Cold snare polypectomy reduced delayed postpolypectomy bleeding compared with conventional hot polypectomy: a propensity score-matching analysis

Comparison of cold snare polypectomy for sessile serrated lesions ≥10 mm between experienced and trainee endoscopists: A propensity score matching cohort study

Objectives

Previous studies of cold snare polypectomy (CSP) for sessile serrated lesions (SSLs) ≥10 mm were performed by experienced endoscopists, and therefore their skills might have significantly influenced results. In this study, we compared the efficacy and safety of CSP for SSLs ≥10 mm between experienced and trainee endoscopists.

Methods

In a 1:1 propensity score matched retrospective cohort study, we compared the complete resection rate, en-bloc resection rate, adverse event rate, and procedure time between experienced and trainee groups. Thirteen endoscopists performed CSP, and we defined the experienced group as endoscopists with board certification from the Japan Gastroenterological Endoscopy Society.

Results

We examined 616 lesions with SSLs ≥10 mm resected by CSP between February 2018 and May 2022. We excluded 61 lesions from the analysis because they had simultaneously undergone hot snare polypectomy (n = 57) or had been taken over by experienced endoscopists from trainees in the CSP procedure (n = 4). Finally, we identified 217 propensity score-matched pairs (n = 434). Between experienced and trainee groups, the results were complete resection rate (100 vs. 100%; p = 1.00), en-bloc resection rate (73.2 vs. 75.6%; p = 0.24), adverse event rate (3.2 vs. 2.8%; p = 0.77), or procedure time (6.2 vs. 5.9 min; p = 0.64).

Conclusions

We have demonstrated the safety and efficacy of CSP for SSLs ≥10 mm performed by experienced and trainee endoscopists.

Cold Snare Polypectomy in Small (<10 mm) Pedunculated Colorectal Polyps: A Systematic Review and Meta-analysis

INTRODUCTION

Endoscopic removal techniques for colorectal polyps include cold snare polypectomy (CSP) and hot snare polypectomy (HSP). Although HSP is recommended for pedunculated polyps (PPs) larger than 10 mm, data regarding use of CSP for PPs <10 mm continues to emerge. We aimed to investigate outcomes of these techniques in small (<10 mm) pedunculated colorectal polyps.

METHODS

Multiple databases were searched till June 2022 to identify studies involving the removal of small PPs with CSP and HSP. Random effects model was used to calculate outcomes and 95% CI. Primary outcome was the pooled rate of successful en-bloc resection. Secondary outcomes were immediate and delayed bleeding with CSP and HSP as well as prophylactic and post resection clip placement.

RESULTS

Six studies including 1025 patients (1111 polyps with a mean size 4 to 8.5 mm) were analyzed. 116 and 995 polyps were removed with HSP and CSP, respectively. The overall pooled rate of successful en-bloc resection with CSP was 99.7% (CI 99.1-99.9; I2 0%). Pooled immediate and delayed bleeding after CSP was 49.8% (CI 46.8-52.91; I2 98%) and 0% (CI 0.00-0.00; I2 0%), respectively. Delayed bleeding was higher with HSP, relative risk 0.05 (CI 0.01-0.43; I2 0%), P =0.006, whereas immediate bleeding was higher with CSP, relative risk 7.89 (CI 4.36-14.29; I2 0%), P <0.00001. Pooled rates of prophylactic clip placement and post-procedure clip placement (to control immediate bleeding) were 55.3% and 47.2%, respectively. Finally, right colon polyp location significantly correlated with frequency of immediate bleeding.

CONCLUSION

Our analysis shows that CSP is safe and effective for resection of small PPs.

AGA Clinical Practice Update on Appropriate and Tailored Polypectomy: Expert Review

DESCRIPTION

In this Clinical Practice Update (CPU), we provide guidance on the appropriate use of different polypectomy techniques. We focus on polyps <2 cm in size that are most commonly encountered by the practicing endoscopist, including use of classification systems to characterize polyps and various polypectomy methods. We review characteristics of polyps that require complex polypectomy techniques and provide guidance on which types of polyps require more advanced management by a therapeutic endoscopist or surgeon. This CPU does not provide a detailed review of complex polypectomy techniques, such as endoscopic submucosal dissection, which should only be performed by endoscopists with advanced training.

METHODS

This expert review was commissioned and approved by the American Gastroenterological Association (AGA) Institute CPU Committee and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership, and underwent internal peer review by the CPU Committee and external peer review through standard procedures of Clinical Gastroenterology and Hepatology. These Best Practice Advice statements were drawn from a review of the published literature and from expert opinion. Because systematic reviews were not performed, these Best Practice Advice statements do not carry formal ratings regarding the quality of evidence or strength of the presented considerations. BEST PRACTICE ADVICE 1: A structured visual assessment using high-definition white light and/or electronic chromoendoscopy and with photodocumentation should be conducted for all polyps found during routine colonoscopy. Closely inspect colorectal polyps for features of submucosally invasive cancer. BEST PRACTICE ADVICE 2: Use cold snare polypectomy for polyps <10 mm in size. Cold forceps polypectomy can alternatively be used for 1- to 3-mm polyps where cold snare polypectomy is technically difficult. BEST PRACTICE ADVICE 3: Do not use hot forceps polypectomy. BEST PRACTICE ADVICE 4: Clinicians should be familiar with various techniques, such as cold and hot snare polypectomy and endoscopic mucosal resection, to ensure effective, safe, and optimal resection of intermediate-size polyps (10-19 mm). BEST PRACTICE ADVICE 5: Consider using lifting agents or underwater endoscopic mucosal resection for removal of sessile polyps 10-19 mm in size. BEST PRACTICE ADVICE 6: Serrated polyps should be resected using cold resection techniques. Submucosal injection may be helpful for polyps >10 mm if margins cannot be well delineated. BEST PRACTICE ADVICE 7: Use hot snare polypectomy to remove pedunculated lesions >10 mm in size. BEST PRACTICE ADVICE 8: Do not routinely use clips to close resection sites for polyps <20 mm. BEST PRACTICE ADVICE 9: Refer patients with polyps to endoscopic referral centers in the context of size ≥20 mm, challenging polypectomy location, or recurrent polyp at a prior polypectomy site. BEST PRACTICE ADVICE 10: Tattoo lesions that may need future localization at endoscopy or surgery. Tattoos should be placed in a location that will not interfere with subsequent attempts at endoscopic resection. BEST PRACTICE ADVICE 11: Refer patients with nonpedunculated polyps with clear evidence of submucosally invasive cancer for surgical evaluation. BEST PRACTICE ADVICE 12: Understand the endoscopy suite's electrosurgical generator settings appropriate for polypectomy or postpolypectomy thermal techniques.

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.

Cold snare endoscopic mucosal resection for colon polyps: a systematic review and meta-analysis

BACKGROUND

 Cold snare endoscopic mucosal resection (CS-EMR) can reduce the risks associated with electrocautery during colon polyp resection. Data on efficacy are variable. This systematic review and meta-analysis aimed to estimate the pooled efficacy and safety rates of CS-EMR.

METHODS

 We conducted a comprehensive literature search of multiple databases, from inception to March 2023, for studies addressing outcomes of CS-EMR for colon polyps. The weighted pooled estimates with 95 %CIs were calculated using the random effects model. I2 statistics were used to evaluate heterogeneity.

RESULTS

 4137 articles were reviewed, and 16 studies, including 2592 polyps in 1922 patients (51.4 % female), were included. Overall, 54.4 % of polyps were adenomas, 45 % were sessile serrated lesions (SSLs), and 0.6 % were invasive carcinomas. Polyp recurrence after CS-EMR was 6.7 % (95 %CI 2.4 %-17.4 %, I2  = 94 %). The recurrence rate was 12.3 % (95 %CI 3.4 %-35.7 %, I2  = 94 %) for polyps ≥ 20 mm, 17.1 % (95 %CI 4.6 %-46.7 %, I2  = 93 %) for adenomas, and 5.7 % (95 %CI 3.2 %-9.9 %, I2  = 50 %) for SSLs. The pooled intraprocedural bleeding rate was 2.6 % (95 %CI 1.5 %-4.5 %, I2  = 51 %), the delayed bleeding rate was 1.5 % (95 %CI 0.8 %-2.7 %, I2  = 18 %), and no perforations or post-polypectomy syndromes were reported, with estimated rates of 0.6 % (95 %CI 0.3 %-1.3 %, I2  = 0 %) and 0.6 % (95 %CI 0.3 %-1.4 %, I2  = 0 %), respectively.

