Hybrid versus Conventional Colorectal Endoscopic Submucosal Dissection: A Multi-Center Randomized Controlled Trial (SHORT-ESD).

BACKGROUND: Hybrid endoscopic submucosal dissection (H-ESD) which utilizes ESD knife along with snare-based resection, has been developed to overcome the technical complexity of conventional ESD (C-ESD). This study aimed to compare the therapeutic outcomes of H-ESD vs. C-ESD for non-pedunculated colorectal lesions ≥20 mm in size. METHODS: We conducted a multicenter randomized controlled trial to compare H-ESD and C-ESD (Short-ESD trial). Patients with colorectal lesions between 20-50 mm in size were randomly assigned (1:1) to H-ESD or C-ESD. Primary outcome was procedure time/speed. Secondary outcomes were en-bloc and complete (R0) resection rates and adverse event rates. RESULTS: A total of 89 patients (median age 63 years; 49.3% women) with median polyp size 30 mm underwent H-ESD (n=40) and C-ESD (n=49). The mean procedure time of H-ESD was significantly shorter than that of C-ESD (41.1±16.3 vs. 54.3±28.2 minutes; p=0.007). The en-bloc and R0 resection rates trended lower in the H-ESD vs C-ESD groups (77.5% vs. 87.8%; p=0.26 and 72.5% vs. 79.6%; p=0.46) without reaching statistical significance. Adverse event rate was similar between H-ESD and C-ESD (10% vs 8.2%; p=1.00). CONCLUSION: Both H-ESD and C-ESD were safe and effective for resection of large colorectal lesions. H-ESD was associated with a shorter procedure time. H-ESD may represent a viable alternative to C-ESD, with the main advantage being easy applicability of a snare-based technique for colorectal lesions. Future studies are needed to further define the most suitable lesions for H-ESD, as to optimize efficiency and safety without compromising resection outcomes. ClinicaTrials.gov NCT NCT05347446.

The Safety of Cold Versus Hot Snare Polypectomy in Polyps 10-20 mm: A Systematic Review and Meta-Analysis.

Colonoscopy remains the primary method for preventing colorectal cancer. Traditionally, hot snare polypectomy (HSP) was the method of choice for removing polyps larger than 5 mm. Yet, for polyps smaller than 10 mm, cold snare polypectomy (CSP) has become the favored approach. Lately, the use of CSP has expanded to include the removal of sessile polyps that are between 10 and 20 mm in size. Our systematic review and meta-analysis aimed to evaluate the safety of cold snare polypectomy (CSP) compared to hot snare polypectomy (HSP) for resecting polyps measuring 10-20 mm. We searched the Medical Literature Analysis and Retrieval System Online (MEDLINE), Embase, and Cochrane databases up to April 2020 to find studies that directly compared CSP to HSP for polyps larger than 10 mm. Our main focus was on assessing the risk of delayed bleeding after polypectomy; a secondary focus was the incidence of any adverse events that required medical intervention post procedure. Our search yielded three comparative studies, two observational studies, and one randomized controlled trial (RCT), together encompassing 1,193 polypectomy procedures. Of these, 485 were performed using CSP and 708 with HSP. The pooled odds ratio (OR) for post-polypectomy bleeding (PPB) was 0.36 (95% confidence interval {CI}: 0.02, 7.13), with a Cochran Q test P-value of 0.11 and an I2 of 53%. For the risk of any adverse events necessitating medical care, the pooled OR was 0.15 (95% CI: 0.01, 2.29), with a Cochran Q test P-value of 0.21 and an I2 of 35%. The quality of the two observational studies was deemed moderate, and the RCT was only available in abstract form, preventing quality assessment. Our analysis suggests that there is no significant difference in the incidence of delayed post-polypectomy bleeding or other adverse events requiring medical attention between CSP and HSP for polyps measuring 10-20 mm.

Peroral endoscopic myotomy for spastic esophageal dysmotility among opioid users: a multicenter propensity score matching study.

