Comparative efficacy of cold polypectomy techniques for diminutive colorectal polyps: a systematic review and network meta-analysis. Surg Endosc. 2018;32:1149-1159. [PMID: 28812188 DOI: 10.1007/s00464-017-5786-4]

Cold Snare Resection in the Colorectum: When to Choose it, When to Avoid it, and How to Do it

Cold snaring is now the preferred resection method for the majority of colorectal polyps encountered during colonoscopy. A key advantage of cold resection over resection utilizing electrocautery is a substantially lower risk of delayed hemorrhage. Cold snare resection is preferred for all lesions ≤10 mm and for nondysplastic sessile serrated lesions of any size but should be avoided when lesions have a significant risk of submucosal invasion or fibrosis. Cold snare resection can be considered for certain lesions 11-19 mm in size and some lateral spreading lesions ≥20 mm. This review discusses tips and techniques to optimize cold snare resection.

High‐Performance Dedicated Snares with Tip Attachments can Overcome Current Disadvantages in Cold Snare Polypectomy

Cold snare polypectomy (CSP) has the disadvantage of a lower histopathological complete resection rate (HCRR) because blunt resection using CSP‐dedicated snares (DSs) causes mucosal retraction into the sheath during capture/resection. In this study, attachments are designed to narrow the sheath tip's inner diameter from 1.8 to 1.3‒1.1 mm to prevent mucosal retraction. Eight prototype snares with different component characteristics are combined with these attachments. Additionally, product version DS with attachment (Smart Snare Cold) and existing DSs, such as Exacto Cold Snare, are prepared. For snare performance evaluation, the force required to resect (FRR) human colonic mucosa, mucosal retraction amount (MRA), and clinical data are obtained. The attachments that narrowed the inner diameter to 1.3 or 1.1 mm reduce the FRR to 74.9%−93.8% and 68.0%−84.9%, respectively, and reduce the MRA to 21.0%−35.3% and 15.1%−26.8%, respectively. Thus, the reduced inner diameter improves resection ability and prevents mucosal retraction. The clinical findings show that Smart Snare Cold has significantly higher muscularis mucosa resection rates and HCRRs than Exacto Cold Snare (P < 0.001 and P = 0.003, respectively). Thus, the novel DS with tip attachment improves the HCRR and overcomes the current CSP disadvantage by simultaneously improving resection ability and preventing mucosal retraction.

HOT VERSUS COLD SNARE FOR COLORECTAL POLYPECTOMIES SIZED UP TO 10MM: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS

BACKGROUND

Colorectal cancer is the third most common cancer, and prevention relies on screening programs with resection complete resection of neoplastic lesions.

OBJECTIVE

We aimed to evaluate the best snare polypectomy technique for colorectal lesions up to 10 mm, focusing on complete resection rate, and adverse events.

METHODS

A comprehensive search using electronic databases was conducted to identify randomized controlled trials comparing hot versus cold snare resection for polyps sized up to 10 mm, and following PRISMA guidelines, a meta-analysis was performed. Outcomes included complete resection rate, en bloc resection rate, polypectomy, procedure times, immediate, delayed bleeding, and perforation.

RESULTS

Nineteen RCTs involving 8720 patients and 17588 polyps were included. Hot snare polypectomy showed a higher complete resection rate (RD, 0.02; 95%CI [+0.00,0.04]; P=0.03; I 2=63%), but also a higher rate of delayed bleeding (RD 0.00; 95%CI [0.00, 0.01]; P=0.01; I 2=0%), and severe delayed bleeding (RD 0.00; 95%CI [0.00, 0.00]; P=0.04; I 2=0%). Cold Snare was associated with shorter polypectomy time (MD -46.89 seconds; 95%CI [-62.99, -30.79]; P<0.00001; I 2=90%) and shorter total colonoscopy time (MD -7.17 minutes; 95%CI [-9.10, -5.25]; P<0.00001; I 2=41%). No significant differences were observed in en bloc resection rate or immediate bleeding.

CONCLUSION

Hot snare polypectomy presents a slightly higher complete resection rate, but, as it is associated with a longer procedure time and a higher rate of delayed bleeding compared to Cold Snare, it cannot be recommended as the gold standard approach. Individual analysis and personal experience should be considered when selecting the best approach.

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.