CONCLUSION

 CS-EMR demonstrated an excellent safety profile for colon polyps, with variable recurrence rates based on polyp size and histology. Large prospective studies are needed to validate these findings.

Cold Versus Hot Snare Polypectomy for Colorectal Polyps: An Updated Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND AND OBJECTIVE

Endoscopic polypectomy is an excellent tool for colon cancer prevention. With the innovation of novel resection techniques, the best method is still being investigated. Hence, we aim to evaluate the efficacy and safety of cold snare polypectomy (CSP) versus hot snare polypectomy (HSP) for colorectal polyp resection.

METHODS

A systematic review and meta-analysis synthesizing evidence from randomized controlled trials retrieved from PubMed, EMBASE, WOS, SCOPUS, and CENTRAL until July 16, 2022. We pooled dichotomous outcomes using risk ratio (RR) with the corresponding CI. This review's protocol was prospectively registered in PROSPERO with ID: CRD42022347496.

RESULTS

We included 18 randomized controlled trials with a total of 4317 patients and 7509 polyps. Pooled RR favored HSP regarding the complete resection rate (RR: 0.96 with 95% CI: 0.95, 1, P = 0.03) and local recurrence incidence (RR: 5.74 with 95% CI: 1.27, 25.8, P = 0.02). Pooled RR favored CSP regarding the colonoscopy time (mean difference: -6.50 with 95% CI: -7.55, -5.44, P = 0.00001) and polypectomy time (mean difference: -57.36 with 95% CI: -81.74, -32.98, P = 0.00001). There was no difference regarding the incidence of immediate bleeding ( P = 0.06) and perforation ( P = 0.39); however, HSP was associated with more incidence of delayed bleeding ( P = 0.01), abdominal pain ( P = 0.007), and postresection syndrome ( P = 0.02).

DISCUSSION

HSP is associated with a higher complete resection and lower recurrence rates; however, HSP is also associated with a higher incidence of adverse events. Therefore, improving the complete resection rate with CSP still warrants more innovation, giving the technique safety and shorter procedure duration.

Does completing advanced endoscopy fellowship improve outcomes after endoscopic mucosal resection?

BACKGROUND

It was reported that about 60% of the physicians in the USA believed that their Gastroenterology fellowship poorly prepared them for large polyp resection. The aim of this study was to compare endoscopic mucosal resection (EMR) efficacy and complication rates between skilled general gastroenterologists who perform high volume of EMR and advanced endoscopists.

METHODS

We identified 140 patients with documented large colonic polyps treated by 4 providers using EMR technique at Carilion Clinic, in Roanoke, Virginia, USA between 01/01/2014-12/31/2017, with follow-up through 10-2018. Information on demographics, clinical and pathological features of high-risk polyps (i.e., size, histology, site, and degree of dysplasia), timing of surveillance endoscopies, tools used during resection, and skills of performing endoscopist's were extracted. The cumulative risks of polyp recurrence after first resection using EMR technique were estimated using Kaplan-Meier curves.

RESULTS

One hundred and forty patients were identified (mean age, 64.1±11.2 years; 47.1% males). Fifty-five polyps (39.3%) were removed by 2 skilled gastroenterologists and 85 (60.7%) were removed by advanced endoscopists. Most of the polyps resected were located in the right colon (63.6%) and roughly half of the polyps were removed in piecemeal fashion. At follow-up endoscopy, the advanced endoscopy group had lower polyp recurrence rates. The median recurrence after polypectomy was significantly different between the groups (0.88 and 1.03 years for skilled gastroenterologists who did not complete and completed EMR hands-on workshops; respectively vs. 3.99 years for the advanced endoscopist who did not complete EMR hands-on workshop, P=0.03).

CONCLUSIONS

There is a need for additional EMR training since polyp recurrence was significantly different between the groups despite high rates of piecemeal resection in the advanced endoscopy groups.

Bleeding After Endoscopic Resection of Colonic Adenomatous Polyps Sized 4-10 mm

Introduction: Colonoscopy with polypectomy is an efficacious procedure in reducing the risk of colorectal cancer development, the precursor are adenomatous polyps. The most common method for resection of polyps measuring 4-10 mm are cold (CSP) and hot snare polypectomy (HSP). CSP has a lower incidence of adverse events, especially delayed post-polypectomy bleeding. Aim: To evaluate the presence of immediate and delayed bleeding in the cold snare polypectomy of sub-centimeter polyps of the colon compared with hot snare polypectomy. Materials and Methods: This prospective clinical study is comprised all patients who were incidentally detected to have adenomatous colonic polyps measuring 4-10 mm during a colonoscopy screening. Polypectomy was done with (hot snare) or without electrocautery (cold snare). After removal of polyps, immediate bleeding, delayed bleeding, and methods for were analyzed. Results: The CSP and HSP groups included 116 patients, 113 (54.4%) polyps in 61 (52.6%) patients with CSP while 95 (45.6%) polyps in 55 (47.4%) patients with HSP. 25 (22.1%) polyps after CSP had immediate bleeding. In 5 patients (20.0%), five hemostatic clips were inserted after CSP for bleeding longer than 150 sek. The average percentage difference between immediate bleeding versus total number of resected polyps using the cold snare method is not statistically significant (p<0.05) (Difference test, p=0.0000). Delayed bleeding was not registered using this method. In the second investigated group (HSP), one patient had delayed bleeding. This was stopped with 2 clips. Immediate bleeding was not registered. Conclusion: CSP is safer than HSP in resecting colon polyps sized 4-10 mm, without risk of delayed bleeding.

Endoscopic mucosal resection using cold snare versus hot snare in treatment for 10-19 mm non-pedunculated colorectal polyps: protocol of a non-inferiority randomised controlled study

INTRODUCTION

Cold polypectomy has the advantages of simple operation, less time-consuming and fewer complications. Guidelines have recommended cold snare polypectomy (CSP) to resect small polyps sized ≤5 mm and sessile polyps sized 6-9 mm. However, evidence is scarce regarding cold resection for non-pedunculated polyps sized ≥10 mm. Cold snare endoscopic mucosal resection (CS-EMR) combining CSP and submucosal injection was designed to improve the complete resection rate and reduce adverse events. We hypothesise that CS-EMR is non-inferior to conventional hot snare endoscopic mucosal resection (HS-EMR) in the resection of 10-19 mm non-pedunculated colorectal polyps.

METHODS AND ANALYSIS

This study is a prospective, randomised, open-label, non-inferiority, single-centre trial. Outpatients scheduled to undergo a colonoscopy and present eligible polyps will be randomised to receive either CS-EMR or HS-EMR. The primary endpoint is the complete resection. Considering that HS-EMR of 10-19 mm colorectal polyps will yield a complete resection rate of at least 92% and a non-inferiority margin of -10%, a total of 232 polyps will be included (one-sided α, 2.5%; β, 20%). The analyses are intended to evaluate first non-inferiority (lower limit 95% CI greater than -10% for group difference) and then superiority (lower limit 95% CI>0%) if non-inferiority is achieved. Secondary endpoints include en-bloc resection, the occurrence of adverse events, the use of endoscopic clips, resection time and cost.

ETHICS AND DISSEMINATION

The study has been approved by the institutional review board of the Peking Union Medical College Hospital (No. K2203). All participants in the trial will provide written informed consent. The results of this trial will be published in an open-access way.

TRIAL REGISTRATION NUMBER

NCT05545787.

