Impact of annual case volume on colorectal endoscopic submucosal dissection outcomes in a large prospective cohort study.

OBJECTIVES: The adoption of colorectal endoscopic submucosal dissection (ESD) is still limited in the West. A recent randomized trial showed ESD is more effective and only slightly riskier than piecemeal endoscopic mucosal resection (EMR); reproducibility outside expert centers was questioned. We evaluated the results according to the annual case volume in a multicentric prospective cohort. METHODS: Between 09/2019 and 09/2022, colorectal ESD was consecutively performed at 13 participating centers classified as low-volume (LV), middle-volume (MV), and high-volume (HV). The main procedural outcomes were assessed. Multivariate and propensity score matching (PSM) analyses were performed. RESULTS: 3770 ESDs were included. HV centers treated larger and more often colonic lesions than MV and LV centers. En bloc, R0 and curative resection rates were 95.2%, 87.4%, and 83.2%, respectively, and were higher at HV than at MV and LV centers. HV centers achieved also a faster dissection speed. Delayed bleeding and surgery for complications rates were 5.4% and 0.8%, respectively, without significant differences. The perforation rate (overall: 9%) was higher at MV than at LV and HV centers. Lesion characteristics, but not volume center, were independently associated with both R1 resection and perforation. However, after PSM, R0 rates were significantly higher at HV than at LV centers, and perforation rates were significantly higher at MV than at HV centers. CONCLUSIONS: Colorectal ESD can be successfully implemented in the West, even in nonexpert centers. However, difficult lesions must still be referred to experts.

Increased risk of gastric cancer in relation with pernicious anaemia in patients with primary antibody deficiency: A nationwide case control study.

BACKGROUND/AIM: We aimed to assess gastrointestinal cancers risks in a large cohort of individuals with primary antibody deficiency (PAD) and their association with risk of autoimmune and inflammatory gastrointestinal diseases. METHODS: Investigating a French national database of inpatient admissions between 2010 and 2018, we identified 12,748 patients with PAD and 38,244 control non-exposed individuals. We performed multiple exposed-non-exposed studies using conditional logistic regression. RESULTS: In comparison with non-exposed patients, PAD patients had increased risk of in situ gastric carcinoma (Odds Ratio (OR) =10.5 [95 % CI 2.2; 50.5]), malignant gastric tumor (OR=3.2 [95 % CI 2.2; 4.4]) and colorectal cancer (OR=1.2 [95 % CI 1; 1.5]). PAD patients had also increased risk of pernicious anaemia (OR=8 |95 % CI 5.6; 11.5]), Crohn's disease (OR= 4.4 [95 % CI 3.5; 5.6]), ulcerative colitis (OR=2.9 [95 % CI 2.4; 3.6]) and coeliac disease (OR=13.3 [95 % CI 9.1; 19.5]). Within patients with gastric cancer, those with PAD had increased risk of pernicious anaemia (OR=8.4 [95 % CI 1.5; 215]; p = 0.01) but not of H. pylori infection. CONCLUSIONS: Risk of gastric cancer is particularly high in PAD patients and notably risk of in situ gastric carcinoma in association with pernicious anaemia. It supports indication of early endoscopic screening in these patients.

Closure of gastrointestinal perforations using an endoloop system and a single-channel endoscope: description of a simple, reproducible, and standardized method.

BACKGROUND: Several endoscopic treatments for iatrogenic perforations are currently available, with some limitations in terms of size, location, complexity, or cost. Our aims were to introduce a novel technique for closure, using an endoloop and clips, to assess its rate of technical success and post-resection complications. METHODS: For closure of large perforations (diameter ≥ 10 mm), two similar techniques were implemented, using a single-channel endoscope. An endoloop was deployed through the operating channel or towed by an endoclip alongside the endoscope. Several clips were utilized to fix it on the muscular layer of defect's margins. The defect was closed, by fastening the loop either directly or after being reattached to the mobile hook. RESULTS: This analysis included eleven patients (72% women, median age 68 years). Eight colorectal, one appendiceal, and two gastric lesions were resected, with a median perforation size of 15 mm. As confirmed by computed tomography, closure of wall defects was achieved successfully in all cases, using a median of 6 clips. Pneumoperitoneum was evacuated in 4 cases. The median hospitalization duration was 4 days, prophylactic antibiotics being prescribed for a median of 7 days. One patient had a small abdominal collection, without requiring drainage, while another presented post-resection bleeding from the mucosal defect. CONCLUSION: The novel techniques, utilizing a single-channel endoscope, clips, and an endoloop, ensuring an edge-to-edge suture of muscular layer, proved to be safe, reproducible, and easy to implement. They exhibit an excellent technical success rate and a minimal incidence of non-severe complications.