Effectiveness and safety of thin vs. thick cold snare polypectomy of small colorectal polyps: Systematic review and meta-analysis

Background and study aims Cold-snare polypectomy (CSP) is considered the standard of care for resection of colorectal polyps ≤10 mm. Data on the efficacy of CSP performed with thin-wire snares compared0 with thick-wire snares are conflicting. We performed a meta-analysis comparing complete resection (CR) and adverse event rates of CSP using thin-wire and thick-wire snares. Patients and methods Comparative studies of adult patients with ≧1 colorectal polyp(s) ≦10 mm who underwent CSP with thin-wire or thick-wire snares were included. We collected data on study, patient, polyp, and snare characteristics. The primary outcome was CR rate. Secondary outcomes were polyp retrieval rate, intraprocedural bleeding, delayed post-polypectomy bleeding, deep mural injury or perforation, patient discomfort, total sedation, and procedure time. We used random-effects models to calculate risk ratios for outcomes. We performed risk of bias assessments, rated the certainty of evidence, and assessed publication bias for all studies. Results We included four randomized controlled trials (RCTs) and two observational studies including 1316 patients with 1679 polyps (826 thin-wire CSPs and 853 thick-wire CSPs). There was no significant difference between thin-wire CSP (92.1%) and thick-wire CSP (87.7%) for RCTs (risk ratio [RR] 1.05, 95% confidence interval [CI] 0.94-1.16) or observational studies (78.1% versus 79.6%, RR 1.03, 95% CI 0.99-1.08). There were no significant differences in polyp retrieval rate or intraprocedural bleeding. There were no cases of delayed bleeding or perforation. Conclusions We found no differences in CR rates for CSP between thin-wire and thick-wire snares. CSP, regardless of snare type, is safe and effective for resection of small colorectal polyps.

Cold snare polypectomy compared to cold forceps polypectomy for endoscopic resection of guideline defined diminutive polyps: A systematic review and meta-analysis of randomized trials

BACKGROUND

International guidelines recommend cold snare polypectomy (CSP) for polyps  < 10 mm in size. However, recent randomized clinical trials (RCTs) showed conflicting results for the use of cold forceps polypectomy (CFP) vs. CSP for the resection of diminutive colorectal polyps (DCPs) (≤ 5 mm), especially for polyps  ≤ 3 mm. Herein we compared CFP with CSP for patients with DCPs in this meta-analysis of RCTs.

METHODS

We systematically searched the Cochrane Library, PubMed and EMBASE databases from inception to November 24, 2022, (Registration number INPLASY2022110135). The primary endpoint was DCP complete resection rate. The secondary endpoints were mean polypectomy time, polyp retrieval rate and complications.

RESULTS

Seven RCTs involving 1023 DCPs were included. The complete resection rate (91.6% vs. 94.7%) for CFP was not significantly lower for polyps ≤ 5 mm (relative risk [RR] = 1.03; 95% confidence interval [CI]: 0.98-1.07). Sub-group analysis showed that the complete resection rate (88.7% vs. 92.4%) for CFP was not significantly lower for DCPs > 3 mm (RR = 1.04; 95% CI: 0.97-1.12). Another sub-group analysis showed that the complete resection rate (97.0% vs. 96.3%) was similar for polyps ≤ 3 mm for CFP vs. CSP (RR = 1.00; 95% CI: 0.98-1.03). The mean polypectomy time was not different between CFP and CSP (95% CI: -11.86-10.18). The polyp retrieval rate (100% vs. 96.9%) was not significantly higher for CFP (RR = 1.02; 95% CI: 0.98-1.07). There were no reported complications in the included studies. The overall study quality was moderate except for the removal of polyps ≤ 5 mm (low-quality evidence).

CONCLUSION

CFP was comparable to CSP for the resection of polyps ≤ 3 mm; however, caution should be taken for DCPs > 3 mm because of the low complete resection rate (< 90%).

COLD SNARE POLYPECTOMY: A SAFE PROCEDURE FOR REMOVING SMALL NON-PEDUNCULATED COLORECTAL LESIONS

BACKGROUND

Polypectomy is an important treatment option for preventing colorectal cancer. Incomplete polyp resection (IPR) is re-cognized as a risk factor for interval cancer.

OBJECTIVE

The primary objective was to evaluate the complete polyp resection (CPR) rate for cold snare polypectomy (CSP) in small non-pedunculated polyps and, secondarily, specimen retrieval and complication rates.

METHODS

We prospectively evaluated 479 polyps <10 mm removed by CSP in 276 patients by an inexperienced endoscopist.

RESULTS

A total of 476 polyps (99.4%) were resected en bloc. A negative margin (classified as CPR) was observed in 435 polyps (90.8%). An unclear or positive margin (classified as IPR) was observed in 43 cases (9.0%) and 1 case (0.2%), respectively, for an overall IPR rate of 9.2% (44/479). The IPR rate was 12.2% in the first half of cases and 5.9% in the second half (P=0.02). Dividing into tertiles, the IPR rate was 15.0% in the first tertile, 6.9% in the second tertile, and 5.7% in the third tertile (P=0.01). Dividing into quartiles, the IPR rate was 15.8% in the first quartile and 5.9% in the fourth quartile (P=0.03). The IPR rate was 6.3% for type 0-IIa lesions and 14.1% for type 0-Is lesions (P=0.01). For serrated and adenomatous lesions, the IPR rate was 9.2%. Specimen retrieval failed in 3.6% of cases. Immediate bleeding (>30 s) occurred in 1 case (0.2%), treated with argon plasma coagulation. No delayed bleeding or perforation occurred.

CONCLUSION

CSP is a safe technique that provides good results for the resection of small non-pedunculated polyps, with a short learning curve.

