Post-polypectomy Bleeding Rate Research Articles

Safety of Cold Snare Polypectomy during Continuous Use of Antithrombotic Drugs for Delayed Post-Polypectomy Bleeding: A Pilot Study

Background: Cold snare polypectomy is a high-risk endoscopic procedure with a low delayed post-polypectomy bleeding rate. However, it is unclear whether delayed post-polypectomy bleeding rates increase during continuous antithrombotic treatment. This study aimed to determine the safety of cold snare polypectomy during continuous antithrombotic treatment. Methods: This single-center, retrospective cohort study enrolled patients who underwent cold snare polypectomy during antithrombotic treatment between January 2015 and December 2021. Patients were divided into continuation and withdrawal groups based on whether they continued with antithrombotic drugs or not. Propensity score matching was performed using age, sex, Charlson comorbidity index, hospitalization, scheduled treatment, type of antithrombotic drugs used, multiple medications used, indication for antithrombotic drugs, and gastrointestinal endoscopist qualifications. The delayed polypectomy bleeding rates were compared between the groups. Delayed polypectomy bleeding was defined as the presence of blood in stools and requiring endoscopic treatment or a decrease in hemoglobin level by 2 g/dL or more. Results: The continuation and withdrawal groups included 134 and 294 patients, respectively. Delayed polypectomy bleeding was observed in 2 patients (1.5%) and 1 patient (0.3%) in the continuation and withdrawal groups, respectively (p = 0.23), before propensity score matching, with no significant difference. After propensity score matching, delayed polypectomy bleeding was observed in 1 patient (0.9%) in the continuation group but not in the withdrawal group, with no significant difference. Conclusion: Cold snare polypectomy during continuous antithrombotic treatment did not significantly increase delayed post-polypectomy bleeding rates. Therefore, this procedure may be safe during continuous antithrombotic treatment.

The Risk of Postpolypectomy Bleeding in Patients Receiving Direct Oral Anticoagulants compared to Warfarin or Nonanticoagulation: A Systematic Review with Meta-Analysis

The aim of our systematic review and meta-analysis was to assess the risk of postpolypectomy bleeding (PPB) in patients exposed to direct oral anticoagulants (DOACs). A systematic search was conducted by searching the PubMed, Embase, and Cochrane Library databases using the following search terms: "(nonvitamin K antagonist oral anticoagulants or NOAC or apixaban or dabigatran or rivaroxaban or edoxaban or DOAC or direct oral anticoagulants) and polypectomy". Studies evaluating the association between DOACs and PPB were identified. The bibliographical search yielded 103 studies. Twelve studies involving 621,279 participants were ultimately included (11 cohort studies, of which 10 were retrospective, and a randomized controlled trial.). Pooled estimates revealed a higher risk of PPB among patients using DOACs than among those without anticoagulation (odds ratio [OR]: 6.170, 95% confidence interval [CI]: 3.079 to 12.363). The same result occurred when DOACs were stopped 24 hours before polypectomy (OR: 8.66, 95% CI: 4.588 to 16.348). No significant difference was noted between overall DOACs and warfarin (OR 0.826, 95% CI 0.583 to 1.172), while for subgroups, dabigatran showed a lower PPB rate than warfarin (OR: 0.582, 95% CI: 0.340 to 0.994). DOACs can significantly raise the risk of PPB, even with 24-hour withdrawal before polypectomy. In addition, a lower risk of PPB was detected for dabigatran than for warfarin.

S161 Cold Snare Endoscopic Mucosal Resection for Colon Polyps: A Systematic Review and Meta-Analysis