Endoscopic En Bloc Versus Piecemeal Resection of Large Nonpedunculated Colonic Adenomas : A Randomized Comparative Trial.

BACKGROUND: Endoscopic resection of adenomas prevents colorectal cancer, but the optimal technique for larger lesions is controversial. Piecemeal endoscopic mucosal resection (EMR) has a low adverse event (AE) rate but a variable recurrence rate necessitating early follow-up. Endoscopic submucosal dissection (ESD) can reduce recurrence but may increase AEs. OBJECTIVE: To compare ESD and EMR for large colonic adenomas. DESIGN: Participant-masked, parallel-group, superiority, randomized controlled trial. (ClinicalTrials.gov: NCT03962868). SETTING: Multicenter study involving 6 French referral centers from November 2019 to February 2021. PARTICIPANTS: Patients with large (≥25 mm) benign colonic lesions referred for resection. INTERVENTION: The patients were randomly assigned by computer 1:1 (stratification by lesion location and center) to ESD or EMR. MEASUREMENTS: The primary end point was 6-month local recurrence (neoplastic tissue on endoscopic assessment and scar biopsy). The secondary end points were technical failure, en bloc R0 resection, and cumulative AEs. RESULTS: In total, 360 patients were randomly assigned to ESD (n = 178) or EMR (n = 182). In the primary analysis set (n = 318 lesions in 318 patients), recurrence occurred after 1 of 161 ESDs (0.6%) and 8 of 157 EMRs (5.1%) (relative risk, 0.12 [95% CI, 0.01 to 0.96]). No recurrence occurred in R0-resected cases (90%) after ESD. The AEs occurred more often after ESD than EMR (35.6% vs. 24.5%, respectively; relative risk, 1.4 [CI, 1.0 to 2.0]). LIMITATION: Procedures were performed under general anesthesia during hospitalization in accordance with the French health system. CONCLUSION: Compared with EMR, ESD reduces the 6-month recurrence rate, obviating the need for systematic early follow-up colonoscopy at the cost of more AEs. PRIMARY FUNDING SOURCE: French Ministry of Health.

Impact of surgery after endoscopically resected high-risk T1 colorectal cancer: results of an emulated target trial.

BACKGROUND AND AIMS: We aimed to compare the long-term outcomes of patients with high-risk T1 colorectal cancer (CRC) resected endoscopically who received either additional surgery or surveillance. METHODS: We used data from routine care to emulate a target trial aimed at comparing 2 strategies after endoscopic resection of high-risk T1 CRC: surgery with lymph node dissection (treatment group) versus surveillance alone (control group). All patients from 14 tertiary centers who underwent an endoscopic resection for high-risk T1 CRC between March 2012 and August 2019 were included. The primary outcome was a composite outcome of cancer recurrence or death at 48 months. RESULTS: Of 197 patients included in the analysis, 107 were categorized in the treatment group and 90 were categorized in the control group. From baseline to 48 months, 4 of 107 patients (3.7%) died in the treatment group and 6 of 90 patients (6.7%) died in the control group. Four of 107 patients (3.7%) in the treatment group experienced a cancer recurrence and 4 of 90 patients (4.4%) in the control group experienced a cancer recurrence. After balancing the baseline covariates by inverse probability of treatment weighting, we found no significant difference in the rate of death and cancer recurrence between patients in the 2 groups (weighted hazard ratio, .95; 95% confidence interval, .52-1.75). CONCLUSIONS: Our study suggests that patients with high-risk T1 CRC initially treated with endoscopic resection may not benefit from additional surgery.

Features of colorectal adenomas among young patients with Lynch syndrome according to path_MMR: Results from the PRED-IdF registry.

