Feasibility of cold snare polypectomy in Japan: A pilot study

Cold snare endoscopic resection of nonpedunculated colorectal polyps larger than 10 mm: a systematic review and pooled-analysis

BACKGROUND AND AIMS

Hot snare polypectomy and EMR are the standard of care in resecting colorectal polyps ≥10 mm. To avoid the risk of electrocautery-induced damage, there is recent evidence about using cold snare polypectomy and cold EMR for such lesions. The aim of this pooled analysis is to report outcomes of cold snare resection for polyps ≥10 mm.

METHODS

PubMed/Medline, Embase, Google Scholar, and Cochrane databases were searched up to July 2018 to identify studies that performed cold snare resection for colorectal polyps ≥10 mm. Primary outcomes were adverse events (bleeding, perforation, and postpolypectomy abdominal pain), and secondary outcomes were the rates of complete resection, overall residual polyp rates, and rates for adenomas versus sessile serrated polyps (SSPs). Subgroup analysis was performed focusing on lesion size, location, and resection technique.

RESULTS

Eight studies were included in the final analysis that included 522 colorectal polyps with a mean polyp size of 17.5 mm (range, 10-60). The overall adverse event rate was 1.1% (95% confidence interval, CI, 0.2%-2.0%; I2 = 0%). Intra- and postprocedural bleeding rates were .7% (95% CI, 0%-1.4%) and .5% (95% CI, .1%-1.2%), respectively, with abdominal pain rate being .6% (95% CI, .1%-1.3%). Polyps ≥20 mm had a higher intraprocedural bleeding rate of 1.3% (95% CI, .7%-3.3%) and abdominal pain rate of 1.2% (95% CI, .7%-3.0%) but no delayed bleedings. No perforations were reported. The complete resection rate was 99.3% (95% CI, 98.6%-100%). Overall pooled residual rates of polyps of any histology, adenomas, and SSPs were 4.1% (95% CI, .2%-8.4%), 11.1% (95% CI, 4.1%-18.1%), and 1.0% (95% CI, .4%-2.4%), respectively, during a follow-up period ranging from 154 to 258 days.

CONCLUSIONS

The results of this systematic review and pooled analysis were excellent with cold snare resection of colorectal polyps >10 mm in terms of postpolypectomy bleeding, complete resection, and residual polyp rates. Randomized controlled trials comparing cold snare resection with hot snare resections of polyps ≥10 mm are required for further investigation.

Analysis of predictive factors for R0 resection and immediate bleeding of cold snare polypectomy in colonoscopy

BACKGROUND

Factors associated with efficacy and safety of cold snare polypectomy (CSP) are not well established. The aim is to elucidate the predictors of R0 resection and immediate bleeding of CSP.

METHODS

We retrospectively reviewed a database of patients who underwent CSP for subcentimetric polyps at the University of Tokyo Hospital in Japan. Using the data regarding the characteristics of patients and polyps, such as location, size, and macroscopic appearance; use of narrow band imaging with magnification (NBI-M); and endoscopists' experience, we revealed the predictive factors associated with R0 resection and immediate post-CSP bleeding by univariate and multivariate analyses.

RESULTS

In total, 399 polyps, in 200 patients without antithrombotics, were removed. Failure of tissue retrieval was noted in 4% of resected lesions. There was no intramucosal carcinoma observed. The overall rate of R0 resection was 46%. Multivariate analysis elucidated that the observation of the polyp with NBI-M was an independent predictor associated with R0 resection (odds ratio [OR] 1.90; p = 0.024). Although immediate post-CSP bleeding occurred in 19 polyps (4.8%), no delayed bleeding or perforation was observed. Multivariate analysis revealed protruded lesion as an independent risk factor for immediate bleeding (OR 3.54; p = 0.018).

CONCLUSIONS

A higher rate of R0 resection with CSP can be achieved by performing colonoscopy with NBI-M, than with white-light imaging. Macroscopic protruding appearance of a polyp is a risk factor for immediate bleeding.

A comparison of the resection rate for cold and hot snare polypectomy for 4-9 mm colorectal polyps: a multicentre randomised controlled trial (CRESCENT study)

OBJECTIVE

To investigate the success rate of cold snare polypectomy (CSP) for complete resection of 4-9 mm colorectal adenomatous polyps compared with that of hot snare polypectomy (HSP).

DESIGN

A prospective, multicentre, randomised controlled, parallel, non-inferiority trial conducted in 12 Japanese endoscopy units. Endoscopically diagnosed sessile adenomatous polyps, 4-9 mm in size, were randomly assigned to the CSP or HSP group. After complete removal of the polyp using the allocated technique, biopsy specimens from the resection margin after polypectomy were obtained. The primary endpoint was the complete resection rate, defined as no evidence of adenomatous tissue in the biopsied specimens, among all pathologically confirmed adenomatous polyps.