Cold polypectomy techniques for small and diminutive colorectal polyps: a systematic review and network meta-analysis of randomized controlled trials

OBJECTIVE

In the management of small and diminutive polyps, cold polypectomy is favored over electrocautery polypectomy. However, the optimal cold polypectomy technique is still controversial. Hence, this review aims to investigate the most effective cold technique for small and diminutive colorectal polyps.

METHODS

We conducted a systematic review and network meta-analysis synthesizing randomized controlled trials (RCTs) which were retrieved by systematically searching PubMed, EMBASE, Web of Science, SCOPUS, and Cochrane through 10 February 2023. R software, (R version 4.2.0) and meta-insight software were used to pool dichotomous outcomes using risk ratio (RR) presented with the corresponding confidence interval (CI). Our protocol was prospectively published in PROSPERO with ID: CRD42022345619.

RESULTS

Nineteen RCTs with 3649 patients and 4800 polyps were included in our analysis. Cold techniques (cold forceps polypectomy (CFP), jumbo forceps polypectomy (JFP), dedicated cold snare polypectomy (D-CSP), conventional cold snare polypectomy (C-CSP), underwater cold snare polypectomy (U-CSP), and cold snare endoscopic mucosal resection (CS-EMR) were included in our comparative analysis. CFP was less effective in achieving complete histological resection than C-CSP (RR: 1.10 with 95% CI [1.03-1.18]), CS-EMR (RR: 1.12 with 95% CI [1.02-1.23]), D-CSP (RR: 1.17 with 95% CI [1.04-1.32]), and U-CSP (RR: 1.21 with 95% CI [1.07-1.38]). However, the rest of the comparisons showed no difference.

CONCLUSION

CFP is the least effective method for small and diminutive polyps' removal, and any snare polypectomy technique will achieve better results, warranting more large-scale RCTs to investigate the most effective snare polypectomy technique.

Impact of Cold Snare vs Cold Forceps Resection of Diminutive Adenomas on Segmental Incomplete Resection Rate

INTRODUCTION

Polypectomy technique, for diminutive lesion resection, is variable among colonoscopists using either cold snare polypectomy (CSP) or cold forceps polypectomy (CFP). While it is well described that CSP is a preferred technique to resect small lesions, there is little data evaluating the impact resection techniques have on metachronous adenoma burden. The aim of this study was to evaluate the rate of incomplete resection attributable to CSP and CFP of diminutive adenomas.

METHODS

This is a 2-center retrospective cohort study evaluating the segmental incomplete resection rate (S-IRR) of diminutive tubular adenomas (TA). S-IRR was calculated by subtracting the segmental metachronous adenoma rate in a specific colonic segment without adenoma from segments with adenoma on index colonoscopy. The primary outcome was the S-IRR of diminutive TA resected by CSP or CFP on index colonoscopy.

RESULTS

A total of 1,504 patients were included in the analysis: 1,235 with TA <6 mm and 269 with TA 6-9 mm as the most advanced lesion. The S-IRR in a segment that had a <6-mm TA incompletely resected by CFP on index colonoscopy was 13%. The S-IRR in a segment that had a <6-mm TA incompletely resected by CSP was 0%. Among 12 included colonoscopists, the range of overall S-IRR was 1.1%-24.4% with an average S-IRR of 10.3%.

DISCUSSION

S-IRR was 13% higher with CFP resection of diminutive TA than with CSP. A proposed S-IRR metric of <5% is a target goal for all diminutive polyp resection because 3/12 colonoscopists achieved this low rate. S-IRR can be used as a methodology to compare and quantify the difference in segmental metachronous adenoma burden across various polypectomy removal methods.

Cold resection for colorectal polyps: where we are and where we are going?

INTRODUCTION

Endoscopic resection of colonic precancerous lesions has been demonstrated to significantly decrease colorectal cancer (CRC) incidence and mortality. Among resection techniques, cold snare polypectomy (CSP) has been shown as a highly feasible, effective and safe option and is widely used in clinical practice, being regarded as the first-line technique for removal of small and diminutive colorectal polyps. On the other hand, conventional hot snare polypectomy (HSP) and endoscopic mucosal resection (EMR), namely the gold standard treatments for larger polyps, may be occasionally associated to complications due to electrocautery injury.

AREAS COVERED

To overcome these shortcomings of electrocautery-based resection techniques, in the last few years CSP has been increasingly assessed as a treatment option for additional indications, with a focus on nonpedunculated colorectal polyps ≥10 mm.

EXPERT OPINION

This review aims to present current and widened indications of CSP discussing the latest findings from the most remarkable studies, with an insight into technical issues, novelties and potential advances in the near future.

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.

Different endoscopic treatments for small colorectal polyps: A systematic review, pair-wise, and network meta-analysis

Background and study aims

In recent years, cold snare polypectomy (CSP) has been increasingly used for small polyps (<10 mm) instead of hot snare polypectomy (HSP). However, evidence-based research regarding the effectiveness and safety of CSP and HSP are still lacking. Additionally, for 4-10 -mm non-pedunculated polyps, the polyp removal method is still controversial. Therefore, it is clinically significant to conduct pair-wise and network meta-analyses to assess such resection methods.