BACKGROUND: Lynch syndrome (LS) is the most frequent inherited colorectal cancer syndrome. AIM: To assess the burden of adenoma in LS patients under 50 years-old followed in the PRED-IdF network. METHODS: From January 2010 to January 2019, all patients under 50 years of age with a confirmed LS germline mutation were included. The main objective was the description of adenomas characteristics according to path_MMR. RESULTS: We analyzed data from 708 patients (mean age 34.8 ± 8.6), of which 41.8 % were male. Among these patients, 37.6% had path_MLH1, 45.4% path_MSH2, 13.9% path_MSH6, 2.9% path_PMS2, and 1.2% path_EpCAM. The analysis included 1721 (70.9%) follow-up colonoscopies. A total of 682 adenomas were detected, including 140 (20.5%) advanced adenomas. The adenoma detection rates during the first and follow-up colonoscopies were 19.2% and 20.5%, respectively. Most adenomas were <10 mm (57.9%), located in the proximal colon (334, 48.9%), and presented as non-polypoid lesions (493, 72.3%). The median growth time for adenomas was 23 months (range 9-114) irrespective of the path_MMR mutation (p = 0.62). CONCLUSION: LS patients under 50 years of age have a high burden of adenomas, particularly small non-polypoid adenomas located in the proximal colon. These results highlight the need for intensive screening, with a particular focus on the proximal colon.

Factors associated with early failure of peroral endoscopic myotomy in achalasia.

BACKGROUND AND AIMS: Achalasia can be treated very effectively with peroral endoscopic myotomy (POEM), but factors associated with early failure remain to be determined, especially in European cohorts. METHODS: All consecutive adult patients who underwent a first POEM to treat primary achalasia were included in this multicenter retrospective study. Early failure was defined by an Eckardt score (ES) >3 at 3 months after POEM. When evaluating factors predictive of early failure, 2 cohorts were considered: one consisted of the total population, for whom only basic variables were collected, and the other a cohort built for a case-control study that included matched early-failure and early-success patients (ratio, 1:2). RESULTS: Among 746 patients, the early failure rate was 9.4%. Predictive factors were age ≤45 years (P = .019), achalasia types I and III (P < .001), and the development of a severe adverse event during the procedure (P = .023). In the case-control study, the only additional independent risk factor for early failure was a high pre-POEM ES (P = .001). Only the retrosternal pain subscore was significantly associated with the early failure rate. CONCLUSION: The early failure rate of POEM used to treat primary achalasia is <10%. Younger age, type I/III achalasia, and a high pre-POEM ES were significantly associated with failure.

Non eosinophilic chronic stricturing esophagitis: Lessons from thirty eight cases.

BACKGROUND AND AIMS: The endoscopic workup of dysphagia can lead to the diagnosis of atypical esophagitis, with thickened esophageal mucosa, strictures, mucosal exudates, furrows, and sloughing. While these aspects suggest eosinophilic esophagitis, pathology might not report the presence of eosinophils, but rather chronic inflammation, with spongiosis, parakeratosis, and lymphocytic infiltrate. We aimed to report the management of this disease and assess the prevalence of associated dermatological conditions. METHODS: We retrospectively evaluated the medical records of our patients with non-eosinophilic stricturing esophagitis for clinical, endoscopy, and pathology data. Patients were evaluated by a dermatologist. A blood immunoassay and skin biopsy were performed if needed. RESULTS: Thirty-eight patients (twenty-six women) were included in the study. The median age at onset of symptoms was 56.5 years, with a median duration of symptoms of two years. Thirty-five patients presented with dysphagia at diagnosis and eighteen with weight loss. At endoscopy, a single esophageal stenosis was diagnosed in 19 patients, localized in the upper third in 22 patients. Thirty patients received endoscopic treatment (dilatation in 29/38 and local triamcinolone injection in 11/38 patients). In 21 patients, oral, skin or vulvo-anal lesions were found on dermatological examination. Nineteen patients received systemic treatment, including corticosteroids, immunosuppressive drugs and plasmapheresis. Five patients developed esophageal squamous cell carcinoma. CONCLUSION: The management of non-eosinophilic chronic stricturing esophagitis is challenging, because of a low contribution of esophageal biopsies and the refractory nature of the strictures. In our experience, a dermatological evaluation helped in 55% of cases to introduce a systemic treatment, leading to limit the use of endoscopic dilatation. Endoscopic follow-up is needed, considering the significant risk of esophageal squamous cell carcinoma.

Achalasia and Hiatal Hernia: A Rare Association and a Therapeutic Challenge.

