Numerous guidelines recommend photodocumentation (PD) of large colorectal polyps ≥10 mm (LP) preresection relative to an open snare or forceps, and suggests postresection PD of the clear resection base. However, no quality metrics have been proposed. We recently reported that preresection and postresection PD occurred in 82% and 52% of 1693 resected LPs, respectively; however, the quality of PD was not ascertained.

To assess the quality of preresection and postresection PD of LPs based on consensus definitions.

Images of LPs resected between 2016 and 2021 were reviewed by 3 gastroenterologists and 1 fellow for assessment of (1) high-quality preresection PD (enough polyp visualized to estimate size), (2) presence of a tool relative to the LP, (3) estimated polyp size, and (4) high-quality postresection PD (clean base without visible polyp tissue). Confidence levels in PD quality assessment and estimated size were provided. Agreement on size was assessed using free-marginal kappa.

One hundred ninety-nine LPs with both preresection and postresection images were included. Reviewers' assessment of high-quality preresection PD ranged from 49% to 82% and 51% to 70% for high-quality postresection PD. One percent of preresection images demonstrated an open snare or forceps relative to the LP. Only 74% to 89% of polyps were estimated by reviewers to be ≥10 mm [Kappa=0.66 (95% CI: 0.48-0.64)]. High-level confidence in PD quality and size assessment was lowest in the fellow compared with established gastroenterologists.

Although guidelines recommend PD of LPs preresection and postresection, the quality of PD appears suboptimal. Quality standards in LP PD should be considered and the impact of high-quality PD on patient outcomes should be studied.

Incomplete resection rates vary among endoscopists performing cold snare polypectomy. Cold snare endoscopic mucosal resection (CS-EMR) is the technique of cold resection after submucosal injection to reduce incomplete resection. This study aimed to evaluate the efficacy and safety of CS-EMR for small colorectal polyps compared to hot snare endoscopic mucosal resection (HS-EMR). Preplanned sample size required 70 polyps to CS-EMR group or HS-EMR group, respectively. Patients with polyps sized 6-9 mm were randomly allocated to either the CS-EMR or the HS-EMR group. The primary outcome was residual or recurrent adenoma (RAA) rate. A total of 70 and 68 polyps were resected using CS-EMR and HS-EMR, respectively. In the intention-to-treat population, the RAA rate was 0% in the CS-EMR group and 1.5% in the HS-EMR group (risk difference [RD], - 1.47; 95% confidence interval [CI] - 4.34 to 1.39). En bloc resection rate was 98.6% and 98.5% (RD, - 0.04; 95% CI - 4.12 to 4.02); the R0 resection rate was 55.7% and 82.4% (RD, - 27.80; 95% CI - 42.50 to  - 13.10). The total procedure time was 172 s (IQR, 158-189) in the CS-EMR group and 186 s (IQR, 147-216) in the HS-EMR group (median difference, - 14; 95% CI - 32 to 2). Delayed bleeding was 2.9% vs 1.5% (RD, 1.37; 95% CI - 3.47 to 6.21) in both groups, respectively. CS-EMR was non-inferior to HS-EMR for the treatment of small colorectal polyps. CS-EMR can be considered one of the standard methods for the removal of colorectal polyps sized 6-9 mm.

Tip-in endoscopic mucosal resection (EMR) has a high en bloc resection rate for large colorectal neoplasms. However, non-experts' performance in Tip-in EMR has not been investigated. We investigated whether Tip-in EMR can be achieved effectively and safely even by non-experts.

This retrospective study included consecutive patients who underwent Tip-in EMR for 15-25 mm colorectal nonpedunculated neoplasms at a Japanese tertiary cancer center between January 2014 and December 2020. Baseline characteristics, treatment outcomes, learning curve of non-experts, and risk factors of failing self-achieved en bloc resection were analyzed.

A total of 597 lesions were analyzed (438 by experts and 159 by non-experts). The self-achieved en bloc resection (69.8% vs 88.6%, P < 0.001) and self-achieved R0 resection (58.3% vs 76.5%, P < 0.001) rates were significantly lower in non-experts with <10 cases of experience than in experts, but not in non-experts with >10 cases. Adverse event (P = 0.165) and local recurrence (P = 0.892) rates were not significantly different between experts and non-experts. Risk factors of failing self-achieved en bloc resection were non-polypoid morphology (OR 3.4, 95% CI 1.6-7.3, P = 0.001), lesions with an underlying semilunar fold (OR 3.6, 95% CI 1.6-7.3, P < 0.001), positive non-lifting sign (OR 3.1, 95% CI 1.2-8.0, P = 0.023), and non-experts with an experience of ≤10 cases (OR 3.6, 95% CI 2.1-6.3, P < 0.001).

The clinical outcomes of Tip-in EMR for 15-25 mm lesions performed by non-experts were favorable.

Studies suggest that patients with type two diabetes mellitus (T2D) may be at increased risk of post-colonoscopy colorectal cancer (PCCRC). We investigated clinical and molecular characteristics and survival of T2D patients with PCCRC to elucidate how T2D-related PCCRC may arise.

We identified T2D patients with colorectal cancer (CRC) from 1995 to 2015 and computed prevalence ratios (PRs) comparing clinical and molecular characteristics of CRC in T2D patients with PCCRC vs. in T2D patients with colonoscopy-detected CRC (dCRC). We also followed T2D patients from the diagnosis of PCCRC/dCRC until death, emigration, or study end and compared mortality using Cox-proportional hazards regression models adjusted for sex, age, year of CRC diagnosis, and CRC stage.

Compared with dCRC, PCCRC was associated with a higher prevalence of proximal CRCs (54% vs. 40%; PR: 1.43, 95% confidence interval [CI] 1.27-1.62) in T2D patients. We found no difference between PCCRC vs. dCRC for CRC stage, histology, and mismatch repair status. The proportion of CRCs that could be categorized as PCCRC decreased over time. Within one year after CRC, 63% of PCCRC vs. 78% of dCRC patients were alive (hazard ratio [HR] 1.85 [95% CI 1.47-2.31]). Within five years after CRC, 44% of PCCRC vs. 54% of dCRC patients were still alive (HR 1.44 [95% CI 1.11-1.87]).

The increased prevalence of proximally located PCCRCs and the poorer survival may suggest overlooked colorectal lesions as a predominant explanation for T2D-related PCCRC, although altered tumor progression cannot be ruled out.