Introduction: Cold snare endoscopic mucosal resection (CS-EMR) has become increasingly popular for the removal of colon polyps > 10 mm. CS-EMR can potentially avert some of the risks associated with the use of electrocautery during polyp resection without compromising clinical efficacy. Therefore, we conducted a systematic review and meta-analysis to evaluate the efficacy and safety of CS-EMR in removing colon polyps. Methods: We conducted a comprehensive literature search of MEDLINE, EMBASE, Cochrane, ClinicalTrials.gov, and Scopus databases for studies published in the English language addressing outcomes of CS-EMR for colon polyps from database inceptions through April 2022. The weighted pooled estimates with the 95% confidence interval (CI) were calculated. Cochran Q test and I2 statistics were used to evaluate heterogeneity. Results: We identified 3599 articles on the initial search, and 32 full-text studies were assessed for eligibility. Fifteen studies met inclusion criteria. There were three randomized controlled trials, six prospective, and six retrospective studies. Six studies were from the United States, two each from Australia, China, and Japan, one from the United Kingdom, and one from Greece. A total of 2382 polyps were removed from 1756 patients. 45% were females. Polyps ranged from 6-80 mm in size, and 72.4% were proximal to the splenic flexure. In addition, 50.4% of the polyps were NICE I or serrated lesions and 48.5% were NICE II, and 0.1% were NICE III. Polyp recurrence rate after CS-EMR was 9.4 % (95% CI: 3.3-15.6%, I2= 95.8%), piecemeal resection rate 59.4% (95% CI: 46.3-72.4%, I2= 99.9%), and complete histological resection rate (defined by post polypectomy biopsies) was 93.1% (95% CI: 88.7-97.6%, I2=90.8%). For adverse events, delayed post-polypectomy bleeding rate was 0.8% (95% CI: 0.3-1.3%, I2= 21.4%), perforation and the post-polypectomy syndrome rate was 0.3% (95% CI: 0-0.5%, I2= 0%) (Figure). Given significant heterogeneity in recurrence rate, subgroup analyses were performed. Recurrence rate in serrated lesions (n=484) was 3.8% (95% CI: 0.2-7.4%, I2= 76.7%), in polyps < 20 mm (n= 137) 0.8% (95% CI: -0.7-2.3%, I2= 0%), and in polyps ≥ 20 mm (n=617) 15.7% (95% CI: 2.6-28.7%, I2= 95.2%). Conclusion: CS-EMR has an excellent safety profile and acceptable recurrence rate for resection of colon polyps, especially for polyps < 20 mm and serrated lesions. However, large prospective studies to validate safety and efficacy are needed.Figure 1.: Forest plots of A) recurrence rate, B) complete histological resection, C) delayed post polypectomy bleeding, and D) perforation of cold snare endoscopic mucosal resection in colon polyps

Risk of post-polypectomy bleeding after endoscopic mucosal resection in patients receiving antiplatelet medication: comparison between the continue and hold groups.

Current guidelines recommend continuing aspirin and discontinuing clopidogrel for colon polypectomy, but evidence for endoscopic mucosal resection (EMR) is insufficient. We aimed to assess post-polypectomy bleeding (PPB) in patients receiving antiplatelet agents and underwent EMR for various polyp sizes. A single-center, prospective observational study was performed. Patients who underwent at least one EMR for polypectomy and those who received aspirin or clopidogrel were included. We compared PPB between the antiplatelet hold group (stopped antiplatelet therapy at least 5days before the procedure) and continue group (antiplatelet therapy was maintained or stopped within 5days before the procedure). Among patients who underwent EMR, 305 took aspirin (hold group 257, continue group 48) and 77 took clopidogrel (hold group 66, continue group 11). The mean number of polyps was four, and the mean size was 8.6mm. There was no difference in the major PPB rate between the hold and continue groups among aspirin users (2.0% vs. 4.2%, P = 0.30), but it was significantly higher in the continue group than in the hold group among clopidogrel users (18.2% vs. 0%, P = 0.02). In patient- and polyp-based logistic regression analysis of clopidogrel users, the number of EMRs (OR 2.12, 95% CI 1.16-3.88), polyp size (OR 1.26, 95% CI 1.06-1.49), and continuing clopidogrel (OR 9.75, 95% CI 1.99-47.64) were independent risk factors for PPB. Continuous administration of antiplatelet agents was significantly associated with higher PPB in clopidogrel users, but not in aspirin users. Endoscopists should consider holding clopidogrel if the EMR includes polypectomy.

Timing of Resumption of Anticoagulation After Polypectomy and Frequency of Post-procedural Complications: A Post-hoc Analysis.

Optimal timing for anticoagulation resumption after polypectomy is unclear. We explored the association between timing of anticoagulation resumption and occurrence of delayed post-polypectomy bleeding (PPB) and thromboembolic (TE) events. We performed a post-hoc analysis of patients in an earlier study whose anticoagulants were interrupted for polypectomy. We compared rates of clinically important delayed PPB and TE events in relationship to timing of anticoagulant resumption. Late resumption was defined as > 2days after polypectomy. Among 437 patients, 351 had early and 86 late resumption. Compared to early resumers, late resumers had greater polypectomy complexity. PPB rate was higher (but not significantly) in the late versus early resumers (2.3% vs. 0.9%, 1.47% greater, 95% CI [-2.58 to 5.52], p = 0.26). TE events were more frequent in late versus early resumers [0% vs. 1.2% at 30days, 0% vs. 2.3%, 95% CI 0.3-8, (p = 0.04) at 90days]. On multivariate analysis, timing of restarting anticoagulation was not a significant predictor of PPB (OR 0.97, 95% CI 0.61-1.44, p = 0.897). Significant predictors were number of polyps ≥ 1cm (OR 4.14, 95% CI 1.27-13.66, p = 0.014) and use of fulguration (OR 11.43, 95% CI 1.35-80.80, p = 0.014). Physicians delayed anticoagulation resumption more commonly after complex polypectomies. The timing of restarting anticoagulation was not a significant risk factor for PPB and late resumers had significantly higher rates of TE events within 90days. Considering the potentially catastrophic consequences of TE events and the generally benign outcome of PPBs, clinicians should be cautious about delaying resumption of anticoagulation after polypectomy.