Background/Aims: Achalasia and hiatal hernia are rarely associated. The aim of the current study is to explore the clinical and manometric findings in patients with achalasia and hiatal hernia, and to determine if the presence of a hiatal hernia should influence therapeutic management in patients with achalasia. Methods: This retrospective single center analysis included a group of patients with achalasia and hiatal hernia (study group) and a group of matched patients with achalasia but no hiatal hernia (control group). We recorded demographic, clinical, endoscopic, and manometric parameters and compared initial presentation and treatment outcomes between the groups. Results: Between 2015 and 2022, achalasia was diagnosed in 294/1513 (19.4%) patients. Concomitant hiatal hernia was identified in 13/294 (4.4%) patients. Compared to patients with achalasia and no hiatal hernia, patients in the study group had lower Eckardt scores at baseline (5.4 ± 2.0 vs 7.8 ± 2.4; P = 0.005) but similar integrated relaxation pressure. Following treatment, patients in the study and control group had similar clinical success and prevalence of gastroesophageal reflux symptoms. Conclusions: Hiatal hernia is rarely associated with achalasia. The presence of a hiatal hernia should not influence treatment decisions in patients with achalasia.

Diagnostic Yield of Repeat Endoscopic Ultrasound-Guided Fine Needle Biopsy for Solid Pancreatic Lesions.

PATIENTS AND METHODS: we performed a retrospective case-control study, including cases with repeat EUS FNB for a solid pancreatic lesion, matched on a 1:2 ratio on age, sex, tumor location and presence of chronic pancreatitis with cases diagnosed on the first EUS FNB. RESULTS: thirty-four cases and 68 controls were included in the analysis. Diagnostic accuracies were 80% and 88% in the repeat and single EUS FNB groups, respectively (p = 0.824). The second EUS FNB had a sensitivity of 80%, a specificity of 75%, a positive predictive value of 96%, and a negative predictive value of 33%. Of the 34 patients in the repeat EUS FNB group, 25 (74%) had a positive diagnosis with the second EUS FNB, 4 (12%) after surgery due to a second negative EUS FNB, 4 (12%) during clinical follow-up, and 1 (3%) after a third EUS FNB. Of the 25 patients diagnosed on the repeat EUS FNB, 17 (68%) had pancreatic adenocarcinomas, 2 (8%) neuroendocrine tumors, 2 (8%) other autoimmune pancreatitis, 2 (8%) chronic pancreatitis nodules, 1 (4%) renal cancer metastasis, and 1 (4%) other malignant diagnostic. There were no complications reported after the second EUS FNB in this study. CONCLUSION: repeat EUS FNB made a diagnosis in three fourths of patients with solid pancreatic lesions and a first negative EUS FNB, with 26% of benign lesions. This supports the repetition of EUS FNB sampling in this clinical situation.

Endoscopic submucosal dissection versus endoscopic mucosal resection for early esophageal adenocarcinoma.

OBJECTIVES: Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) allow endoscopic resection of early esophageal adenocarcinoma. The choice between the two techniques takes into account the morphology of the lesion, and the experience of the endoscopist. The aim of this study was to compare EMR to ESD for the treatment of early esophageal adenocarcinoma. METHODS: Patients who underwent an endoscopic resection for esophageal adenocarcinomas between March 2015 and December 2019 were included. ESD was compared to EMR in terms of clinical, procedural, histologic, and oncologic outcomes. RESULTS: 85 patients were included: 57 ESD and 28 EMR. The median (IQR) diameter of the lesion was 20(15-25) mm in the ESD group, and 15(8-16) mm in the EMR group, p<0.01. ESD allowed en bloc resection in 100% of cases, and EMR in 39% of cases, p<0.001. The R0 and curative resection rate in the ESD group versus the EMR group were 88% and 67%, respectively, versus 21% and 11%, p<0.001. We recorded one severe adverse event, in the EMR group. After a median (IQR) follow-up of 27.5 (14.5-38.7) months, the local recurrence rate was 23% vs. 18% (p = 0.63), and the overall survival 89% vs. 86% (p = 0.72), in the ESD and EMR groups, respectively. CONCLUSION: ESD was as safe as EMR and allowed higher en bloc, R0 and curative resection rates. Although these results did not translate into long-term outcomes, these data prompt for a broader adoption of ESD for the resection of esophageal lesions suspected of harboring early esophageal adenocarcinoma.

"Transanal endoscopic microsurgery" with a flexible colonoscope (F-TEM): a new endoscopic treatment for suspicious deep submucosal invasion T1 rectal carcinoma.