Incomplete resection rates of 4- to 20-mm non-pedunculated colorectal polyps when using wide-field cold snare resection with routine submucosal injection

Background and study aims  Incomplete resection of 4- to 20-mm colorectal polyps occur frequently (> 10 %), putting patients at risk for post-colonoscopy colorectal cancer. We hypothesized that routine use of wide-field cold snare resection with submucosal injection (CSP-SI) might reduce incomplete resection rates (IRRs). Patients and methods  Patients aged 45 to 80 years undergoing elective colonoscopies were enrolled in a prospective clinical study. All 4- to 20-mm non-pedunculated polyps were resected using CSP-SI. Post-polypectomy margin biopsies were obtained to determine IRRs through histopathology assessment. The primary outcome was IRR, defined as remnant polyp tissue found on margin biopsies. Secondary outcomes included technical success and complication rates. Results  A total of 429 patients (median age 65 years, 47.1 % female, adenoma detection rate 40 %) with 204 non-pedunculated colorectal polyps 4 to 20 mm removed using CSP-SI were included in the final analysis. CSP-SI was technical successful in 97.5 % (199/204) of cases (5 conversion to hot snare polypectomy). IRR for CSP-SI was 3.8 % (7/183) (95 % confidence interval [CI] 2.7 %-5.5 %). IRR was 1.6 % (2/129), 16 % (4/25), and 3.4 % (1/29) for adenomas, serrated lesions, and hyperplastic polyps respectively. IRR was 2.3 % (2/87), 6.3 % (4/64), 4.0 % (6/151), and 3.1 % (1/32) for polyps 4 to 5 mm, 6 to 9 mm, < 10 mm, and 10 to 20 mm, respectively. There were no CSP-SI-related serious adverse events. Conclusions  Use of CSP-SI results in lower IRRs compared to what has previously been reported in the literature for hot or cold snare polypectomy when not using wide-field cold snare resection with submucosal injection. CSP-SI showed an excellent safety and efficacy profile, however comparative studies to CSP without SI are required to confirm these results.

Endoscopic resection of non-ampullary duodenal adenomas: Is cold snaring the promised land?

Due to the high risk of morbidity and mortality associated with surgical resection in this tract, endoscopic resection (ER) has taken the place of surgical resection as the first line treatment for non-ampullary duodenal adenomas. However, due to the anatomical characteristics of this area, which enhance the risk of post-ER problems, ER in the duodenum is particularly difficult. Due to a lack of data, no ER technique for superficial non-ampullary duodenal epithelial tumours (SNADETs) has yet been backed by strong, high-quality evidence; yet, traditional hot snare-based techniques are still regarded as the standard treatment. Despite having a favourable efficiency profile, adverse events during duodenal hot snare polypectomy (HSP) and hot endoscopic mucosal resection, such as delayed bleeding and perforation, have been reported to be frequent. These events are primarily caused by electrocautery-induced damage. Thus, ER techniques with a better safety profile are needed to overcome these shortcomings. Cold snare polypectomy, which has already been shown as a safer, equally effective procedure compared to HSP for treatment of small colorectal polyps, is being increasingly evaluated as a potential therapeutic option for non-ampullary duodenal adenomas. The aim of this review is to report and discuss the early outcomes of the first experiences with cold snaring for SNADETs.

Bleeding Risk With Cold Snare Polypectomy of ≤10 mm Pedunculated Colon Polyps

OBJECTIVES

Pedunculated polyps (PPs) in the colon are usually resected with hot snare polypectomy to prevent immediate postpolypectomy bleeding (IPPB). This study aimed to evaluate the safety of CSP of <10 mm PPs.

MATERIALS AND METHODS

Patients undergoing colonoscopy from February 18, 2019, to April 24, 2020, and were found to have at least 1 ≤10 mm PP resected with CSP were included prospectively in a continuous quality improvement project to assess the risk of IPPB and delayed postpolypectomy bleeding. Polyp location, size, and pathology, as well as the method of resection, were recorded. In addition, we assessed the occurrence and severity of IPPB and the need for intervention.

RESULTS

We found 239 eligible polyps in 182 patients. The mean (SD) age was 58.8 (8.3) years, and 61% were males. IPPB occurred in 72 of 239 polyps, corresponding to a per-polyp bleeding percentage of 30.1% and in 65 of 182 patients, equating to a per-patient bleeding rate of 35.7%. We successfully treated bleeding by endoscopic hemostasis in 57%; the remaining 31 polyps (43%) did not require endoscopic intervention. There was no association between IPPB with age, gender, or use of aspirin or antithrombotic agents. In the bivariate model, polyp size and pathology were not associated with the risk of IPPB. Right-sided polyps were associated with a reduced risk of IPPB in the bivariate model by 61% (odds ratio=0.39; 95% confidence interval, 0.21-0.74; P =0.0057). In the multivariate model, choking the polyp base decreased the likelihood of IPPB by 97% (odds ratio=0.03; 95% confidence interval, 0.00-0.86; P =0.0459). There were no instances of delayed bleeding, perforation, or postpolypectomy syndrome.

CONCLUSIONS

CSP can be used for resection of ≤10 mm PPs. It is associated with a lower risk of immediate bleeding than the common perception among gastroenterologists.

Safety and efficacy of a new cold snare technique with clipping for colorectal angioectasia

Colorectal angioectasia is a major cause of lower gastrointestinal bleeding. Use of antithrombotic agents is expected to increase with aging of the population, and bleeding from angioectasia is an important issue. Although the effectiveness of endoscopic mucosal resection for colorectal angioectasia has been reported, there are no reports of cold snare technique for angioectasia (CSA). From February 2018 to February 2022, the safety of CSA was evaluated at Omori Red Cross Hospital. We investigated the incidence of bleeding (delayed post-polypectomy bleeding (DPPB) and immediate bleeding) after CSA and the incidence of rebleeding requiring repeated endoscopic treatment. During the study period, 106 angioectasias were identified during colonoscopy. We only targeted patients with bloody stools and/or anemia requiring treatment for bleeding from angioectasia. Finally, we included 11 angioectasias in this study. Rates of DPPB and rebleeding after CSA were 0 %. The rate of immediate bleeding during CSA was 27.3 % (3/11). Dilated capillaries could be observed pathologically in nine of 11 lesions (81.8 %). CSA was safe and can be a new treatment option in the future. To confirm our results and verify the long-term safety and efficacy of CSA, further studies are desirable.

Cold snare polypectomy versus cold endoscopic mucosal resection for small colorectal polyps: a multicenter randomized controlled trial

BACKGROUND

Cold snare polypectomy (CSP) is recommended for the resection of small colorectal polyps. However, few studies have investigated the efficacy of cold endoscopic mucosal resection (cold EMR) for small polyps. Thus, the aim of this study was to investigate the efficacy and safety of cold EMR compared with CSP for small colorectal polyps.

METHODS

This was a multicenter, randomized trial conducted in three tertiary centers from January 2018 to February 2021. Patients with polyps sized 6-10 mm were randomized to CSP or cold EMR group. After polypectomy, two additional biopsies were performed to assess the completeness of resection. The primary outcome was complete polyp resection rate. Secondary outcomes were total procedure time and rate of adverse events such as immediate bleeding, delayed bleeding, and perforation.

RESULTS

A total of 444 polyps in 327 patients were assessed and randomly assigned to each group. Of those, 425 polyps were finally analyzed based on pathology results. The complete resection rate was not significantly different between cold EMR and CSP groups (91.9% vs 89.8%, p = 0.24). However, the total procedure time was significantly increased in cold EMR (87.6 s vs. 45.8 s, p < 0.001). The rate of polypectomy adverse events was not significantly different between the two groups. No patient had massive bleeding or perforation.

CONCLUSIONS

There was no difference in complete resection rate or adverse events between CSP and cold EMR. However, CSP reduced the total procedure time.

Risk Factors of Delayed Bleeding After Cold Snare Polypectomy for Colorectal Polyps: A Multicenter Study

BACKGROUND

Delayed bleeding (DB) rarely occurs after cold snare polypectomy (CSP) for colorectal polyps, but no large-scale studies have investigated this. The present study evaluated the rate, characteristics, and risk factors of DB of CSP.