Practicing endoscopists frequently perform and teach screening colonoscopies and polypectomies, but there is no standardized method to train and assess physicians who perform polypectomy procedures. The authors created a polypectomy simulation-based mastery learning (SBML) curriculum and hypothesized that completion of the curriculum would lead to immediate improvement in polypectomy skills and skill retention at 6 and 12 months after training.

The authors performed a pretest-posttest cohort study with endoscopists who completed SBML and were randomized to follow-up at 6 or 12 months from May 2021 to August 2022. Participants underwent SBML training, including a pretest, a video lecture, deliberate practice, and a posttest. All learners were required to meet or exceed a minimum passing standard on a 17-item skills checklist before completing training and were randomized to follow-up at 6 or 12 months. The authors compared simulated polypectomy skills performance on the checklist from pretest to posttest and posttest to 6- or 12-month follow-up test.

Twenty-four of 30 eligible participants (80.0%) completed the SBML intervention, and 20 of 24 (83.3%) completed follow-up testing. The minimum passing standard was set at 93% of checklist items correct. The pretest passing rate was 4 of 24 participants (16.7%) compared with 24 of 24 participants (100%) at posttest ( P < .001). There were no significant differences in passing rates from posttest to combined 6- and 12-month posttest in which 18 of 20 participants (90.0%) passed.

Before training and despite years of clinical experience, practicing endoscopists demonstrated poor performance of polypectomy skills. SBML was an effective method for practicing endoscopists to acquire and maintain polypectomy skills during a 6- to 12-month period.

Inflammatory bowel disease (IBD) increases the risk of dysplasia and colorectal cancer (CRC). Moreover, colitis-associated CRC is responsible for a disproportionate number of CRC-related mortality. For this reason, societies recommend screening and surveillance colonoscopy as the standard of care for patients with ulcerative colitis and Crohn's colitis. Nonetheless, interval cancer defined as CRC detected within the appropriate surveillance interval might still occur despite following guideline recommendations. Even though there is limited data on risk factors associated with interval CRC in IBD, patient and disease-associated factors and technical aspects of the surveillance might play a role. This review aims to provide information on the epidemiology of interval CRC in IBD, the factors that might be associated with its occurrence, and the challenges of CRC screening and dysplasia management in patients with IBD.

Serrated lesions (SLs) including traditional serrated adenomas (TSA), large hyperplastic polyps (HP) and sessile serrated lesions (SSLs) are associated with high incomplete resection rates. Margin ablation combined with EMR (EMR-T) has become routine to reduce local recurrence while cold snare polypectomy (CSP) is becoming recognized as equally effective for large SLs. Our aim was to evaluate local recurrence rates (LRR) and the use of margin ablation in preventing recurrence in a retrospective cohort study.

Patients undergoing resection of ≥15 mm colorectal SLs from 2010-2022 were identified through a pathology database and electronic medical records search. Hereditary CRC syndromes, first follow-up > 18 months or no follow-up, surgical resection were excluded. Primary outcome was LRRs (either histologic or visual) during the first 18-month follow-up. Secondary outcomes were LRRs according to size, and resection technique.

191 polyps in 170 patients were resected (59.8% women; mean age, 65 years). The mean size of polyps was 22.4 mm, with 107 (56.0%) ≥20 mm. 99 polyps were resected with EMR, 39 with EMR-T, and 26 with CSP. Mean first surveillance was 8.2 mo. Overall LRR was 18.8% (36/191) (16.8% for ≥20 mm, 17.9% for ≥30 mm). LRR was significantly lower after EMR-T when compared with EMR (5.1% vs. 23.2%; p = 0.013) or CSP (5.1% vs. 23.1%; p = 0.031). There was no difference in LRR between EMR without margin ablation and CSP (p = 0.987).

The local recurrence rate for SLs ≥15 mm is high with 18.8% overall recurrence. EMR with thermal ablation of the margins is superior to both no ablation and CSP in reducing LRRs.

Neoplastic polyp removal is important for colorectal cancer prevention. Endoscopists have proposed cold snare endoscopic mucosal resection (CS-EMR) as a solution to solve positive cutting edges and postoperative bleeding. However, many controversies regarding its specific performance in practice have been reported. The aim of this pooled analysis was to report the efficacy and safety of CS-EMR.

PubMed/Medline, Embase, Google Scholar, and the Cochrane Library searched up to January 2022 to identify studies in which CS-EMR was performed for the removal of colorectal polyps measuring less than 20 mm. The primary outcome was the complete resection rate (CRR), and the secondary outcome was the rate of adverse events.

Eleven studies were included in the final analysis, which included 861 colorectal polyps. The overall CRR with CS-EMR was 96.3% (95% CI, 93.9-98.2%). The early and delayed bleeding rates of CS-EMR were 3.1% (95% CI, 1.2-5.5%) and 1.4% (95% CI, 0.6-2.4%), respectively. There were no statistical significances between CS-EMR and cold snare polypectomy (CSP) in terms of the CRR and adverse events, as well as CS-EMR and hot snare endoscopic mucosal resection (HS-EMR).

For resecting colorectal polyps measuring ≤20 mm, CS-EMR is an effective attempt. However, compared with CSP and HS-EMR, CS-EMR did not improve the efficiency and safety of polypectomy as expected. Multicenter randomized controlled trials are needed to compare CSP with CS-EMR in the resection of <10 mm polyps and HSP with CS-EMR in the resection of ≥10 mm polyps.

Colonoscopy is effective to detect and remove colorectal lesions. However, after a negative colonoscopy, cancers could be detected during the interval follow-up. This study was designed to identify characteristics and risk factors for postcolonoscopy colorectal cancer - interval type.

Medical records of individuals who were newly diagnosed with colorectal cancer between January 2018 and December 2019 were reviewed. Clinical, demographic, and endoscopic variables were analyzed. Those with the diagnosis of colorectal cancer between two consecutive colonoscopies performed within the appropriated surveillance range were considered to have postcolonoscopy colorectal cancer - interval type. A comparison between the group of patients with non-postcolonoscopy colorectal cancer - interval type and the group of patients with postcolonoscopy colorectal cancer - interval type was then performed.