Safety of endoscopic mucosal resection of large colonic polyps in elderly patients: a systematic review and meta-analysis.

BackgroundEndoscopic mucosal resection (EMR) is a procedure commonly used for large sessile and flat polyps. However, it may cause bleeding, perforation, and complications related to anesthesia. There are limited data on the safety and efficacy of EMR in the elderly. Therefore, we conducted a comprehensive review and meta-analysis to assess EMR safety in elderly patients.MethodsWe searched MEDLINE, Embase, Cochrane Central Register of Controlled Trials, and Web of Science Core Collection for studies evaluating EMR for large colorectal lesions (>20 mm) in older patients (75+ years). Our primary result was post-polypectomy bleeding and perforation, while our secondary outcome was recurrence or residual polyp.ResultsThe meta-analysis included 6 studies with 2903 patients. The rate of post-polypectomy bleeding was 5.3% (95% confidence interval [CI] 2.3-11.7%), I2=73.7%; and perforation was 1.9% (95%CI 0.9-3.8%), I2=0%, in patients over 75 years old. The pooled risk of post-polypectomy bleeding was 2.4%, 95%CI 1.2-4.8%, I2=0%; and perforation was 2.1%, 95%CI 0.7-5.8%, I2=8.6%, in patients over 80 years old. The risk of post-polypectomy bleeding (odds ratio [OR] 0.922, 95%CI 0.359-2.367, I2=0%); and perforation (OR 1.066, 95%CI 0.188-6.031, I2=0%) did not differ significantly between patients aged over 80 and younger patients. The pooled rate of residual or recurrence of polyps in patients aged over 80 was significantly higher (25%, 95%CI 17-35.3%, I2=59.5%) vs. younger patients (OR 2.234, 95%CI 1.549-3.223, I2=0%).ConclusionEMR is as safe for the elderly as it is for younger patients, and is not associated with a greater risk of bleeding or perforation.

Clip Closure Does Not Reduce Risk of Bleeding After Resection of Large Serrated Polyps: Results From a Randomized Trial

Serrated polyps are important colorectal cancer precursors and are most commonly located in the proximal colon, where post-polypectomy bleeding rates are higher. There is limited clinical trial evidence to guide best practices for resection of large serrated polyps (LSPs). In a multicenter trial, patients with large (≥20 mm) non-pedunculated polyps undergoing endoscopic mucosal resection (EMR) were randomized to clipping of the resection base or no clipping. This analysis is stratified by histologic subtype of study polyp(s), categorized as serrated [sessile serrated lesions (SSLs) or hyperplastic polyps (HPs)] or adenomatous, comparing clip vs control groups. The primary outcome was severe post-procedure bleeding within 30 days of colonoscopy. A total of 179 participants with 199 LSPs (191 SSLs and 8 HPs) and 730 participants with 771 adenomatous polyps were included in the study. Overall, 5 patients with LSPs (2.8%) experienced post-procedure bleeding compared with 42 (5.8%) of those with adenomas. There was no difference in post-procedure bleeding rates between patients in the clip vs control group among those with LSPs (2.3% vs 3.3%, respectively, difference 1.0%; P= NS). However, among those with adenomatous polyps, clipping was associated with a lower risk of post-procedure bleeding (3.9% vs 7.6%, difference 3.7%; P= .03) and overall serious adverse events (5.5% vs 10.6%, difference 5.1%; P= .01). The post-procedure bleeding risk for LSPs removed via EMR is low, and there is no discernable benefit of prophylactic clipping of the resection base in this group. This study indicates that the benefit of endoscopic clipping following EMR may be specific for >2 cm adenomatous polyps located in the proximal colon. gov, Number: NCT01936948.

Risk factors for post-polypectomy bleeding; a retrospective case-control study of a high-volume colonoscopy center.

