate of endoscopic ultrasound and computed tomography in diagnosing pancreatic neuroendocrine neoplasms including small lesions: A multicenter study.

BACKGROUND/PURPOSE: The detection ability and role of different imaging modalities to detect pancreatic neuroendocrine neoplasms (PNENs) including small lesions is unclear. This study aimed to compare the ability of endoscopic ultrasound (EUS) and computed tomography (CT) to detect PNENs. METHODS: Data of patients who underwent EUS and contrast-enhanced CT and were diagnosed with PNENs were analyzed. The detection rates of pancreatic lesions with EUS and CT based on tumor size and influencing factors were investigated. RESULTS: For 256 PNEN lesions, the detection rate of EUS was better than that of CT (94.5% vs 86.3%; P < .001). EUS was significantly superior to CT for PNENs ≤5 mm (58.3% vs 16.7%; P = .006) and 5-10 mm (97.7% vs 79.5%; P = .008). There was no significant difference in the detection rate between EUS and CT for PNENs >10 mm (98.4% vs 96.4%; P = .375). Size (≤5 mm) and insulinoma were independent factors associated with poor EUS and CT detection rates. CONCLUSIONS: Endoscopic ultrasound exhibited better detection ability than CT, with an excellent detection rate for PNENs >5 mm, except for insulinomas. CT could detect PNENs >10 mm, which are amenable to treatment.

Learning Curve of Endoscopic Retrograde Cholangiopancreatography Using Single-Balloon Enteroscopy.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) in patients with surgically altered anatomy is technically difficult. Extensive training is required to develop the ability to perform this procedure. AIMS: To investigate the learning curve of single-balloon-assisted enteroscopy ERCP (SBE-ERCP). METHODS: We conducted a retrospective, observational case series at a single center. We evaluated the SBE-ERCP procedures between April 2011 and February 2021. The main outcomes were the rate of reaching the target site and the success rate of the entire procedure. These parameters were additionally expressed as a learning curve. RESULTS: A total of 687 SBE-ERCP procedures were analyzed. The learning curve was analyzed in blocks of 10 cases. In this study, seven endoscopists, experts in conventional ERCP, were included. The overall SBE-ERCP procedural success rate was 92.2% (634/687 cases). Combining all data from individual endoscopists' evaluation periods, the insertion and success rates of the SBE-ERCP procedures gradually increased with increased experience performing SBE-ERCP. The insertion success rates for the number of SBE-ERCP cases (< 20, 21-30, > 30) were 82.9%, 92.9%, and 94.3%, respectively; the procedure success rates were 74.3%, 81.4%, and 92.9%, respectively. The endoscopists who had performed > 30 SBE-ERCP cases had a success rate of ≥ 90%. CONCLUSIONS: Our results suggest that performing > 30 cases is one of the targets for conventional ERCP experts to become competent in performing SBE-ERCP in patients with a surgically altered anatomy.

Severe acute respiratory syndrome coronavirus 2 prevalence in saliva and gastric and intestinal fluid in patients undergoing gastrointestinal endoscopy in coronavirus disease 2019 endemic areas: Prospective cross-sectional study in Japan.

OBJECTIVES: Gastrointestinal endoscopy (GIE) is useful for the early detection and treatment of many diseases; however, GIE is considered a high-risk procedure in the coronavirus disease 2019 (COVID-19) pandemic era. This study aimed to explore the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positivity in saliva and gastrointestinal fluids to which endoscopy medical staff are exposed. METHODS: The study was a single-center cross-sectional study. From June 1 to July 31, 2020, all patients who underwent GIE at Yokohama City University Hospital were registered. All patients provided 3 mL of saliva. For upper GIE, 10 mL of gastric fluid was collected through the endoscope. For lower GIE, 10 mL of intestinal fluid was collected through the endoscope. The primary outcome was the positive rate of SARS-CoV-2 in saliva and gastrointestinal fluids. We also analyzed serum-specific antibodies for SARS-CoV-2 and patients' background information. RESULTS: A total of 783 samples (560 upper GIE and 223 lower GIE samples) were analyzed. Polymerase chain reaction (PCR) on saliva samples did not show any positive results in either upper or lower GIE samples. However, 2.0% (16/783) of gastrointestinal fluid samples tested positive for SARS-CoV-2. No significant differences in age, sex, purpose of endoscopy, medication, or rate of antibody test positivity were found between PCR positive and PCR negative cases. CONCLUSIONS: Asymptomatic patients, even those with no detectable virus in their saliva, had SARS-CoV-2 in their gastrointestinal tract. Endoscopy medical staff should be aware of infection when performing procedures. The study was registered as UMIN000040587.

IgG4-related sclerosing cholangitis may be a risk factor for cancer.