RESULTS

A total of 796 eligible polyps were detected in 538 of 912 patients screened for eligibility between September 2015 and August 2016. The complete resection rate for CSP was 98.2% compared with 97.4% for HSP. The non-inferiority of CSP for complete resection compared with HSP was confirmed by the +0.8% (90% CI -1.0 to 2.7) complete resection rate (non-inferiority p<0.0001). Postoperative bleeding requiring endoscopic haemostasis occurred only in the HSP group (0.5%, 2 of 402 polyps).

CONCLUSIONS

The complete resection rate for CSP is not inferior to that for HSP. CSP can be one of the standard techniques for 4-9 mm colorectal polyps. (Study registration: UMIN000018328).

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.

Histological Comparison of Cold versus Hot Snare Resections of the Colorectal Mucosa

BACKGROUND

Delayed postpolypectomy bleeding occurs more frequently after hot resection than after cold resection.

OBJECTIVE

To elucidate the underlying mechanism, we performed a histological comparison of tissue after cold and hot snare resections.

DESIGN

This is a prospective study, registered in the University Hospital Medical Information Network (UMIN000020104).

SETTING

This study was conducted at Aizu Medical Center, Fukushima Medical University, Japan.

PATIENTS

Fifteen patients scheduled to undergo resection of colorectal cancer were enrolled.

INTERVENTION

On the day before surgery, 2 mucosal resections (hot and cold) of normal mucosa were performed on each patient using the same snare without saline injection. The difference was only the application of electrocautery or not. Resection sites were placed close to the cancer to be included in the surgical specimen.

MAIN OUTCOME MEASURES

The primary outcome measure was the depth of destruction. Secondary outcome measures included the width of destruction, depth of the remaining submucosa, and number of vessels remaining at the resection sites. The number and diameter of vessels in undamaged submucosa were also evaluated.

RESULTS

All cold resections were limited to the shallow submucosa, whereas 60% of hot resections advanced to the deep submucosa and 20% to the muscularis propria (p < 0.001). There was no significant difference in the width of destruction. The number of remaining large vessels after hot resections trended toward fewer (p = 0.15) with a decreased depth of remaining submucosa (p = 0.007). In the deep submucosa, the vessel diameter was larger (p < 0.001) and the number of large vessels was greater (p = 0.018).

LIMITATIONS

Histological assessment was not blinded to the 2 reviewers. Normal mucosa was used instead of adenomatous tissue.

CONCLUSIONS

Hot resection caused damage to deeper layers involving more large vessels. This may explain the mechanism for the reduced incidence of hemorrhage after cold snare polypectomy. See Video Abstract at http://links.lww.com/DCR/A631.

Comparison of cold and hot snaring polypectomy for small colorectal polyps: study protocol for a randomized controlled trial

Background

Colorectal cancer remains a considerable challenge in healthcare nowadays. Most patients’ disease develops via the adenoma–carcinoma sequence; colonoscopy with polypectomy effectively reduces both mortality and incidence by removing precancerous adenomas. Previous studies showed that polypectomy without electrocautery (cold snaring polypectomy) is a safe and time-saving procedure to manage polyps < 10 mm. However, randomized controlled trials have failed to prove the superiority of cold snaring polypectomy for reducing the risk of delayed bleeding in comparison with hot snaring polypectomy, generally because of their low statistical power that was limited by sample sizes. In this study, we aim to compare the risk of delayed bleeding following cold and hot snaring polypectomy based on a large sample size.

Methods

This is a prospective multicentre randomized controlled trial to compare cold and hot snaring polypectomy for the treatment of small colorectal polyps. A total of 4258 patients with small polyps (4–10 mm) will be randomized 1:1 to each group. Colonoscopy and polypectomy will be performed by 17 experienced endoscopists at six study sites. The randomization will be performed via an online website. Pathological examination using image-enhanced endoscopy with either narrow-band imaging or chromoendoscopy will be conducted to confirm optically and histologically that complete resections have been achieved, respectively. The primary outcome measurement is the risk of delayed bleeding. The secondary outcome measurements include the number of hemoclip applications, complete eradication confirmed optically and histologically, tissue retrieval rate, procedure time, emergency unit visits, and any adverse events such as immediate bleeding or perforation.