Post-polypectomy bleeding (PPB) remains an uncommon although serious complication of colonoscopy. The aim of this study is to determine the PPB-prevalence in a secondary care hospital and its associated risk factors. We collected data from 581 patients, with the removal of 1593 polyps between August 2017 and August 2019. A univariate binary logistic regression analysis was conducted retrospectively. PPB occurred in only 10 cases, representing 1.7% of patients: immediate in 1.2% and delayed in 0.5%. The number of removed polyps per patient [4.5 (SD 2.59) for hemorrhagic vs. 2.74 (SD 1.98) for non-hemorrhagic group] and the propofol dose [232 mg (SD 93.07) for hemorrhagic vs. 133 mg (SD 57.28) for non-hemorrhagic group] were relevant patient-related risk factors. The polyp-based analysis showed the polyp size [18.4 mm (SD 10.44) for hemorrhagic vs. 4.42 mm (SD 4.29) for non-hemorrhagic group], the morphology [wide-based: OR 24.83 (95 % CI 2.76 - 223.44), pedunculated: OR 56.67 (95 % CI 5.03 - 638.29)], the location at ileocecal valve [OR 20.48, 95 % CI 1.81 - 231.97)], and the polypectomy method [hot snare piecemeal with epinephrine injection: OR 75.38 (95 % CI 7.67 - 741.21)] as significant risk factors for PPB, too. The low rate of PPB confirms the safety of the procedure in non-tertiary, high-volume colonoscopy centers. The number of polyps removed per patient, the polyp size, morphology and location, as well as the sedation dose and the method of polypectomy were shown as relevant risk factors.

S1051 Similar Rates of Histologic-Confirmed Recurrence After Endoscopic Mucosal Resection (EMR) of Non-Pedunculated Polyps Among General Gastroenterologists and Advance Endoscopists

Introduction: Endoscopic mucosal resection (EMR) technique is the most common approach for non-pedunculated colonic polyps ≥20 mm. EMR is usually performed by both general gastroenterologists and advance endoscopists. EMR performed by advanced endoscopists have been associated with decreased risk of incomplete polyp resection, but little is known about the recurrence rate of large non-pedunculated polyps performed by general gastroenterologists. Thus, we aim to investigate recurrence rate and EMR characteristics for non-pedunculated polyps ≥20 mm performed by general gastroenterologists. Methods: Retrospective study of patients who undergone EMR of non-pedunculated polyps ≥20 mm at Ben Taub and Veteran’s Affairs (VA) hospital in Houston, Texas from 2012 to 2019. Patients who had two stage procedures, non-neoplastic histology or evidence of invasive cancer were excluded. Patients were divided by type of endoscopist who performed index colonoscopy. Demographic data, polyp and resection characteristics were analyzed. Univariate and multivariate analyzed were performed. Results: A total of 522 non-pedunculated polyps were included from 470 unique patients. 271 polyps had EMR performed by general gastroenterologists and 199 polyps by advance endoscopists. 177 lesions in the general gastroenterologist group completed at least 1 surveillance colonoscopy, 49 (27.7%) had histologic recurrence. 150 lesions in the advance endoscopists group completed at least 1 surveillance colonoscopy, 46 (30.7%) had histologic recurrence. The average polyp size of the cohort was 28.6 mm. Polyps from male patients (85.6% vs 74.4%, P = 0.002) at the VA hospital (82.7% vs 55.3%, P ≤ 0.001) were more likely to be resected by general gastroenterologists. Other demographic characteristics were comparable among groups. There were no significant differences between groups in polyp size, histological recurrence, delayed post-polypectomy bleeding and/or post procedural pain prompting abdominal imaging. Advance endoscopists were more likely to use clips for prophylactic defect closure and less likely to have intraprocedural bleeding (Table 1). Conclusion: General gastroenterologists had a similar recurrence rate after EMR of non-pedunculated polyps ≥20 mm compared with advanced endoscopists. Advance endoscopists had less intraprocedural bleeding but delayed post-polypectomy bleeding rate was comparable.Table 1.: Univariable and multivariable logistic regression analysis of polyp resection characteristics

ID: 3523875 POST-POLYPECTOMY BLEEDING WITH PROPHYLACTIC CLIPS: EAST MEETS WEST

The rate of post-polypectomy bleeding (PPB) per colonoscopy is 0.44%. Studies have shown that PPB rate is affected by polyp size and colon location, but there has been no comparison between population regions. We sought to investigate the PPB difference when prophylactic clips were employed post-polypectomy between East- and West-based populations.