METHODS

We conducted a multicenter retrospective study at 10 Japanese institutions. A total of 18,007 patients underwent CSP for colorectal polyps ≤ 10 mm in size from March 2015 to September 2019, and cases of DB (DB group) were analyzed for the rate, antithrombotic drugs, polyp size, morphology, location, and risk factors. As a control, 269 non-bleeding cases (non-DB group) with 606 polyps who underwent CSP at the same 10 facilities in the 2-week study period were extracted.

RESULTS

We analyzed 26 DB cases with 28 lesions, and the total DB rate was 0.14% (26/18,007). The DB group had significantly higher rates of using antiplatelets (42.3% vs. 13.0%, p < 0.001) and anticoagulants (19.2% vs. 2.6%, p = 0.002), and significantly higher rates of polyp size ≥ 5 mm (67.9% vs. 45.2%, p = 0.015), rectal lesion (25.0% vs. 6.6%, p = 0.003), and polypoid lesion (89.3% vs. 55.3%, p < 0.001) than the non-DB group. A multivariate analysis (odds ratio; 95% confidence interval) for patient characteristics showed antiplatelet use (4.521; 1.817-11.249, p = 0.001) and anticoagulant use (7.866; 20.63-29.988, p = 0.003) as independent risk factors for DB. Polyp size ≥ 5 mm (3.251; 1.417-7.463, p = 0.005), rectal lesion (3.674; 1.426-9.465, p = 0.007), and polypoid lesion (7.087; 20.81-24.132, p = 0.002) were also risk factors for lesion characteristics.

CONCLUSIONS

The rate of DB was 0.14% and antithrombotic drug use, polyp size, location, and morphology were related to it.

Resection depth for small colorectal polyps comparing cold snare polypectomy, hot snare polypectomy and underwater endoscopic mucosal resection

Background and study aims  Small colorectal polyps are removed by various methods, including cold snare polypectomy (CSP), hot snare polypectomy (HSP), and underwater endoscopic mucosal resection (UEMR), but the indications for using these methods are unclear. We retrospectively assessed the efficacy of CSP, HSP, and UEMR for small polyps, focusing on the depth of the resected specimens. Patients and methods  Outpatients with non-pedunculated small polyps (endoscopically diagnosed as 6 to 9 mm), resected by two endoscopists between July 2019 and September 2020, were enrolled. We histologically evaluated the specimens resected via CSP, HSP, and UEMR. The main outcome was the containment rate of the muscularis mucosa (MM) and submucosa (SM) tissues. Results  Forty polyps resected via CSP (n = 14), HSP (n = 12), or UEMR (n = 14) were enrolled after excluding 13 polyps with resection depths that were difficult to determine. The rates of specimens containing MM and SM tissue differed significantly (57 % and 29 % for CSP, 92 % and 83 % for HSP, and 100 % and 100 % for UEMR, respectively ( P  = 0.005 for MM and P  < 0.001 for SM tissue). Multiple logistic regression analysis showed UEMR was an independent factor relating to the containment of SM tissue. The thickness of SM tissue by CSP, HSP, and UEMR were 52 μm, 623 μm, and 1119 μm, respectively ( P  < 0.001). The thickness by CSP was significantly less than those by HSP and UEMR ( P  < 0.001, Bonferroni correction). Conclusions  UEMR could be the best method to contain SM tissue without injection. Further studies are needed to evaluate the indication of UEMR for small polyps.

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.

Polypectomy for Diminutive and Small Colorectal Polyps

Diminutive and small colorectal polyps are common findings during colonoscopies, and rarely contain dysplastic elements and progress to colorectal cancer. With improving technology and the advent of artificial intelligence, detection rates of small or diminutive polyps and adenomas are rising, resulting in increasing costs associated with colonoscopy. Incomplete resection rates are an outcome of interest because it correlates with interval colorectal cancer. More effort is warranted to standardize training programs and sensitize endoscopists to the importance of personal performance as a quality metric of colonoscopy. This article reviews indications, methods, and recent developments in polypectomy for small and diminutive polyps.

Polypectomy for Large Polyps with Endoscopic Mucosal Resection

Beginning in 1955, when the saline injection was first described to prevent transmural injury during polyp fulguration, endoscopic mucosal resection (EMR) has grown exponentially, both in scope and in practice. Because EMR is an organ-preserving technique even for large polyps, this allows for comparable outcomes to surgery, but substantially improved cost savings and significantly reduced morbidity and mortality. To achieve this, however, one must master the 4 fundamental components that are critical to the success of EMR- time, team, tools, and technique. This article aims to provide a compendium of state of the art updates within the field of endoluminal resection.

Safety of cold snare polypectomy with periprocedural antithrombotic agents for colorectal polyps: a systematic review and meta-analysis

BACKGROUND

We aimed to study the safety of cold snare polypectomy (CSP) for colorectal polyps in patients administered periprocedural antithrombotic agents.

METHODS

We searched the PubMed, Embase, and Cochrane Library databases through June 2021. The primary outcomes were the rates of delayed and immediate bleeding (requiring endoscopic hemostasis). Secondary outcomes included thromboembolic events. Meta-analysis using odds ratios (ORs) and corresponding 95% confidence intervals (CIs) was performed to compare the outcomes.

RESULTS

Seventeen studies, including five randomized trials, were included. Over 96% of polyps were ⩽1 cm. The pooled rates of delayed and immediate bleeding for patients receiving CSP and periprocedural antithrombotic agents were 1.6% and 10.5%, respectively. Both the delayed (OR = 4.02, 95% CI = 1.98-8.17) and immediate bleeding (OR = 5.85, 95% CI = 3.84-8.89) rates were significantly higher in patients using periprocedural antithrombotic agents than in non-users. Although both antiplatelet agents and anticoagulants increased the risk of delayed bleeding, the risks associated with the use of direct oral anticoagulants (DOACs; 2.5%) or multiple agents (3.9%) were particularly high. Compared to their counterparts, diminutive polyps and uncomplicated lesions not requiring hemoclipping were associated with lower risks of delayed bleeding (pooled estimates of 0.4% and 0.18%, respectively). Thromboembolic risk was similar among patients using and not using periprocedural antithrombotic agents.

CONCLUSIONS

CSP with periprocedural antiplatelet agents and warfarin may be feasible, especially for diminutive polyps. However, drug discontinuation should be considered with the use of DOACs or multiple agents which entail higher bleeding risk even with hemoclipping.

Evaluation of cold snare polypectomy for small pedunculated (Ip) polyps with thin stalks: a prospective clinical feasibility study

BACKGROUND

Although the use of cold snare polypectomy (CSP) has spread rapidly, no prospective studies evaluating the safety of CSP for pedunculated (Ip) polyps have been carried out.

AIM

We performed this study to provide an accurate evaluation of the safety of CSP for Ip polyps.

METHODS

This is a prospective study (UMIN000035687). From January 2019 to February 2021, the safety of CSP for use on Ip polyps <10 mm with thin stalks was evaluated at our hospital. The primary outcome measure was the incidence of bleeding (delayed post-polypectomy bleeding (DPPB) and immediate bleeding).

RESULTS

During the study period, 89 consecutive patients (including 92 colonoscopies and 114 polyps) were prospectively enrolled. The en-bloc resection rate was 100%. The rate of DPPB after CSP was 0%, however, DPPB after conversion to HSP occurred in 1 case (33.3% (1/3)). The rate of immediate bleeding during CSP was 28.9% (33/114). Polyps with diameters ≥6 mm (OR (95% CI): 2.77 (1.041-7.376); p = .041) were extracted as independent risk factors for immediate bleeding during CSP for Ip polyps. In all, 104 (91.2%) polyps were low-grade adenomas, and the percentage of cases with negative pathological margins was 96.5% (110/114).

