Risk factors and prediction model for delayed bleeding after cold snare polypectomy: a retrospective study.

BACKGROUND: Delayed bleeding (DB) is a serious complication after cold snare polypectomy (CSP) for polyps in the colon. The present study aimed to investigate the incidence and risk factors of DB after CSP and to develop a risk-scoring model for predicting DB. METHODS: A retrospective study was conducted in four Chinese medical institutions. 10650 patients underwent CSP from June 2019 to May 2023. The study analyzed the rate of DB and extracted the general clinical information and polyp-related information of patients with postoperative DB. As a control, non-DB patients who received CSP at the same 4 hospitals were analyzed. A multivariate Cox regression analysis was performed to develop the prediction model. The model was further validated using a Kaplan-Meier log-rank analysis, receiver operating characteristic curve (ROC) plot and risk plot. RESULTS: In our study, we found a 0.24% rate of DB and the risk factors were history of hypertension, hyperlipidemia, antithrombotics use, antiplatelet use, anticoagulant use, abdominal operation, sigmoid colon lesion, hematoma, cold snare defect protrusion, polyp size, wound size, the grade of wound bleeding, and morphology of Ip. These factors were incorporated into the prediction model for DB after CSP. For 1, 3, and 5 days of bleeding, the AUC of the ROC curve was 0.912, 0.939, and 0.923, respectively. The Kaplan-Meier analysis indicated that the high-risk group had a significantly higher risk of DB than the low-risk group. CONCLUSIONS: This study screened the risk factors and established a prediction model of DB after CSP. The results may help preventing and reducing the DB rate after CSP of colorectal polyps.

Efficacy and Safety of Cold Snare Polypectomy versus Cold Endoscopic Mucosal Resection for Resecting 3-10 mm Colorectal Polyps: Systematic Review and Meta-Analysis of Randomized Controlled Trials.

INTRODUCTION: The safety and efficacy of cold snare polypectomy (CSP) compared to those of cold endoscopic mucosal resection (CEMR) have been reported. This meta-analysis compared the efficacy and safety of CEMR and CSP. METHODS: PubMed, Embase, Web of Science, and Cochrane Library databases were systematically searched to identify randomized controlled trials comparing the efficacy and safety of CEMR and CSP in removing 3-10 mm polyps. The outcomes assessed included complete resection rate, intraoperative bleeding rate, delayed bleeding rate, perforation, and polyp removal time. The results are reported as risk ratios (RR) and 95% confidence intervals (CIs) derived from a Mantel-Haenszel random-effects model. RESULTS: Seven studies comprising 1,911 polyps were included in the analysis. The complete resection rate of CEMR was comparable to that of CSP (RR: 1.01, 95% CI: 0.99-1.04, p = 0.32). Comparable results were also demonstrated for intraoperative bleeding rate (polyp-based analysis: RR: 1.22, 95% CI: 0.33-4.43, p = 0.77), delayed bleeding rate (polyp-based analysis: RR: 1.34, 95% CI: 0.44-4.15, p = 0.61), and polyp removal time (mean difference: 28.31 s, 95% CI: -21.40-78.02, p = 0.26). No studies reported cases of perforation. CONCLUSION: CEMR has comparable efficacy and safety to CSP in removing 3-10 mm polyps. Further randomized controlled trials with long-term follow-up are warranted to compare and validate efficacy.

Cold Snare Polypectomy With or Without Submucosal Injection for Endoscopic Resection of Colorectal Polyps: A Meta-Analysis of Randomized Controlled Trials.