ID: 3521647 EFFECT OF CLIP CLOSURE ON OUTCOMES AFTER RESECTION OF LARGE SERRATED POLYPS: RESULTS FROM A RANDOMIZED TRIAL

Serrated polyps, particularly sessile serrated lesions (SSL), are important colorectal cancer precursors. Endoscopic management of serrated polyps often differs from that of adenomatous polyps due to morphology and other specific endoscopic features. SSLs are most commonly located in the proximal colon, where post-polypectomy bleeding rates are higher. There is limited clinical trial evidence to guide best practices for resection of large serrated polyps.

Risk of postpolypectomy bleeding in patients taking direct oral anticoagulants or clopidogrel

The usage of direct oral anticoagulants (DOACs) to prevent and treat thromboembolic events is gradually increasing. We aimed to evaluate the outcomes of patients taking DOACs after polypectomy. We retrospectively reviewed 131 patients taking DOACs and 270 taking clopidogrel who underwent polypectomy between November 2010 and December 2017. The risk of delayed postpolypectomy bleeding (PPB) was evaluated and compared. A total of 989 polyps were removed (320 polyps in the DOAC and 669 polyps in the clopidogrel group). DOACs and clopidogrel were discontinued for 2.8 ± 1.7 days and 5.8 ± 2.5 days before polypectomy, respectively. DOACs and clopidogrel were restarted on 1.6 ± 2.9 days and 1.7 ± 1.1 days after polypectomy, respectively. According to per polyp analysis, delayed PPB rate was 1.6% in both groups (p = 0.924). Logistic regression analysis was performed after propensity score matching and revealed that DOACs did not increase the delayed PPB risk compared to clopidogrel (OR 0.929, 95% CI 0.436–1.975, p = 0.847). With the majority following the antithrombotic discontinuation guidelines, the incidence of delayed PPB was 3.1% in the patients taking DOACs. The delayed PPB risk was not greater in those taking DOACs than in those taking clopidogrel.

Postpolypectomy bleeding of colorectal polyps in patients with continuous warfarin and short-term interruption of direct oral anticoagulants

Postpolypectomy bleeding (PPB) is the most common adverse event after colorectal polypectomy. Use of anticoagulants is an important risk factor for PPB. This study aimed to evaluate PPB in patients receiving treatment with warfarin and direct oral anticoagulants (DOACs). Between August 2017 and July 2019, 5449 patients with 12,601 polyps who underwent endoscopic snare resection of colorectal polyps were enrolled. Endoscopic snare resection was performed in patients receiving continuous warfarin (C-warfarin) and in patients who experienced 1 day cessation of (O-) of DOACs in accordance with the Japanese Gastroenterological Endoscopy Society guidelines. The PPB rate in the group receiving anticoagulants was statistically higher than that in the group without anticoagulants (8.5% [33/387] vs 1.2% [63/5,062], respectively; P< .001). By multivariate logistic regression analysis, male gender (odds ratio [OR], 2.17; P= .007), warfarin (OR, 4.64; P< .001), DOACs (OR, 6.59; P< .001), and multipolyp removal (OR, 1.77; P= .007) were significant risk factors for PPB. PPB was observed in 9 and 21 patients in the C-warfarin and O-DOACs groups, respectively: C-warfarin (8.0% [9/113]), O-dabigatran (6.1% [2/33]), O-rivaroxaban (14.8% [9/61]), O-apixaban (9.8% [9/92]), and O-edoxaban (1.8% [1/56]). The PPB rate with the O-edoxaban group was significantly lower than that with the O-rivaroxaban group (P< .05). Use of anticoagulant therapy was an independent risk factor for PPB. The rates of PPB in patients receiving C-warfarin and O-DOACs were also higher than those in patients not receiving anticoagulants. Edoxaban may be safe through short-term withdrawal in patients undergoing endoscopic snare resection of colorectal polyps.

S3362 Hermansky-Pudlak Syndrome: A Rare Cause of Postpolypectomy Bleeding: A Case Report and Review of Literature