During the study period, 491 patients were newly diagnosed with colorectal cancer. Among them, 61 (12.4%) had postcolonoscopy colorectal cancer - interval subtype. Postcolonoscopy colorectal cancer - interval type was three times more prevalent on the proximal colon (p = 0.014) and was associated with the presence of two or more cardiovascular risk factors (aOR = 4.25; p = 0.016), cholecystectomy in the past (aOR = 10.09; p = 0.019), and family history of colorectal cancer on a first-degree relative (aOR = 4.25; p = 0.006). Moreover, isolated cardiovascular risk factors revealed a protective effect for the absence of all cardiovascular risk factors (aOR = 20; p = 0.034). The ROC curve associated with the multivariate model revealed a predictive power of 77.8% (p < 0.001).

Postcolonoscopy colorectal cancer - interval type is more common in the proximal colon and in patients with a family history (first-degree relative) of colorectal cancer, two or more cardiovascular risk factors, and a history of cholecystectomy. All of these are easily detectable in clinical practice and may be of extreme importance in the control of postcolonoscopy colorectal cancer in the near future.

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

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

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

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

Large (≥20 mm) nonpedunculated colorectal polyps (LNPCPs) may have synchronous LNPCPs in up to 18% of cases. The nature of this relationship has not been investigated. We aimed to examine the relationship between individual LNPCP characteristics and synchronous colonic LNPCPs.

Consecutive patients referred for resection of LNPCPs over 130 months until March 2022 were enrolled. Serrated lesions and mixed granularity LNPCPs were excluded from analysis. Patients with multiple LNPCPs resected were identified, and the largest was labelled as dominant. The primary outcome was the identification of individual lesion characteristics associated with the presence of synchronous LNPCPs.

There were 3149 of 3381 patients (93.1%) who had a single LNPCP. In 232 (6.9%) a synchronous lesion was detected. Solitary lesions had a median size of 35 mm with a predominant Paris 0-IIa morphology (42.9%) and right colon location (59.5%). In patients with ≥2 LNPCPs, the dominant lesion had a median size of 40 mm, Paris 0-IIa (47.6%) morphology, and right colon location (65.9%). In this group, 35.8% of dominant LNPCPs were non-granular compared with 18.7% in the solitary LNPCP cohort. Non-granular (NG)-LNPCPs were more likely to demonstrate synchronous disease, with left colon NG-LNPCPs demonstrating greater risk (odds ratio, 4.78; 95% confidence interval, 2.95-7.73) than right colon NG-LNPCPs (odds ratio, 1.99; 95% confidence interval, 1.39-2.86).

We found that 6.9% of LNPCPs have synchronous disease, with NG-LNPCPs demonstrating a greater than 4-fold increased risk. With post-colonoscopy interval cancers exceeding 5%, endoscopists must be cognizant of an individual's LNPCP phenotype when examining the colon at both index procedure and surveillance.

gov, NCT01368289; NCT02000141; NCT02198729.

Various endoscopic resection techniques have been proposed for the treatment of nonpedunculated colorectal polyps sized 6-20 mm, however the optimal technique still remains unclear.

A comprehensive literature review was conducted for randomized controlled trials (RCTs), investigating the efficacy of endoscopic treatments for the management of 6-20 mm nonpedunculated colorectal polyps. Primary outcomes were complete and en bloc resection rates and adverse event rate was the secondary. Effect size on outcomes is presented as risk ratio (RR; 95% confidence interval [CI]).

Fourteen RCTs (5219 polypectomies) were included. Endoscopic mucosal resection(EMR) significantly outperformed cold snare polypectomy(CSP) in terms of complete [(RR 95%CI): 1.04(1.00-1.07)] and en bloc resection rate [RR:1.12(1.04-1.21)]. EMR was superior to hot snare polypectomy (HSP) [RR:1.04(1.00-1.08)] regarding complete resection, while underwater EMR (U-EMR) achieved significantly higher rate of en bloc resection compared to CSP [RR:1.15(1.01-1.30)]. EMR yielded the highest ranking for complete resection(SUCRA-score 0.81), followed by cold-snare EMR(CS-EMR,SUCRA-score 0.76). None of the modalities was different regarding adverse event rate compared to CSP, however EMR and CS-EMR resulted in fewer adverse events compared to HSP [RR:0.44(0.26-0.77) and 0.43(0.21-0.87),respectively].

EMR achieved the highest performance in resecting 6-20 mm nonpedunculated colorectal polyps, with this effect being consistent for polyps 6-9 and ≥10 mm; findings supported by very low quality of evidence.

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.

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.

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.

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).

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

Colorectal cancer is one of the most common cancers globally. Recent reductions in mortality rates have been primarily attributed to screening programs. The State of Qatar established a national bowel cancer screening program in 2016.

Fecal immunochemical testing (FIT) was used for average-risk individuals aged 50 to 74 years. Fecal immunochemical testing -positive participants were referred for total colonoscopy to detect polyps and cancers.

Among 32,751 FIT invitees, 11,130 took the test, and 758 (6%) of those were FIT positive. Of these, 375 (56.13%) participants underwent a colonoscopy, and polyps were detected in 198 (52.8%) and cancers in 19 (5.1%) participants. The adenoma detection rate exceeded 40%.

The high yield of polyps and cancers in the screening program justifies an active, resource-intensive, and organized bowel cancer screening effort. The high adenoma detection rate in a FIT-based program warrants recalibration of target adenoma detection rates in screening programs.

Endoscopic screening with polypectomy reduces the incidence of colorectal cancer (CRC). Incomplete polyp removal may attenuate the effect of screening. This randomized trial compared cold snare polypectomy (CSP) with hot snare polypectomy (HSP) in terms of complete polyp resection.

We included patients ≥ 40 years of age at eight hospitals in four countries who had at least one non-pedunculated polyp of 4-9 mm detected at colonoscopy. Patients were randomized 1:1 to CSP or HSP. Biopsies from the resection margins were obtained systematically after polypectomy in both groups. We hypothesized that CSP would be non-inferior to HSP, with a non-inferiority margin of 5 %. Logistic regression models were fitted to identify the factors explaining incomplete resection.

425 patients, with 601 polyps, randomized to either CSP or HSP were included in the analysis. Of 318 polyps removed by CSP and 283 polyps removed by HSP, 34 (10.7 %) and 21 (7.4 %) were incompletely resected, respectively, with an adjusted risk difference of 3.2 % (95 %CI -1.4 % to 7.8 %). There was no difference between the groups in terms of post-polypectomy bleeding, perforation, or abdominal pain. Independent risk factors for incomplete removal were serrated histology (odds ratio [OR] 3.96; 95 %CI 1.63 to 9.66) and hyperplastic histology (OR 2.52; 95 %CI 1.30 to 4.86) in adjusted analyses.