CONCLUSIONS

CSP for Ip polyps was safe and had good outcomes. We believe that Ip polyps could be included as an indication for CSP, and that CSP may become the next step in the 'cold revolution.' To confirm our results and verify CSP's inclusion in future guidelines, prospective, randomized studies are necessary.

Safety and Efficacy of Cold Snare Polypectomy Without Submucosal Injection for Large Sessile Serrated Lesions: A Prospective Study

BACKGROUND & AIMS

Cold snare polypectomy (CSP) has become the standard resection method for small colorectal polyps (<10 mm). Sessile serrated lesions (SSL) have low prevalence of advanced histology irrespective of size, and thus could be amenable to CSP. In this study, we evaluated the safety and efficacy of CSP for SSLs ≥10 mm.

METHODS

Between November 2018 and January 2020, we prospectively enrolled 300 consecutive patients who underwent CSP for 474 SSLs ≥10 mm. To delineate SSL borders, indigo carmine chromoendoscopy and/or image-enhanced endoscopy was conducted. Piecemeal CSP (pCSP) was performed in cases where en-bloc resection was difficult. Biopsy specimens were obtained from the margins of the post-polypectomy defect to confirm complete resection. Surveillance colonoscopy was performed to screen for local recurrence.

RESULTS

All lesions were successfully resected using CSP without submucosal injection. The median diameter of the resected lesions was 14 mm, and pCSP was used to resect 106 (22%) lesions. Post-polypectomy biopsies revealed residual serrated tissue in only one case (0.2%). Adverse events included immediate bleeding in 8 (3%) patients; no delayed bleeding events occurred, irrespective of the use of antithrombotic drugs. During a 7-month median follow-up period, surveillance colonoscopies were performed for 384 lesions (81%), and no local recurrences were detected.

CONCLUSIONS

CSP without submucosal injection is a safe and effective treatment for SSLs ≥10 mm. UMIN Clinical Trials, Number: UMIN000034763.

A Comparative Study of Early Mucosal Healing Following Hot Polypectomy and Cold Polypectomy

Background

Cold polypectomy (CP) and hot polypectomy (HP) are both accepted methods for polypectomy. In recent years, the use of CP has increased for reasons of safety. However, there have been few investigations of conditions at follow-up early after resection. This prospective study from a single center aimed to compare colonic mucosal healing at 1 week following HP vs CP of benign colonic polyps <10 mm in diameter.

Material/Methods

Six patients with a total of 52 lesions under 10 mm in size were randomized to either the HP group (n=25) or CP group (n=27) using information in opaque envelopes. One week after endoscopic treatment, the site of treatment was evaluated using colonoscopy. We assessed the mean tumor size, ulcer diameter, exposed blood vessels, residual lesion, and complications.

Results

Mean tumor size did not differ between the 2 groups (CP vs HP: 5.41 mm vs 5.68 mm). The CP group had a smaller ulcer base diameter (2.70 mm vs 4.84 mm; P<0.05) and fewer exposed blood vessels than the HP group (3.7% vs 36.0%; P<0.05). One residual lesion was found in the CP group. No patients experienced delayed perforation or post-polypectomy bleeding.

Conclusions

Our study findings showed that at 1-week follow-up, cold polypectomy resulted in improved colonic mucosal healing, with a smaller ulcer diameter and fewer blood vessels, when compared with hot polypectomy.

Efficacy of cold endoscopic mucosal resection vs conventional endoscopic mucosal resection in treatment of nonpedunculated colorectal polyps sized 5-10 mm

BACKGROUND

Cold snare polypectomy (CSP) has been gradually applied to remove small colorectal polyps (6-9 mm). Cold endoscopic mucosal resection (EMR) is based on CSP technology combined with submucosal injection of water. Studies have reported that the histological complete resection rate of cold EMR of 6-9 mm colorectal adenoma is significantly better than that of CSP. However, there are few studies on the efficacy of cold EMR vs conventional EMR.

AIM

To compare the efficacy and safety of cold EMR and conventional EMR for 5-10 mm colorectal adenomas.

METHODS

From August 2019 to December 2020, consecutive hospitalized patients who underwent colorectal polypectomy at the Digestive Endoscopy Center of our hospital were screened for eligible polyps. Eligible polyps were randomized to be treated with either cold EMR or conventional EMR according to a random number table (1:1). The histological complete resection rate, immediate postpolypectomy bleeding, and delayed postpolypectomy bleeding were analyzed.

RESULTS

One hundred and eighty-one patients with 195 eligible polyps were included, including 90 patients with 98 polyps in the cold EMR group and 91 patients with 97 polyps in the conventional EMR group. The en bloc resection rate of polyps in the overall population was 98.5%, and there was no perforation. The overall rate of histological complete resection was 91.8% in the cold EMR group and 95.9% in the EMR group (difference: 4.1%; 95%CI: -3.9-12.3). Subgroup analysis by polyp size showed that the histological complete resection rates were 94.6% and 100% for 5-7 mm polyps (difference: 5.4%; 95%CI: -8.3-19.5), and 90.2% and 93.8% for 8-10 mm polyps (difference: 3.6%; 95%CI: -7.8-15.4). The immediate postpolypectomy bleeding rates of the cold EMR and conventional EMR groups were 2.0% and 1.0%, and the delayed postpolypectomy bleeding rates were 0% and 1%, respectively; there was no statistically significant difference between the two groups.

CONCLUSION

Cold EMR is a safe and effective treatment for 5-10 mm colorectal adenoma, with a histological complete resection rate not inferior to that of conventional endoscopic mucosal resection.

Management of Less Than 10-mm-Sized Pedunculated (Ip) Polyps with Thin Stalk: Hot Snare Polypectomy Versus Cold Snare Polypectomy

BACKGROUND

Although the use of cold snare polypectomy (CSP) has spread rapidly, its safety for pedunculated (Ip) polyps remains controversial. In particular, the outcomes of hot snare polypectomy (HSP) and CSP for Ip polyps have not been previously compared.

AIMS

This study evaluated whether the rate of delayed postpolypectomy bleeding (DPPB) after CSP for Ip polyps was higher than that after HSP for Ip polyps and compared other outcomes (the rates of immediate bleeding and pathological margins) between the HSP and CSP procedures.

METHODS

A total of 5905 colorectal polyps in 4920 patients were resected at Omori Red Cross Hospital between October 2012 and June 2019. The polyps were divided into two groups: the HSP group (86 polyps, 64 patients) and the CSP group (102 polyps, 87 patients). The primary outcome measure was the incidence of DPPB. The secondary outcome measures were the incidences of immediate bleeding during the procedure and pathological margins of the resected specimen.

RESULTS

The rate of immediate bleeding during CSP was significantly higher than that for the HSP group [38.2% (39/102) versus 3.5% (3/86); p < 0.001]. However, the rate of DPPB was significantly higher in the HSP group than in the CSP group [4.7% (4/86) versus 0% (0/102); p < 0.001]. The rate of DPPB after CSP was 0%.

CONCLUSIONS

This is the first study to compare the outcomes of HSP and CSP for Ip polyps. CSP is safer than HSP for Ip polyps measuring < 10 mm in diameter.

Endoscopic polypectomy devices

Video 1Use of submucosal injection prior to en-bloc endoscopic mucosal resection.Video 2Use of a detachable loop ligating device prior to hot snare resection of a pedunculated polyp.

Effect of Instruction on Preventing Delayed Bleeding after Colorectal Polypectomy and Endoscopic Mucosal Resection

Background: The frequency of delayed bleeding after colorectal polypectomy has been reported as 0.6–2.8%. With the increasing performance of polypectomy under continuous use of antithrombotic agents, care is required regarding delayed post-polypectomy bleeding (DPPB). Better instruction to educate endoscopists is therefore needed. We aimed to evaluate the effect of instruction and factors associated with delayed bleeding after endoscopic colorectal polyp resection. Methods: This single-center, retrospective study was performed to assess instruction in checking complete hemostasis and risk factors for onset of DPPB. The incidence of delayed bleeding, comorbidities, and medications were evaluated from medical records. Characteristics of historical control patients and patients after instruction were compared. Results: A total of 3318 polyps in 1002 patients were evaluated. The control group comprised 1479 polyps in 458 patients and the after-instruction group comprised 1839 polyps in 544 patients. DPPB occurred in 1.1% of polyps in control, and 0.4% in after-instruction. Instruction significantly decreased delayed bleeding, particularly in cases with antithrombotic agents. Hot polypectomy, clip placement, and use of antithrombotic agents were significant independent risk factors for DPPB even after instruction. Conclusion: The rate of delayed bleeding significantly decreased after instruction to check for complete hemostasis. Even after instruction, delayed bleeding can still occur in cases with antithrombotic agents or hot polypectomy.