BACKGROUND AND AIMS: Opioid-induced esophageal dysfunction (OIED) often presents as spastic esophageal disorders (SEDs) and esophagogastric junction outflow obstruction (EGJOO). The aim of this study was to evaluate and compare clinical outcomes of peroral endoscopic myotomy (POEM) for SEDs and EGJOO among opioid users and nonusers. METHODS: This propensity score (PS) matching study included consecutive opioid users and nonusers who underwent POEM for SEDs and EGJOO between January 2018 and September 2022. The following covariates were used for the PS calculation: age, sex, duration of symptoms, Eckardt score, type of motility disorder, and length of myotomy during POEM. Clinical response was defined as a post-POEM Eckardt score ≤3. RESULTS: A total of 277 consecutive patients underwent POEM during the study period. PS matching resulted in the selection of 64 pairs of patients strictly matched 1:1 (n = 128) with no statistically significant differences in demographic, baseline, or procedural characteristics or in the parameters considered for the PS between the 2 groups. Clinical response to POEM was significantly lower among opioid users (51 of 64 [79.7%]) versus nonusers (60 of 64 [93.8%]) (P = .03) at a median follow-up of 18 months. Among opioid users, higher opioid dose (>60 morphine milligram equivalents per day) was associated with a higher likelihood of failure to respond to POEM (odds ratio, 4.59; 95% confidence interval, 1.31-3.98; P = .02). CONCLUSIONS: Clinical response to POEM for SEDs and EGJOO is significantly lower among opioid users versus nonusers. There was a dose-relationship between opioids and response to POEM, with higher daily opioid usage associated with a higher likelihood of treatment failure.

Development and initial validation of a video-based peroral endoscopic myotomy assessment tool.

BACKGROUND AND AIMS: Video analysis has emerged as a potential strategy for performance assessment and improvement. We aimed to develop a video-based skill assessment tool for peroral endoscopic myotomy (POEM). METHODS: POEM was deconstructed into basic procedural components through video analysis by an expert panel. A modified Delphi approach and 2 validation exercises were conducted to refine the POEM assessment tool (POEMAT). Twelve assessors used the final POEMAT version to grade 10 videos. Fully crossed generalizability (G) studies investigated the contributions of assessors, endoscopists' performance, and technical elements to reliability. G coefficients below .5 were considered unreliable, between .5 and .7 as modestly reliable, and above .7 as indicative of satisfactory reliability. RESULTS: After task deconstruction, discussions, and the modified Delphi process, the final POEMAT comprised 9 technical elements. G analysis showed low variance for endoscopist performance (.8%-24.9%) and high interrater variability (range, 63.2%-90.1%). The G score was moderately reliable (≥.60) for "submucosal tunneling" and "myotomy" and satisfactorily reliable (≥.70) for "active hemostasis" and "mucosal closure." CONCLUSIONS: We developed and established initial content and response process validity evidence for the POEMAT. Future steps include appraisal of the tool using a wider range of POEM videos to establish and improve the discriminative validity of this tool.

Snare Tip Soft Coagulation vs Argon Plasma Coagulation vs No Margin Treatment After Large Nonpedunculated Colorectal Polyp Resection: a Randomized Trial.

BACKGROUND & AIMS: Thermal treatment of the defect margin after endoscopic mucosal resection (EMR) of large nonpedunculated colorectal lesions reduces the recurrence rate. Both snare tip soft coagulation (STSC) and argon plasma coagulation (APC) have been used for thermal margin treatment, but there are few data directly comparing STSC with APC for this indication. METHODS: We performed a randomized 3-arm trial in 9 US centers comparing STSC with APC with no margin treatment (control) of defects after EMR of colorectal nonpedunculated lesions ≥15 mm. The primary end point was the presence of residual lesion at first follow-up. RESULTS: There were 384 patients and 414 lesions randomized, and 308 patients (80.2%) with 328 lesions completed ≥1 follow-up. The proportion of lesions with residual polyp at first follow-up was 4.6% with STSC, 9.3% with APC, and 21.4% with control subjects (no margin treatment). The odds of residual polyp at first follow-up were lower for STSC and APC when compared with control subjects (P = .001 and P = .01, respectively). The difference in odds was not significant between STSC and APC. STSC took less time to apply than APC (median, 3.35 vs 4.08 minutes; P = .019). Adverse event rates were low, with no difference between arms. CONCLUSIONS: In a randomized trial STSC and APC were each superior to no thermal margin treatment after EMR. STSC was faster to apply than APC. Because STSC also results in lower cost and plastic waste than APC (APC requires an additional device), our study supports STSC as the preferred thermal margin treatment after colorectal EMR. (Clinicaltrials.gov, Number NCT03654209.).

Low delayed bleeding and high complete closure rate of mucosal defects with the novel through-the-scope dual-action tissue clip after endoscopic resection of large nonpedunculated colorectal lesions (with video).