In this randomized trial, non-inferiority for CSP could not be demonstrated. Polyps with serrated histology are more prone to incomplete resection compared with adenomas. CSP can be used safely for small polyps in routine colonoscopy practice.

The use of forceps for removal of nondiminutive polyps is associated with incomplete resection compared with snare polypectomy. However, few studies have characterized the frequency of forceps polypectomy for nondiminutive polyps or identified strategies to improve this practice. To address this gap, we estimated the prevalence and predictors of forceps polypectomy in clinical practice and examined the effectiveness of a multicomponent intervention to reduce inappropriate forceps polypectomy.

We retrospectively reviewed all colonoscopies with polypectomies performed at 2 U.S. health systems between October 1, 2017, and September 30, 2019. We used a mixed-effects logistic regression model to examine the effect of a multicomponent intervention, including provider education and a financial incentive, to reduce inappropriate forceps polypectomy, defined as use of forceps polypectomy for polyps ≥5 mm.

A total of 9968 colonoscopies with 25,534 polypectomies were performed by 42 gastroenterologists during the study period. Overall, 8.5% (n = 2176) of polyps were removed with inappropriate forceps polypectomy. Inappropriate forceps polypectomy significantly decreased after the intervention (odds ratio [OR], 0.34, 95% confidence interval [CI], 0.30-0.39), from 11.4% (n = 1539) to 5.3% (n = 637). Predictors of inappropriate forceps polypectomy included inadequate bowel prep (OR, 1.25; 95% CI, 1.06-1.47), polyps in the right colon (vs left: OR, 1.29; 95% CI, 1.09-1.51), and number of polyps removed (OR, 0.96; 95% CI, 0.94-0.97). Inappropriate forceps polypectomy also varied by gastroenterologist (median OR, 3.43). In a post hoc analysis, the proportion of polyps >2 mm removed with forceps decreased from 50.0% before the intervention to 43.0% after it (OR, 0.62; 95% CI, 0.58-0.68).

Inappropriate forceps polypectomy is common but modifiable. The proportion of nondiminutive polyps removed with forceps polypectomy should be considered as a quality measure.

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.

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.

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.

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.

Postcolonoscopy colorectal cancers (PCCRCs) account for up to 50% of colorectal cancers (CRCs) in patients with inflammatory bowel disease (IBD). We investigated characteristics of IBD patients with PCCRC and their survival.

We identified IBD patients (ulcerative colitis [UC] and Crohn's disease) diagnosed with CRC from 1995 to 2015. We defined PCCRC as diagnosed between 6 and 36 months, and detected CRC (dCRC) as diagnosed within 6 months after colonoscopy. We computed prevalence ratios comparing PCCRC vs dCRC and followed up patients from the diagnosis of PCCRC/dCRC until death, emigration, or study end. Mortality was compared using Cox proportional hazards regression models adjusted for sex, age, year of CRC diagnosis, and stage. The main analyses focused on patients with UC.

Among 23,738 UC patients undergoing colonoscopy, we identified 352 patients with CRC, of whom 103 (29%) had PCCRC. Compared with dCRC, PCCRC was associated with a higher prevalence of metastatic cancer (33% vs 20%; prevalence ratio, 1.64; 95% CI, 1.13-2.38), cancers showing mismatch repair deficiency (79% vs 56%; prevalence ratio, 1.40; 95% CI, 1.13-1.72), and proximally located cancers (54% vs 40%; prevalence ratio, 1.34; 95% CI, 1.06-1.69). The 1- and 5-year adjusted hazard ratios of death for PCCRC vs dCRC among UC patients were 1.29 (95% CI, 0.77-2.18) and 1.24 (95% CI, 0.86-1.79), respectively.

The characteristics of UC-related PCCRC suggest tumor biology as an important factor in the progression to cancer. However, the prognosis of PCCRC appears similar to that of dCRC.

For decades, conventional adenomas were the only known precursor lesions of colorectal cancer (CRC). Accordingly, education and research regarding CRC prevention were mainly focused on adenomas. The groundbreaking discovery that serrated polyps (SPs) also have the potential to develop into CRCs, and seem to account for a considerable proportion of sporadic CRCs, has led to a paradigm shift in the prevention, diagnosis, and treatment of CRC. Studies in recent years have led to our current understanding of SPs and associated CRC, but a lot of work is still to be done to further improve knowledge about this serrated neoplasia pathway and the clinical management of SPs and serrated polyposis syndrome (SPS). In this review, we reflect on the current understanding of SPs with respect to terminology, detection, resection, and surveillance and reflect on the management of SPS.

Colonoscopy is an effective screening procedure in colorectal cancer prevention programs; however, colonoscopy practice can vary in terms of lesion detection, classification, and removal. Artificial intelligence (AI)-assisted decision support systems for endoscopy is an area of rapid research and development. The systems promise improved detection, classification, screening, and surveillance for colorectal polyps and cancer. Several recently developed applications for AI-assisted colonoscopy have shown promising results for the detection and classification of colorectal polyps and adenomas. However, their value for real-time application in clinical practice has yet to be determined owing to limitations in the design, validation, and testing of AI models under real-life clinical conditions. Despite these current limitations, ambitious attempts to expand the technology further by developing more complex systems capable of assisting and supporting the endoscopist throughout the entire colonoscopy examination, including polypectomy procedures, are at the concept stage. However, further work is required to address the barriers and challenges of AI integration into broader colonoscopy practice, to navigate the approval process from regulatory organizations and societies, and to support physicians and patients on their journey to accepting the technology by providing strong evidence of its accuracy and safety. This article takes a closer look at the current state of AI integration into the field of colonoscopy and offers suggestions for future research.

To compare recurrence rates among three endoscopic treatment modalities for 5-9 mm left-sided colorectal polyps.

Consecutive adults referred for elective colonoscopy (1/2015-1/2018) with at least one polyp of eligible size (5-9 mm) located distally to the splenic flexure were randomly assigned (1:1:1) to one of three treatment modalities: (1) cold snare polypectomy (CSP), (2) hot snare polypectomy (HSP) and (3) argon plasma coagulation (APC) ablation (50-60 W, flow: 2 l/min). The polyp site was marked with an endoscopic tattoo, and a follow-up colonoscopy with scar biopsies was performed >6 months after the index procedure. Outcomes were polyp recurrence rate and occurrence of complications.