BACKGROUND/PURPOSE: The relationship between autoimmune pancreatitis (AIP) and malignancy has been reported. However, the potential risk for cancer in patients with immunoglobulin 4 (IgG4)-related sclerosing cholangitis (IgG4-SC) is unclear. The present study aimed to evaluate the incidence of cancer in IgG4-SC patients. METHODS: We retrospectively collected clinical data for 121 patients diagnosed with IgG4-SC from 7 hospitals. We calculated the standardized incidence ratio (SIR) of cancer in IgG4-SC patients based on the national cancer rates. The SIR of the period after the diagnosis of IgG4-SC were calculated. RESULTS: The mean follow-up period was 6.4 years, with 121 IgG4-SC patients. During the follow-up period, 26 patients had cancer, and 29 cancers were diagnosed. The SIR of cancer after the diagnosis of IgG4-SC was 1.90 (95% confidence interval [CI] 1.67-2.21). The SIR of pancreatic and bile duct cancer was 10.30 and 8.88, respectively. The SIR of cancer in <1 year, 1-5 years, and >5 years after diagnosis of IgG4-SC were 2.58, 1.01, and 2.44, respectively. CONCLUSIONS: IgG4-SC patients have a high risk of cancer including pancreatic and bile duct cancer. The risk of cancer was high less <1 year and >5 years after diagnosis of IgG4-SC. Therefore, IgG4-SC patients may require careful long-term follow-up.

Covered metallic stent placement for biliary drainage could be promising in the coming era of neoadjuvant chemo-radiation therapy for all pancreatic cancer.

BACKGROUND/PURPOSE: The role of endoscopic preoperative biliary drainage for pancreatic head cancer is controversial because of the high incidence of stent occlusion before surgery. We sought to validate a suitable stent for biliary drainage in patients with pancreatic cancer undergoing neoadjuvant chemotherapy (NAC)/neoadjuvant chemoradiotherapy (NAC-RT). METHODS: We evaluated patients who received preoperative neoadjuvant therapy for pancreatic head cancer between January 2013 and December 2019. A covered metal (CMS) or plastic stent (PS) was inserted in symptomatic patients for biliary drainage. Recurrent biliary obstruction (RBO), success rate of endoscopic drainage, adverse events, and surgical outcomes were compared between the CMS and PS groups. RESULTS: Occurrence rate of RBO was significantly higher with PS (97%) vs CMS (15%, P < .001), and time to RBO was significantly longer with CMS vs PS (not reached vs 40.5 days, P < .001). Delayed schedule associated with RBO for neoadjuvant chemotherapy was significantly lower in CMS vs PS (14% vs 50%, P < .05). There was no difference in postoperative bleeding, operation time, complications, and rate of a microscopically margin-negative resection between groups. CONCLUSIONS: Use of CMS during NAC/NAC-RT allows for safe chemotherapy without causing cholangitis or biliary obstruction and for surgery to be performed.

Pathological Findings of the Host Immune Reaction in the Tumor Microenvironment of Gastroenteropancreatic Neuroendocrine Neoplasms.

Objective Neuroendocrine neoplasms (NENs) are rare and indolent diseases, but the efficacy of treatment without surgical resection is temporary and limited. Targeted immunotherapy is an important treatment strategy in several cancers. However, the tumor and host immune reactions in the NEN microenvironment are poorly understood. Therefore, we investigated the immune checkpoint system and host immune response in pathological NEN specimens. Methods The expression of the mismatch repair proteins MSH2, MSH6, PMS2, and MLH1 was immunohistochemically detected in archival tissue samples obtained from 20 patients with gastroenteropancreatic NENs. We additionally assessed the expression of programmed death (PD)-1, PD-L1, and the tumor-infiltrating lymphocyte (TIL) markers CD8 and family of transcription factor P3 (FOXP3). Results All 20 NENs expressed the mismatch repair proteins MSH2, MSH6, PMS2, and MLH1. The PD-L1 and/or PD-1 expression in the tumor cells and/or TILs was confirmed in 75% of the cases. PD-1-, CD8-, and FOXP3-positive TILs were more frequently associated with PD-L1-positive tumors than with PD-L1 negative tumors (PD-1: 19.5 vs. 7.3, CD8: 18.1 vs. 7.1, FOXP3: 13.2 vs. 3.2, p=0.438, p=0.419, P=0.603, respectively). The number of cells positive for PD-1 tended to gradually increase in increasing grade of NENs but did not reach significance (Grade 1: 5.8, Grade 2: 10.2, NEC: 18.1, p=0.903). Conclusion NENs consistently express mismatch repair proteins but have a high expression of PD-L1 and/or PD-1 in the tumor microenvironment. NEC and PD-L1-positive NENs may be immunologically "hot" tumors, so an immunological approach may be an appropriate treatment strategy for these tumors.