BACKGROUND AND AIMS: Complete closure after endoscopic resection of large nonpedunculated colorectal lesions (LNPCLs) can reduce delayed bleeding but is challenging with conventional through-the-scope (TTS) clips alone. The novel dual-action tissue (DAT) clip has clip arms that open and close independently of each other, facilitating tissue approximation. We aimed to evaluate the rate of complete closure and delayed bleeding with the DAT clip after endoscopic resection of LNPCLs. METHODS: This was a multicenter prospective cohort study of all patients who underwent defect closure with the DAT clip after EMR or endoscopic submucosal dissection (ESD) of LNPCLs ≥20 mm from July 2022 to May 2023. Delayed bleeding was defined as a bleeding event requiring hospitalization, blood transfusion, or any intervention within 30 days after the procedure. Complete closure was defined as apposition of mucosal defect margins without visible submucosal areas <3 mm along the closure line. RESULTS: One hundred seven patients (median age, 64 years; 42.5% women) underwent EMR (n = 63) or ESD (n = 44) of LNPCLs (median size, 40 mm; 74.8% right-sided colon) followed by defect closure. Complete closure was achieved in 96.3% (n = 103) with a mean of 1.4 ± .6 DAT clips and 2.9 ± 1.8 TTS clips. Delayed bleeding occurred in 1 patient (.9%) without requiring additional interventions. CONCLUSIONS: The use of the DAT clip in conjunction with TTS clips achieved high complete defect closure after endoscopic resection of large LNPCLs and was associated with a .9% delayed bleeding rate. Future comparative trials and formal cost-analyses are needed to validate these findings. (Clinical trial registration number: NCT05852457.).

Benefits of EUS-guided gastroenterostomy over surgical gastrojejunostomy in the palliation of malignant gastric outlet obstruction: a large multicenter experience.

BACKGROUND AND AIMS: Palliation of malignant gastric outlet obstruction (mGOO) allows resumption of peroral intake. Although surgical gastrojejunostomy (SGJ) provides durable relief, it may be associated with a higher morbidity, interfere with chemotherapy, and require an optimum nutritional status. EUS-guided gastroenterostomy (EUS-GE) has emerged as a minimally invasive alternative. We aimed to conduct the largest comparative series to date between EUS-GE and SGJ for mGOO. METHODS: This multicenter retrospective study included consecutive patients undergoing SGJ or EUS-GE at 6 centers. Primary outcomes included time to resumption of oral intake, length of stay (LOS), and mortality. Secondary outcomes included technical and clinical success, reintervention rates, adverse events (AEs), and resumption of chemotherapy. RESULTS: A total of 310 patients were included (EUS-GE, n = 187; SGJ, n = 123). EUS-GE exhibited significantly lower time to resumption of oral intake (1.40 vs 4.06 days, P < .001), at lower albumin levels (2.95 vs 3.33 g/dL, P < .001), and a shorter LOS (5.31 vs 8.54 days, P < .001) compared with SGJ; there was no difference in mortality (48.1% vs 50.4%, P = .78). Technical (97.9% and 100%) and clinical (94.1% vs 94.3%) success was similar in the EUS-GE and SGJ groups, respectively. EUS-GE had lower rates of AEs (13.4% vs 33.3%, P < .001) but higher reintervention rates (15.5% vs 1.63%, P < .001). EUS-GE patients exhibited significantly lower interval time to resumption of chemotherapy (16.6 vs 37.8 days, P < .001). Outcomes between the EUS-GE and laparoscopic (n = 46) surgical approach showed that EUS-GE had shorter interval time to initiation/resumption of oral intake (3.49 vs 1.46 days, P < .001), decreased LOS (9 vs 5.31 days, P < .001), and a lower rate of AEs (11.9% vs 17.9%, P = .003). CONCLUSIONS: This is the largest study to date showing that EUS-GE can be performed among nutritionally deficient patients without affecting the technical and clinical success compared with SGJ. EUS-GE is associated with fewer AEs while allowing earlier resumption of diet and chemotherapy.

East versus West: Comparisons and Implications in Adaptation to Practice.