One hundred nineteen patients were enrolled, of whom 112 (62.5% males, mean age 61.1 ± 9.9 years) with 121 polyps (CSP, 39; HSP, 45; APC, 37) returned for follow-up colonoscopy. Mean polyp size was 6.7 ± 0.91 mm, 58% were located in the sigmoid, 33% in the rectum and 8% in the descending colon. The majority of polyps resected by CSP or HSP were neoplastic (tubular adenomas: 25.9%, tubulovillous adenomas: 11.1% and sessile serrate adenomas/polyps: 17.5%). No cases of delayed bleeding or perforation occurred. Scar biopsies at follow-up colonoscopy (performed after a mean interval of 13.4 ± 3.8 months) revealed 7 (5.8%) cases of polyp recurrence, showing no significant difference among the three treatment groups [CSP, 3/39 (7.7%); HSP, 1/45 (2.2%); APC, 2/37 (5.4%); P = 0.51).

CSP, HSP and APC-ablation are effective and well-tolerated treatment modalities for 5-9 mm left-sided colorectal polyps. The present randomized study did not detect any difference in polyp recurrence rate among the three endoscopic techniques.

Using the algorithm of the World Endoscopy Organisation (WEO), we have studied retrospectively all colorectal cancers, both detected and non-detected by the Basque Country screening programme from 2009 to 2017. In the screening programme 61,335 colonoscopies were performed following a positive Faecal Immunochemical test (FIT) (≥20 µg Hb/g faeces) and the 128 cases of post-colonoscopy colorectal cancer (PCCRC) detected were analysed. Among them, 50 interval type PCCRCs were diagnosed (before the recommended surveillance), 0.8 cases per 1000 colonoscopies performed, and 78 non-interval type PCCRCs (in the surveillance carried out at the recommended time or delayed), 1.3 per 1000 colonoscopies. Among the non-interval type PCCRCs, 61 cases were detected in the surveillance carried out at the recommended time (type A) and 17 when the surveillance was delayed (type B), 1 case per 1000 colonoscopies performed and 0.28 cases per 1000 colonoscopies performed, respectively. Interval type PCCRC is less frequent than non-interval type PCCRC. In interval type PCCRCs, CRCs detected in advanced stages (stages III-IV) were significantly more frequent than those detected in early stages, compared to those of non-interval type PCCRCs (OR = 3.057; 95% CI, 1.410-6.625; p < 0.005). Non-interval type B PCCRCs are less frequent than non-interval type A PCCRCs, but the frequency of advanced stages is higher in interval type B PCCRCs.

Colorectal adenoma detection has been associated with cancer prevention effectiveness. Clinical trials have been conceived to determine the role of several interventions to increase the detection of pre-malignant lesions. We hypothesized that colonoscopy in the setting of such trials have higher pre-malignant lesion detection rates.

We performed a cross-sectional study comparing the detection of pre-malignant lesions in 147 randomly sampled non-research colonoscopies and 294 from the control groups of two prospective trials. We included outpatients aged 40-79 who had no personal history of CRC.

Baseline characteristics were similar between the two groups. The pre-malignant lesion detection rate in the trial vs control group was 65.6% vs 44.2% (OR 2.411; 95% CI 1.608-3.614; p<0.001), the polyp detection rate was 73.8% vs 59.9% (OR 1.889; 95% CI 1.242-2.876; p=0.003), the adenoma detection rate was 62.6% vs 44.2% (OR 2.110; 95% CI 1.411-3.155; p<0.001) and the sessile serrated lesion detection rate was 17% vs 4.1% (OR 4.816; 95% CI 2.014-11.515; p<0.001). The mean number of pre-malignant and sessile serrated lesions was 1.70 vs 1.06 (p=0.002) and 0.32 vs 0.06 (p=0.001) lesions per colonoscopy. In a multivariate analysis with each single potential confounder, there was no significant change in any of the study outcomes.

Patients involved in colonoscopy trials may benefit from higher quality examinations, as shown by the higher detection rates. Institutions should consider supporting clinical research in colonoscopy as a simple means to improve colonoscopy quality and colorectal cancer prevention.

Incomplete resection of neoplastic polyps is considered an important reason for the development of colorectal cancer. However, there are no data on the natural history of polyps that were incompletely removed.

To examine the risk for metachronous neoplasia during surveillance colonoscopy after documented incomplete polyp resection.

Observational cohort study of patients who participated in the CARE (Complete Adenoma REsection) study (2009 to 2012).

2 academic medical centers.

Patients who had resection of a 5- to 20-mm neoplastic polyp, had a documented complete or incomplete resection, and had a surveillance examination.

Segment metachronous neoplasia, defined as the proportion of colon segments with at least 1 neoplastic polyp at first surveillance examination, was measured. Segment metachronous neoplasia was compared between segments with a prior incomplete polyp resection (incomplete segments) and those with a prior complete resection (complete segments), accounting for clustering of segments within patients.

Of 233 participants in the original study, 166 (71%) had at least 1 surveillance examination. Median time to surveillance was shorter after incomplete versus complete resection (median, 17 vs. 45 months). The risk for any metachronous neoplasia was greater in segments with incomplete versus complete resection (52% vs. 23%; risk difference [RD], 28% [95% CI, 9% to 47%]; P = 0.004). Incomplete segments also had a greater number of neoplastic polyps (mean, 0.8 vs. 0.3; RD, 0.50 [CI, 0.1 to 0.9]; P = 0.008) and greater risk for advanced neoplasia (18% vs. 3%; RD, 15% [CI, 1% to 29%]; P = 0.034). Incomplete resection was the strongest independent factor associated with metachronous neoplasia (odds ratio, 3.0 [CI, 1.12 to 8.17]).

Potential patient selection bias due to incomplete follow-up.

This natural history study found a statistically significantly greater risk for future neoplasia and advanced neoplasia in colon segments after incomplete resection compared with segments with complete resection.

None.

Some colorectal cancers (CRCs) may be missed during colonoscopies. We aimed to determine the clinicopathological, biological, and genomic characteristics of post-colonoscopy CRCs (PCCRCs).

Of the 1,619 consecutive patients with 1,765 CRCs detected between 2008 and 2016, 63 patients with 67 PCCRCs, when colonoscopies were performed 6-60 months before diagnosis, were recruited. After excluding patients with inflammatory bowel disease, familial polyposis syndrome, CRCs that developed from diminutive adenomatous polyps, and recurrent CRCs after endoscopic resection, 32 patients with 34 PCCRCs were enrolled. The lesions' clinicopathological features, mismatch repair proteins (MMRs), and genomic alterations were investigated.

