Risk assessment for delayed hemorrhagic complication of colonic polypectomy: polyp-related factors and patient-related factors

Safety and Efficacy of Cold Compared With Hot Endoscopic Mucosal Resection of Large Nonpedunculated Colorectal Polyps: Systematic Review and Meta-Analysis

INTRODUCTION

Endoscopic mucosal resection (EMR) is traditionally performed using electrosurgical cautery (hot snare) to resect premalignant colorectal polyps. Recent data have suggested the superior safety of cold EMR (c-EMR), even for polyps ≥20 mm in size. We aimed to perform a systematic review and meta-analysis to assess the safety and efficacy of c-EMR compared with traditional (hot) EMR (h-EMR).

METHODS

We performed a comprehensive systematic review ending in December 2024. The primary outcome of interest was the odds of delayed bleeding for c-EMR compared with h-EMR of nonpedunculated colorectal polyps ≥20 mm in size. Odds ratios (ORs) with 95% confidence intervals (CIs) are reported. The secondary outcomes included early bleeding, perforation, and polyp recurrence. Publication bias was assessed using the classic fail-safe test. Forest plots were used to report the pooled effect estimates. Heterogeneity was assessed using I2 .

RESULTS

Our systematic review identified 1,632 unique citations, a total of 3 randomized controlled trials and 4 nonrandomized comparative studies were identified and included in the primary analyses. Four additional cohort studies were included in the secondary analyses. On random-effects modeling, c-EMR was associated with a significantly lower risk of delayed bleeding (OR 0.25, 95% CI 0.11-0.57, P = 0.001, I2 = 0%), early bleeding (OR 0.34, 95% CI 0.2-0.6, P < 0.001, I2 = 0%), and perforation (OR 0.14, 95% CI 0.04-0.51, P = 0.003, I2 = 0%) than h-EMR. c-EMR was associated with a higher rate of recurrence (OR 1.81, 95% CI 1.01-3.25, P = 0.045, I2 = 72%).

DISCUSSION

c-EMR has a superior safety profile to h-EMR for nonpedunculated colorectal polyps ≥20 mm in size, but strategies to manage the higher odds of recurrence remain essential.

High Joule heat as a risk factor for post-endoscopic submucosal dissection electrocoagulation syndrome: A multicenter prospective study

BACKGROUND

Thermal damage may lead to inflammation of the peeled mucosal surface during endoscopic submucosal dissection (ESD).

AIM

To determine the effect of Joule heat on the onset of post-ESD electrocoagulation syndrome (PECS).

METHODS

In this prospective study, PECS was characterized by in-hospital fever (white blood cell count: ≥ 10000 μ/L or body temperature ≥ 37.5 °C) and abdominal pain (visual analog scale score ≥ 30 mm during hospitalization or increased by ≥ 20 mm from baseline at admission). High Joule heat was defined as 15390 J. Between April 2020 and April 2024, 209 patients underwent colorectal ESD; those with intraoperative perforation or penetration were excluded. The remaining 202 patients were divided into the PECS and non-PECS groups.

RESULTS

PECS occurred in 30 (14.9%) patients. Multivariate analysis revealed high Joule heat as an independent factor associated with PECS (odds ratio = 7.96; 95% confidence interval: 2.91-21.8, P < 0.01). The procedure time and presence of lesions in the right colon were not associated with PECS.

CONCLUSION

Accumulated thermal damage on the peeled mucosal surface should be considered during PECS onset. This thermal damage is likely a major component of the mechanism underlying PECS.

A dynamic online nomogram for predicts delayed postoperative bleeding after colorectal polyp surgery

This study aims to analyze the risk factors associated with delayed postoperative bleeding (DPPB) following colorectal polyp surgery, develop a dynamic nomogram and evaluate the model efficacy, provide a reference for clinicians to identify the patients at high risk of DPPB. Retrospective study was done on patients who underwent endoscopic colorectal polypectomy at the First Hospital of Lanzhou University from January 2020 to March 2023. Differences between the group with and without DPPB were compared, and independent risk factors for DPPB occurrence were identified through univariate analysis and combination LASSO and logistic regression. A dynamic nomogram was constructed based on multiple logistic regression to predict DPPB following colorectal polyp surgery. Model evaluation included receiver operating characteristic (ROC), Calibration curve, Decision curve analysis (DCA). DPPB occurred in 38 of the 1544 patients included. multivariate analysis showed that direct oral anticoagulants (DOACs), polyp location in the right hemi colon, polyp diameter, drink, and prophylactic hemoclips were the independent risk factors for DPPB and dynamic nomogram were established. Model validation indicated area under the ROC curve values of 0.936, 0.796, and 0.865 for the training set, validation set, and full set, respectively. The calibration curve demonstrated a strong alignment between the predictions of the column-line diagram model and actual observations. The decision curve analysis (DCA) displayed a significant net clinical benefit across the threshold probability range of 0-100%. The dynamic nomogram aids clinicians in identifying high-risk patients, enabling personalized diagnosis and treatment.

Adverse Events after Different Endoscopic Resection Procedures for Small and Intermediate-Sized Colorectal Polyps

INTRODUCTION

Cold snare polypectomy (CSP) and underwater endoscopic mucosal resection (UEMR) have been developed recently, in addition to conventional methods, but adverse events of each method have not been fully clarified. We compared the outcomes of each method for the appropriate choice.

METHODS

Patients who underwent CSP, endoscopic mucosal resection (EMR)/hot snare polypectomy (HSP), or UEMR for small and intermediate-sized colorectal polyps between April 2017 and June 2020 were retrospectively examined. The rate of adverse events and recurrences due to each method were determined as the main outcomes. Clinical factors related to adverse events were examined.

RESULTS

A total of 1,025 patients with 3,163 polyps underwent polypectomy using any of the methods. CSP, EMR/HSP, and UEMR were performed for 704 (22.2%), 2,145 (67.8%), and 314 polyps (9.9%), and the median size for each method was 4, 6, and 7 mm, respectively. Delayed bleeding for CSP, EMR/HSP, and UEMR was 0%, 0.2%, and 0.6% (p = 0.15), and perforation was 0%, 0.1%, and 0%, respectively (p = 0.62). Recurrence after CSP, EMR/HSP, and UEMR was 0.3%, 0.09%, and 1.3%, respectively (p < 0.01). Recurrence for UEMR was significantly higher in the early stage of procedure introduction (p = 0.015). Oral anticoagulants were the risk factor for delayed bleeding (p < 0.01, respectively).

CONCLUSION

There was no significant difference regarding adverse events among each method for small and intermediate-sized polyps, although the recurrence rate after UEMR was higher than other methods.

Risk factors for delayed colorectal postpolypectomy bleeding: a meta-analysis

BACKGROUND

To systematically analyze risk factors for delayed postpolypectomy bleeding (DPPB) in colorectum.

METHODS

We searched seven large databases from inception to July 2022 to identify studies that investigated risk factors for DPPB. The effect sizes were expressed by relative risk (RR) and 95% confidence interval (95% CI). The heterogeneity was analyzed by calculating I2 values and performing sensitivity analyses.

RESULTS

A total of 15 articles involving 24,074 subjects were included in the study. The incidence of DPPB was found to be 0.02% (95% CI, 0.01-0.03), with an I2 value of 98%. Our analysis revealed that male sex (RR = 1.64), history of hypertension (RR = 1.54), anticoagulation (RR = 4.04), polyp size (RR = 1.19), polyp size ≥ 10 mm (RR = 2.43), polyp size > 10 mm (RR = 3.83), polyps located in the right semicolon (RR = 2.48) and endoscopic mucosal resection (RR = 2.99) were risk factors for DPPB.

CONCLUSIONS

Male sex, hypertension, anticoagulation, polyp size, polyp size ≥ 10 mm, polyps located in the right semicolon, and endoscopic mucosal resection were the risk factors for DPPB. Based on our findings, we recommend that endoscopists should fully consider and implement effective intervention measures to minimize the risk of DPPB.

Cold snare defect protrusion and incomplete polyp resection after forced cold snare polypectomy: a prospective observational study

BACKGROUND

Cold snare defect protrusions (CSDPs) that occur after cold snare polypectomy (CSP) are considered indicators of incomplete polyp resection (IPR). We have sometimes experienced difficulty resecting polyps with snaring alone; in such cases, a forcible pull on the snare by the endoscopist is necessary. We call this procedure "forced CSP (FCSP)." However, no previous studies have evaluated this procedure.