Methods

We searched PubMed, Embase, and the Cochrane library for randomized controlled trials (RCTs). Only studies that involved the resection of polyps <10 mm were included. Outcomes included the complete resection rate, polyp retrieval rate, procedure-related complications, and procedure times.

Results

Overall, 23 RCTs (5,352 patients) were identified. In meta-analysis compared CSP versus HSP for polyps <10 mm, CSP showed lower complete resection rate than HSP although with no statistically significant difference [odds ratio (OR): 0.77, 95% confidence interval (CI): 0.56-1.06]. CSP showed a lower risk of major post-polypectomy complications compared to HSP (OR: 0.28, 95% CI: 0.11-0.73). In the network meta-analysis for 4-10 mm non-pedunculated polyps, HSP, and endoscopic mucosal resection (EMR) showed a higher complete resection rate than CSP (OR: 2.7, 95% CI: 1.3-9.2 vs. OR: 2.6, 95% CI: 1.0-10) but a significantly longer time than CSP (WMD: 16.55 s, 95% CI [7.48 s, 25.25 s], p < 0.001), (WMD: 48.00 s, 95% CI [16.54 s, 79.46 s], p = 0.003). Underwater CSP ranked third for complete resection with no complications.

Conclusion

For <10 mm polyps, CSP is safer than HSP, especially for patients taking antithrombotic drugs. For 4-10 mm non-pedunculated polyps, HSP, and EMR have higher complete resection rates than CSP.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022315575.

Progression in clinical application of cold snare resection technique in colorectal polyps

The cold snare resection technique has been recommended by European and American societies and gradually applied in clinical practice. However, due to the operating habits of endoscopists and the insufficient understanding of the cold resection technique, it has not been fully used in colorectal polyps. In this paper, we review the application status of cold snare resection technique, its use in patients treated with antithrombotic drugs, and postoperative histological changes.

Outcomes of thin versus thick-wire snares for cold snare polypectomy: a systematic review and meta-analysis

BACKGROUND/AIMS

Cold snare polypectomy (CSP) is commonly used for the resection of colorectal polyps ≤10 mm. Data regarding the influence of snare type on CSP effectiveness are conflicting. Hence, this meta-analysis aimed to compare the outcomes and safety of thin- and thick-wire snares for CSP.

METHODS

A comprehensive search of the literature published between 2000 and 2021 was performed of various databases for comparative studies evaluating the outcomes of thin- versus thick-wire snares for CSP.

RESULTS

Five studies with data on 1,425 polyps were included in the analysis. The thick-wire snare was comparable to the thin-wire snare with respect to complete histological resection (risk ratio [RR], 1.03; 95% confidence interval [CI], 0.97-1.09), overall bleeding (RR, 0.98; 95% CI, 0.40-2.40), polyp retrieval (RR, 1.01; 95% CI, 0.97-1.04), and involvement of submucosa in the resection specimen (RR, 1.28; 95% CI, 0.72-2.28). There was no publication bias and a small study effect, and the relative effects remained the same in the sensitivity analysis.

CONCLUSION

CSP using a thin-wire snare has no additional benefit over thick-wire snares in small colorectal polyps. Factors other than snare design may play a role in improving CSP outcomes.

A Pilot Randomized Trial of Polypectomy Techniques for 4 to 6 mm Colonic Polyps

BACKGROUND AND GOALS

There is variation in polypectomy techniques for resection of small polyps. Aim was to compare techniques for 4 to 6 mm polyps for recurrent adenoma, efficiency, and adverse events and to establish methodological factors for definitive trial.

MATERIALS AND METHODS

The study was a randomized controlled trial. Outpatients with ≥1, 4 to 6 mm polyps were randomized to cold forceps (CF), cold snare (CS), and hot snare (HS). Polypectomy site was marked with SPOT to assess for recurrence at the original polypectomy site during surveillance colonoscopy. To assess feasibility of a definitive trial we measured (1) rates of patient refusal, participation, ineligibility; (2) retention; (3) recurrent neoplasia; and (4) sample size for a definitive trial.

RESULTS

Three hundred fifty-three patients were randomized to 1 of the 3 polypectomy techniques, of whom 260 (73.6%) completed the initial colonoscopy (mean age 57 y, 50.4% women), with 91, 87, and 82 patients randomized to CF, CS, and HS polypectomy, respectively. Mean time for polyp resection for CF, CS, and HS were 198.8, 58.5, and 96.8 seconds, respectively, with CS and HS requiring less time than CF (P<0.001). One hundred sixty-four (63.1%) completed surveillance colonoscopy. Polyp recurrences were 9 (14.5%) with CF, 5 (9.6%) with CS, and 0 (0%) with HS. Although the recurrence relative risks with CF and CS polypectomy were 1.84 and 1.65 as compared with HS, respectively, neither was statistically significant.