BACKGROUND AND AIMS: The impact of submucosal injection during cold snare polypectomy (CSP) remains uncertain. We conducted an evidence-based comparison of conventional CSP (C-CSP) and CSP with submucosal injection (SI-CSP) for colorectal polyp resection. METHODS: PubMed, Embase, and the Cochrane Library databases were searched for randomized controlled trials (RCTs) comparing C-CSP with SI-CSP. Major outcomes included the rates of complete resection, en bloc resection, polyp retrieval, and adverse events, as well as the duration of polypectomy. Data were analyzed by using a random-effects model. RESULTS: A total of seven RCTs were included. Complete resection rates for all polyps (RR 0.98; 95% CI 0.93-1.03), polyps ≤ 10 mm (RR 0.99; 95% CI 0.96-1.02) and polyps > 10 mm (RR 0.92; 95% CI 0.69-1.12) were not substantially different between C-CSP and SI-CSP groups. En bloc resection rate (RR 0.93; 95% CI 0.79-1.09) and polyp retrieval rate (RR 1.00; 95% CI 0.99-1.01) were also not significantly different between the two groups. The SI-CSP group required a prolonged polypectomy time than the C-CSP group (SMD - 0.89; 95% CI -1.29 to -0.49). Adverse events were rare in both groups. CONCLUSIONS: SI-CSP is not an optimal substitute for CSP in the resection of colorectal polyps, particularly diminutive and small polyps.

Effect of Cold Versus Hot Snare Polypectomy on Colon Postpolypectomy Bleeding in Patients with End-Stage Renal Disease: A Retrospective Cohort Study.

BACKGROUND: Patients with end-stage renal disease (ESRD) who undergo polypectomy may experience postpolypectomy bleeding. To reduce the risk of delayed postpolypectomy bleeding among the general population, cold snare polypectomy (CSP) is recommended for removing colon polyps smaller than 1 cm. Nevertheless, only few studies have examined the effect of CSP on patients with ESRD. METHODS: We retrospectively analyzed the data of patients with ESRD who underwent colonoscopic polypectomy for polyps larger than 5 mm at a Taiwanese university hospital from January 2014 to January 2023. The main outcome was delayed postpolypectomy bleeding within 30 days. Multivariate analysis was conducted to adjust for major confounders. RESULTS: A total of 557 patients with ESRD underwent colonoscopic polypectomy during the study period: 201 underwent CSP and 356 underwent hot snare polypectomy (HSP). Delayed postpolypectomy bleeding occurred in 27 patients (4.8%). The rate of delayed postpolypectomy bleeding was lower in patients with ESRD who underwent CSP than in those who underwent HSP (1.9% vs. 6.4%, P = 0.022). The percentage of patients who did not experience postpolypectomy bleeding within 30 days after CSP remained lower than that observed after HSP (P = 0.019, log-rank test). Multivariate analysis demonstrated immediate postpolypectomy bleeding and HSP to be independent risk factors for delayed postpolypectomy bleeding. A nomogram prognostic model was used to predict the potential of delayed postpolypectomy bleeding within 30 days in patients with ESRD. CONCLUSIONS: Compared with HSP, CSP is more effective in mitigating the risk of delayed postpolypectomy bleeding in patients with ESRD.

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

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

The efficacy and safety of cold snare versus hot snare polypectomy for endoscopic removal of small colorectal polyps: a systematic review and meta-analysis of randomized controlled trials.

PURPOSE: The optimal technique for removing small colorectal polyps ranging from 5 to 10 mm in size remains uncertain. In order to compare the efficacy and adverse events between cold snare polypectomy (CSP) and hot snare polypectomy (HSP) for removing small polyps, we conducted a systematic review and meta-analysis of available randomized controlled trials. METHODS: We conducted a comprehensive search of MEDLINE, EMBASE, and the Cochrane Library databases from 1998 to May 2023 to identify randomized controlled trials that evaluated the efficacy and safety of cold snare polypectomy (CSP) and hot snare polypectomy (HSP) for resecting small colorectal polyps. The primary outcome measure was the incomplete resection rate (IRR). RESULTS: Seven studies that met our study criteria, with a total of 3178 included polyps, were included in our analysis. The incomplete resection rate (IRR) was found to be significantly higher in the CSP group compared to the HSP group (risk ratio [RR] 1.57 [1.17-2.11], P = 0.003). Although the CSP group had a higher local recurrence rate than the HSP group, the difference was not statistically significant (RR: 3.98 [0.66-23.84], P = 0.13). The polyp retrieval rates were not significantly different between the two groups (RR: 1.00 [0.99-1], P = 0.22). Perforation was not reported or mentioned in any of the seven studies. The overall immediate bleeding rate was significantly higher in the CSP group than the HSP group (RR: 2.26 [1.63-3.14], P < 0.001), but immediate postpolypectomy bleeding requiring additional intervention was similar between the groups (RR: 1.08 [0.54-2.17], P = 0.82). The delayed bleeding rate (RR: 0.83 [0.45-1.55], P = 0.56) and specific polypectomy time (RR: -0.46 [-1.05-0.12], P = 0.12) were also similar between the groups. CONCLUSIONS: The meta-analysis shows a significantly higher IRR for CSP compared with HSP when removing small polyps.