METHODS

This was a prospective observational study. From November 2020 to June 2021, the frequency, safety, and validity of FCSP were evaluated at our hospital. We distinguished CSP with snaring alone performed by the assistant as conventional CSP, and CSP requiring a forcible pull on the snare by the endoscopist as FCSP.

RESULTS

Of 1315 polyps removed, 105 underwent FCSP (8%). The perforation rate was 0% in both groups. The rate of CSDP after the procedure was 96.2% (101/105) with FCSP and 6.4% (77/1210) with conventional CSP (P<0.001). The rate of IPR was 12.5% (13/104) with FCSP and 6.2% (75/1208) with conventional CSP (P=0.02). Multivariable analysis identified polyps located in the cecum (risk ratio [RR], 1.13; 95%CI 1.050-1.179; P=0.003) and polyps ≥6mm in diameter (RR, 2.37; 95%CI 2.146-2.542; P<0.001) as independent risk factors for FCSP.

CONCLUSIONS

FCSP was performed on 105 polyps (8%) in this study. FCSP may be associated with the occurrence of CSDP and IPR. Further studies are necessary to confirm our results.

Onset Time and Characteristics of Postprocedural Bleeding after Endoscopic Resection of Colorectal Lesions: A Multicenter Retrospective Study

INTRODUCTION

Postprocedural bleeding is a major adverse event after endoscopic resection of colorectal lesions, but the optimal surveillance time after endoscopy is unclear. In this study, we determined onset time and characteristics of postprocedural bleeding events.

METHODS

We retrospectively screened patients who underwent endoscopic resection of colorectal lesions at three German hospitals between 2010 and 2019 for postprocedural bleeding events using billing codes. Only patients who required re-endoscopy were included for analysis. For identified patients, we collected demographic data, clinical courses, characteristics of colorectal lesions, and procedure-related variables. Factors associated with late-onset bleeding were determined by univariate and multivariate logistic regression analysis.

RESULTS

From a total of 6,820 patients with eligible billing codes, we identified 113 cases with postprocedural bleeding after endoscopic mucosal (61.9%) or snare resection (38.1%) that required re-endoscopy. The median size of the culprit lesion was 20 mm (interquartile range 14-30 mm). The median onset time of postprocedural bleeding was day 3 (interquartile range: 1-6.5 days), with 48.7% of events occurring within 48 h. Multivariate logistic regression analysis demonstrates that a continued intake of antiplatelet drugs (OR: 3.98, 95% CI: 0.89-10.12, p = 0.025) and a flat morphology of the colorectal lesion (OR: 2.98, 95% CI: 1.08-8.01, p = 0.031) were associated with an increased risk for late postprocedural bleeding (>48 h), whereas intraprocedural bleeding was associated with a decreased risk (OR: 0.12, 95% CI: 0.04-0.50, p = 0.001).

CONCLUSION

Significant postprocedural bleeding can occur up to 18 days after endoscopic resection of colorectal lesions, but was predominantly observed within 48 h. Continued intake of antiplatelet drugs and a flat polyp morphology are associated with risk for late postprocedural bleeding.

Novel through-the-scope suture closure of colonic EMR defects (with video)

BACKGROUND AND AIMS

Large colon polyps removed by EMR can be complicated by delayed bleeding. Prophylactic defect clip closure can reduce post-EMR bleeding. Larger defects can be challenging to close using through-the-scope clips (TTSCs), and proximal defects are difficult to reach using over-the-scope techniques. A novel, through-the-scope suturing (TTSS) device allows direct closure of mucosal defects without scope withdrawal. The goal of this study was to evaluate the rate of delayed bleeding after the closure of large colon polyp EMR sites with TTSS.

METHODS

A multicenter retrospective cohort study was performed involving 13 centers. All defect closure by TTSS after EMR of colon polyps ≥2 cm from January 2021 to February 2022 were included. The primary outcome was rate of delayed bleeding.

RESULTS

A total of 94 patients (52% female; mean age, 65 years) underwent EMR of predominantly right-sided (n = 62 [66%]) colon polyps (median size, 35 mm; interquartile range, 30-40 mm) followed by defect closure with TTSS during the study period. All defects were successfully closed with TTSS alone (n = 62 [66%]) or with TTSS and TTSCs (n = 32 [34%]), using a median of 1 (interquartile range, 1-1) TTSS system. Delayed bleeding occurred in 3 patients (3.2%), with 2 requiring repeated endoscopic evaluation/treatment (moderate).

CONCLUSION

TTSS alone or with TTSCs was effective in achieving complete closure of all post-EMR defects, despite a large lesion size. After TTSS closure with or without adjunctive devices, delayed bleeding was seen in 3.2% of cases. Further prospective studies are needed to validate these findings before wider adoption of TTSS for large polypectomy closure.

Underwater versus conventional endoscopic mucosal resection for sessile colorectal polyps: an updated systematic review and meta-analysis

BACKGROUND

underwater endoscopic mucosal resection (uEMR) without submucosal injection for sessile colorectal polyps was introduced as a new replacement for conventional EMR (cEMR). However, the optimal resection strategy remains a topic of debate. Hence, this meta-analysis was performed to compare the efficacy and safety of uEMR and cEMR in patients with sessile colorectal polyps.

METHODS

a comprehensive search of the literature from 2000 till January 2022 was performed from Medline, CENTRAL and Embase for randomized controlled trials (RCTs) comparing cEMR vs uEMR for colorectal polyps. The evaluated outcomes included en bloc resection, R0 resection, procedure time, overall bleeding and recurrence. Pooled risk ratios (RR) with 95 % confidence interval were calculated using a random effect model.

RESULTS

six studies were included, out of which four were full-text articles and two were conference abstracts. En bloc resection (RR 1.26, 95 % CI: 1.00-1.60), R0 resection (RR 1.10, 95 % CI: 0.96-1.26), overall bleeding (RR 0.85, 95 % CI: 0.54-1.34) and recurrence rate (RR 0.75, 95 % CI: 0.45-1.27) were comparable between uEMR and cEMR. However, uEMR was associated with a shorter procedure time (mean difference [MD] -1.55 minutes, 95 % CI: -2.71 to -0.39). According to the subgroup analysis, uEMR led to a higher rate of en bloc resection (RR 1.41, 95 % CI: 1.07-1.86) and R0 resection (RR 1.19, 95 % CI: 1.01-1.41) for polyps ≥ 10 mm in size.

CONCLUSION

both uEMR and cEMR have a comparable safety and efficacy. For polyps larger than 10 mm, uEMR may have an advantage over cEMR and should be the topic for future studies.

Efficacy and Safety of Gel Immersion Endoscopic Mucosal Resection for Non-Pedunculated Colorectal Polyps

Underwater endoscopic mucosal resection (UEMR) has become a popular endoscopic resection method for large colorectal neoplasms. However, visualization can be poor during UEMR due to the presence of intestinal fluid. Gel immersion endoscopic mucosal resection (GIEMR), using a specially developed gel (Viscoclear®, Otsuka Pharmaceutical Factory, Tokushima, Japan), can improve the visual field. However, reports of GIEMR for colorectal polyps are limited. Herein, we evaluated the short-term outcomes of GIEMR for non-pedunculated colorectal neoplasms (NPCRN). This single-center, retrospective, and observational study includes 25 lesions in 20 patients with NPCRN who underwent GIEMR between January and October 2022. The short-term outcomes and adverse events were evaluated. The lesion locations were as follows: right colon, 18 lesions; left colon, 7 lesions; and rectum, none. The median tumor diameter was 15 (IQR, 10–18) mm. Histological classification was as follows: sessile serrated lesion, 9 cases; adenoma, 12 cases; and intramucosal adenocarcinoma, 4 cases. The overall en bloc resection rates and R0 resection rates were 80% (20/25) and 72% (18/25). For NPCRN in 10–19 mm, the en bloc resection rate was 75% (12/16), with an R0 resection rate of 69% (11/16). No post-polypectomy bleeding, perforation, or post-coagulation syndrome were observed. The findings of our study provide preliminary evidence of the efficacy and safety of GIEMR for NPCRN. Therefore, GIEMR may be a promising novel endoscopic resection method for NPCRN.

Risk of Delayed Bleeding after Cold Snare Polypectomy in Patients with Antithrombotic Therapy

BACKGROUND

Cold snare polypectomy is being increasingly adopted; however, there are few reports of cold snare polypectomy regarding antithrombotic therapy.