Endoscopic submucosal dissection (ESD) is the preferred strategy for the resection of large superficial neoplasia throughout the gastrointestinal tract in Asian countries. The transition of ESD to the West has been slower because of various regional and training differences. Nonetheless, over the past couple of decades, the steady growth of ESD mentors in the West and the introduction of viable training pathways and dedicated devices and accessories have led to the increasing adoption of ESD and other third space endoscopic procedures.

A novel through-the-scope helix tack-and-suture device for mucosal defect closure following colorectal endoscopic submucosal dissection: a multicenter study.

BACKGROUND: Complete closure of large mucosal defects following colorectal endoscopic submucosal dissection (ESD) with through-the-scope (TTS) clips is oftentimes not possible. We aimed to report our early experience of using a novel TTS suturing system for the closure of large mucosal defects after colorectal ESD. METHODS: We performed a retrospective multicenter cohort study of consecutive patients who underwent attempted prophylactic defect closure using the TTS suturing system after colorectal ESD. The primary outcome was technical success in achieving complete defect closure, defined as a < 5 mm residual mucosal defect in the closure line using TTS suturing, with or without adjuvant TTS clips. RESULTS: 82 patients with a median defect size of 30 (interquartile range 25-40) mm were included. Technical success was achieved in 92.7 % (n = 76): TTS suturing only in 44 patients (53.7 %) and a combination of TTS suturing to approximate the widest segment followed by complete closure with TTS clips in 32 (39.0 %). Incomplete/partial closure, failure of appropriate TTS suture deployment, and the need for over-the-scope salvage closure methods were observed in 7.3 % (n = 6). One intraprocedural bleed, one delayed bleed, and three intraprocedural perforations were observed. There were no adverse events related to placement of the TTS suture. CONCLUSION: The TTS suture system is an effective and safe tool for the closure of large mucosal defects after colorectal ESD and is an alternative when complete closure with TTS clips alone is not possible.

Rare solitary giant hamartomatous polyp of the stomach removed by endoscopic submucosal dissection.

Video 1Endoscopic submucosal dissection of a large solitary gastric hamartomatous polyp.

Factors associated with complete clip closure after endoscopic mucosal resection of large colorectal polyps.

BACKGROUND AND STUDY AIM : Delayed bleeding is a common adverse event following endoscopic mucosal resection (EMR) of large colorectal polyps. Prophylactic clip closure of the mucosal defect after EMR of nonpedunculated polyps larger than 20 mm reduces the incidence of severe delayed bleeding, especially in proximal polyps. This study aimed to evaluate factors associated with complete prophylactic clip closure of the mucosal defect after EMR of large polyps. METHODS : This is a post hoc analysis of the CLIP study (NCT01936948). All patients randomized to the clip group were included. Main outcome was complete clip closure of the mucosal resection defect. The defect was considered completely closed when no remaining mucosal defect was visible and clips were less than 1 cm apart. Factors associated with complete closure were evaluated in multivariable analysis. RESULTS : In total, 458 patients (age 65, 58 % men) with 494 large polyps were included. Complete clip closure of the resection defect was achieved for 338 polyps (68.4 %); closure was not complete for 156 (31.6 %). Factors associated with complete closure in adjusted analysis were smaller polyp size (odds ratio 1.06 for every millimeter decrease [95 % confidence interval 1.02-1.08]), good access (OR 3.58 [1.94-9.59]), complete submucosal lifting (OR 2.28 [1.36-3.90]), en bloc resection (OR 5.75 [1.48-22.39]), and serrated histology (OR 2.74 [1.35-5.56]). CONCLUSIONS : Complete clip closure was not achieved for almost one in three resected large nonpedunculated polyps. While stable access and en bloc resection facilitate clip closure, most factors associated with clip closure are not modifiable. This highlights the need for alternative closure options and measures to prevent bleeding.

Concomitant neuroendocrine tumor and gastrointestinal stromal tumor in a duodenal fine needle aspiration: A cytologic clue for neurofibromatosis type 1.

The identification of two cell populations displaying different cytologic characteristics in the same fine needle aspiration (FNA), one with an epithelioid appearance and the other spindle cell morphology, is an extremely rare phenomenon and potentially represents a source of diagnostic confusion. Depending on the lineage and relationship of the two cell types, the differential diagnosis is broad and encompasses a wide spectrum of entities. The current case describes the presence of nests and clusters of neuroendocrine cells associated with rare spindle cell fragments of gastrointestinal stromal tumor (GIST) in the same fine needle aspiration of a duodenal mass. Our literature analysis revealed that such combined cytologic findings were hitherto never reported and the concurrence of well-differentiated neuroendocrine tumor (NET) and GIST is almost pathognomonic for neurofibromatosis type 1 (NF-1).