CONCLUSIONS

CS and HS polypectomy require less time than CF. HS polypectomy may have a lower risk for recurrent neoplasia. High attrition rate is a challenge in conducting randomized controlled trial with polyp recurrence as endpoint.

Quality Indicators for the Detection and Removal of Colorectal Polyps and Interventions to Improve Them

Modifiable risk factors for postcolonoscopy colorectal cancer include suboptimal lesion detection (missed neoplasms) and inadequate lesion removal (incomplete polypectomy) during colonoscopy. Competent detection and removal of colorectal polyps are thus fundamental to ensuring adequate colonoscopy quality. Several well-researched quality metrics for polyp detection have been implemented into clinical practice, chief among these the adenoma detection rate. Less data are available on quality indicators for polyp removal, which currently include complete resection rates and skills assessment tools. This review summarizes the available literature on quality indicators for the detection and removal of colorectal polyps, as well as interventions to improve them.

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.

Comparison of cold biopsy forceps vs cold snare for diminutive colorectal polyp removal: A multicenter non-inferiority randomized controlled trial

BACKGROUND

European guidelines recommends the use of cold snare polypectomy (CSP) for removal of diminutive colorectal polyps (DCP). However, for DCP < 4 mm cold biopsy forceps (CBF) may be optional. We aimed to compare the efficacy of CSP with CBF for removal of DCP in routine colonoscopy.

METHODS

We conducted a multicenter non-inferiority randomized controlled trial. After screening, 123 patients were prospectively included and 180 DCPs were removed by either CBF or CSP after randomization (1:1). The primary end-point was the histological complete resection rate defined by negative additional biopsies taken from the edge of the polypectomy ulcer site.

RESULTS

Among DCPs, 121 (67.2%) adenomas or sessile serrated lesions were considered for the analysis. Polyps were 4 [1-5] mm in size, mostly flat (55.4%) and located in the proximal colon (44.6%). The en bloc resection rate was higher in the CSP group than the CBF group (91.7% vs. 42.6%, p < 0.001). The histological complete resection rate was comparable in the two groups (93.33% vs 90.16%; p = 0.527), even for polyps < 4 mm (91.30% vs 91.30%; p = 1). All specimens were retrieved and there was no difference in terms of procedure times and adverse events. Finally, univariate analysis did not identify any potential factor associated with complete resection rate.

CONCLUSION

In this study, CSP was comparable to CBF for the removal of DCP. Therefore, CBF may be considered as an alternative technique for resection of DCP, together with CSP, ClinicalTrials.gov registry (NCT04727918).

Cold versus hot polypectomy/endoscopic mucosal resection-A review of current evidence

BACKGROUND

Colonoscopy with polypectomy substantially reduces the risk of colorectal cancer (CRC) but interval cancers still account for 9% of all CRCs, some of which are due to incomplete resection.

AIM

The aim of this review is to compare the outcomes of cold and hot endoscopic resection and provide technical tips and tricks for optimizing cold snare polypectomy.

RESULTS

Cold snare polypectomy (CSP) is the standard technique for small (≤10 mm) colorectal polyps. For large colonic polyps (>10 mm), hot resection techniques with use of electrocautery (polypectomy or endoscopic mucosal resection) were recommended until recently. However, the use of electrocoagulation brings serious adverse effects in up to 9% of the patients, such as delayed bleeding, post-polypectomy syndrome and perforation. In recent years, efforts have been made to improve the polypectomy with cold snare in order to avoid these adverse effects of electrocoagulation without compromising the efficacy of the resection. Several authors have recently shown that the complication rates of CSP of polyps >10 mm is close to zero and recurrence rates varies between 5-18%. Lower recurrence rates are found in serrated lesions (<8%).

Evidence-based clinical practice guidelines for management of colorectal polyps

BACKGROUND

The Japanese Society of Gastroenterology (JSGE) published ''Daicho Polyp Shinryo Guideline 2014'' in Japanese and a part of this guideline was published in English as "Evidence-based clinical practice guidelines for management of colorectal polyps" in the Journal of Gastroenterology in 2015. A revised version of the Japanese-language guideline was published in 2020, and here we introduce a part of the contents of revised version.

METHODS

The guideline committee discussed and drew up a series of clinical questions (CQs). Recommendation statements for the CQs were limited to items with multiple therapeutic options. Items with established conclusions that had 100% agreement with previous guidelines (background questions) and items with no (or old) evidence that are topics for future research (future research questions: FRQs) were given descriptions only. To address the CQs and FRQs, PubMed, ICHUSHI, and other sources were searched for relevant articles published in English from 1983 to October 2018 and articles published in Japanese from 1983 to November 2018. The Japan Medical Library Association was also commissioned to search for relevant materials. Manual searches were performed for questions with insufficient online references.

RESULTS

The professional committee created 18 CQs and statements concerning the current concept and diagnosis/treatment of various colorectal polyps, including their epidemiology, screening, pathophysiology, definition and classification, diagnosis, management, practical treatment, complications, and surveillance after treatment, and other colorectal lesions (submucosal tumors, nonneoplastic polyps, polyposis, hereditary tumors, ulcerative colitis-associated tumors/carcinomas).