AIMS

This study aimed to investigate the real-world safety of cold snare polypectomy during antithrombotic therapy.

METHODS

We collected data from consecutive patients undergoing cold snare polypectomy in a single hospital between 2013 and 2017. Indications for cold snare polypectomy were any ≤ 10 mm polyp. The primary outcome was delayed bleeding. We compared rates of delayed bleeding between patients with and without antithrombotic therapy and analyzed risk factors for delayed bleeding using binary logistic regression model with firth procedure.

RESULTS

In 2152 patients (mean age 67.6 years; male 1411), 4433 colorectal polyps (mean diameter 5.0 mm) underwent cold snare polypectomy. Clipping during the procedure was performed for 5.8%. Delayed bleeding occurred in 0.51% (11/2152) of patients and 0.25% (11/4433) of polyps, but no major delayed bleeding occurred. A total of 244 (11%) patients received antithrombotic therapy. Patients on antithrombotic therapy were older (p < 0.001), more likely male (p < 0.001) and had cold snare polypectomy in the proximal colon (p = 0.011). The rate of delayed bleeding was higher in patients on antithrombotic therapy (1.64% vs. non-antithrombotic therapy 0.37%, p = 0.009). Larger polyp size (> 5 mm), use of clips, and antithrombotic therapy were significant risk factors for delayed bleeding. There was no clear association between specific antithrombotic agents and delayed bleeding.

CONCLUSIONS

Delayed bleeding after cold snare polypectomy was rare even in patients with antithrombotic therapy, and no major delayed bleeding occurred.

Patient Selection, Risks, and Long-Term Outcomes Associated with Colorectal Polyp Resection

The 2 most significant complications of colonoscopy with polypectomy are bleeding and perforation. Although the incidence rates are generally low (<1%), these can be avoided by recognizing pertinent risk factors, which can be patient, polyp, and technique/device related. Endoscopists should be equipped to manage bleeding and perforation. Currently available devices and techniques to achieve hemostasis and manage colon perforations are reviewed.

Postpolypectomy fever in patients with serious infection: a report of two cases

BACKGROUND

Postpolypectomy fever (PPF) is a rare complication in patients after colonoscopy. Because of the absence of evidence of microperforation and abdominal tenderness, patients with PPF usually present mild clinical symptoms with a good prognosis.

CASE PRESENTATION

In this study, all patients who underwent colonoscopic examination in our hospital between January 2019 and December 2019 were enrolled. Of these, two patients developed PPF after polypectomy, exhibiting serious infection without definitive fever foci. One patient experienced rapidly aggravated type 1 respiratory failure and abnormal hepatic function, which were attributed to colonoscopy-associated infection. After active antibiotic therapy, both patients were discharged without any complications.

CONCLUSIONS

In summary, our study provides novel insights into patients with PPF who develop serious infections with life-threatening complications.

Prophylactic clip closure for mucosal defects is associated with reduced adverse events after colorectal endoscopic submucosal dissection: a propensity-score matching analysis

Background

It is unclear whether prophylactic endoscopic closure after colorectal endoscopic submucosal dissection (ESD) reduces the risk of postoperative adverse events due to variability in lesion characteristics. Therefore, we conducted a retrospective study using propensity score matching to evaluate the efficacy of prophylactic clip closure in preventing postoperative adverse events after colorectal ESD.

Methods

This single-center retrospective cohort study included 219 colorectal neoplasms which were removed by ESD. The patients were allocated into the closure and non-closure groups, which were compared before and after propensity-score matching. Post-ESD adverse events including major and minor bleeding and delayed perforation were compared between the two groups.

Results

In this present study, 97 and 122 lesions were allocated to the closure and non-closure groups, respectively, and propensity score matching created 61 matched pairs. The rate of adverse events was significantly lower in the closure group than in the non-closure group (8% vs. 28%, P = 0.008). Delayed perforation occurred in two patients in the non-closure group, whereas no patient in the closure group developed delayed perforation. In contrast, there were no significant differences in other postoperative events including the rate of abdominal pain; fever, white blood cell count, and C-reactive protein; and appetite loss between the two groups.

Conclusions

Propensity score matching analysis demonstrated that prophylactic closure was associated with a significantly reduced rate of adverse events after colorectal ESD. When technically feasible, mucosal defect closure after colorectal ESD may result in a favorable postoperative course.

Delayed Bleeding After Endoscopic Resection of Colorectal Polyps: Identifying High-Risk Patients

Delayed post-polypectomy bleeding (DPPB) is a potentially severe complication of therapeutic colonoscopy which can result in hospital readmission and re-intervention. Over the last decade, rates of DPPB reported in the literature have fallen from over 2% to 0.3–1.2%, largely due to improvements in resection technique, a shift towards cold snare polypectomy, better training, adherence to guidelines on periprocedural antithrombotic management, and the use of antithrombotics with more favourable bleeding profiles. However, as the complexity of polypectomy undertaken worldwide increases, so does the importance of identifying patients at increased risk of DPPB. Risk factors can be categorised according to patient, polyp and personnel related factors, and their integration together to provide an individualised risk score is an evolving field. Strategies to reduce DPPB include safe practices relevant to all patients undergoing colonoscopy, as well as specific considerations for patients identified to be high risk. This narrative review sets out an evidence-based summary of factors that contribute to the risk of DPPB before discussing pragmatic interventions to mitigate their risk and improve patient safety.

Endoscopic management of delayed bleeding after polypectomy of small colorectal polyps: two or more clips may be safe

Background

The resection of small colorectal polyps (≤10 mm) is routine for endoscopists. However, the management of one of its main complications, namely delayed (within 14 days) postpolypectomy bleeding (DPPB), has not been clearly demonstrated. We aimed to assess the role of coloscopy in the management of DPPB from small colorectal polyps and identify the associated factors for initial hemostatic success.

Methods

We conducted a retrospective study of 69 patients who developed DPPB after the removal of colorectal polyps of ≤10 mm and underwent hemostatic colonoscopy at the Sixth Affiliated Hospital of Sun Yat-sen University (Guangzhou, China) between April 2013 and June 2021. Demographics, clinical variables, and colonoscopic features were collected independently. We applied univariate and multivariate analyses to assess factors associated with initial hemostatic success.

Results

General colonoscopy without oral bowel preparation was successfully performed in all the patients, with a median duration of 23.9 (12.5–37.9) minutes. Among 69 patients, 62 (89.9%) achieved hemostasis after initial hemostatic colonoscopy and 7 (10.1%) rebled 2.7 ± 1.1 days after initial colonoscopic hemostasis and had rebleeding successfully controlled by one additional colonoscopy. No colonoscopy-related adverse events occurred. Multivariate analysis showed that management with at least two clips was the only independent prognostic factor for initial hemostatic success (odds ratio, 0.17; 95% confidence interval, 0.03–0.91; P = 0.04). All the patients who had at least two clips placed at the initial hemostatic colonoscopy required no further hemostatic intervention.

Conclusions

Colonoscopy is a safe, effective, and not too time-consuming approach for the management of patients with DPPB of small colorectal polyps and management with the placement of at least two hemoclips may be beneficial.

High total Joule heat increases the risk of post-endoscopic submucosal dissection electrocoagulation syndrome after colorectal endoscopic submucosal dissection

BACKGROUND

We hypothesized that thermal damage accumulation during endoscopic submucosal dissection (ESD) causes the pathogenesis of post-ESD electrocoagulation syndrome (PECS).

AIM

To determine the association between Joule heat and the onset of PECS.

METHODS

We performed a retrospective cohort study in patients who underwent colorectal ESD from May 2013 to March 2021 in Japan. We developed a novel device that measures swift coagulation time with a sensor adjacent to the electrosurgical coagulation unit foot switch, which enabled us to calculate total Joule heat. PECS was defined as localized abdominal pain (visual analogue scale ≥ 30 mm during hospitalization or increased by ≥ 20 mm from the baseline) and fever (temperature ≥ 37.5 degrees or white blood cell count ≥ 10000 µ/L). Patients exposed to more or less than the median Joule heat value were assigned to the high and low Joule heat groups, respectively. Statistical analyses included Mann-Whitney U and chi-square tests and logistic regression and receiver operating characteristic curve (ROC) analyses.