A newly designed uncovered biliary stent for palliation of malignant obstruction: results of a prospective study.

BACKGROUND: Biliary decompression can reduce symptoms and improve quality of life in patients with malignant biliary obstruction. Endoscopically placed stents have become the standard of care for biliary drainage with the aim of improving hepatic function, relieving jaundice, and reducing adverse effects of obstruction. The purpose of this study was to evaluate the performance characteristics of a newly-designed, uncovered metal biliary stent for the palliation of malignant biliary obstruction. METHODS: This post-market, prospective study included patients with biliary obstruction due to a malignant neoplasm treated with a single-type, commercially available uncovered self-expanding metal stent (SEMS). Stents were placed as clinically indicated for palliation of jaundice and to potentially facilitate neo-adjuvant chemotherapy. The main outcome measure was freedom from recurrent biliary obstruction (within the stent) requiring re-intervention within 1, 3, and 6 months of stent insertion. Secondary outcome measures included device-related adverse events and technical success of stent deployment. RESULTS: SEMS were placed in 113 patients (73 men; mean age, 69); a single stent was inserted in 106 patients, and 2 stents were placed in 7 patients. Forty-eight patients survived and/or completed the 6 month study protocol. Freedom from symptomatic recurrent biliary obstruction requiring re-intervention was achieved in 108 of 113 patients (95.6, 95%CI = 90.0-98.6%) at study exit for each patient. Per interval analysis yielded the absence of recurrent biliary obstruction in 99.0% of patients at 1 month (n = 99; 95%CI = 97.0-100%), 96.6% of patients at 3 months (n = 77; 95%CI = 92.7-100%), and 93.3% of patients at 6 months (n = 48; 95%CI = 86.8-99.9%). In total, only 5 patients (4.4%) were considered failures of the primary endpoint. Most of these failures (4/5) were due to stent occlusion from tumor ingrowth or overgrowth. Overall technical success rate of stent deployment was 99.2%. There were 2 cases of stent-related adverse events (1.8%). There were no cases of post-procedure stent migration, stent-related perforation, or stent-related deaths. CONCLUSIONS: This newly designed and marketed biliary SEMS system appears to be effective at relieving biliary obstruction and preventing re-intervention within 6 months of insertion in the overwhelming majority of patients. The device has an excellent safety profile, and associated high technical success rate during deployment. TRIAL REGISTRATION: The study was registered on clinicaltrials.gov on 14 October 2013 and the study registration number is NCT01962168. University of Massachusetts Medical School did not participate in the study.

Effects of Blended (Yellow) vs Forced Coagulation (Blue) Currents on Adverse Events, Complete Resection, or Polyp Recurrence After Polypectomy in a Large Randomized Trial.

BACKGROUND & AIMS: There is debate over the type of electrosurgical setting that should be used for polyp resection. Some endoscopists use a type of blended current (yellow), whereas others prefer coagulation (blue). We performed a single-blinded, randomized trial to determine whether type of electrosurgical setting affects risk of adverse events or recurrence. METHODS: Patients undergoing endoscopic mucosal resection of nonpedunculated colorectal polyps 20 mm or larger (n = 928) were randomly assigned, in a 2 × 2 design, to groups that received clip closure or no clip closure of the resection defect (primary intervention) and then to either a blended current (Endocut Q) or coagulation current (forced coagulation) (Erbe Inc) (secondary intervention and focus of the study). The study was performed at multiple centers, from April 2013 through October 2017. Patients were evaluated 30 days after the procedure (n = 919), and 675 patients underwent a surveillance colonoscopy at a median of 6 months after the procedure. The primary outcome was any severe adverse event in a per patient analysis. Secondary outcomes were complete resection and recurrence at first surveillance colonoscopy in a per polyp analysis. RESULTS: Serious adverse events occurred in 7.2% of patients in the Endocut group and 7.9% of patients in the forced coagulation group, with no significant differences in the occurrence of types of events. There were no significant differences between groups in proportions of polyps that were completely removed (96% in the Endocut group vs 95% in the forced coagulation group) or the proportion of polyps found to have recurred at surveillance colonoscopy (17% and 17%, respectively). Procedural characteristics were comparable, except that 17% of patients in the Endocut group had immediate bleeding that required an intervention, compared with 11% in the forced coagulation group (P = .006). CONCLUSIONS: In a randomized trial to compare 2 commonly used electrosurgical settings for the resection of large colorectal polyps (Endocut vs forced coagulation), we found no difference in risk of serious adverse events, complete resection rate, or polyp recurrence. Electrosurgical settings can therefore be selected based on endoscopist expertise and preference. Clinicaltrials.gov ID NCT01936948.