Systematic review and meta-analysis of cold snare polypectomy and hot snare polypectomy for colorectal polyps.

BACKGROUND AND AIM: Cold snare polypectomy (CSP) has become increasingly utilized to resect colorectal polyps, given its efficacy and safety. This study aims to compare CSP and hot snare polypectomy (HSP) for resecting small (< 10 mm) and large (10-20 mm) colorectal lesions. METHODS: Relevant publications were obtained from Cochrane Library, Embase, Google Scholar, PubMed, and Web of Science databases. The publication search was limited by English-language and human studies. Pooled mean difference and odds ratios (ORs) were calculated for outcomes of interest. RESULTS: Twenty-three studies were included in this meta-analysis. Pooled OR of delayed post-polypectomy bleeding (DPPB) in the CSP group versus the HSP group was 0.29 (P = 0.0001, I2  = 29%). Subgroup analysis according to lesion size showed a significant reduction in the DPPB rate in lesion sizes 10-20 mm (pooled OR 0.08, P = 0.003, I2  = 0%) and < 10 mm (pooled OR 0.35, P = 0.001, I2  = 27%). Pooled OR of major bleeding in the CSP group was 0.23 (P = 0.0004, I2  = 0%). Subgroup analysis by lesion size revealed a significant decrease in the rate of major bleeding in the CSP group for both lesion sizes 10-20 mm (pooled OR 0.11, P = 0.04) and < 10 mm (pooled OR 0.26, P = 0.003). Complete resection, en bloc resection, and recurrence rate were comparable in the two groups. CONCLUSIONS: Cold snare polypectomy was associated with a lower rate of DPPB and lower risk of major bleeding compared with HSP in both small and large polyps. CSP should be considered as the polypectomy technique of choice for colorectal polyps.

Efficacy and Safety of Cold Snare Polypectomy of Colorectal Polyps 10-15 mm with a Hybrid Snare: A Prospective Observational Pilot Study.

INTRODUCTION: Cold snare polypectomy (CSP) is a safe and effective procedure for small colorectal polyps ≤9 mm. There are only limited data regarding CSP of larger neoplastic lesions. This study evaluated the efficacy and safety of CSP for polyps between 10 and 15 mm in size. METHODS: In this prospective single-arm observational pilot study, patients with a least one polyp 10-15 mm were included. These polyps were preferably removed by CSP using a dedicated hybrid snare. The primary outcome was the histological complete resection rate (CRR) determined by pathologically negative margins of the specimen and no neoplastic tissue obtained from biopsies of the resection site margin. Secondary outcomes were en bloc resection rate, failure of CSP, and incidence of adverse events. RESULTS: A total of 61 neoplastic polyps were removed from 39 patients. Overall CRR was 80.3% (49/61). CSP was feasible in 78.7% (48/61) of polyps and the CRR in this group was 85.4% (41/48). When CSP failed (13/61; 21.3%), lesions were successfully resected by immediate HSP using the same snare with a CRR of 61.5% (8/13) in this group. One patient presented delayed hemorrhage after HSP of a polyp but successful hemostasis was achieved with two hemoclips. No other adverse events occurred. No recurrence was seen on follow-up colonoscopy in cases with incomplete resected polyps. CONCLUSION: CSP seems to be efficient and safe in removing colorectal polyps up to 15 mm. A hybrid snare seems to be particularly advantageous for these polyps as it allows immediate conversion to HSP if CSP might fail in larger polyps. This trial is registered at ClinicalTrials.gov (NCT04464837).

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.

Colorectal cold snare polypectomy: Current standard technique and future perspectives.