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.

Outcomes of Gastrointestinal Polyps Resected Using Underwater Endoscopic Mucosal Resection (UEMR) Compared to Conventional Endoscopic Mucosal Resection (CEMR)

Objective

Underwater endoscopic mucosal resection (UEMR) is reported to be superior to conventional endoscopic mucosal resection (CMER) for the complete resection of large polyps and may offer increased procedural efficiency.

Aims

To compare recurrence rates and adverse events between UEMR and CEMR and define risk factors related to recurrence. Also, to assess recurrence rates in piecemeal endoscopic mucosal resection (EMR) based on the number of pieces resected.

Methods

We identified all patients with large polyps treated using the UEMR technique at Carilion Clinic, Roanoke, VA, USA between January 1, 2014 and December 31, 2017 with follow-up through October of 2018. We matched the UEMR patients with patients treated using the CEMR technique (1:2 matching, respectively). The Kaplan-Meier curve was used to estimate the cumulative risks of polyp recurrence. The Cox proportional hazard analysis was used to assess risk factors for developing polyp recurrence.

Results

Sixty-eight patients (mean age: 63.4 ± 12.5 years; 52.9% males) with polyps removed using the UEMR technique (Group 1) were matched with 122 patients (mean age: 64.4 ± 10.0 years; 51.6% males) who had polyps removed using CEMR (Group 2). Polyps resected in fewer pieces (≤ 3) had lower recurrence rates compared to the ones resected in >3 pieces. Right colon polyps removed using UEMR had a lower recurrence rate compared to right colon polyps resected using CEMR. Polyp size and a high degree of dysplasia were associated with a high risk of polyp recurrence after resection. Completing advanced endoscopy training was also associated with a lower risk of recurrence.

Conclusion

UEMR had a lower recurrence rate compared with CEMR for right colon polyps. Factors associated with recurrence included the degree of training, high-grade dysplasia, and polyp size.

Impact of submucosal saline solution injection for cold snare polypectomy of small colorectal polyps: a randomized controlled study

BACKGROUND AND AIMS

Cold snare polypectomy (CSP) of small colorectal polyps is widely used. However, the technique is still troubled by insufficient resection depth, which may prevent precise pathologic evaluation. In this study, we investigated whether submucosal injection of saline solution helps to achieve deeper resection in CSP.

METHODS

The study was a single-center, prospective, randomized trial. Patients with small (3- to 10-mm diameter) nonpedunculated adenomatous or sessile serrated colorectal polyps were randomly allocated to either conventional CSP (C-CSP) or CSP with submucosal injection (CSP-SI). Primary outcome was the rate of complete muscularis mucosae (MM) resection, defined by the proportion of MM under the tumor more than 80% of the tumor's horizontal dimension. Secondary outcomes were the rates of negative lateral and vertical margins, fragmentation of resected specimens, conversion to hot snare mucosal resection, intraprocedural bleeding, delayed bleeding, and perforation.

RESULTS

Two hundred fourteen patients were randomly assigned to the CSP-SI (n = 107) or C-CSP (n = 107) group. The rate of complete MM resection was 43.9% in the CSP-SI group and 53.3% in the C-CSP group, a statistically insignificant difference. The rates of negative lateral margin and vertical margin (42.3% and 56.7%, respectively) in the CSP-SI group were significantly lower than those (58% and 76%) in the C-CSP group (P = .03 and P = .006, respectively). There was no polypectomy-related major bleeding or perforation.

CONCLUSIONS

Saline solution injection into the submucosa did not improve the resection depth of CSP of small colorectal polyps, and the method resulted in lower rates of negative lateral and vertical margins of resected lesions. (Clinical trial registration number: UMIN000037980.).

Prospective randomized trial comparing the pocket-creation method and conventional method of colorectal endoscopic submucosal dissection

BACKGROUND AND AIMS

Colorectal endoscopic submucosal dissection (ESD) is recognized as a challenging procedure. Previously, we reported that a new ESD strategy using the pocket-creation method (PCM) is useful for colorectal ESD, but no prospective randomized study has evaluated the efficacy of the PCM. The aim of this study was to evaluate the efficacy and safety of PCM for colorectal ESD compared with the conventional method (CM).

METHODS

This was a prospective randomized controlled trial at 3 institutions in Japan. Patients with superficial colorectal neoplastic lesions >20 mm predicted to be intramucosal were randomly assigned to undergo ESD using the PCM or CM. Primary outcome was the ESD completion rate defined as completion of colorectal ESD with an en bloc resection using the assigned ESD method without changing to other methods or assisted by other devices.

RESULTS

We analyzed 59 patients with 59 colorectal tumors in the PCM group and 55 in the CM group. The ESD completion rate was significantly higher in the PCM group compared with the CM group (93% [55/59] vs 73% [40/55]; P  = .01). En bloc resection rates, R0 resection rates, procedure time, and dissection speed were not significantly different between the 2 groups. The incidence of adverse events was similar in the 2 groups.

CONCLUSIONS

Use of the PCM allows the endoscopist to complete the procedure with the intended method more often than the CM with similar clinical outcomes. (Clinical trial registration number: UMIN 000024394.).

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.

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.

Safety of Cold Snare Polypectomy in Patients Receiving Treatment with Antithrombotic Agents

BACKGROUND

With the aging of the population and rising incidence of thromboembolic events, the clinical use of antithrombotic agents is also increasing. There are few reports yet on the management of antithrombotic agent use in patients undergoing cold snare polypectomy (CSP).

AIMS

The aim of this study was to evaluate whether continued administration of antithrombotic agents in patients undergoing CSP would be associated with an increased rate of delayed post-polypectomy bleeding (DPPB).

METHODS

A total of 1177 colorectal polyps in 501 patients were resected at Omori Red Cross Hospital between October 2017 and March 2018. The polyps were divided into two groups depending on whether the patients received antithrombotic agent treatment or not: the antithrombotic group (911 polyps) and the no-antithrombotic group (266 polyps).

RESULTS

Among the 1177 polyp resections, there was no case of DPPB, including in the antithrombotic group. Immediate bleeding occurred in a total of 63 (5.4%) cases. Polyp location in the rectum (OR (95% CI) 2.64 (1.223-5.679); p = 0.013), polyp size ≥ 6 mm (OR (95% CI) 4.64 (2.719-7.933); p < 0.001), polypoid growth pattern (OR (95% CI) 2.78 (1.607-4.793); p < 0.001), and antithrombotic agent use (OR (95% CI) 2.98 (1.715-5.183); p < 0.001) were identified as significant risk factors of immediate bleeding.

CONCLUSIONS

Continued use of antithrombotic agents does not increase the risk of DPPB, even in those receiving multiple antithrombotic agents. Thus, it is safe to perform CSP even in multiple agent users. Prospective, randomized studies are necessary to confirm our results.

The Cold Revolution: How Far Can It Go?

Cold resection for small colonic polyps, and larger lesions, is being rapidly and widely adopted. Driven by an impressive safety and cost profile compared with conventional polypectomy, these advantages are offset by the limitations of smaller and shallower resection, and absent thermal effects that may permit persistence of residual neoplasia. To overcome this, optimal cold snare technique requires inclusion of a margin of normal mucosa and a piecemeal resection technique for larger polyps. This article examines the fundamentals of cold snare resection and evidence for its application, theorizes on limits to its application, and identifies areas for further research.