Endoscopic ultrasound-guided liver biopsy using a 22-G fine needle biopsy needle: a prospective study.

BACKGROUND: Endoscopic ultrasound-guided liver biopsy (EUS-LB) using a 19-gauge (19-G) EUS needle is becoming increasingly popular. We evaluated the efficacy and safety of a 22-G EUS fine needle biopsy (FNB) needle for performing EUS-LB. METHODS: Patients referred for evaluation of elevated liver enzymes and without obstructive disease requiring endoscopic retrograde cholangiopancreatography (ERCP) were included. Using a 22-G FNB needle, two passes were made from the left lobe and one from the right. The main outcome measure was adequacy of the specimen for histology interpretation, and the secondary outcome was the safety of EUS-guided liver biopsy with a 22-G FNB needle. Patients were followed for post-procedure complications for 30 days. RESULTS: 40 patients (median age 61 years; 26 women) underwent EUS-LB. Analyzing by needle passes, the median longest core fragment was 12 mm (1st quartile - 3rd quartile 10 mm - 16.25 mm, interquartile range [IQR] 6.25 mm) from the left lobe and 11 mm (10 mm - 15.75 mm, IQR 5.75 mm) from the right lobe. The median cumulative core length per patient was 55 mm (44.5 mm - 68 mm, IQR 23.5 mm). The median cumulative number of complete portal triads (CPTs) per patient was 42 (28.5 - 53, IQR 24.5). The specimen was considered adequate in all 40 patients (100 %). Self-limiting abdominal pain was reported in 6 patients (15 %). CONCLUSIONS: EUS-LB using a 22-G FNB needle is a safe and viable alternative to the use of larger gauge needles, yielding adequate tissue for evaluation of parenchymal disease in 100 % of the patients.

Clip Closure Prevents Bleeding After Endoscopic Resection of Large Colon Polyps in a Randomized Trial.

BACKGROUND & AIMS: Bleeding is the most common severe complication after endoscopic mucosal resection of large colon polyps and is associated with significant morbidity and cost. We examined whether prophylactic closure of the mucosal defect with hemoclips after polyp resection reduces the risk of bleeding. METHODS: We performed a multicenter, randomized trial of patients with a large nonpedunculated colon polyp (≥20 mm) at 18 medical centers in North America and Spain from April 2013 through October 2017. Patients were randomly assigned to groups that underwent endoscopic closure with a clip (clip group) or no closure (control group) and followed. The primary outcome, postprocedure bleeding, was defined as a severe bleeding event that required hospitalization, a blood transfusion, colonoscopy, surgery, or another invasive intervention within 30 days after completion of the colonoscopy. Subgroup analyses included postprocedure bleeding with polyp location, polyp size, or use of periprocedural antithrombotic medications. We also examined the risk of any serious adverse event. RESULTS: A total of 919 patients were randomly assigned to groups and completed follow-up. Postprocedure bleeding occurred in 3.5% of patients in the clip group and 7.1% in the control group (absolute risk difference [ARD] 3.6%; 95% confidence interval [CI] 0.7%-6.5%). Among 615 patients (66.9%) with a proximal large polyp, the risk of bleeding in the clip group was 3.3% and in the control group was 9.6% (ARD 6.3%; 95% CI 2.5%-10.1%); among patients with a distal large polyp, the risks were 4.0% in the clip group and 1.4% in the control group (ARD -2.6%; 95% CI -6.3% to -1.1%). The effect of clip closure was independent of antithrombotic medications or polyp size. Serious adverse events occurred in 4.8% of patients in the clip group and 9.5% of patients in the control group (ARD 4.6%; 95% CI 1.3%-8.0%). CONCLUSIONS: In a randomized trial, we found that endoscopic clip closure of the mucosal defect following resection of large colon polyps reduces risk of postprocedure bleeding. The protective effect appeared to be restricted to large polyps located in the proximal colon. ClinicalTrials.gov no: NCT01936948.