RESULTS

We evaluated 151 patients. The PECS incidence was 10.6% (16/151 cases), and all patients were followed conservatively and discharged without severe complications. In multivariate analysis, high Joule heat was an independent PECS risk factor. The area under the ROC curve showing the correlation between PECS and total Joule heat was high [0.788 (95% confidence interval: 0.666-0.909)].

CONCLUSION

Joule heat accumulation in the gastrointestinal wall is involved in the onset of PECS. ESD-related thermal damage to the peeled mucosal surface is probably a major component of the mechanism underlying PECS.

In situ gelling and dissolvable hydrogels for use as on-demand wound dressings for burns

Currently, no dressings utilized in burn clinics provide adhesion, hydration or mechanical strength on the same order as human skin as well as the ability to be atraumatically removed. We report the synthesis, characterization, and in vivo evaluation of in situ polymerized and subsequent dissolvable hydrogels as burn wound dressings. Hydrogel dressings, from a small library of synthesized materials form in situ, exhibit storage moduli between 100-40 000 Pa, dissolve on-demand within 10 minutes to 90 minutes, swell up to 350%, and adhere to both burned and healthy human skin at 0.2-0.3 N cm-2. Further, results from an in vivo porcine second degree burn model demonstrate functional performance with healing equivalent to conventional treatments with the added benefit of facile, in situ application and subsequent removal via dissolution.

Complications of colonoscopy in Japan: An analysis using large-scale health insurance claims data

BACKGROUND AND AIM

In Japan, screening colonoscopy for colorectal cancer is expected to reduce colorectal cancer mortality, although its complication rate has not been sufficiently examined. The aim of this study is to analyze severe complications due to colonoscopy.

METHODS

As a study population, we retrospectively used commercially anonymized health insurance claims data covering 5.71 million patients from January 2005 to August 2018. We extracted patients who received colonoscopy with lesions resection or without treatment. Main outcomes were rates of hemorrhage, perforation, fatal events, and their risk factors.

RESULTS

Among 341 852 colonoscopy without treatment in 260 128 patients (mean age: 49.6 ± 11.7 years), the rates of hemorrhage, perforation, and fatal events were 0.0059% (95% confidence interval [CI] 0.0031-0.0085), 0.0032% (95% CI 0.0011-0.0052), and 0.00029% (95% CI 0-0.0012), respectively. Regarding hemorrhage, compared with the rate for patients <50 years old (0.0050%), the rates for those 50-59, 60-69, and ≥70 years old were 0.0095% (P = 0.17), 0.0031% (P = 0.17), and 0%, respectively. Regarding perforation, compared with patients <50 years old (0.0056%), the rates for those 50-59, 60-69, and ≥70 years old were 0%, 0.0015% (P = 0.99), and 0.0102% (P = 0.99), respectively. A multivariate analysis for risk factors showed no significant findings for hemorrhage and perforation without treatment. Among 123 087 colonoscopy with lesions resection in 102 058 patients (mean age: 53.7 ± 9.3 years), the rates of hemorrhage, perforation, and fatal events were 0.136% (95% CI 0.1157-0.1572), 0.033% (95% CI 0.0228-0.0437), and 0.00081% (95% CI 0-0.0035), respectively.

CONCLUSIONS

The analysis using health insurance claims data demonstrated the safety of colonoscopy.

Endoscopic characteristics influencing postpolypectomy bleeding in 1147 consecutive pedunculated colonic polyps: a multicenter retrospective study

BACKGROUND AND AIMS

Postpolypectomy bleeding is the most common adverse event with pedunculated polyps. We clarified the endoscopic characteristics influencing postpolypectomy bleeding for pedunculated colonic polyps.

METHODS

We reviewed clinical data for 1147 pedunculated colonic polyps removed by polypectomy in 5 Japanese institutions. Pedunculated polyps were defined as polyps with a stalk length ≥5 mm. Analyzed clinical data were age, sex, polyp location/size, stalk length/width, prophylactic clipping or endoloop before polypectomy, injecting the stalk, closing the polypectomy site, antithrombotic agent use, and endoscopist experience. Postpolypectomy bleeding was classified as immediate bleeding or delayed bleeding.

RESULTS

Immediate and delayed bleeding was observed in 8.5% (97/1147) and 2% (23/1147) of polypectomies, respectively. Comparing immediate bleeding with nonbleeding, multivariate analysis showed that stalk width ≥6 mm (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.1-3.4) was a significant risk factor for immediate bleeding. For polyp size ≥15 mm, prophylactic endoloop use (OR, .17; 95% CI, .04-.72) was a significant inhibiting factor. Comparing delayed bleeding with nonbleeding, multivariate analysis showed that prophylactic clipping before polypectomy (OR, 4.2; 95% CI, 1.3-13) and injecting the stalk (OR, 4.0; 95% CI, 1.4-12) were significant risk factors for delayed bleeding.

CONCLUSIONS

The increased risk for delayed bleeding with injecting the stalk and prophylactic clipping before polypectomy suggests that simple resection with coagulation mode is a suitable strategy in endoscopic resection of pedunculated polyps. Moreover, prophylactic endoloop use was highly likely to inhibit immediate bleeding with polyp size ≥15 mm.

Risk of delayed bleeding after hot snare polypectomy and endoscopic mucosal resection in the colorectum with continuation of anticoagulants

Background

Current guidelines recommend the temporary discontinuation of anticoagulants before colonoscopic polypectomy, but the effect of this practice on reducing the risk of delayed bleeding after hot snare polypectomy (HSP) and endoscopic mucosal resection (EMR) remains unclear. Our aim was to assess the impact of anticoagulants on the risk of colorectal delayed bleeding after HSP and EMR, and evaluate the necessity of drug withdrawal.

Methods

We reviewed the clinical data of patients with colorectal polyps using antithrombotic drugs who underwent HSP and/or EMR between January 2016 and September 2020 at Nagaoka Red Cross Hospital. After excluding antiplatelet users, patients were classified into those who continued anticoagulants [continuation group: 50 patients (93 lesions)] and those who discontinued anticoagulants [discontinuation group: 87 patients (190 lesions)].

Results

Delayed bleeding occurred in 12 lesions, and there was no significant difference in the incidence rates between the continuation and the discontinuation groups (3.2% vs. 4.7%; P=0.756). Logistic regression analysis showed that continued use of anticoagulants was not a significant risk factor for delayed bleeding compared to anticoagulant discontinuation (odds ratio, 0.670; 95% CI, 0.177-2.537; P=0.556). There was no significant difference in the incidence rate and risk of delayed bleeding, regardless of the length of the anticoagulant withdrawal period.

Conclusions

Continued use of anticoagulants, compared to their discontinuation, did not increase the risk of colorectal delayed bleeding after HSP and EMR. Our results suggest that current guideline recommendations for anticoagulant withdrawal before colonoscopic polypectomy may be reconsidered.

Trial Registration

UMIN000040449.

Temporary In Situ Hydrogel Dressings for Colon Polypectomies

Currently, no dressings are utilized after removal of polyps during a colonoscopy rendering these tissue sites susceptible to bleeding, sepsis, and perfusion. We report the design specifications, synthesis, and ex vivo evaluation of in situ polymerized hydrogels as colon wound dressings post polypectomy. The hydrogels exhibited varied properties to include moduli between 100 and 16 000 Pa, dissolution times between 4 h to 7 days or longer, swelling up to 200%, and adhesion to colon tissue from 0.1 to 0.4 N/cm². The hydrogels displayed minimal cytotoxicity, prevented the migration/spread of bacteria, and exhibited rapid gelation, a requirement for application to the lumen of the colon via an endoscope. This work highlights the structure-property relationship of hydrogels prepared from N-hydroxysuccinimide functionalized PEG cross-linkers and hyperbranched polyethylenimines or 4-arm PEG-NH₂ star polymers, and their potential as colon wound dressings.

Child-Pugh B or C Cirrhosis Increases the Risk for Bleeding Following Colonoscopic Polypectomy

Background/Aims

The risk for colonoscopic postpolypectomy bleeding (PPB) in patients with chronic liver disease (CLD) remains unclear. We determined the incidence and risk factors for colonoscopic PPB in patients with CLD, especially those with liver cirrhosis.

Methods

We retrospectively reviewed the medical records of patients with CLD who underwent colonoscopic polypectomy at Seoul National University Hospital between 2011 and 2014. The study endpoints were immediate and delayed PPB.