Best Practices for Resection of Diminutive and Small Polyps in the Colorectum

Diminutive colorectal lesions are polyps and flat lesions 1 to 5 mm in size, and small are 6 to 9 mm in size. The best resection method is the cold snare. Cold forceps are acceptable for 1- to 3-mm lesions, but should not be used to piecemeal polyps. Cold snaring has few complications and is more effective than cold forceps for 4- to 5-mm polyps and as effective and more efficient than hot snaring for 6- to 9-mm polyps.

Endoscopic Management of Post-Polypectomy Bleeding

Post-polypectomy bleeding (PPB) is one of the most common complications of endoscopic polypectomy. There are multiple risk factors related to patient and polyp characteristics that should be considered. In most cases, immediate PPB can be effectively managed endoscopically when recognized and managed promptly. Delayed PPB can manifest in a myriad of ways. In severe delayed PPB, resuscitation for hemodynamic stabilization should be prioritized, followed by endoscopic evaluation and therapy once the patient is stabilized. Future areas of research in PPB include the risks of direct oral anticoagulants and of specific electrosurgical settings for hot-snare polypectomy vs. cold-snare polypectomy, benefits of closure of post-polypectomy mucosal defects using through-the-scope clips, and prospective comparative evaluation of newer hemostasis agents such as hemostatic spray powder and over-the-scope clips.

Risk factors for incomplete polyp resection after cold snare polypectomy

BACKGROUND

Incomplete polyp resection (IPR) is recognized as a risk factor for interval colorectal cancer (ICC), and is, therefore, an important issue in polypectomy. Cold snare polypectomy (CSP) is a procedure that does not involve electrocautery and has no burn effect. Therefore, there is the possibility that the risk of ICC associated with IPR is higher in cases undergoing CSP than in those undergoing hot polypectomy. However, little is known about the risk factors for IPR after CSP.

PURPOSE

Precise identification of the risk factors can lead to prevention of IPR after CSP. Therefore, we performed this observational study for accurate identification of the risk factors for IPR after CSP.

METHODS

Medical records of a total of 501 patients with 1177 colorectal polyps that were resected at Omori Red Cross Hospital between October 2017 and March 2018 were retrospectively reviewed. The lateral and deep margins of the resected polyps were evaluated to check for the resection completeness.

RESULTS

Among the 1177 polyp resections, 1163 were included in the final analysis. IPR was detected in 206 (17.7%) cases. Performance of the resection by a trainee (OR (95% CI) 1.87 (1.328-2.632); P < 0.001) was identified as an independent risk factor for IPR in patients undergoing CSP.

CONCLUSIONS

Performance of the polypectomy by a trainee was identified as a significant risk factor for IPR in patients undergoing CSP. Prospective, randomized studies are necessary in the future to develop effective methods for the prevention/control of IPR after CSP.

Practice patterns and predictors of prophylactic endoscopic clip usage during polypectomy

Background and study aims  Prophylactic endoscopic clips are commonly placed during polypectomy to reduce risk of delayed bleeding, although evidence to support this practice is unclear. Our study aimed to: (1) identify variables associated with prophylactic clip use; (2) explore variability between endoscopists' clipping practices and (3) study temporal trends in prophylactic clip use. Patients and methods  This was a retrospective cohort study in a high-volume unit dedicated to screening-related colonoscopies. Colonoscopies involving polypectomy from 2008 to 2014 were reviewed. The primary outcome was prophylactic clipping status, both at the patient level and per polyp. Hierarchical regression models yielded adjusted odds ratios (AORs) to determine predictors of prophylactic clipping. Results  A total of 8,366 colonoscopies involving 19,129 polypectomies were included. Polyp size ≥ 20 mm was associated with higher clip usage (AOR 2.94; 95 % CI: 2.43, 3.54) compared to polyps < 10 mm. Right-sided polyps were more likely to be clipped (AOR 2.78; 95 % CI: 2.34, 3.30) relative to the rectum. Surgeons clipped less than gastroenterologists (OR 0.52; 95 % CI: 0.44, 0.63). From 2008 to 2014, the crude proportion of prophylactically clipped cases increased by 7.4 % (95 % CI: 7.1, 7.6) from 1.9 % to 9.3 %. Significant inter-endoscopist variability in clipping practices was observed, notably, for polyps < 10 mm. Conclusions  Prophylactic clip usage was correlated with established risk factors for delayed bleeding. Significantly increased clip usage over time was shown. Given that evidence does not clearly support prophylactic clipping, there is a need to educate practitioners and limit healthcare resource utilization.

Comparison of Underwater vs Conventional Endoscopic Mucosal Resection of Intermediate-Size Colorectal Polyps

BACKGROUND & AIMS

Endoscopic mucosal resection (EMR) with submucosal injection is an established method for removing colorectal polyps, although the en bloc resection rate decreases when polyp size exceeds 10 mm. Piecemeal resection increases local recurrence. Underwater EMR (UEMR) is an effective technique for removal of sessile colorectal polyps and we investigated whether it is superior to conventional EMR (CEMR).

METHODS

We conducted a multicenter randomized controlled trial at 5 institutions in Japan. Patients with endoscopically diagnosed, intermediate-size (10-20 mm) sessile colorectal lesions were randomly assigned to undergo UEMR or CEMR. Only the most proximal lesion was registered. The UEMR procedure included immersion of the entire lumen in water and snare resection of the lesion without submucosal injection of normal saline. We analyzed outcomes of 108 colorectal lesions in the UEMR group and 102 lesions in the CEMR group. R0 resection was defined as en bloc resection with a histologically confirmed negative resection margin. The primary endpoint was the difference in the R0 resection rates between groups.

RESULTS

The proportions of R0 resections were 69% (95% confidence interval [CI] 59%-77%) in the UEMR group vs 50% (95% CI 40%-60%) in the CEMR group (P = .011). The proportions of en bloc resections were 89% (95% CI 81%-94%) in the UEMR group vs 75% (95% CI 65%-83%) in the CEMR group (P = .007). There was no significant difference in median procedure time (165 vs 175 seconds) or proportions of patients with adverse events (2.8% in the UEMR group vs 2.0% in the CEMR group).

CONCLUSIONS

In a multicenter randomized controlled trial, we found that UEMR significantly increased the proportions of R0 resections for 10- to 20-mm sessile colorectal lesions without increasing adverse events or procedure time. Use of this procedure should be encouraged. Trials registry number: UMIN000018989.

Cold snare polypectomy: Indications, devices, techniques, outcomes and future

Colonoscopy has been shown to reduce the risk of colon cancer by enabling the removal of precancerous lesions. Although cold snare and hot snare polypectomy have similar retrieval rates and complete resection rates, rates of delayed bleeding tend to be lower with cold snare polypectomy than with hot snare polypectomy, especially for patients taking antithrombotic agents. However, among cold snares there may be differences in terms of the completeness of polyp excision, as complete removal appears more likely with thin-wire dedicated cold snares compared to the traditional, thick-wire cold snares. Cold snare polypectomy may be especially well suited for use in patients taking antithrombotic agents, due to its minimal risk of delayed bleeding. Histological analyses suggest that cold snare polypectomy causes less damage to blood vessels in the submucosal layers, which results in a reduced incidence of hemorrhage compared to hot snare polypectomy. However, cold snare removal of small polyps may result in fragmentation of small specimens during collection and concerns as to whether the resection is complete. An endoscopy biomarker of effective cold snare polypectomy technique is needed to ensure complete removal of non-pedunculated colorectal polyps ≤10 mm. Future uses of cold snare polypectomy may include piecemeal removal of sessile serrated adenoma/polyp lesions >10 mm. Currently, cold snare polypectomy should be considered a primary method for colorectal polyps of less than 10 mm, especially those in the 4- to 10-mm range.