The overall PCCRC-5y rate, rate of intramucosal (Tis) lesions, and rate of T1 or more deeply invasive cancers were 3.7% (66/1,764), 3.9% (32/820), and 3.6% (34/944), respectively. Thirty-three patients' MMRs were investigated; 7 (21%) exhibited deficient MMRs (dMMRs), comprising 4 with T2 or more deeply invasive cancers and 5 whose lesions were in the proximal colon. Twenty-three tumors' genomic mutations were investigated; PIK3CA had mutated in 5 of 6 T2 or more deeply invasive cancers, of which, 4 were located in the proximal colon. Two patients with dMMRs and BRAF mutations had poor prognoses. Sixty-one percent (17/28) of the macroscopic type 0 lesions were superficial. All superficial Tis and T1 PCCRCs were detected <24 months after the negative colonoscopies. They were distributed throughout the colon and rectum.

PCCRCs may be invasive cancers in the proximal colon that exhibit dMMRs and/or PIK3CA mutations or missed early CRCs especially superficial lesions.

One-piece endoscopic mucosal resection (EMR) for lesions >15 mm is still unsatisfactory, and attempted 1-piece EMR for lesions >25 mm can increase perforation risk. Therefore, modifications to ensure 1-piece EMR of 15- to 25-mm lesions would be beneficial. The aim of this study was to investigate whether Tip-in EMR, which anchors the snare tip within the submucosal layer, increases en bloc resection for 15- to 25-mm colorectal lesions compared with EMR.

In this prospective randomized controlled trial, patients with nonpolypoid colorectal neoplasms of 15-25 mm in size were recruited and randomly assigned in a 1:1 ratio to undergo Tip-in EMR or standard EMR, stratified by age, sex, tumor size category, and tumor location. The primary endpoint was the odds ratio of en bloc resection adjusted by location and size category. Adverse events and procedure time were also evaluated.

We analyzed 41 lesions in the Tip-in EMR group and 41 lesions in the EMR group. En bloc resection was achieved in 37 (90.2%) patients undergoing Tip-in EMR and 30 (73.1%) who had EMR. The adjusted odds ratio of en bloc resection in Tip-in EMR vs EMR was 3.46 (95% confidence interval: 1.06-13.6, P = 0.040). The Tip-in EMR and EMR groups did not differ significantly in adverse event rates (0% vs 4.8%) or median procedure times (7 vs 5 minutes).

In this single-center randomized controlled trial, we found that Tip-in EMR significantly improved the en bloc resection rate for nonpolypoid lesions 15-25 mm in size, with no increase in adverse events or procedure time.

"Serrated polyps" is the term used for epithelial lesions of the colon and rectum that have a "sawtooth" pattern on the polyp's surface and crypt epithelium. The so-called serrated pathway describes the progression of sessile serrated adenomas and traditional serrated adenomas to colorectal cancer. Said pathway is well recognized as an alternative mechanism of carcinogenesis and accounts for 15-30% of the cases of colorectal cancer. It also explains a large number of the cases of interval colorectal cancer. Thus, due to their usually aggressive and uncertain behavior, serrated polyps are of the utmost importance in colorectal cancer screening. Our aim was to review the history, current nomenclature, pathophysiology, morphology, treatment, and surveillance of serrated polyps.

Background and study aims  Adequate removal of precancerous polyps is an independent factor in colorectal cancer prevention. Despite advances in polypectomy techniques, there is an increasing rate of surgery for benign polyps. We assessed whether surgical resection is properly utilized for benign colorectal polyps. Patients and methods  We identified 144 patients with surgical resection for benign colorectal polyps. Polyp location, size and the indication for and type of surgery were obtained. For the purposes of this analysis, we assumed that gastroenterologists should assess polyp size accurately, endoscopically resect polyps < 2 cm, and treat incompletely excised polyps on follow-up. Results  A total of 118 patients (82 %) were referred to surgery without attempted endoscopic removal. In 26 (22 %) of 118, the macroscopic polyp size was < 2 cm (23 in right, 3 in the left colon) and 18 (15 %; 14 in the right, four in the left colon) were found to have had size overestimation during endoscopy. Twenty-two (15 %) of 144 underwent surgical resection for incomplete endoscopic resection of adenomas (16 in the right, 6 in the left colon); 12 (54.5 %) had a residual polyp size of < 2 cm (10 in the right colon; 2 in the left colon). In-hospital mortality was 0.7 % and morbidity was 20.1 %. Conclusions  Of the patients, 41 % could have potentially avoided surgical intervention (37 polyps < 2 cm and/or size overestimations precluding endoscopic polypectomy and 22 incomplete resections). When including polyps with size ≥ 2 to < 4 cm, the percentage of patients with avoidable surgery reached 80 %. This confirms the need to develop standardized quality metrics for endoscopic polypectomies and for better overall training of endoscopists performing these procedures. Given the risks of surgery, referral to an experienced gastroenterologist should be considered as a first step.

 Endoscopic screening with polypectomy has been shown to reduce colorectal cancer incidence in randomized trials. Incomplete polyp removal and subsequent development of post-colonoscopy cancers may attenuate the effect of screening. This study aimed to quantify the extent of incomplete polyp removal.

 We included patients aged 50-75 years with nonpedunculated polyps ≥ 5 mm removed during colonoscopy at four hospitals in Norway. To evaluate completeness of polyp removal, biopsies from the resection margins were obtained after polypectomy. Logistic regression models were fitted to identify factors explaining incomplete resection.

 246 patients with 339 polyps underwent polypectomy between January 2015 and June 2017. A total of 12 polyps were excluded due to biopsy electrocautery damage, and 327 polyps in 246 patients (mean age 67 years [range 42-83]; 52 % male) were included in the analysis. Overall, 54 polyps (15.9 %) in 54 patients were incompletely resected. Histological diagnosis of the polyp (sessile serrated lesions vs. adenoma, odds ratio [OR] 10.9, 95 % confidence interval [CI] 3.9-30.1) and polyp location (proximal vs. distal colon, OR 2.8, 95 %CI 1.0-7.7) were independent risk factors for incomplete removal of polyps 5-19 mm. Board-certified endoscopists were not associated with lower rates of incomplete resection compared with trainees (14.0 % vs. 14.2 %), OR 1.0 (95 %CI 0.5-2.1).

Incomplete polyp resection was frequent after polypectomy in routine clinical practice. Serrated histology and proximal location were independent risk factors for incomplete resection. The performance of board-certified gastroenterologists was not superior to that of trainees.