Discussion

We hypothesize that cold snaring polypectomy can reduce the risk of delayed bleeding by avoiding thermal injury. In addition, this study will also compare cold and hot snaring polypectomy in terms of the complete eradication rate and procedure time. Based on data collected, we will demonstrate that cold snaring polypectomy is a safe, effective, and economic procedure for small colorectal polyps. The results will also provide additional data on which to develop recommendations for treating small colorectal polyps.

Trial registration

ClinicalTrials.gov, NCT03373136. Registered on 29 November 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2743-z) contains supplementary material, which is available to authorized users.

Should hot biopsy forceps be abandoned for polypectomy of diminutive colorectal polyps?

Standardized approach to polypectomy of diminutive colorectal polyps (DCPs) is lacking since cold biopsy forceps have been associated with high levels of recurrence, hot biopsy forceps are considered inadequate and risky and cold snaring is currently under investigation for its efficacy and safety. This has led to confusion and a gap in clinical practice. This article discusses the usefulness and contemporary practical applicability of hot biopsy forceps and provides well-intentioned criticism of the new European guidelines for the treatment of DCPs. Diminutive colorectal polyps are a source of frustration for the endoscopist since their small size is accompanied by a considerable risk of premalignant neoplasia and a small but non-negligible risk of advanced neoplasia and even cancer. Since the proportion of diminutive colorectal polyps is substantial and exceeds that of larger polyps, their effective removal poses a considerable workload and a therapeutic challenge. During the last decade, the introduction of cold snaring to routine endoscopy practice has attempted to overcome the use of prior techniques, such as hot biopsy forceps. It is important to recognize that with the exception of endoscopic methods that are obviously unsafe and inadequate to serve their purpose, all other interventional endoscopic methods are operator-dependent in the sense that specific expertise and training are obligatory for the success of any therapeutic intervention. Since relevant publications on hot biopsy forceps are still in favor of its careful use, as it has not yet demonstrated inferiority compared with newer techniques, it would be prudent for any medical practitioner to evaluate the available tools and judge any new proposed technique based on the evidence before it is adopted.

Width and depth of resection for small colorectal polyps: hot versus cold snare polypectomy

BACKGROUND AND AIMS

Curability is associated with resection width and depth in polypectomy. We evaluated the resection width and depth achieved with hot snare polypectomy (HSP) and cold snare polypectomy (CSP) for small colorectal polyps.

METHODS

In this single-center, prospective, randomized controlled study, patients with rectal or rectosigmoid polyps ≤10 mm in diameter were treated with HSP or CSP. Resection width was evaluated as mucosal defect size, measured immediately postprocedure and 1 day later. Resection depth was histologically evaluated using obtained specimens.

RESULTS

Fifty-two patients were enrolled. Mean lesion size was 5.6 mm with HSP (n = 27) and 5.8 mm with CSP (n = 25). Mean mucosal defect diameter immediately after HSP and CSP was 5.1 mm and 7.5 mm, respectively (P < .001). The diameter 1 day after the procedure increased by 29% (95% confidence interval [CI], 17%-41%) with HSP and decreased by 25% (95% CI, 18%-32%) with CSP (P < .001). Muscularis mucosa was obtained similarly with HSP and CSP (96% [95% CI, 82%-99%] vs 92% [95% CI, 75%-98%]; P = .603). Submucosal tissue was obtained significantly more frequently with HSP than with CSP (81% [95% CI, 63%-92%] vs 24% [95% CI, 11%-43%]; P < .001).

CONCLUSIONS

The resection width immediately after CSP was larger than that after HSP but was significantly smaller at day 1 after resection. Although the resection depth after CSP was more superficial, muscularis mucosa was obtained in most specimens. Thus, CSP has sufficient resection width and depth to enable complete polyp resection and potentially has a superior safety profile than HSP.

Extended cold snare polypectomy for small colorectal polyps increases the R0 resection rate

BACKGROUND AND STUDY AIMS

 Despite widespread use of cold snare polypectomy (CSP), the R0 resection rate is not well documented. We perform extended CSP, resecting polyps with a > 1 mm circumferential margin. The aim of this study is to compare the R0 resection rate of extended CSP with conventional CSP and to assess safety.

PATIENTS AND METHODS

From April 2014 to September 2016, 712 non-pedunculated colorectal polyps, < 10 mm in size, resected using CSP from 316 patients were retrospectively analyzed.