INTRODUCTION: Post-polypectomy bleeding (PPB) is one of the most common complications of endoscopic therapy. The rate of PPB to be 0.4% per colonoscopy performed in patients at a high risk of colon polyps. However, the risk of post polypectomy bleeding is higher in patients with bleeding diathesis or platelet dysfunction. Here we report an interesting case of PPB in a patient with bleeding diathesis due to Hermansky-Pudlak syndrome. CASE DESCRIPTION/METHODS: A 68 year old Hispanic man of Puerto Rican descent presented to emergency department with 2 day history of small amount of hematochezia twice daily . One day prior to this event he underwent screening colonoscopy which showed 2 polyps (12 and 14 mm in size) which were removed with the help of a hot snare polypectomy. Post- intervention hemostatic clip and epinephrine were injected. Pathology showed inflammatory polyps. He had medical comorbids of hypertension and Hermansky Pudlak Syndrome . On initial examination in the emergency department, patient was afebrile, with stable vital signs. His abdominal examination revealed no tenderness and digital rectal examination showed brown stool with no hematochezia. Rest of the review of systems and physical examination was unremarkable. Laboratory tests showed a decrease in hemoglobin from a baseline of 13 gm/dl to 11.0 gm/dl. Rest of the laboratory work up was unremarkable. Hematology service was consulted in view of underlying condition and advised to give DDAVP (1-desamino-8-D-arginine vasopressin). Patient was admitted to the medicine floor for observation. He did not have any further episodes of rectal bleeding and his hemoglobin level remained stable during this time. Subsequently he was discharged with outpatient gastroenterology follow up. DISCUSSION: Hermansky-Pudlak syndrome(HPS) is a rare autosomal disorder characterized by oculocutaneous albinism, a bleeding diathesis secondary to platelet dysfunction, and other organ involvement specific to certain types including granulomatous colitis and pulmonary fibrosis. HPS is very uncommon with a prevalence of 1 in 1000,000, However, it is common in Puerto Ricans, affecting approximately 1 in 1,800 people. There is no definitive treatment for HPS. Our goal is to guide the appropriate management of these patients specially perioperatively in major and minor procedures such as routine screening colonoscopies to prevent any adverse events.

Mo1754 POST-POLYPECTOMY BLEEDING IN PATIENTS ON DIRECT-ACTING ORAL ANTICOAGULANTS: A SYSTEMATIC REVIEW AND META-ANALYSIS

Since coming into practice in 2010, direct oral anticoagulants (DOACs) have become an increasingly popular form of anticoagulation. However, it is unclear which form of polypectomy intervention or peri-procedural anticoagulation management is best for reducing post-polypectomy bleeding (PPB) risk in the setting of DOAC usage. The aim of our study was to assess the efficacy of polypectomy approaches and management of anticoagulation in minimizing PPB in patients on DOACs. A systematic review of electronic databases was performed through September 2019, including PubMed, MEDLINE, EMBASE, and Cochrane. Two authors independently screened manuscripts and extracted data using Covidence. We included prospective, retrospective, case-control, cohort, and randomized controlled trials that evaluated PPB in patients on DOACs who underwent colonoscopy with polypectomy. The primary outcome was overall PPB rate in patients undergoing snare polypectomy versus endoscopic mucosal resection. We compared approaches to anticoagulation which included heparin bridge, no heparin bridge, and continuation of DOAC. Random effect analyses and 95% confidence intervals (CI) were calculated for all outcomes. Between-study heterogeneity was quantified using the Q statistic and I2 (p<0.05 was considered significant). 973 citations were reviewed, of which 9 were included in the final analysis. The majority were retrospective cohort studies. In total, the studies comprised 2,977 patients with average age of 72.4 years and study follow-up period ranging from 2 to 6 years. Studies defined PPB as hematochezia requiring endoscopic hemostasis occurring 14 to 30 days post endoscopy. Endoscopic submucosal dissection was associated with a significantly higher rate of PPB compared to snare polypectomy. There was a tendency towards higher PPB rates in hot snare versus cold snare polypectomy cases, though this did not reach statistical significance. There were no statistically significant bleeding rates amongst various anticoagulation management strategies. However, PPB effects sizes did tend to be larger in cases where anticoagulation was continued peri-procedurally (Table 1). There was insufficient data to determine the role of prophylactic clips after polypectomy. PPB is a serious adverse effect of colonoscopy. We found that in patients on DOACs, performing endoscopic submucosal dissection is associated with higher PPB rates compared to snare polypectomy. However, for patients at high risk of thromboembolism, our results suggest that continuation of DOAC may not increase the risk of PPB as compared to heparin bridging or discontinuation of anticoagulation altogether. More high-quality studies are needed to further discern amongst various anticoagulation and PPB-prevention strategies.

Colonoscopic post-polypectomy bleeding in patients on uninterruptedclopidogrel therapy: A systematic review and meta-analysis.