Hot snare vs. cold snare polypectomy for endoscopic removal of 4 - 10 mm colorectal polyps during colonoscopy: a systematic review and meta-analysis of randomized controlled studies

Introduction  In recent years, cold snare polypectomy (CSP) has increasingly been used over hot snare polypectomy (HSP) for the removal of colorectal polyps (4 - 10 mm in size). However, the optimal technique (CSP vs. HSP), in terms of complete polyp resection and complications, is uncertain. Our aim was to compare incomplete resection rate (IRR) of polyps and complications using CSP vs. HSP. Methods  Randomized controlled studies (RCTs) comparing CSP and HSP for removal of 4 - 10 mm colorectal polyps were considered. Studies were included in the analysis if they obtained biopsy specimens from the resection margin to confirm the absence of residual tissue and reported complications. IRR and complication rate were the outcome measures. Pooled rates were reported as Odds Ratios (OR) or risk difference with 95 % Confidence Interval (CI). Results  In total, three RCTs were included in the final analysis. A total of 1051 patients with 1485 polyps were randomized to either HSP group (n = 741 polyps) or CSP group (n = 744 polyps). The overall IRR did not differ between the two groups (HSP vs. CSP: 2.4 % vs. 4.7 %; OR 0.51, 95 %CI 0.13 - 1.99, P  = 0.33, I ²  = 73 %). The HSP group had a lower rate of overall complications compared to the CSP group (3.7 % vs. 6.6 %; OR 0.53, 95 % CI 0.3 - 0.94, P  = 0.03, I ²  = 0 %). Polyp retrieval rates were not different between the two groups (99 % vs. 98.1 %). Conclusion  Our results suggest that HSP and CSP techniques can be effectively used for the complete removal of 4 - 10 mm colorectal polyps; however, HSP has a lower incidence of overall complications.

Resection rates and safety profile of cold vs. hot snare polypectomy in polyps sized 5-10 mm and 11-20 mm

BACKGROUND AND AIMS

Hot snare (HS) is widely used for the resection of adenomas >5 mm. The cold snare (CS) has a better safety profile and is more cost-effective. The aims of this study were to evaluate effectiveness and safety of CS polypectomy (CSP) compared to HS polypectomy (HSP) for adenomas sized 5-10 mm and 11-20 mm.

METHODS

4018 colonoscopies performed within "quality certificate for screening colonoscopy" with one polypectomy of an adenoma sized 5-20 mm each were included. Retrieval rates, complete resection rates and complication rates were assessed and compared between CSP and HSP for adenomas sized 5-10 mm and 11-20 mm. Histologic subgroups were additionally assessed.

RESULTS

Complete resection rates (5-10 mm: CSP: 89.4% vs. HSP: 87.9%, p = 0.33; 11-20 mm: CSP: 81.8% vs. 80.9%; p = 1), retrieval rates (5-10 mm: CSP: 99.5% vs. HSP: 99.4%, p = 0.76; 11-20 mm: CSP: 100% vs. HSP: 99%, p = 1) and complication rates (5-10 mm: CSP: 0.2% vs. HSP: 0.2%; p = 1; 11-20 mm: CSP: 0% vs. HSP: 1%, p = 1) were equal between CSP and HSP for adenomas sized 5-10 mm as well as 11-20 mm. For serrated adenomas sized 5-10 mm, HSP was superior to CSP (88.7% vs. 77.2%, p < 0.05) regarding the complete resection rate, but not for advanced adenomas (HSP: 89.1% vs. 87.3%, p = 0.69) or adenomas with high-grade dysplasia (HSP: 76.7% vs. 75%, p = 1).

CONCLUSION

This study further supports the use of CSP for polyps sized 5-10 mm and additionally suggests also using CSP for polyps sized 11-20 mm. These findings, as well as the best method for resection of serrated polyps should be validated in further studies.

Risk of delayed bleeding before and after implementation of cold snare polypectomy in a screening colonoscopy setting

Background and study aims  Cold snare polypectomy (CSP) is considered to be effective in reducing risk of delayed bleeding but randomized trials fail to support this owing to the small sample size. The current study aimed to compare risk of delayed bleeding before and after implementation of CSP in a screening colonoscopy setting. Patients and methods  This study retrospectively analyzed a prospectively maintained screening colonoscopy database in a university hospital in Taiwan. We compared the rate of delayed bleeding before and after implementation within similar periods (18 months and 15 months) and the respective number of polypectomies (1,304 and 1,255) performed to remove small and diminutive polyps. The main outcome measurement was delayed bleeding within the two periods. Multivariate analysis was performed to adjust for major confounders. Results  A total of 1,304 and 1,225 subjects received hot snare polypectomy (HSP) and CSP in two separate periods, respectively. Compared with the HSP, the CSP had a lower rate of delayed bleeding (0.1 % vs . 1.1 %, P  < 0.001), severe bleeding (0 % vs. 0.7 %, P  < 0.01), need for second-look colonoscopy (0 % vs. 0.8 %, P  < 0.01), and emergency service visits (0.1 % vs . 1.0 %, P  < 0.01). Total procedure time (12.60 ± 11.45 vs . 16.48 ± 14.27 min/person, P  < 0.01) and duration of hospital stay (1.18 ± 0.50 vs . 1.53 ± 5.78 hour/person, P  < 0.03) were also shorter after CSP implementation. Multivariate analysis showed that HSP was an independent risk factor for delayed bleeding after adjusting for age, gender, and number of polyps (adjusted odds ratio 14.4;95 % confidence interval = 1.88 - 110.6). Conclusion  Implementation of CSP significantly reduces risk of delayed bleeding associated with removing small and diminutive polyps in screening colonoscopy.

Efficacy and safety of cold versus hot snare polypectomy for resecting small colorectal polyps: Systematic review and meta-analysis

BACKGROUND AND AIM

Safety and effectiveness of cold snare polypectomy (CSP) compared with hot snare polypectomy (HSP) has been reported. The aim of the present study is to carry out a meta-analysis of the efficacy and safety of HSP and CSP.

METHODS

Randomized controlled trials were reviewed to compare HSP with CSP for resecting small colorectal polyps. Outcomes reviewed include complete resection rate, polyp retrieval, delayed bleeding, perforation and procedure time. Outcomes were documented by pooled risk ratios (RR) with 95% confidence intervals (CI) using the Mantel-Haenszel random effect model.

RESULTS

Eight studies were reviewed in this meta-analysis, including 1665 patients with 3195 polyps. Complete resection rate using HSP was similar to CSP (RR: 1.02, 95% CI: 0.98-1.07, P = 0.31). Polyp retrieval after HSP was similar to CSP (RR: 1.00, 95% CI: 1.00-1.01, P = 0.60). Delayed bleeding rate after HSP was higher than after CSP, although not significantly (patient basis: RR: 7.53, 95% CI: 0.94-60.24, P = 0.06; polyp basis: RR: 7.35, 95% CI: 0.91-59.33, P = 0.06). Perforation was not reported in all eight studies. Total colonoscopy time for HSP was significantly longer than CSP (mean difference 7.13 min, 95% CI: 5.32-8.94, P < 0.001). Specific polypectomy time for HSP was significantly longer than CSP (mean difference 30.92 s, 95% CI: 9.15-52.68, P = 0.005).

CONCLUSION

This meta-analysis shows significantly shorter procedure time using CSP compared with HSP. CSP tends toward less delayed bleeding compared with HSP. We recommend CSP as the standard treatment for resecting small benign colorectal polyps.

Advances in CRC Prevention: Screening and Surveillance

Colorectal cancer (CRC) is among the most commonly diagnosed cancers and causes of death from cancer across the world. CRC can, however, be detected in asymptomatic patients at a curable stage, and several studies have shown lower mortality among patients who undergo screening compared with those who do not. Using colonoscopy in CRC screening also results in the detection of precancerous polyps that can be directly removed during the procedure, thereby reducing the incidence of cancer. In the past decade, convincing evidence has appeared that the effectiveness of colonoscopy as CRC prevention tool is associated with the quality of the procedure. This review aims to provide an up-to-date overview of recent efforts to improve colonoscopy effectiveness by enhancing detection and improving the completeness and safety of resection of colorectal lesions.