Effect of preventive closure of the frenulum after endoscopic papillectomy: A prospective pilot study.

BACKGROUND AND AIM: The usefulness of preventive closure of the frenulum after endoscopic papillectomy (EP) could reduce bleeding. The feasibility and safety of clipping were evaluated in this prospective pilot study. METHODS: This study involved 40 consecutive patients who underwent preventive closure of the frenulum by clipping just after EP. The outcome data were compared with those of the previous 40 patients in whom no preemptive closure had been performed (no-closure group) (UMIN000014783). Additionally, the bleeding sites were examined. RESULTS: The clipping procedure was successful in all patients. As compared to the no-closure group, the rate of bleeding (P = 0.026) and period of hospital stay (P < 0.001) were significantly reduced in the closure group. There was no difference in the procedure time between the two groups. Furthermore, the incidence rates of pancreatitis and perforation were comparable in the two groups. The bleeding was noted in the frenulum area rather than at any other site in 90.9% of cases. CONCLUSION: Preventive closure of the frenulum after EP is an effective, safe, rational, and economical method to reduce the incidence of delayed bleeding, without prolonging the procedure time or increasing the risk of post-procedure pancreatitis perforation.

Three-dimensional analysis of pancreatic fat by fat-water magnetic resonance imaging provides detailed characterization of pancreatic steatosis with improved reproducibility.

BACKGROUND: Since pancreatic steatosis is reported as a possible risk factor for pancreatic cancer, the development of a non-invasive method to quantify pancreatic steatosis is needed. Proton density fat fraction (PDFF) measurement is a magnetic resonance imaging (MRI) based method for quantitatively assessing the steatosis of a region of interest (ROI). Although it is commonly used for quantification of hepatic steatosis, pancreatic PDFF can greatly vary depending on the ROI's location because of the patchy nature of pancreatic fat accumulation. In this study, we attempted to quantify pancreatic steatosis by fat-water MRI with improved reproducibility. METHODS: Using the MRI images of 159 patients with nonalcoholic fatty liver disease, we attempted to calculate the average PDFF of whole pancreas. We set ROIs covering the entire area of the pancreas appearing in every slice and calculated the average PDFF from all the voxels included in the pancreas. We named this average value as whole-pancreatic PDFF and evaluated the reproducibility of the measured values. In addition to whole-pancreatic PDFF, we measured the average PDFF of the pancreatic head (head-PDFF) and that of the pancreatic body plus tail separately and analyzed their correlation with the clinical characteristics of the patients. RESULTS: The mean inter-examiner coefficient of variation of the whole-pancreatic PDFF was 11.39%. The whole-pancreatic PDFF was correlated with age (p = 0.039), body mass index (p = 0.0093) and presence/absence of diabetes (p = 0.0055). The serum level of low-density lipoprotein cholesterol was inversely correlated with the head-PDFF. CONCLUSION: We developed a new measurement method of the pancreatic PDFF with greater reproducibility. Using this method, we characterized pancreatic steatosis in detail. This novel measurement method allows accurate estimation of the severity of pancreatic steatosis and is therefore useful for the detailed characterization of pancreatic steatosis.

Investigation of the Local Recurrence Rate after Colorectal Endoscopic Mucosal Resection: Is Incomplete Polyp Resection Really a Clinically Important Problem? Analysis of the Rationale for the "Resect and Discard" Strategy.

Background/Aims: The "Resect and Discard" strategy is a potentially useful strategy. At present, only the lesion size and accuracy of diagnosis are cited as considerations for clinical adoption of this strategy. On the other hand, histopathology of the resected specimens after Endoscopic Mucosal Resection (EMR) reveals often an unclear or positive-margin status, implying Incomplete Polyp Resection (IPR). If IPR indeed increased the risk of local recurrence, histopathological evaluation of the margin would be indispensable and clinical adoption of this strategy is difficult. The aim of this study is to verify the association between IPR and the risk of local recurrence. Methods: The 1872 polyps and 603 EMR cases in 597 patients who had EMR between May 2013 and May 2014 were enrolled. The local recurrence rate until 3 years after the EMR in cases with the target lesions of the "Resect and Discard" strategy was determined in the negative-margin and IPR groups. Results: The final analysis was performed using the data of 1092 polyps, and 222 were categorized into the IPR group. There were no cases of recurrence in either of the groups. Conclusion: This is the world's first report conducted to examine the correlation of IPR and the local recurrence rate for clinical practice of "Resect and Discard" strategy. There is the possibility that pathological evaluation of the margins after EMR in patients with small polyps can be skipped.