Current guidelines recommend temporary cessation of clopidogrel for 7-10 days for patients on clopidogrel undergoing colonoscopy with polypectomy. However, recent prospective randomized controlled trials have advocated for uninterrupted clopidogrel, due to similar post-polypectomy bleeding (PPB) rates with and without continued clopidogrel therapy. Thus, a meta-analysis was conducted to assess the risk of PPB rate in patients on continued clopidogrel therapy. Systemically identified publications were used to compare the rate of PPB in patients on continued clopidogrel therapy with those who had interrupted clopidogrel therapy. The primary outcome was the incidence of PPB. The secondary outcomes were immediate PPB, delayed PPB and serious cardio-thrombotic events. This study has been registered in PROSPERO (no. CRD42018118325). A total of five studies were identified, which included 655 patients in the continued clopidogrel group and 6620 patients in the control group. There was an increased risk of PPB with continued clopidogrel [P=0.0003; risk ratio (RR), 1.96; 95% confidence interval (CI), 1.36-2.83). The rate of immediate PPB was slightly higher in the continued clopidogrel group (5.77% vs. 1.77%, respectively), but was not statistically significant (P=0.06; RR, 1.57; 95%CI, 0.98-2.51). The rate of delayed PPB was increased in the continued clopidogrel group (P=0.0008; RR, 3.10; 95%CI, 1.60-5.98). However, no significant difference in serious cardio-thrombotic events was observed within 30 days (P=0.74; RR, 0.78; 95%CI, 0.18-3.40). Although continued clopidogrel therapy decreased the incidence of serious cardio-thrombotic events, the risk of delayed PPB was increased. Therefore, endoscopists should make all preparations to prevent bleeding in the perioperative period for patients at high thrombotic risk and on continued clopidogrel therapy, if polypectomy cannot be reasonably postponed.

Effect of antiplatelet agent number, types, and pre-endoscopic management on post-polypectomy bleeding: validation of endoscopy guidelines.

It remains unclear whether type of antiplatelet (AP) therapy, AP combination therapy, and AP continuing or switching strategy affect the risk of post-polypectomy bleeding (PPB). In this study, we sought to elucidate this risk. We analyzed 1050 patients who underwent colonoscopic polypectomy: 525 AP users and 525 controls matched for age, sex, comorbidities, concomitant non-steroidal anti-inflammatory drugs use, and polyp characteristics who did not receive antithrombotics. PPB risk was evaluated by AP number, type, and continuing or switching strategies during the peri-endoscopic period. In multivariate analysis, bleeding risk increased significantly as the number of AP agents used increased (monotherapy, adjusted odds ratio [aOR], 3.7; dual antiplatelet therapy (DAPT), 4.6; triple antiplatelet therapy (TAPT), 11.1) compared with controls. With monotherapy, significantly increased PPB risk was found for aspirin (aOR 4.3), thienopyridine (aOR 6.3), and cilostazol (aOR 5.9), but not for eicosapentaenoic acid or other APs (beraprost, limaprost, sarpogrelate, dilazep, or dipyridamole). With DAPT, significantly increased PPB risk was found for combination aspirin plus cilostazol, but not aspirin plus other APs. Bleeding rates for continuing monotherapy were 4.3% for aspirin and 0% for thienopyridine, cilostazol, and other APs, respectively. Analysis of this large polypectomy dataset showed that the use of low-dose aspirin, thienopyridine, or cilostazol and a combination of these is associated with increased PPB risk. Although PPB risk was high with DAPT or TAPT, PPB rate in any antiplatelet monotherapy even with a continuing strategy was low at < 5%.

Training interventions to improve adenoma detection rates during colonoscopy: a systematic review and meta-analysis.

Colonoscopies are effective means of detecting and removing precancerous adenomatous polyps. The adenoma detection rate (ADR) is a marker of colonoscopy quality and an independent predictor of colorectal cancer incidence. Focused training interventions may improve an endoscopist's ADR, but the supporting research is limited. This systematic review and meta-analysis identified, critically appraised, and meta-analyzed data from randomized trials (RCTs) evaluating the effect of training interventions on ADRs. Ovid Medline, EMBASE, CENTRAL, Eric, CINAHL, Scopus, Web of Science, and ClinicalTrials.gov were searched for RCTs investigating the effect of an educational intervention on ADRs. Two reviewers independently screened, identified, and extracted trial-level data. Internal validity was assessed in duplicate using the Risk of Bias tool. Our primary outcome was the ADR. Secondary outcomes were advanced ADR, adenocarcinoma detection rate, polyp detection rate, and withdrawal times. Safety outcomes were post-polypectomy bleeding rate and colonoscopy-related perforation rate. From 2837 screened citations, we identified 3 trials (119 endoscopists) meeting our inclusion criteria. Training interventions were associated with a trend toward increased ADRs (odds ratio 1.16, 95% confidence interval (CI) 1.00-1.34; I2 83%; 3 trials; 119 endoscopists). When limited to screening colonoscopies, the odds ratio for ADRs associated with training interventions was 1.17 (95% CI 1.00-1.36; I2 80%; 3 trials; 119 endoscopists). There was a high level of heterogeneity between the trials' training interventions. Training intervention improved the advanced ADR, adenocarcinoma detection rate, polyp detection rate, and withdrawal times. Safety outcomes were not reported. A focused training intervention was associated with a strong trend toward increased ADRs among certified endoscopists. While the described training interventions definitely show promise, further efforts around continuing professional developments activities are needed to more consistently improve ADRS among certified endoscopists.