Results

A total of 1,267 consecutive patients with CLD were included in the study. Immediate PPB occurred significantly more often in the Child-Pugh (CP) B or C cirrhosis group (17.5%) than in the CP-A (6.3%) and chronic hepatitis (4.6%) groups (p<0.001). Moreover, the incidence of delayed PPB in the CP-B or C cirrhosis group (4.4%) was significantly higher than that in the CP-A (0.7%) and chronic hepatitis (0.2%) groups (p<0.001). The independent risk factors for immediate PPB were CP-B or C cirrhosis (p=0.011), a platelet count <50,000/μL (p<0.001), 3 or more polyps (p=0.017), endoscopic mucosal resection or submucosal dissection (p<0.001), and polypectomy performed by trainees (p<0.001). The independent risk factors for delayed PPB were CP-B or C cirrhosis (p=0.009), and polyps >10 mm in size (p=0.010).

Conclusions

Patients with CP-B or C cirrhosis had an increased risk for bleeding following colonoscopic polypectomy.

Prophylactic clipping after endoscopic mucosal resection of large nonpedunculated colorectal lesions: A meta-analysis

BACKGROUND AND AIM

It is not clear whether prophylactic clipping after endoscopic mucosal resection (EMR) of large nonpedunculated colorectal lesions (LNPCLs) prevents delayed bleeding (DB). We aimed to conduct a meta-analysis to clarify the efficacy of prophylactic clipping in prevention of DB following EMR of LNPCLs.

METHODS

We searched PubMed, EMBASE, Web of Science, ScienceDirect, Cochrane Library databases, and ClinicalTrials.gov for studies that compared clipping versus (vs) nonclipping in prevention of DB following EMR of LNPCLs. Pooled odds ratio (OR) was determined using a random effects model. The pooled ORs of DB, perforation, and post-polypectomy syndrome in the clipping group compared with the nonclipping group comprised the outcomes. Subgroup analyses based on study design, polyp location, and completeness of wound closure were performed.

RESULTS

Five studies with a total of 3112 LNPCLs were extracted. Prophylactic clipping reduced the risk of DB compared with nonclipping (3.3% vs 6.2%, OR: 0.494, P = 0.002) following EMR of LNPCLs. In subgroup analysis, prophylactic clipping reduced DB of LNPCLs at proximal location (3.8% vs 9.8%, P = 0.029), but not of them at distal location (P = 0.830). Complete wound closure showed superior efficacy to prevent DB compared with partial closure (2.0% vs 5.4%, P = 0.004). No benefit of clipping for preventing perforation or post-polypectomy syndrome was observed (P = 0.301 and 0.988, respectively).

CONCLUSIONS

Prophylactic clipping can reduce DB following EMR of LNPCLs at proximal location. Besides, complete wound closure showed superior efficacy to prevent DB compared with partial closure. Further cost analyses should be conducted to implement the most cost-effective strategies.

Prophylactic clipping to prevent delayed colonic post-polypectomy bleeding: meta-analysis of randomized and observational studies

BACKGROUND AND AIMS

Delayed post-polypectomy bleeding (DPPB) is a commonly described adverse event following polypectomy. Prophylactic clipping may prevent DPPB in some patient subgroups. We performed a meta-analysis to assess both the efficacy and real-world effectiveness of prophylactic clipping.

METHODS

We performed a database search through March 2020 for clinical trials or observational studies assessing prophylactic clipping and DPPB. Pooled risk ratios (RR) were calculated using random effects models. Subgroup, sensitivity, and meta-regression analyses were performed to elucidate clinical or methodological factors associated with effects on outcomes.

RESULTS

A total of 2771 citations were screened, with 11 randomized controlled trials (RCTs) and 9 observational studies included, representing 24,670 colonoscopies. DPPB occurred in 2.0% of patients overall. The pooled RR of DPPB was 0.47 (95% CI 0.29-0.77) from RCTs enrolling only patients with polyps ≥ 20 mm. Remaining pooled RCT data did not demonstrate a benefit for clipping. The pooled RR of DPPB was 0.96 (95% CI 0.61-1.51) from observational studies including all polyp sizes. For patients with proximal polyps of any size, the RR was 0.73 (95% CI 0.33-1.62) from RCTs. Meta-regression confirmed that polyp size ≥ 20 mm significantly influenced the effect of clipping on DPPB.

CONCLUSION

Pooled evidence demonstrates a benefit when clipping polyps measuring ≥ 20 mm, especially in the proximal colon. In lower-risk subgroups, prophylactic clipping likely results in little to no difference in DPPB.

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

BACKGROUND AND AIMS

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).

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Role of prophylactic hemoclip placement in prevention of delayed post-polypectomy bleeding for large colon polyps: a meta-analysis of randomized controlled trials

Background

Polypectomy is a widely used and effective procedure to treat precancerous polyps. Delayed post-polypectomy bleeding (DPPB), a common complication of polypectomy, may diminish the utility of this procedure. Previous data on the efficacy of hemoclips has been conflicting, therefore we aimed to collectively evaluate and analyze the data to reach a definitive conclusion on the efficacy of using hemoclips to prevent incidences of DPPB in patients with large polyps (≥10 mm).

Methods

We identified a total of 261 studies based on our previously defined search strategy. After screening, we included 6 randomized controlled trials. A meta-analysis was performed comparing the use of prophylactic application of hemoclips to a standard group without prophylactic clip placement for large polyps.

Results

We found a statistically significant reduction in the incidence of DPPB when using hemoclips for large polyps. The overall incidence of DPPB was lower in the hemoclip group compared to the standard group for all large polyps ≥10 mm (relative risk 0.51, 95% confidence interval 0.35-0.75; P=0.01; I ²=0%).

Conclusions

The use of hemoclips in achieving hemostasis for large polyps has a beneficial effect and appears to prevent DPPB. This reinforces the routine clinical practice of using hemoclips in polypectomy procedures.

Is Submucosal Injection Helpful in Cold Snare Polypectomy for Small Colorectal Polyps?

BACKGROUND/AIMS

Cold snare polypectomy (CSP) is an effective method of polyp removal for small colorectal polyps. However, the effect of submucosal injection in cold snare endoscopic mucosal resection (CS-EMR) for small polyps is unclear. Therefore, this study aimed to evaluate the effect of submucosal injection in CS-EMR for small polyps.

METHODS

Between 2018 and 2019, 100 consecutive small colorectal polyps (5-10 mm) were identified in 58 patients. The first 50 consecutive polyps were removed by CS-EMR, and the remaining 50 were removed by CSP. Demographic data, clinical data, endoscopic findings, procedure times, complication rates, and pathology data were collected.

RESULTS

No difference in the complete resection rate was observed between the CS-EMR and CSP groups. A total of 9 polyps showed post-polypectomy bleeding (7 had immediate bleeding, 1 had delayed bleeding, and 1 had both immediate and delayed bleeding). No difference in the bleeding rate was observed between the two groups. In multivariate analysis, warfarin (odds ratio [OR], 42.334; 95% confidence interval [CI], 1.006-1,781.758) and direct-acting oral anticoagulants (OR, 35.244; 95% CI, 3.853-322.397) showed a significantly increased risk of bleeding.

CONCLUSION

The effect of submucosal injection in CSP was not significant for small colorectal polyps.

Prophylactic clipping not effective in preventing post-polypectomy bleeding for < 20-mm colon polyps: A multicenter, open-label, randomized controlled trial

BACKGROUND AND AIM

Prophylactic clipping (PC) after polypectomy has the potential to prevent post-polypectomy bleeding (PPB). We aimed to evaluate the effectiveness of PC in preventing PPB for < 20-mm polyps.

METHODS

This multicenter, open-label, randomized controlled trial conducted from December 2013 to June 2017 at 10 institutions randomly assigned 1080 patients with < 20-mm colon polyps to the non-PC and PC groups. Allocation factors were institution, antiplatelet drug use, and polyp number. The primary endpoint was differences in PPB rates between the groups. The severity of PPB and post-procedural abdominal symptoms were also investigated. These endpoints in intention-to-treat and per-protocol (PP) analyses were evaluated.

RESULTS

We investigated 1039 patients with 2960 lesions. There was no significant difference between the groups in characteristics including age, sex, hypertension, diabetes, hyperlipidemia, antiplatelet drug use, and lesion characteristics such as type and size. Excluding the clip used in the non-PC group, intraoperative bleeding, and deviation of protocol, 903 patients were investigated in PP analysis. There was no significant difference in the PPB rate between the non-PC and PC groups (2.7% vs 2.3%, P = 0.6973 [intention-to-treat analysis]; 3.0 vs 2.4%, P = 0.7353 [PP analysis]). Severe PPB (≥ grade 3) was similar between the groups. Total procedure time was significantly shorter in the non-PC group than in the PC group (31 vs 36 min, P = 0.0002). Post-procedural abdominal fullness was less common in the non-PC group than in the PC group (20.8% vs 25.6%, P = 0.0833).