CONCLUSIONS

After evaluation by the moderators, evidence-based clinical practice guidelines for management of colorectal polyps were proposed for 2020. This report addresses the therapeutic related CQs introduced when formulating these guidelines.

Endoscopic resection of local recurrences of diminutive polyps by cold forceps polypectomy

OBJECTIVES

Cold forceps polypectomy (CFP) is an effective treatment for diminutive colorectal polyps. However, polyps occasionally recur, and there is no consensus on their long-term clinical management. Therefore, we investigated the short- and long-term clinical outcomes of re-CFP for recurrent diminutive colorectal polyps.

MATERIALS AND METHODS

This was a follow-up of a multicenter, prospective study investigating the clinical outcomes of diminutive colorectal polyps excised by CFP with narrowband imaging-enhanced endoscopy and jumbo forceps. We evaluated short-term outcomes of re-CFP and patients at 1-year follow-up post re-CFP for recurrent colorectal polyps to determine long-term recurrence rates. Additionally, complete resection rates, clinicopathological features, number of forceps bites, and rate of short-term adverse events managed by re-CFP were evaluated.

RESULTS

At 1-year follow-up, local recurrence was identified in 18 patients from the original study. The mean size of local recurrent polyps was 1.5 ± 0.6 mm, and all recurrent lesions were < 3 mm. Re-CFP could successfully excise locally recurrent polyps in all cases. All recurrent lesions were low-grade adenomas; no adverse events were reported. Additionally, 16 of 18 patients were evaluated endoscopically at 2-year follow-up; no recurrence was observed.

CONCLUSIONS

Recurrent lesions following initial CFP were small and pathologically benign, and re-CFP was an effective treatment.

Polypectomy Techniques

Polyps in the upper and lower gastrointestinal tract can be premalignant or malignant lesions that can be treated endoscopically in early stages to prevent morbidity and more invasive procedures. This article critically reviews the techniques available and provides recommendations for endoscopic polypectomy.

Dedicated Cold Snare vs. Traditional Snare for Polypectomy of Diminutive and Small Lesions in a Porcine Model: A Research Group for Endoscopic Instruments and Stents (REIS) Study

BACKGROUND/AIMS

The aim of this in vivo animal study was to evaluate the effectiveness and safety of dedicated cold snare (DCS) compared with those of traditional snare (TS) for cold snare polypectomy (CSP).

METHODS

A total of 36 diminutive (5 mm) and 36 small (9 mm) pseudolesions were made by electrocoagulation in the colons of mini-pigs.

RESULTS

For the diminutive lesions, there were no significant differences in technical success rate, procedure time, or complete resection rate between the DCS and TS groups; the rate of uneven resection margin in the DCS group was significantly lower than that of the TS group. For small lesions, technical success rate and complete resection rate were significantly higher in the DCS group than in the TS group (100% [18/18] vs. 55.6% [10/18], p=0.003; 94.4% [17/18] vs. 40% [4/10], p=0.006). In addition, the procedure duration was significantly shorter, and the rate of uneven resection margin was significantly lower in the DCS group (28.5 sec vs. 66.0 sec, p=0.006; 11.1% [2/18] vs. 100% [10/10], p<0.001). Two cases of perforation occurred in the DCS group. Multivariate analysis revealed that DCS use was independently associated with complete resection.

CONCLUSION

DCS is superior to TS in terms of technical success, complete resection, and reducing the duration of the procedure for CSP of small polyps.

Indications for Cold Polypectomy Stratified by the Colorectal Polyp Size: A Systematic Review and Meta-Analysis

Objectives:

Cold polypectomy (CP) is widely used because of its safety profile. This systematic review and meta-analysis aimed to clarify the indications for CP based on polyp size.

Methods:

We searched PubMed and the Cochrane Library for randomized controlled trials that compared cold snare polypectomy (CSP) and other procedures for polyps ≤10 mm. Large-scale prospective observational studies were also searched to assess delayed bleeding rates. The studies were integrated to assess the risk ratio for incomplete resection rates according to polyp size. The Cochrane risk of bias tool was used to evaluate the study bias. The certainty of cumulative evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation system.

Results:

We found 280 articles and reviewed their eligibility. We selected and extracted 12 randomized controlled trials and 3 prospective observational studies. The risk ratio of incomplete resection of polyps ≤10 mm using CSP compared with hot snare polypectomy (HSP) was 1.36 (95% confidence interval [CI], 0.92-2.01). The risk ratio for incomplete removal using CSP compared with cold forceps polypectomy (CFP) was 0.50 (95% CI, 0.31-0.82). For polyps ≤3 mm, the risk ratio of CSP compared with CFP was 1.40 (95% CI, 0.39-4.95). Certainty of cumulative evidence was considered low. No delayed bleeding after CP was reported after the treatment of 3446 polyps.