182 A Comparison of the Mucosal Defects and Healing by Hot Snare Polypectomy (HSP) vs. Cold Snare Polypectomy (CSP) for Endoscopic Removal of Colorectal Polyps

INTRODUCTION: Screening colonoscopy with polypectomy of small polyp substantially reduces colorectal cancer incidence and mortality. CSP and HSP are two major methods for polypectomy. The basic difference of CSP and HSP is the use of a high frequency generator of HSP. HSP may damage deeper vessels with increased risk of delayed healing, thereby post-polypectomy bleeding and even perforation. For this reason, CSP is usually considered safer, in recent years, CSP has increasingly been used for the removal of colorectal polyps. On the other hand, CSP is concerned associate with a rate of incomplete resection. So far few studies have confirmed endoscopically the early condition after treatment. In this study, through a randomized controlled study, we evaluated to compare mucosal defects and healing one week after treatment, from polypectomy using CSP vs. HSP. METHODS: The 52 patients has tumor size under 10 mm were randomly divided into two groups using opaque envelopes: CP (n = 27) and HP (n = 25). We compared the mean tumor size, ulcer diameter one week after endoscopic treatment, exposed blood vessels, residual recurrence and contingencies for CSP and HSP. Pathological diagnosis of complete resection was defined as no evidence of adenomatous tissue in the biopsied specimens, among all pathologically confirmed adenomatous polyps. RESULTS: The overall the mean tumor size did not differ between the two groups (CSP vs. HSP: 5.44 mm vs. 5.32 mm). Ulcer base diameter one week after treatment is CSP group had a smaller compared to the HSP group (2.7 mm vs. 4.84 mm; P &lt; 0.001). And the CSP group had a lower exposed blood vessels compared to the HSP group (7.4% vs. 36.0%; P &lt; 0.05). Delayed perforation or bleeding was not recognized in any patient during the one weeks after treatment. One case of residual recurrence was admitted to CSP group. CONCLUSION: Our study findings show that although there is no difference tumor diameter between the two techniques, the size of ulcer diameter one weeks after treatment, resection time and the rate of post-polypectomy bleeding is lower with CSP. However remnant recurrence was observed only in CSP. In clinically, CSP can be safely used as one of the effectively techniques for the resection colorectal polyps, but It is important to make an accurate endoscopic diagnosis and exclude cancer before treatment.

Post-polypectomy bleeding in hot-snare polypectomy of colonic polyps under continued warfarin or short interruption of direct oral anticoagulants.

Newly published guidelines of the Japanese Gastroenterological Endoscopy Society (JGES) suggest to consider endoscopic procedures with high risk of bleeding without stopping warfarin and with stopping direct oral anticoagulants (DOACs) only on the day of the procedure. In this study, we aimed to test the validity of these recommendations. We retrospectively reviewed medical records of 344 patients with anticoagulant therapy who underwent hot-snare polypectomy between January 2012 and October 2018. Patients (n= 132) with interruption of anticoagulants (3-7days for warfarin and 2-3days for DOACs before the procedure) and without heparin-bridging were excluded. Among the remaining 212 patients, the incidence of post-polypectomy bleeding was compared between the following 2 patient groups: patients who had interruption of anticoagulants with heparin-bridging (HB group, n= 139) and patients treated according to the new JGES guideline (FG group, n= 73). The rate of post-polypectomy bleeding (PPB) in FG group (9.6%) was not significantly different from that in HB group (12.9%, p = 0.5). In subgroup analysis, the incidence of bleeding in patients with warfarin (12.2%) and with DOAC (6.3%) in FG group was not significantly different from corresponding figures in HB group (14.2%, 0%). In multivariate analysis, number of resected polyps was associated with PPB, but the administration of anticoagulants according to the new guidelines was not a significant risk factor for PPB (p= .98). Our study affirms the recommendations of JGES for the management of anticoagulants in patients who undergo colonic polypectomy regarding post-polypectomy bleeding.