BACKGROUND: Endoscopic techniques allow resections of deep submucosal invasion rectal carcinoma, but mostly are facing issues such as costs, follow-up care or size limit. Our aim was to design a new endoscopic technique, which retains the advantages over surgical resections while eliminating the disadvantages mentioned above. PATIENTS AND METHODS: We propose a technique for the resection of the superficial rectal tumours, with highly suspicious deep submucosal invasion. It combines steps of endoscopic submucosal dissection, muscular resection and edge-to-edge suture of the muscular layers, finally performing the equivalent of a "transanal endoscopic microsurgery" with a flexible colonoscope (F-TEM). RESULTS: A 60-year-old patient was referred to our unit, following the discovery of a 15 mm distal rectum adenocarcinoma. The computed tomography and the endoscopic ultrasound examination revealed a T1 tumour, without secondary lesions. Considering that the initial endoscopic evaluation highlighted a depressed central part of the lesion, with several avascular zones, an F-TEM was performed, without severe complication. The histopathological examination revealed negative resection margins, without risk factors for lymph node metastasis, no adjuvant therapy being proposed. CONCLUSION: F-TEM allows endoscopic resection of highly suspicious deep submucosal invasion T1 rectal carcinoma and it proves to be a feasible alternative to surgical resection or other endoscopic treatments as endoscopic submucosal dissection or intermuscular dissection.

Mechanisms of esophageal stricture after extensive endoscopic resection: a transcriptomic analysis.

Background and study aims Esophageal stricture is the most frequent adverse event after endoscopic resection for early esophageal neoplasia. Currently available treatments for the prevention of esophageal stricture are poorly effective and associated with major adverse events. Our aim was to identify transcripts specifically overexpressed or repressed in patients who have developed a post-endoscopic esophageal stricture, as potential targets for stricture prevention. Patients and methods We conducted a prospective single-center study in a tertiary endoscopy center. Patients scheduled for an endoscopic resection and considered at risk of esophageal stricture were offered inclusion in the study. The healthy mucosa and resection bed were biopsied on Days 0, 14, and 90. A transcriptomic analysis by microarray was performed, and the differences in transcriptomic profile compared between patients with and without esophageal strictures. Results Eight patients, four with esophageal stricture and four without, were analyzed. The mean ± SD circumferential extension of the mucosal defect was 85 ±â€Š11 %. The transcriptomic analysis in the resection bed at day 14 found an activation of the interleukin (IL)-1 group (Z score = 2.159, P  = 0.0137), while interferon-gamma (INFγ) and NUPR1 were inhibited (Z score = -2.375, P  = 0.0022 and Z score = -2.333, P  = 0.00131) in the stricture group. None of the activated or inhibited transcripts were still significantly so in any of the groups on Day 90. Conclusions Our data suggest that IL-1 inhibition or INFγ supplementation could constitute promising targets for post-endoscopic esophageal stricture prevention.

Airborne transmission of SARS-Cov2: What consequences for digestive endoscopy?

The SARS-Cov-2 disease disrupted essential hospital procedures, such as gastrointestinal (GI) endoscopy, due to concerns about air transmission and the risk of exposing health care workers. With the spread of the pandemic, air transmission was considered as the main source of SARS-Cov2 transmission. This raised the problem of transmission by aerosolization of viral particles in operating rooms as well as endoscopy units. This is in line with the known airborne transmission of many other respiratory viruses. The risk of SARS-Cov-2 transmission during GI endoscopy was initially reduced by controlled measures, involving personal protections (mask…), restricted access to endoscopy rooms, and detection of infected patients. Gastrointestinal endoscopy generates aerosols, which may carry viruses. In addition, the endoscopy system may facilitate the diffusion of virus particles or fomites considering the forced-air cooling system used to maintain a stable temperature inside the box (25°C). The volume of air that goes through the light source box is high (240-300 m3 for a 1-h period). Moreover, the light system contains an air pump to inflate air inside the gut lumen. In order to isolate people from hazard, different levels of protection and solutions to avoid airborne transmission of microorganisms should be proposed, such as the reinforcement of personal protective equipment, the change in the way people work and engineering control of the risk.

Predictive factors of radiofrequency ablation failure in the treatment of dysplastic Barrett's esophagus.