Conclusions:

CSP and HSP may result in the same complete resection rates for polyps ≤10 mm. For polyps ≤3 mm, CFP and CSP may have the same resection rates (PROSPERO registration number: CRD42019122132).

Discrepancy between self-reported and actual colonoscopy polypectomy practices for the removal of small polyps

BACKGROUND AND AIMS

Cold snare polypectomy (CSP) is associated with higher rates of complete resection compared with cold biopsy forceps (CBF) for the removal of small polyps (4-9 mm). This study aimed to evaluate self-reported polypectomy preferences and actual practice patterns among endoscopists at an academic center and to identify factors associated with the use of CSP for small polyps.

METHODS

In phase A, endoscopists completed a survey evaluating preferences for polypectomy techniques. In phase B, we performed a retrospective analysis of all consecutive colonoscopies with polypectomy (January 2016 to September 2018). Uni- and multivariate analysis were performed to identify factors associated with CSP for small polyps.

RESULTS

Nineteen of 26 (73%) endoscopists completed the survey (phase A); 3 (15.8%) were interventional endoscopists. Most respondents indicated that they use CSP (89.5%) for small polyps and identified no reasons for choosing CBF over CSP (73.7%). In phase B, we identified 1118 colonoscopies with 2625 polypectomies for polyps ≤9 mm. Most diminutive polyps (≤3 mm) were removed with CBF (819 of 912; 90%). CBF (46.2%) was also preferentially used for removal of small polyps (n = 1713), followed by hot snare polypectomy (27.2%), and CSP (26.6%). On multivariate analysis, interventional endoscopists were associated with a higher likelihood of using CSP for small polyps (odds ratio, 1.38; 95% confidence interval, 1.07-1.79; P = .01).

CONCLUSIONS

Significant discrepancy exists between self-reported preferences and actual polypectomy practices. CBF is still preferentially used over CSP for the removal of polyps sized 4-9 mm; further strategies are needed to monitor and implement adequate polypectomy techniques.

Clinical implications of decision making in colorectal polypectomy: an international survey of Western endoscopists suggests priorities for change

Introduction  Colonoscopy prevents colorectal cancer via the detection and resection of premalignant polyps. This effect may be attenuated by variations in polypectomy, with multiple techniques available and a wide range of experience amongst endoscopists. We assessed current practice against the best available contemporary evidence. Methods  An online survey was distributed to members of the gastroenterological and surgical societies of seven countries during July 2017. Images of colorectal polyps were presented and respondents requested to provide the polypectomy technique they would employ in their daily practice. Responses were compared to the evidence-based techniques in the 2017 ESGE Colorectal Polypectomy Guideline. Results  In total, 707 endoscopists (627 physicians, 71 surgeons, 9 nurse endoscopists, median practice duration 18 years) completed the survey. Of these, 3.1 % selected hot biopsy forceps and 5.2 % hot snare polypectomy (without submucosal lifting) to remove a 3 mm ascending colon polyp. Only 43.3 % selected cold snare polypectomy (CSP) to remove an 8 mm ascending colon polyp. Surgical referral was selected by 16.7 % of respondents for a 45 mm transverse colon polyp without endoscopic evidence of submucosal invasive cancer (SMIC). Endoscopic resection was selected by 12.0 % for an 80 mm sigmoid polyp with imaging consistent with deep SMIC, and a further 26.4 % selected tertiary endoscopist referral, suggesting they had not appreciated that it was endoscopically unresectable. Conclusion  CSP is underutilized for small polyp resection despite its favorable safety and efficacy. Benign polyps are commonly referred for surgery and overt SMIC is underappreciated using endoscopic imaging. Addressing these issues may reduce diathermy-related adverse events, surgery, and unnecessary colonoscopic procedures for patients and reduce rates of post-colonoscopy colorectal cancer.

Jumbo biopsy forceps versus cold snares for removing diminutive colorectal polyps: a prospective randomized controlled trial

BACKGROUND AND AIMS

Cold snare polypectomy (CSP) and jumbo forceps polypectomy (JFP) have been shown to be effective for removing diminutive colorectal polyps (DCPs) (≤5 mm). However, no study has compared complete resection rates between CSP and JFP for DCPs. The aim of this study was to compare the efficacy and safety of JFP with CSP for the removal of DCPs.

METHODS

This was a prospective randomized controlled trial from 2 tertiary-care referral centers. A total of 1003 patients were screened, and 169 patients with 196 DCPs were enrolled. The main outcome was complete polyp resection rate.

RESULTS

Of 196 diminutive polyps, 177 (90.3%) were adenomatous polyps. The overall complete resection rate was 92.1% (163/177). The complete resection rate was not significantly different between JFP and CSP groups (92.0% vs 92.2%; P = .947). JFP achieved complete resection rates comparable with CSP for polyps >3 mm (90.3% vs 89.8%; P = .928). Polypectomy procedure time, tissue retrieval rate, and rate of postpolypectomy adverse events were not significantly different between the 2 groups.