Screening for colorectal cancer (CRC) with colonoscopy has been credited for the majority of the decline in mortality over the past 40 years. However, colonoscopy is hampered by frequent interval cancers (ICs) occurring within 36 months after the last examination. Risk factors for IC imply that most misses are amenable to improved colonoscopic techniques. This study had two primary objectives: (1) to determine whether the proportion of persons with ICs has declined in association with improved approaches to the quality of colonoscopy and (2) to determine unrecognized causes for missed diagnoses.

This is a retrospective, single-center study of persons with CRC having been diagnosed within 6-36 months since the most recent colonoscopy between 2006 and 2015. Participants, ages 50 and 89 years, were evaluated specifically for technical features and findings of the most recent colonoscopy.

Thirty-nine persons met the inclusion criteria for IC. Mean age was 69.3 years, range 50-86 years, women were 58%, races included 95% Caucasian, 2.5% Asian, and 2.5% African-American, and history of a first-degree relative with CRC was 26%. Symptoms led to the interval diagnosis in 83%, including iron-deficient anemia (38%), bleeding (25%), abdominal/pelvic pain (18%), and change in bowel habit (2.5%). Preexisting neoplasia was present in 72%. The CRC was located in the proximal colon in 51%. Late-stage disease was present in 45%. When compared to persons with an initial diagnosis of screen-detected late-onset CRC, differences were noted for older age, more women, more with a family history of CRC, and more with late-stage disease. The ratio of interval cancers to new cancers ranged between 6 and 11.5%. Findings indicating a "difficult examination" were observed in 14 cases (36%) compared to "easy or no difficulty" examinations in 25 (65%) cases. In a biennial analysis of IC rates between 2006 and 2015, the percentage of IC remained stable between 6 and 11.5%.

ICs have been stable constituting 6-11.5% of all CRCs. A "difficult examination" was often associated with IC, may be a risk factor for this problem, and may be an important clue warranting further study.

Colorectal cancer (CRC) is the third most common cancer in men and women in the United States. CRC screening efforts are directed toward removal of adenomas and sessile serrated lesions and detection of early-stage CRC. The purpose of this article is to update the 2009 American College of Gastroenterology CRC screening guidelines. The guideline is framed around several key questions. We conducted a comprehensive literature search to include studies through October 2020. The inclusion criteria were studies of any design with men and women age 40 years and older. Detailed recommendations for CRC screening in average-risk individuals and those with a family history of CRC are discussed. We also provide recommendations on the role of aspirin for chemoprevention, quality indicators for colonoscopy, approaches to organized CRC screening and improving adherence to CRC screening. CRC screening must be optimized to allow effective and sustained reduction of CRC incidence and mortality. This can be accomplished by achieving high rates of adherence, quality monitoring and improvement, following evidence-based guidelines, and removing barriers through the spectrum of care from noninvasive screening tests to screening and diagnostic colonoscopy. The development of cost-effective, highly accurate, noninvasive modalities associated with improved overall adherence to the screening process is also a desirable goal.

the process that leads to the development of colorectal cancer takes many years and most tumors originate from polyps and non-polypoid lesions. Techniques of endoscopic resection are surgical treatment options, even in case of large lesions or with initial invasion. This study aimed to evaluate the recurrence and surgical complementation rates after endoscopic resection of large colorectal non-pedunculated lesions.

a retrospective, longitudinal and descriptive trial was performed via an analysis of colonoscopies with the resection of non-pedunculated lesions larger than 3 cm, performed between 2014 and 2017.

sixty-two lesions were included from 61 patients and 32 (52.5 %) were female. The age ranged from 36 to 89 years, with a mean age of 60.5 years. Lesions had an average diameter of 40.08 mm, ranging from 30 to 80 mm. Regarding the location of the lesions, the most frequent colonic segments were the ascending and rectum, both accounting for 22.6 %. Considering the morphologic endoscopic classification, 67.7 % were granular laterally spreading tumors (LST), 38.8 % were homogeneous granular and 29 % were mixed granular. The most frequent histological types were tubulovillous adenoma (30.7 %) and intramucosal adenocarcinoma (29 %). The resection technique was piecemeal mucosectomy in 85.5 %. Five lesions were removed by en bloc mucosectomy, two (3.2 %) by endoscopic submucosal dissection (ESD) and two (3.2 %) by a hybrid technique. The recurrence rate was 25.8 %. Three patients needed complementary surgical treatment and the clinical success of endoscopic treatment was 95.1 %.

recurrence rate after endoscopic resection of large colorectal lesions was 25.8 % and surgical complementation rate due to failure in the endoscopic treatment of recurrence was 4.8 %.

Incomplete resection of neoplastic colorectal polyps can result in postcolonoscopy colorectal cancer. We performed a systematic review and meta-analysis to determine the incomplete resection rate (IRR) of colorectal polyps and associated factors.

We searched MEDLINE, EMBASE, EBM Reviews, and CINAHL to identify full-text articles that reported IRRs of polyps 1 to 20 mm, published until March 2019. Exclusion criteria were studies of inflammatory bowel disease cohorts, referrals for difficult polypectomy, polyp sizes larger than 20 mm, and endoscopic submucosal resection and/or dissection as polypectomy approaches. IRRs were calculated based on findings from biopsies taken at polypectomy sites or assessments of margins of resected polyps. The primary outcome was IRR for snare removal of polyps 1 to 20 mm. Secondary outcomes included IRR for polyps 1 to 10 mm and 10 to 20 mm, IRR for hot and cold snare removal of polyps 1 to 10 mm and 10 to 20 mm, IRR of snare removal with or without submucosal injection, and IRR for forceps and cold snare removal of polyps 1 to 5 mm.

We identified 6148 reports and used 32 studies, with a total of 9282 polyps, in our quantitative analysis. The IRR for snare removal of polyps 1 to 20 mm was 13.8% (95% confidence interval [CI] 10.3-17.3; 13 studies, 5128 polypectomies). IRRs were 15.9% for snare removal of polyps 1 to 10 mm (95% CI 9.6-22.1; 9 studies, 2531 polypectomies) and 20.8% for snare removal of polyps 10 to 20 mm (95% CI 12.9-28.8; 6 studies, 412 polypectomies). The IRR for hot snare removal of polyps 1 to 10 mm was 14.2% (95% CI 5.2-23.2) vs 17.3% for cold snare polypectomy (95% CI 14.3‒20.3). The IRR for forceps removal of polyps 1 to 5 mm was 9.9% (95% CI 7.1-13.0) vs 4.4% for snare polypectomy (95% CI 2.9-6.1).