INTRODUCTION: Radiofrequency ablation (RFA) has become the recommended endoscopic treatment for flat dysplastic Barrett's esophagus. However, the outcomes of this treatment are variable across European countries. Our aim was to report the results of a French high-volume center, and to investigate factors associated with treatment failure. METHODS: We conducted a single-center retrospective study from a prospectively collected database from 2011 to 2020, including all consecutive patients treated with RFA for flat dysplastic Barrett's esophagus. The primary endpoint was the failure rate of esophageal radiofrequency treatment, defined as either persistence of intestinal metaplasia at the end of treatment, or neoplastic progression during RFA. RESULTS: 96 patients treated with a median of four RFA sessions for a mean C5M6 Barrett's esophagus were included in the analysis. Complete eradication of intestinal metaplasia and dysplasia were achieved in 59% and 79% of patients, respectively, resulting in a treatment failure rate of 41%. Ten patients experienced neoplastic progression during treatment. We recorded 14% of post-RFA esophageal strictures, all successfully treated by endoscopic dilatation. Univariate analysis identified the length of Barrett's esophagus and the absence of hiatal hernia as predictive factors for treatment failure, however not confirmed in multivariate analysis. CONCLUSION: In our experience, RFA of flat dysplastic Barrett's esophagus had a 41% treatment failure rate. The length of the Barrett's segment might be associated with treatment failure. Although our results confirm a role for RFA in the management of dysplastic Barrett's esophagus, the treatment failure rate was higher than expected. This suggest that endoscopists, even in high-volume centers, should receive specific training in RFA.

A new system to prevent SARS-CoV-2 and microorganism air transmission through the air circulation system of endoscopes.

Background and study aims Evidence for the modes of transmission of SARS-CoV-2 remains controversial. Recently, the potential for airborne spread of SARS-CoV-2 has been stressed. Air circulation in gastrointestinal light source boxes and endoscopes could be implicated in airborne transmission of microorganisms. Methods The ENDOBOX SC is a 600 × 600 mm cube designed to contain any type of machine used during gastrointestinal endoscopy. It allows for a 100-mm space between a machine and the walls of the ENDOBOX SC. To use the ENDOBOX SC, it is connected to the medical air system and it provides positive flow from the box to the endoscopy room. The ENDOBOX SC uses medical air to inflate the digestive tract and to decrease the temperature induced by the microprocessors or by the lamp. ENDOBOX SC has been investigated in different environments. Results An endoscopic procedure performed without ventilation was interrupted after 40 minutes to prevent computer damage. During the first 30 minutes, the temperature increased from 18 °C to 31 °C with a LED system. The procedure with fans identified variations in temperature inside the ENDOBOX SC from 21 to 26 °C (±â€Š5 °C) 1 hour after the start of the procedure. The temperature was stable for the next 3 hours. Conclusions ENDOBOX SC prevents the increase in temperature induced by lamps and processors, allows access to all necessary connections into the endoscopic columns, and creates a sterile and positive pressure volume, which prevents potential contamination from microorganisms.

Outcomes of endoscopic mucosal resection for large superficial non-ampullary duodenal adenomas.

Endoscopic mucosal resection (EMR) is the recommended treatment for superficial non-ampullary duodenal epithelial tumors larger than 6 mm. This endoscopic technique carries a high risk of adverse events. Our aim was to identify the risk factors for adverse events following EMR for non-ampullary duodenal adenomatous lesions. We retrospectively analyzed a prospectively collected database of consecutive endoscopic resections for duodenal lesions at a tertiary referral center for therapeutic endoscopy. We analyzed patients with non-ampullary duodenal adenomatous lesions ≥ 10 mm resected by EMR, and searched for factors associated with adverse events after EMR. 167 duodenal adenomatous lesions, with a median size of 25 (25-40) mm, were resected by EMR between January 2015 and December 2020. Adverse events occurred in 37/167 (22.2%) after endoscopic resection, with 29/167 (17.4%) delayed bleeding, 4/167 (2.4%) immediate perforation and 4/167 (2.4%) delayed perforation. In logistic regression, the size of the lesion was the only associated risk factor of adverse events (OR = 2.81, 95% CI [1.27; 6.47], p = 0.012). Adverse events increased mean hospitalization time (7.7 ± 9 vs. 1.9 ± 1 days, p < 0.01). None of the currently recommended preventive methods, particularly clips, affected the adverse event rate. EMR of centimetric and supracentimetric duodenal adenomatous lesions carries a high risk of adverse events, increasing with the size of the lesion and with no benefit from any preventive method. These results suggest that these procedures should be performed in expert centers, and underline the need for novel endoscopic tools to limit the rate of adverse events.