CONCLUSIONS

Both JFP and CSP achieved complete resection rates of >90% for DCPs. Thus, JFP may be considered for polypectomy of DCPs. (International clinical trial registry number: KCT0002805.).

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.

BEST POLYPECTOMY TECHNIQUE FOR SMALL AND DIMINUTIVE COLORECTAL POLYPS: A SYSTEMATIC REVIEW AND META-ANALYSIS

BACKGROUND

Polypectomy of colorectal polyps is the mainstay of colorectal cancer prevention. Identification of the best polypectomy technique is imperative.

OBJECTIVE

This review aims at comparing efficacy of nine different resection methods for small colorectal polyps (<10 mm).

METHODS

We searched and selected only randomized controlled trials. Primary outcome was complete resection rates of small polyps by histological eradication. Secondary outcomes were: adverse events, retrieval tissue failures rates and duration of procedure.

RESULTS

Eighteen trials including 3215 patients and 5223 polyps were analysed. Overall, cold polypectomy had a significantly shorter time of procedure than hot polypectomy (RD -5.92, 95%CI -9.90 to -1.94, P<0.05), with no statistical difference on complete histological eradication (RD 0.08, 95%CI -0.03 to 0.19, P>0.05). Regarding cold polypectomy techniques, cold snare was found superior to cold forceps on complete and en-bloc resection rates and less time consuming. When comparing endoscopic mucosal resection (EMR) with hot-snare and cold-snare, the latter showed no-inferiority on histological eradication, adverse events or retrieval tissue failure rates.

CONCLUSION

Cold polypectomy is the best technique for resection of small colorectal polyps. Among cold methods, dedicated cold snare was found superior on histological eradication. Cold snare endoscopic mucosal resection might be considered an option for polyps from 5 to 9 mm.

Endoscopic resection techniques for colorectal neoplasia: Current developments

Endoscopic polypectomy and endoscopic mucosal resection (EMR) are the established treatment standards for colorectal polyps. Current research aims at the reduction of both complication and recurrence rates as well as on shortening procedure times. Cold snare resection is the emerging standard for the treatment of smaller (< 5mm) polyps and is possibly also suitable for the removal of non-cancerous polyps up to 9 mm. The method avoids thermal damage, has reduced procedure times and probably also a lower risk for delayed bleeding. On the other end of the treatment spectrum, endoscopic submucosal dissection (ESD) offers en bloc resection of larger flat or sessile lesions. The technique has obvious advantages in the treatment of high-grade dysplasia and early cancer. Due to its minimal recurrence rate, it may also be an alternative to fractionated EMR of larger flat or sessile lesions. However, ESD is technically demanding and burdened by longer procedure times and higher costs. It should therefore be restricted to lesions suspicious for high-grade dysplasia or early invasive cancer. The latest addition to endoscopic resection techniques is endoscopic full-thickness resection with specifically developed devices for flexible endoscopy. This method is very useful for the treatment of smaller difficult-to-resect lesions, e.g., recurrence with scar formation after previous endoscopic resections.

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.

Impact of 2 generational improvements in colonoscopes on adenoma miss rates: results of a prospective randomized multicenter tandem study

BACKGROUND AND AIMS

Numerous randomized studies have shown that changing certain features of colonoscopes, usually incorporated when switching from one endoscope generation to the next, mostly do not increase adenoma yield. There is, however, indirect evidence that it may be necessary to skip one instrument generation (ie, changing from one generation to the next but one) to achieve this effect.

METHODS

We compared the latest-generation colonoscopes from one company (Olympus Exera III, 190-C) with the next to last one (Olympus 160/5-C) in a prospective multicenter study randomized for the order of colonoscopes in a tandem fashion, involving 2 different examiners. Patients with increased risk for colorectal neoplasia undergoing colonoscopy (positive fecal occult blood test, personal/familial history of colorectal cancer/adenoma, rectal bleeding, recent change in bowel movements) were included. The primary outcome was the adenoma miss rate with the 190 (190-C) colonoscope in comparison with the 160/5 colonoscope (160/5-C).

RESULTS

A total of 856 patients (48.8% male; mean age, 58.3 years) with a personal (41%) or family (38%) history of colorectal neoplasia, rectal bleeding (19%), and other indications were included. Of the 429 patients in the 190-C first group, 16.6% (95% confidence interval [CI], 13.0%-20.1%) had at least one adenoma missed during the first procedure, compared with 30.2% (95% CI, 25.9%-34.6%) in the group with 160/5-C first (P < .001). Similarly, the adenoma detection rate during the first colonoscopy was 43.8% versus 36.5% (P = .030) for 190-C versus 160/5-C, respectively.

CONCLUSIONS

This randomized tandem trial showed lower adenoma miss rates and higher adenoma detection rates for the newer 190 colonoscopes compared with the 160/5 series. These results suggest that it takes multiple improvements, such as those implemented over 2 instrument generations, before an effect on adenoma (miss) rate can be observed. (Study registration number: ISRCTN 2010-A01256-33.).