It has been shown that resection of adenomatous colorectal polyps can reduce mortality due to colorectal cancer. In daily clinical practice, simpler and safer methods of colorectal polypectomy have been sought to enable endoscopists to resect all detected lesions. Among these, cold snare polypectomy (CSP) is widely used in clinical practice because of its advantages in shortening procedure time, reducing delayed bleeding risk, and lowering treatment costs, while maintaining a similar complete resection rate for lesions smaller than 10 mm when compared to conventional hot snare polypectomy. This review introduces the findings of previous studies that investigated the efficacy and safety of the CSP procedure for nonpedunculated polyps smaller than 10 mm, and describes technical points to remember when practicing CSP based on the latest evidence, including using a thin wire snare specifically designed for CSP, and observing the surrounding mucosa of the resection site with chromoendoscopy or image-enhanced endoscopy to ensure that there is no residual lesion. This review also describes the potential of expanding the indication of CSP as a treatment for lesions larger than 10 mm, those with pedunculated morphology, those located near the appendiceal orifice, and for patients under continuous antithrombotic agent therapy. Finally, the perspective on optimal treatments for recurrent lesions after CSP is also discussed, despite the limited related evidence and data.

Factors determining the resection ability of snares in cold snare polypectomy: Construction of an ex vivo model for accurately evaluating resection ability.

OBJECTIVES: Cold snare polypectomy (CSP)-dedicated snares (DSs) may have a higher resection ability than conventional snares. However, a model that can accurately and objectively evaluate and compare the resection ability of each snare has yet to be determined, and characteristics of snare parts that increase resection ability remain unknown. Therefore, we elucidated DSs' resection ability and all characteristics of the parts required for acquiring high resection ability. METHODS: An ex vivo model for evaluating resection ability was generated using human colons obtained from forensic autopsy specimens. The force required to resect a 15 mm wide human colonic mucosa (FRR) was measured using this model; if the FRR is small, the resection ability is high. Next, after measuring the stiffness of each snare part, the correlation between the stiffness and resection ability was analyzed. RESULTS: The force required to resect using SnareMaster Plus, Micro-Tech Cold Snare, Captivator Cold, Exacto Cold Snare, or Captivator II was 13.6 ± 1.0, 12.5 ± 1.2, 7.4 ± 1.2, 6.5 ± 1.0, and 28.7 ± 3.7 N, respectively. All DSs had significantly lower FRR than the conventional snare (Captivator II) and had higher resection ability (P < 0.001). A negative correlation was found between FRR and sheath or wire spindle stiffness, with correlation coefficients of 0.72 (P = 0.042) or 0.94 (P < 0.001), respectively. Moreover, 1 × 7 type wire rings had significantly higher friction coefficients than 1 × 3 type wire rings (P < 0.002). CONCLUSION: Sheath and wire spindle stiffness should be increased to increase resection ability; 1 × 7 type wire rings may be suitable for CSP-snare parts.

A Comparison of Incomplete Resection Rate of Large and Small Colorectal Polyps by Cold Snare Polypectomy.

BACKGROUND & AIMS: There are limited data regarding the safety and efficacy of cold snare polypectomy (CSP) for large colorectal polyps. We evaluated factors affecting the clinical outcomes of CSP for polyps between 5 and 15 mm in size. METHODS: This was a prospective single-center observational study involving 1000 patients undergoing colonoscopy. Polyps (5-15 mm) were removed using CSP, and biopsies were taken from the resection margin. The primary outcome was the incomplete resection rate (IRR), and was determined by the presence of residual neoplasia on biopsy. Correlations between IRR and polyp size, morphology, histology, and resection time were assessed by generalized estimating equation model. RESULTS: A total of 440 neoplastic polyps were removed from 261 patients. The overall IRR was 2.27%, 1.98% for small (5-9 mm) vs 3.45% for large (10-15 mm) polyps (P = .411). In univariate analysis, the IRR was more likely to be related to sessile serrated lesions (odds ratio [OR], 6.93; 95% confidence interval [CI], 1.88-25.45; P = .004), piecemeal resection (OR, 11.83; 95% CI, 1.20-116.49; P = .034), and prolonged resection time >60 seconds (OR, 7.56; 95% CI, 1.75-32.69; P = .007). In multivariable regression analysis, sessile serrated lesions (OR, 6.45; 95% CI, 1.48-28.03; P = .013) and resection time (OR, 7.39; 95% CI, 1.48-36.96; P = .015, respectively) were independent risk factors for IRR. Immediate bleeding was more frequent with resection of large polyps (6.90% vs 1.42%; P = .003). No recurrence was seen on follow-up colonoscopy in 37 cases with large polyps. CONCLUSIONS: CSP is safe and effective for removal of colorectal polyps up to 15 mm in size, with a low IRR. (ClinicalTrials.gov; Number: NCT03647176).