CONCLUSION

Prophylactic clipping is not effective in preventing PBB for < 20-mm colon polyps (UMIN000012163).

The risk of post-polypectomy bleeding among patients receiving antithrombotic agents: A prospective observational study

BACKGROUND

In July 2012, the Japan Gastroenterological Endoscopy Society updated their guidelines for gastroenterological endoscopy in patients receiving antithrombotic therapy. Colonoscopic polypectomy procedures are associated with a high risk of bleeding.

OBJECTIVES

The present study evaluated the safety of colonoscopic polypectomy procedures in terms of bleeding, among patients receiving antithrombotic therapy.

DESIGN AND SETTING

Prospective observational study conducted in a tertiary-level public cardiovascular hospital in Istanbul, Turkey.

METHODS

Colonoscopic polypectomies carried out in a single endoscopy unit between July 2018 and July 2019 were evaluated prospectively. The patients' data, including age, gender, comorbidities, whether antithrombotic drug use was ceased or whether patients were switched to bridging therapy, polyp size, polyp type, polyp location, histopathology, resection methods (hot snare, cold snare or forceps) and complications relating to the procedures were recorded.

RESULTS

The study was completed with 94 patients who underwent a total of 167 polypectomy procedures. As per the advice of the physicians who prescribed antithrombotic medications, 108 polypectomy procedures were performed on 60 patients without discontinuing medication and 59 polypectomy procedures were performed on 34 patients after discontinuing medication. The age, gender distribution and rate of bleeding did not differ significantly between the patients whose medication was discontinued and those whose medication was continued (P > 0.05).

CONCLUSION

This study found that the colonoscopic polypectomy procedure without discontinuation of antithrombotic medication did not increase the risk of bleeding. This procedure can be safely performed by experienced endoscopists in patients with an international normalized ratio (INR) below 2.5.

Risk of colonoscopic post-polypectomy bleeding in patients after the discontinuation of antithrombotic therapy

BACKGROUND/AIMS

Few studies have examined the incidence of post-polypectomy bleeding (PPB) after discontinuation of antithrombotic therapies. Therefore, this study aimed to evaluate the incidence of PPB and thromboembolic events in patients whose antithrombotic agents were discontinued before colonoscopy.

MATERIALS AND METHODS

We retrospectively selected all patients who underwent colon polypectomy at a community hospital. A total of 282 patients (540 polypectomies) discontinued antithrombotic agents (group 1), and 1,648 patients (2,827 polypectomies) did not take antithrombotic agents (group 2). The cessation periods before and after polypectomies were 4 and 3 days for warfarin, 5 and 3 days for anti-platelet agents, and 7 and 5 days of combination therapy, respectively. Main outcome measurements were the incidence of PPB and thromboembolic events.

RESULTS

Immediate PPB rates were 3.9% (11/282) in group 1 and 4.6% (76/1648) in group 2 (adjusted odds ratio [OR], 0.85; 95% confidence interval [CI], 0.42-1.72; p=0.65). Delayed PPB rates were 1.4% (4/282) in group 1 and 1.1% (18/1648) in group 2 (adjusted OR, 1.24; 95% CI, 0.36-4.24; p=0.732). No thromboembolic events were observed in either group.

CONCLUSION

Our cessation periods were appropriate, and further shortening of these periods is possible.

Blood group O is a risk factor for delayed post-polypectomy bleeding

BACKGROUND

Blood group O of ABO blood group system is considered as a risk factor for various bleeding events, but the relationship with endoscopic treatment-associated bleeding has yet to be investigated. This study aimed to evaluate whether blood group O is associated with delayed bleeding after colorectal endoscopic resection.

METHODS

This was a retrospective observational study based on medical records at four university hospitals in Japan. We reviewed the records for consecutive patients who underwent colorectal endoscopic resection from January 2014 through December 2017. The primary outcome was the incidence of delayed bleeding, defined as hematochezia or melena, requiring endoscopy, transfusion, or any hemostatic intervention up to 28 days after endoscopic resection. Multivariate logistic regression analysis was performed to adjust the impact of blood group O on the delayed bleeding.

RESULTS

Among 10,253 consecutive patients who underwent colorectal endoscopic resection during the study period, 8625 patients met the criteria. In total, delayed bleeding occurred in 255 patients (2.96%). The O group had significantly more bleeding events compared with the non-O group (A, B, and AB) (relative risk, 1.62 [95% confidence interval, 1.24-2.10]; P < 0.001). In multivariate logistic regression analysis, blood group O remained an independent risk factor for the bleeding (adjusted odds ratio, 1.60 [95% confidence interval, 1.18-2.17]; P = 0.002).

CONCLUSIONS

Blood group O was associated with an increased risk of delayed bleeding in patients undergoing colorectal endoscopic resection. Preoperative screening for ABO blood group could improve risk assessments.

Underwater vs conventional endoscopic mucosal resection in treatment of colorectal polyps: A meta-analysis

BACKGROUND

Underwater endoscopic mucosal resection (UEMR) of colorectal lesions is emerging as an alternative method to conventional endoscopic mucosal resection (EMR); however, it is still controversial whether there is a difference in the effectiveness between UEMR and EMR.

AIM

To evaluate the effectiveness and safety of UEMR in the treatment of colorectal polyps.

METHODS

Clinical studies comparing the effectiveness or safety of UEMR in the treatment of colorectal polyps were searched in medical databases, including PubMed, Embase, Cochrane Library, CNKI, and Wanfang Data, monographs, theses, and papers presented at conferences. Statistical analyses were performed using Revman 5.3 software.

RESULTS

Seven non-randomized controlled trials and one randomized controlled trial met the inclusion criteria. In total, 1382 patients (1511 polyps) were included in the study, including 722 who received UEMR and 789 who received EMR. In the UEMR and EMR groups, the en bloc resection rates were 85.87% and 73.89%, respectively, with a relative risk (RR) value of 1.14 (95% confidence interval [CI]: 1.01-1.30; P < 0.05). In the sub-group analysis, the en bloc resection rate showed no statistically significant difference between the EMR and UEMR groups for polyps less than 20 mm in diameter. However, a statistically significant difference was found between the EMR and UEMR groups for polyps equal to or greater than 20 mm in diameter. The post-endoscopic resection recurrence rates at 3-6 mo of the UEMR and EMR groups were 3.26% and 15.17%, respectively, with an RR value of 0.27 (95%CI: 0.09-0.83; P < 0.05). The post-endoscopic resection recurrence rates of UEMR and EMR at 12 mo were 6.25% and 14.40%, respectively, with an RR value of 0.43 (95%CI: 0.20-0.92; P < 0.05). Additionally, the incidence of adverse events was 8.17% and 6.21%, respectively, with an RR value of 1.07 (95%CI: 0.50-2.30; P > 0.05).

CONCLUSION

UEMR is an effective technique for colorectal polyps and appears to have some advantages over EMR, particularly with regard to some treatment outcomes.

The effect of prophylactic hemoclip placement and risk factors of delayed post-polypectomy bleeding in polyps sized 6 to 20 millimeters: a propensity score matching analysis

BACKGROUND

Delayed post-polypectomy bleeding (PPB) is a major complication of polypectomy. The effect of prophylactic hemoclipping on delayed PPB is uncertain. The aim of this study was to evaluate the effectiveness of prophylactic hemoclipping and identify the risk factors of delayed PPB.

METHODS

Patients with polyps sized 6 to 20 mm underwent snare polypectomy from 2015 to 2017 were retrospectively reviewed. The patients with prophylactic hemoclipping for delayed PPB prevention were included in the clipping group, and those without prophylactic hemoclipping were included in the non-clipping group. The incidence of delayed PPB and time to bleeding were compared between the groups. Multivariate analysis was used to identify the risk factors of delayed PPB. Propensity score matching was used to minimize potential bias.