RESULTS

 We divided lesions into conventional CSP (n = 263) and extended CSP groups (n = 449). The baseline characteristics of these two groups were not significantly different in univariate or multivariate analyses. Sessile polyps comprised 94 % (668/712), and the remaining were flat-elevated polyps. Mean size of polyps (±standard deviation) was 4.2 ± 1.5 mm. The most frequent pathology was low grade adenoma (97 %, 689/712). The R0 resection rate was significantly higher in the extended CSP group (439/449 [98 %]) than in the conventional CSP group (222/263 [84 %], P  < 0.001). There was no delayed bleeding or perforation in either group (conventional CSP group, 0/263, 95 % confidence interval: 0.0 - 1.4 % and extended CSP group, 0/449, 95 % confidence interval: 0.0 - 0.8 %).

CONCLUSIONS

 Extended CSP results in a higher R0 resection rate compared with conventional CSP. Extended CSP did not result in a higher rate of delayed bleeding or perforation. Extended CSP is a safe and promising procedure for endoscopic resection of non-pedunculated colorectal polyps < 10 mm in size.

Safety of cold polypectomy for small colorectal neoplastic lesions: a prospective cohort study in Japan

BACKGROUND

Cold polypectomy has been widely accepted for removal of small colorectal polyps. However, no large-scale prospective study exists as for its safety in Japan. We investigated this issue in this single-center, prospective cohort study in a total of 1198 colorectal polyps resected with cold polypectomy.

PATIENTS AND METHODS

Four hundred and seventy-four patients who underwent cold polypectomy for colorectal neoplastic lesions less than 10-mm diameter between September 2014 and October 2016 were enrolled. Primary outcome was the incidence of delayed bleeding within 2 weeks after the procedure. Secondary outcomes were the rate of immediate bleeding, perforation, endoscopic en bloc resection, and advanced histology.

RESULTS

Cold polypectomy was performed on 1198 polyps in the 474 patients. No delayed bleeding or colonic perforation was observed. Immediate bleeding during the procedure, requiring endoscopic hemostasis, occurred in 97 lesions (8.1%), and all of them were successfully managed endoscopically. The endoscopic en bloc resection rate was 97.2%. Twenty-eight lesions (2.3%) were histologically diagnosed as advanced neoplasia; among them, three lesions were well-differentiated adenocarcinomas, and in two of them, a negative margin was not histologically confirmed.

CONCLUSIONS

Cold polypectomy for small colorectal polyps is a safe technique without significant complication, but careful endoscopic diagnosis at cold polypectomy is necessary to identify advanced neoplasia. The reliability of cold polypectomy in excision of polyps with high-grade neoplasia should be established before the procedure becomes standard in the excision of small colorectal polyps.

CLINICAL TRIAL REGISTRATION NUMBER

UMIN000014812.

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

BACKGROUND AND STUDY AIMS

 Cold snare polypectomy (CSP) for small colorectal polyps has lower incidence of adverse events, especially delayed postpolypectomy bleeding (DPPB). However, few data are available on comparisons of the incidence of DPPB of CSP and hot polypectomy (HP). The aim of this study was to evaluate the incidence of DPPB after CSP and compare it with that of HP. A propensity score model was used as a secondary analysis.

PATIENTS AND METHODS

 This was a retrospective cohort study conducted in a single municipal hospital. We identified 539 patients with colorectal polyps from 2 mm to 11 mm in size who underwent CSP (804 polyps in 330 patients) or HP (530 polyps in 209 patients) between July 2013 and June 2015.

RESULTS

 There were no cases of DPPB in the CSP group. Conversely, DPPB occurred in 4 patients (1.9 %) after HP, resulting in a significant difference between the CSP and HP groups (0.008 % vs 0 %, P  = 0.02). Propensity score-matching analysis created 402 matched pairs, yielding a significantly higher DPPB rate in the HP group than CSP group (0.02 % vs 0 %, P  = 0.04). However, significantly more patients in the CSP group had unclear horizontal margins that precluded assessment (83 vs 38 cases, P  < 0.001). The retrieval failure rate was significantly higher in the CSP group than in the HP group (3 % vs 0.7 %, P  = 0.01).

CONCLUSIONS

DPPB was less frequent with CSP than HP, as selected by the propensity score-matching model. Our findings indicate that CSP is recommended polypectomy in daily clinical setting. However, special care should be taken during polyp retrieval and horizontal margin assessment, and these issues could be taken into account in follow-up after CSP.

Histopathological analysis of cold snare polypectomy and its indication for colorectal polyps 10-14 mm in diameter

BACKGROUND AND AIM

Cold snare polypectomy (CSP) is commonly used for treating colorectal polyps <10 mm in diameter. We evaluated the analysis and safety of CSP for larger polyps.