In a systematic review and meta-analysis, we found that colorectal polyps 1 to 20 mm are frequently incompletely resected, and that risk increases for polyps 10 mm or larger. There is no difference in IRRs of cold vs hot snares for polyps 1 to 10 mm. Snare polypectomy should be used over forceps for polyps 1 to 5 mm.

Residual neoplasia after macroscopically complete EMR of large colon polyps has been reported in 10% to 32% of resections. Often, residual polyps at the site of prior polypectomy are fibrotic and nonlifting, making additional resection challenging.

This document reviews devices and methods for the endoscopic treatment of fibrotic and/or residual polyps. In addition, techniques reported to reduce the incidence of residual neoplasia after endoscopic resection are discussed.

Descriptions of technologies and available outcomes data are summarized for argon plasma coagulation ablation, snare-tip coagulation, avulsion techniques, grasp-and-snare technique, EndoRotor endoscopic resection system, endoscopic full-thickness resection device, and salvage endoscopic submucosal dissection.

Several technologies and techniques discussed in this document may aid in the prevention and/or resection of fibrotic and nonlifting polyps.

Incomplete resection of colorectal neoplasia decreases the efficacy of colonoscopy. Conventional resection (CR) of polyps, performed in a gas-distended colon, is the current standard, but incomplete resection rates of approximately 2% to 30% for nondiminutive (>5 mm), nonpedunculated lesions are reported. Underwater resection (UR) is a novel technique. The aim of this study was to determine the incomplete resection rates of colorectal lesions removed by UR versus CR.

In a randomized controlled trial, patients with small (6-9 mm) and large (≥10 mm) nonpedunculated lesions were assigned to CR (gas-distended lumen) or UR (water-filled, gas-excluded lumen). Small lesions in both arms were removed with a dedicated cold snare. For CR, large lesions were removed with a hot snare after submucosal injection. For UR, large lesions were removed with a hot snare without submucosal injection. Four-quadrant biopsy samples around the resection sites were used to evaluate for incomplete resection.

Four hundred sixty-two eligible polyps (248 UR vs 214 CR) from 255 patients were removed. Incomplete resection rates for UR and CR were low and did not differ (2% vs 1.9%, P = .91). UR was performed significantly faster for lesions ≥10 mm in size (10-19 mm, 2.9 minutes vs 5.6 minutes, P < .0001); ≥20 mm, 7.3 minutes vs 9.5 minutes, P = .015).

Low incomplete resection rates are achievable with UR and CR. UR is effective and safe with the advantage of faster resection and potential cost savings for removal of larger (≥10 mm) lesions by avoiding submucosal injection. As an added approach, UR has potential to improve the cost-effectiveness of colonoscopy by increasing efficiency and reducing cost while maintaining quality. (Clinical trial registration number: NCT02889679.).

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.

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.

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).

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.

Background and study aims  The completeness of a polyp resection is an important determinant of quality in colonoscopy, and may reduce incidence of interval cancers. Incomplete resection rates (IRR) vary widely and range from 6.5 % to 22.7 %. Residual disease is more likely with larger polyps, for sessile serrated adenomas, and with more proximal lesions. Chromoendoscopy is increasingly employed in lesion detection. The aims of this study were to assess local IRR, and to determine whether chromoendoscopy could correctly identify residual disease post polypectomy. Patients and methods  This was a prospective study examining post polypectomy sites. Chromoendoscopy (0.13 % indigo carmine) was applied to resection bases to identify residual disease. Targeted base biopsies were taken from identified residual disease (positive group) or random base biopsies were taken when a clear base was visualised (negative group). Overall rates of incomplete resection were documented. Reported rates post chromoendoscopy and actual histological rates were documented and compared. Results  A total of 102 polyps were identified for inclusion, of which 15 % (n = 16) were excluded. Resection quality was evaluated in 86 polyps of 61 patients (female n = 33 54 %; mean Age 62.3 years). Polyps were mainly removed by cold snare (n = 71, 82.5 %). Most polyps (n = 58, 67 %) measured between 5 to 10 mm. Polyps were largely located in the right colon (n = 57, 66 %). Overall histological residual disease occurred in 17 /86 (19.6 %). Chromoendoscopy correctly identified residual disease in 13 of 17 bases (76.5 %). Only four of /86 (4.6 %) of polyp bases were missclassified post-chromoendoscopy (odds ratio 0.284 (95 % CI 0.0857-0.9409), P  = 0.03). Conclusion  Indigo carmine chromoendoscopy improves early detection of residual disease post polypectomy, reducing incomplete resection rates.

Objective This study aims to elucidate the association between the clinical characteristics of post-colonoscopy colorectal cancer (PCCRC) and quality indicators (QIs) of colonoscopy. Methods Patients with PCCRC who underwent total colonoscopy (TCS) and were histologically diagnosed with adenocarcinoma within six months to five years of the last examination were included in this study. PCCRC and normally detected cancer (NDC) identified within the same period were compared in terms of their clinicopathological characteristics. Furthermore, the QIs at PCCRC detection were compared to those at the last examination. Results Patients with PCCRC had a significantly higher rate of colon surgery history than those with NDC (PCCRC: 25/76, 32.9%; NDC: 31/1,437, 2.2%; p<0.001), but the invasion depth in these patients was significantly shallower (PCCRC: ≤Tis/≥T1, 37/39; NDC: ≤Tis/≥T1, 416/1,021; p<0.001). Among patients with PCCRC, the T1b group had significantly more non-polypoid growth (NPG)-type cases than PG-type CRC cases (p=0.018). The adenoma detection rate (ADR) of colonoscopists performing TCS was 30.2-52.8%. Furthermore, the ADR of colonoscopists at the time of PCCRC detection (36.7%±5.9%) was significantly higher than that of colonoscopists who performed the last examination (34.9%±4.4%; p=0.034). The withdrawal time for negative colonoscopy (WT-NC) at detection was significantly longer than that at the last examination (at detection: 494.3±253.8 s; at last examination: 579.5±243.6 s; p=0.010). Conclusion Given that these PCCRC cases were post-colon surgery cases, had a long WT-NC, and were detected by colonoscopists with a high ADR, most cases showed lesions that were missed during the previous colonoscopy. Caution should be practiced in order to avoid missing flat, NPG-type tumors.