RESULTS

After propensity score matching, 612 patients with 806 polyps were in the clipping group, and 576 patients with 806 polyps were in the non-clipping group. There were no significant differences in the incidence of delayed PPB and days to bleeding between two groups (0.8% vs 1.3%, p = 0.4; 3.4 ± 1.94 days vs 4.13 ± 3.39 days, p = 0.94). In the multivariate analysis, the polyp size [Odds ratio (OR):1.16, 95% confidence interval (CI):1.01-1.16, p = 0.03), multiple polypectomies (OR: 4.64, 95% CI:1.24-17.44, p = 0.02) and a history of anticoagulant use (OR:37.52, 95% CI:6.49-216.8, p < 0.001) were associated with delayed PPB.

CONCLUSIONS

In polyps sized 6 to 20 mm, prophylactic hemoclip placement did not decrease the risk of delayed PPB. Patients without risk factors including multiple polypectomies and anticoagulant use are no need to performing prophylactic hemoclipping.

Prophylactic hemoclips in prevention of delayed post-polypectomy bleeding for ≥ 1 cm colorectal polyps: meta-analysis of randomized controlled trials

Background and aim  Studies evaluating the role of prophylactic hemoclips (HC) in prevention of delayed post-polypectomy bleeding (DPPB) have reported conflicting results. We conducted a meta-analysis of randomized controlled trials (RCTs) to evaluate the role of prophylactic HC placement in prevention of DPPB for polyps ≥ 1 cm in size. Methods  We reviewed several databases to identify RCTs evaluating the role of HC in prevention of DPPB. The outcomes assessed included prevention of DPPB with polyps 1 to 1.9 cm, ≥ 2 cm, any polyp ≥ 1 cm, proximal colon polyps, distal colon polyps, and perforation. We analyzed data using a fixed effect model and reported summary pooled risk ratios (RR) with 95 % confidence intervals (CI). We assessed heterogeneity with the I ² statistic. Results  We included nine RCTs with 4550 patients. For polyps ≥ 2 cm, there was a statistically significantly lower risk of DPPB with use of HC; RR 0.55, 95 % CI 0.36, 0.86. There was also a statistically significantly lower risk for proximal colon polyps ≥ 2 cm; RR 0.41 (0.24, 0.70) but no significant difference for distal polyps; RR 1.23 (0.45, 3.32). There was also no significant difference in risk for polyps 1 to 1.9 cm; RR 1.07 (0.59, 1.97). There was no significant reduction in risk of perforation with HC use for any polyp size. Conclusions  Prophylactic HC placement is effective in prevention of DPPB from proximal colon polyps ≥ 2 cm, but of no significant benefit for polyps 1 to 1.9 cm in size or for distal colon polyps ≥ 2 cm.

Recognizing Post-Endoscopy Complications: A Database Filter Reduces Quality Assurance Workload for Inpatients

BACKGROUND AND AIMS

Documentation of complications of gastrointestinal endoscopy within the commonly used endoscopy documentation systems are mostly limited to acute complications during endoscopy included in the post-procedural endoscopy report. We tested a documentation system-based filter to reduce the workload by maintaining a high sensitivity to recognize post-endoscopy complications.

METHODS

Of all inpatient endoscopic resections during 1 year and all endoscopic retrograde cholangiopancreatography (ERCP) procedures during 4 months in 1 tertiary referral centre, post-procedural complications during hospital stay were individually analyzed retrospectively from the hospital databases (gold standard). In comparison, information technology-based filters were assessed searching for specific tests and data within 2 days after endoscopy and/or until discharge. These were second endoscopy, surgery, or an abdominal computed tomography (CT) or haemoglobin drop ≥2 g/dL for endoscopic resection. For ERCP cases, any case with lipase determination and post-ERCP CT scan was selected. Main outcomes were the sensitivity of these filters to recognize post-endoscopy complications and the percentage of workload reduction.

RESULTS

Three hundred twenty-two inpatients who underwent endoscopic resections and 302 ERCP cases (all inpatients) were included. Post-endoscopy complications occurred in 7.14% (endoscopic resection) and 3.7% (ERCP). The above-mentioned filters identified 100% of all resection and post-ERCP complications compared to detailed case file analysis, at the same time reducing the quality management workload to 14 and 31%, respectively.

CONCLUSIONS

Post-procedural monitoring of advanced endoscopic procedures performed on inpatient procedures has a high sensitivity (100%) and reduces case-by-case screening workload for complications by 70-85%. Outpatient interventions, however, require a different system for monitoring of post-endoscopy complications after discharge.

Development of a definition and rules for causal attribution of post-colonoscopy bleeding

Background

Post-colonoscopy bleeding (PCB) is an important colonoscopy quality indicator that is recommended to be routinely collected by colorectal cancer screening programs and endoscopy quality improvement programs. We created a standardized and reliable definition of PCB and set of rules for attributing the relatedness of PCB to a colonoscopy.

Methods

PCB events were identified from colonoscopies performed at the Forzani & MacPhail Colon Cancer Screening Centre. Existing definitions and relatedness rules for PCB were reviewed by the authors and a draft definition and set of rules was created. The definition and rules were revised after initial testing was performed using a set of 15 bleeding events. Information available for each event included the original endoscopy report and data abstracted from the emergency or inpatient record by a trained research assistant. A validation set of 32 bleeding events were then reviewed to assess their interrater reliability by having three endoscopists and one research assistant complete independent reviews and three endoscopists complete a consensus review. The Kappa statistic was used to measure interrater reliability.

Results

The panel classified 28 of 32 events as meeting the definition of PCB and rated 7, 8 and 6 events as definitely, probably and possibly related to the colonoscopy, respectively. The Kappa for the definition of PCB for the three independent reviews was 0.82 (substantial agreement). The Kappa for the attribution of the PCB to the colonoscopy by the three endosocopists was 0.74 (substantial agreement). The research assistant had a high agreement with the panel for both the definition (100% agreement) and application of the causal criteria (kappa 0.95).

Conclusions

A standardized definition of PCB and attribution rules achieved high interrater reliability by endoscopists and a non-endoscopist and provides a template of required data for event adjudication by screening and quality improvement programs.

Intra-abdominal bleeding as a rare complication after colonic endoscopic mucosal resection in a patient taking direct oral anticoagulants

We describe the case of an 84-year old female who was taking rivaroxaban 30 mg/day and had a medical history of atrial fibrillation. She underwent endoscopic mucosal resection of a 5-mm adenoma located in the hepatic flexure of the transverse colon. Following the procedure, she developed gradually intensifying abdominal pain, with the appearance of small amount of blood in the feces. For that reason, she visited our facility on the 5th day post-endoscopic mucosal resection. At the time of the visit, contrast-enhanced abdominal computed tomography revealed no extravasation or free air; however, bloody ascites was confirmed in the peritoneal cavity. Thus, the patient was diagnosed with post-endoscopic mucosal resection intra-abdominal hemorrhage and hospitalized the same day. After admission, rivaroxaban was discontinued and patient condition monitored. Because subsequent abdominal computed tomography revealed no distinct increase in bloody ascites, no interventional radiological or surgical procedure was performed, and the patient was discharged after providing only conservative treatment. While hemorrhage and perforation are the main complications after colonic endoscopic mucosal resection, so far, there have been a few reports on the occurrence of intra-abdominal hemorrhage following endoscopic mucosal resection. Emergency treatment is sometimes required in patients with intra-abdominal hemorrhage. It is important to keep in mind that this complication, although very rare, may occur, particularly in patients taking anticoagulants.

Safety and efficacy of cold snare polypectomy for pedunculated (Ip) polyps measuring less than 10 mm in diameter

BACKGROUND

Although cold snare polypectomy (CSP) has spread rapidly, it still remains controversial whether CSP is safe for pedunculated (Ip) polyps.

PURPOSE

The aim of this study was to evaluate whether CSP for Ip polyps measuring less than 10 mm in diameter might be associated with an increased rate of delayed post-polypectomy bleeding (DPPB).

METHODS

A total of 1641 colorectal polyps in 634 patients were resected at Omori Red Cross Hospital between April 2018 and December 2018. The polyps were divided into two groups depending on the morphology: the Ip group (90 polyps), and the non-Ip group (1551 polyps).

RESULTS

Among the 1641 polyps, there was no case of DPPB, including in the Ip group. Immediate bleeding occurred in a total of 101 (6.2%) cases. Polyp location in the rectum (OR (95% CI), 3.61 (1.843-7.092); p < 0.001), polyp diameter ≥ 6 mm (OR (95% CI), 2.65 (1.702-4.132); p < 0.001), Ip morphology (OR (95% CI), 15.66 (9.262-26.49); p < 0.001), and treatment with antithrombotic agents (OR (95% CI), 2.18 (1.358-3.501); p = 0.0012) were identified as significant risk factors for immediate bleeding.