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.

Long-term outcomes of cold snare polypectomy for superficial non-ampullary duodenal epithelial tumors.

BACKGROUND AND AIM: The effectiveness of cold snare polypectomy (CSP) for superficial non-ampullary duodenal epithelial tumors (SNADETs) regarding long-term outcomes is not fully clarified. This study aimed to investigate long-term outcomes of CSP for SNADETs. METHODS: Patients diagnosed with sporadic SNADETs and treated with CSP at Chiba University Hospital between March 2015 and May 2018 were retrospectively analyzed. Long-term outcomes, short-term outcomes, and adverse events were investigated. RESULTS: In total, 35 patients with 46 lesions were included. The en-bloc resection rate was 97.8%. Thirty-seven lesions (80.4%) were diagnosed as adenomatous. The R0 resection rate for adenomatous lesions was 70.3%. Follow-up investigations more than 12 months after CSP were completed for 35 adenomatous lesions (94.6%). The median observation period after CSP was 48 months. One patient whose observation period was only 3 months died from chronic heart failure with cardiac sarcoidosis 6 months after CSP. No patient died from SNADETs. The relapse-free survival rate at 12 months after CSP was 97.1%. One recurrence (2.7%) was observed 12 months after CSP. We removed the recurrence lesion with CSP and cold forceps polypectomy. No new recurrence occurred within the observation period. No perforation or post-operative bleeding occurred for CSP. CONCLUSIONS: Cold snare polypectomy for diminutive and small SNADETs is a safe and useful procedure with a high en-bloc resection rate and long-term local control capability.

Endoscopic follow-up of mucosal defect after hot versus cold snare polypectomy in animal model.

BACKGROUND AND AIM: Cold snare polypectomy (CSP) has received increasing attention in recent years, but few studies have assessed defect repair after polypectomy. Therefore, we compared the repair of mucosal defect after CSP and hot snare polypectomy (HSP) in a rabbit model. METHODS: Resection of normal colonic mucosa using both HSP and CSP were performed in 40 male New Zealand white rabbits by an experienced endoscopist. Follow-up colonoscopy was performed after 7 and 15 days by another endoscopist. We assessed mucosal defect repair, status of healing, scar formation, and intraoperative or delayed complications (including perforation and bleeding). RESULTS: Eight animals died of intraoperative or delayed perforation; follow-up colonoscopy was performed in 32 animals. On follow-up colonoscopy at 7 days after operation, 78.1% cases in the CSP group showed healing of mucosal defect compared with none in the HSP group (P < 0.001); mucosal repair score in the CSP group was significantly higher than HSP group (P < 0.001). On follow-up colonoscopy at 15 days, mucosal defect after CSP had completely healed in all cases (100%) versus 96.9% after HSP (P = 0.313). Among these healed defects, scar formation was observed in 2 of 32 cases in the CSP group compared with 19 of 31 in the HSP group (P < 0.001). Intraoperative perforation rate was significantly higher in the HSP group (15% vs 2.5%; P = 0.048). CONCLUSIONS: Mucosal defect repair after CSP is quicker compared with HSP and is more likely to result in scarless healing. HSP is more likely to cause perforation in the thin colon walls.

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.

Underwater versus conventional cold snare polypectomy of colorectal polyps 4-9 mm in diameter: a prospective randomized controlled trial.