METHODS

We retrospectively analyzed 1006 colorectal polyps resected with CSP. Indication for CSP was polyps 2-14 mm that were diagnosed as benign neoplastic polyp by magnifying endoscopy. Various clinicopathological characteristics were analyzed. Multivariate analyses were used to determine the independent risk factors for failure of complete CSP resection. With respect to polyp size, we compared the therapeutic outcomes between polyps <10 mm and ≥10 mm. Additionally, the presence of muscularis mucosa in resected specimens was analyzed.

RESULTS

Rates of en bloc resection and postoperative hemorrhage were 98.8% and 0.1%, respectively. Seven hundred and ninety-one neoplastic lesions were analyzed and negative margins were found in 70.5% of the lesions, Multivariate analysis showed that non-polypoid morphology, histology of intramucosal cancer + high-grade adenoma and sessile serrated adenoma and polyp were significant factors for incomplete resection. With respect to the difference between lesions ≥10 mm than in those <10 mm, rates of cancer and positive/unclear margins were significantly higher (5.0% vs 0.9%, P < 0.001; 40.6% vs 27.7%, P = 0.007) in the ≥10 mm with rates of postoperative hemorrhage not significantly different (0.8% vs 0.0%). Additionally, the loss of muscularis mucosa was found in 27.8% of all lesions.

CONCLUSION

CSP is a safe procedure for polyps 2-14 mm. However, CSP has limitations in terms of the histopathological margin and loss of muscularis mucosa in specimens.

Removal of diminutive colorectal polyps: A prospective randomized clinical trial between cold snare polypectomy and hot forceps biopsy

AIM

To compare the efficacy and safety of cold snare polypectomy (CSP) and hot forceps biopsy (HFB) for diminutive colorectal polyps.

METHODS

This prospective, randomized single-center clinical trial included consecutive patients ≥ 20 years of age with diminutive colorectal polyps 3-5 mm from December 2014 to October 2015. The primary outcome measures were en-bloc resection (endoscopic evaluation) and complete resection rates (pathological evaluation). The secondary outcome measures were the immediate bleeding or immediate perforation rate after polypectomy, delayed bleeding or delayed perforation rate after polypectomy, use of clipping for bleeding or perforation, and polyp retrieval rate. Prophylactic clipping after polyp removal wasn't routinely performed.

RESULTS

Two hundred eight patients were randomized into the CSP (102), HFB (106) and 283 polyps were evaluated (CSP: 148, HFB: 135). The en-bloc resection rate was significantly higher with CSP than with HFB [99.3% (147/148) vs 80.0% (108/135), P < 0.0001]. The complete resection rate was significantly higher with CSP than with HFB [80.4% (119/148) vs 47.4% (64/135), P < 0.0001]. The immediate bleeding rate was similar between the groups [8.6% (13/148) vs 8.1% (11/135), P = 1.000], and endoscopic hemostasis with hemoclips was successful in all cases. No cases of perforation or delayed bleeding occurred. The rate of severe tissue injury to the pathological specimen was higher HFB than CSP [52.6% (71/135) vs 1.3% (2/148), P < 0.0001]. Polyp retrieval failure was encountered CSP (7), HFB (2).

CONCLUSION

CSP is more effective than HFB for resecting diminutive polyps. Further long-term follow-up study is required.

Histological outcomes between hot and cold snare polypectomy for small colorectal polyps

BACKGROUND/AIM

To compare the complete resection rate of hot and cold snare polypectomy for small colorectal polyps.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of 233 consecutive patients with 461 colorectal polyps up to 10 mm in diameter that were treated by hot or cold snare polypectomy between April 2014 and August 2016. Lesions treated by hot snare polypectomy (n = 137) and cold snare polypectomy (n = 324) were compared. The histological complete resection rates were evaluated between the two groups. We analyzed the relationship between factors for complete resection and clinical factors using multivariate analysis.

RESULTS

There was a significantly higher complete resection rate in hot snare polypectomy than in cold snare polypectomy (70.5% vs. 47.3%; P < 0.001). In the analysis of subgroups categorized according to polyp size, the complete resection rate for hot snare polypectomy was significantly higher than that for cold snare polypectomy among polyps ≥6 mm (69.0% vs. 43.5%; P < 0.001). Among polyps ≤5 mm, no significant difference regarding the complete resection rate was observed between the methods (81.3% vs. 53.4%; P = 0.057). There was no significant difference in the incidence of adverse events between the two groups. Multivariate analysis revealed that using hot snare polypectomy (odds ratio 3.03; P < 0.001), small lesion size (odds ratio 1.57; P = 0.049), and lesion location in the left colon (odds ratio 1.73; P = 0.007) were independent factors for complete resection.

CONCLUSION

Hot snare polypectomy provides a higher complete resection rate than does cold snare polypectomy for larger (6-10 mm) subcentimeter colorectal polyps.