CONCLUSIONS

This is the first study conducted to examine the safety of CSP for Ip polyps measuring less than 10 mm in diameter. CSP can be performed with a high level of safety even for Ip polyps. Based on our findings, we believe that Ip polyps could be included as an indication for CSP. However, prospective, randomized studies are necessary to confirm our results.

Clinical validation of risk scoring systems to predict risk of delayed bleeding after EMR of large colorectal lesions

BACKGROUND AND AIMS

The Endoscopic Resection Group of the Spanish Society of Endoscopy (GSEED-RE) model and the Australian Colonic Endoscopic Resection (ACER) model were proposed to predict delayed bleeding (DB) after EMR of large superficial colorectal lesions, but neither has been validated. We validated and updated these models.

METHODS

A multicenter cohort study was performed in patients with nonpedunculated lesions ≥20 mm removed by EMR. We assessed the discrimination and calibration of the GSEED-RE and ACER models. Difficulty performing EMR was subjectively categorized as low, medium, or high. We created a new model, including factors associated with DB in 3 cohort studies.

RESULTS

DB occurred in 45 of 1034 EMRs (4.5%); it was associated with proximal location (odds ratio [OR], 2.84; 95% confidence interval [CI], 1.31-6.16), antiplatelet agents (OR, 2.51; 95% CI, .99-6.34) or anticoagulants (OR, 4.54; 95% CI, 2.14-9.63), difficulty of EMR (OR, 3.23; 95% CI, 1.41-7.40), and comorbidity (OR, 2.11; 95% CI, .99-4.47). The GSEED-RE and ACER models did not accurately predict DB. Re-estimation and recalibration yielded acceptable results (GSEED-RE area under the curve [AUC], .64 [95% CI, .54-.74]; ACER AUC, .65 [95% CI, .57-.73]). We used lesion size, proximal location, comorbidity, and antiplatelet or anticoagulant therapy to generate a new model, the GSEED-RE2, which achieved higher AUC values (.69-.73; 95% CI, .59-.80) and exhibited lower susceptibility to changes among datasets.

CONCLUSIONS

The updated GSEED-RE and ACER models achieved acceptable prediction levels of DB. The GSEED-RE2 model may achieve better prediction results and could be used to guide the management of patients after validation by other external groups. (Clinical trial registration number: NCT03050333.).

Colorectal Polyp Prevalence According to Alcohol Consumption, Smoking and Obesity

This study aimed to analyze colorectal polyp prevalence associated with health behavior. Data from 1180 Korean men (young adult (YA), aged 40-49; middle age (MA) aged 50-59; old aged (OA), aged 60-79 years) were collected. Health behavior included alcohol consumption, smoking status, and obesity. Obesity was determined using body mass index (BMI) and waist circumference (WC). Odds ratio (OR) was calculated by logistic regression. The prevalence of polyps increased for current smokers by 2.642 times in the YA group, 3.468 times in the MA group, and 3.104 times in the OA group compared to the never-smokers. The OR for WC increased in subjects with obesity by 1.514 in the MA and 1.451 in the OA group compared to normal. The prevalence of three or more polyps increased with WC obesity by 2.3 times in YA, 2.2 times in MA, and 1.9 times in OA compared to normal WC. Therefore, smoking cessation and obesity management may reduce the risk of colorectal polyps.

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.

The effect of prophylactic hemoclips on the risk of delayed post-endoscopic mucosal resection bleed for upper and lower gastrointestinal lesions: a retrospective cohort study

Background

Endoscopic mucosal resection (EMR) is a minimally invasive procedure used for the treatment of lesions in the gastrointestinal (GI) tract. There is increased usage of hemoclips during EMR for the prevention of delayed bleeding. This study aimed to evaluate the effect of hemoclips in the prevention of delayed bleeding after EMR of upper and lower GI tract lesions.

Method

This is a retrospective cohort study using the Kaiser Permanente Southern California (KPSC) EMR registry. Lesions in upper and lower GI tracts that underwent EMR between January 2012 and December 2015 were analyzed. Rates of delayed bleeding were compared between the hemoclip and no-hemoclip groups. Analysis was stratified by upper GI and lower GI lesions. Lower GI group was further stratified by right and left colon. We examined the relationship between clip use and several clinically-relevant variables among the patients who exhibited delayed bleeding. Furthermore, we explored possible procedure-level and endoscopist-level characteristics that may be associated with clip usage.

Results

A total of 18 out of 657 lesions (2.7%) resulted in delayed bleeding: 7 (1.1%) in hemoclip group and 11 (1.7%) in no-hemoclip group (p = 0.204). There was no evidence that clip use moderated the effects of the lesion size (p = 0.954) or lesion location (p = 0.997) on the likelihood of delayed bleed. In the lower GI subgroup, clip application did not alter the effect of polyp location (right versus left colon) on the likelihood of delayed bleed (p = 0.951). Logistic regression analyses showed that the clip use did not modify the likelihood of delayed bleeding as related to the following variables: use of aspirin/NSAIDs/anti-coagulants/anti-platelets, pathologic diagnoses (including different types of colon polypoid lesions), ablation, piecemeal resection. The total number of clips used was 901 at a minimum additional cost of $173,893.

Conclusion

Prophylactic hemoclip application did not reduce delayed post-EMR bleed for upper and lower GI lesions in this retrospective study performed in a large-scale community practice setting. Routine prophylactic hemoclip application during EMR may lead to significantly higher healthcare cost without a clear clinical benefit.

Heparin bridge is associated with more post-polypectomy bleeding and emergency department visits among anticoagulated patients

Background:

Among patients undergoing colonoscopy, anticoagulants are usually stopped and are sometimes substituted by a heparin bridge (hep-bridge). We aimed to assess adverse events associated with hep-bridge compared to temporary cessation of anticoagulants (no-bridge).

Methods:

This was a single-center, retrospective cohort study that included anticoagulated patients undergoing colonoscopy between 2013 and 2016 at a Veterans Affairs Medical Center. In the no-bridge cohort, warfarin was stopped for 5 days and novel anticoagulants for 2 days pre-procedure. In the hep-bridge cohort, anticoagulants were stopped and were substituted by subcutaneous enoxaparin. The primary outcome was post-polypectomy bleeding. Secondary outcomes included cardiovascular events, all-cause adverse events and emergency department or unscheduled ambulatory office visits within 30 days. The predictive values of the HAS-BLED and CHADS₂ scores were evaluated.

Results:

A total of 662 patients were included, of whom 551 underwent polypectomy (mean age 68.6 years; 97.6% male). Four hundred seventy colonoscopies were performed with no-bridge and 192 with hep-bridge. Post-polypectomy bleeding occurred in 6.0% of procedures: 5.7% in the no-bridge cohort compared to 13.0% of hep-bridge procedures (P=0.0038). Cardiovascular or thrombotic events occurred after 2.6% of the no-bridge and 5.2% of the hep-bridge procedures (P=0.1176). Emergency department or unscheduled office visits within 30 days were reported after 18.7% of the no-bridge procedures and 29.7% of the hep-bridge procedures (P<0.0001). Neither CHADS₂ nor HASBLED scores predicted bleeding.

Conclusion:

The use of hep-bridge was associated with a greater incidence of post-polypectomy bleeding and more emergency department and unscheduled office visits compared with cessation of all anticoagulants.

Japan Gastroenterological Endoscopy Society guidelines for colorectal endoscopic submucosal dissection/endoscopic mucosal resection

Suitable lesions for endoscopic treatment include not only early colorectal carcinomas but also several types of precarcinomatous adenomas. It is important to establish practical guidelines wherein preoperative diagnosis of colorectal neoplasia and selection of endoscopic treatment procedures are appropriately outlined and to ensure that actual endoscopic treatment is useful and safe in general hospitals when carried out in accordance with guidelines. In cooperation with the Japanese Society for Cancer of the Colon and Rectum, the Japanese Society of Coloproctology, and the Japanese Society of Gastroenterology, the Japan Gastroenterological Endoscopy Society compiled colorectal endoscopic submucosal dissection/endoscopic mucosal resection guidelines by using evidence-based methods in 2014. The first edition of these guidelines was published 5 years ago. Accordingly, we have published the second edition of these guidelines based on recent new knowledge and evidence.