BACKGROUND AND AIMS: Cold snare polypectomy (CSP) has been reported as safe and effective method for the removal of small colorectal polyps. However, some studies showed low R0 resection rate. Underwater endoscopic mucosal resection is an effective technique to increase the proportions of complete resection. Therefore, the aim was to compare the rate of R0 resection of colorectal polyps 4-9 mm in diameter between conventional CSP (C-CSP) and underwater CSP (U-CSP). METHODS: This study was a prospective randomized controlled trial. A total of 198 polyps (4-9 mm) in 110 patients were enrolled between December 2019 and June 2020. The polyps were randomized to be treated with either C-CSP (100 polyps) or U-CSP (98 polyps). RESULTS: The R0 resection rate was significantly higher in U-CSP group than in C-CSP groups (84.7% vs. 59.0%; p < 0.001). The polyp retrieval rate of C-CSP and U-CSP was 94.5% and 100% (p = 0.030). The rate of polyp fragmentation of C-CSP and U-CSP group was 5.3% and 0% (p = 0.027). The resection time and retrieval time were longer in C-CSP than U-CSP (45.0 ± 37.7 s vs. 34.1 ± 21.2 s, p = 0.032 and 51.9 ± 67.7 s vs. 12.7 ± 12.4 s, p < 0.001). No clinically significant bleeding or perforation occurred in either group. CONCLUSIONS: The results of this study were excellent with U-CSP of 4-9 mm colorectal polyps in terms of R0 resection, polyp retrieval and fragmentation rate, and procedure/retrieval time. Therefore, U-CSP is a safe and effective technique for removing colorectal polyps 4-9 mm in diameter. KCT (0004530).

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.

Cold snare polypectomy for superficial non-ampullary duodenal epithelial tumor: a prospective clinical trial (pilot study).

BACKGOUND: Cold snare polypectomy (CSP) can minimize the risk of adverse events and has become a standard treatment for small colorectal polyps. CSP might also be suitable for small superficial non-ampullary duodenal epithelial tumors (SNADETs). This study aimed to evaluate the safety of CSP for SNADETs. METHODS: The major indication criteria were as follows: (1) endoscopically diagnosed SNADET, (2) ≤ 10 mm, and (3) a single primary lesion. CSP was performed using an electrosurgical snare without electrocautery. Follow-up endoscopy and scar biopsy were performed 3 months after CSP. The primary endpoint was the delayed adverse events rate. RESULTS: In total, 21 patients were enrolled. Two and 19 lesions were located in the duodenal bulb and 2nd portion, respectively; the median lesion size was 8 mm. CSP was attempted for all lesions; three lesions could not be resected without electrocautery and were removed by conventional endoscopic mucosal resection (EMR). The rate of spurting bleeding after CSP was 0%. The median procedure time was 12 min, the median resected specimen size was 12 mm, and the rate of en bloc resection was 81% (17/21). No adverse events were observed intraoperatively, with no delayed adverse events after CSP. Histopathology revealed 15 adenomas, 4 cancers (intramucosal), and 2 non-neoplastic lesions. The horizontal margins were negative/positive/undetermined in 9, 1, and 11 cases, respectively. All vertical margins were negative. Only one recurrence was detected by follow-up endoscopy 3 months after CSP. CONCLUSIONS: CSP can be performed safely for small SNADETs. CLINICAL TRIAL REGISTRATION: This trial was registered with the University Hospital Medical Information Network Clinical Trials Registry ( http://www.umin.ac.jp/ctr/index.htm ), and the registration number is UMIN000019157.

Guidelines for Colorectal Cold Polypectomy (supplement to "Guidelines for Colorectal Endoscopic Submucosal Dissection/Endoscopic Mucosal Resection").

The Japan Gastroenterological Endoscopy Society published the second edition of the "Guidelines for Colorectal Endoscopic Submucosal Dissection/Endoscopic Mucosal Resection" in 2019 to clarify the indications for colorectal endoscopic mucosal resection (EMR) and endoscopic submucosal dissection and to ensure appropriate preoperative diagnoses as well as effective and safe endoscopic treatment in front-line clinical settings. Endoscopic resection with electrocautery, including polypectomy and EMR, is indicated for colorectal polyps. Recently, the number of facilities introducing and implementing cold polypectomy without electrocautery has increased. Herein, we establish supplementary guidelines for cold polypectomy. Considering that the level of evidence for each statement is limited, these supplementary guidelines must be verified in clinical practice.