Incomplete endoscopic resection of colorectal polyps: a prospective quality assurance study

Emerge of colorectal cancer in Lynch syndrome despite colonoscopy surveillance: A challenge of hide and seek

Even with colonoscopy surveillance, Lynch syndromes (LS) carriers still develop colorectal cancer (CRC). The cumulative incidence of CRCs under colonoscopy surveillance varies depending on the affected mismatch repair (MMR) gene. However, the precise mechanisms driving these epidemiological patterns remain incompletely understood. In recent years, several potential mechanisms explaining the occurrence of CRCs during colonoscopy surveillance have been proposed in individuals with and without LS. These encompass biological factors like concealed/accelerated carcinogenesis through a bypassed adenoma stage and accelerated progression from adenomas. Alongside these, various colonoscopy-related factors may contribute to formation of CRCs under colonoscopy surveillance, like missed yet detectable (pre)cancerous lesions, detected yet incompletely removed (pre)cancerous lesions, and colonoscopy-induced carcinogenesis due to tumor cell reimplantation. In this comprehensive literature update, we reviewed these potential factors and evaluated their relevance to each MMR group in an attempt to raise further awareness and stimulate research regarding this conflicting phenomenon.

Recurrence rate after piecemeal endoscopic mucosal resection of <20 mm non-pedunculated colorectal lesions: should we worry about the risk?

INTRODUCTION

There is scarce data focused on recurrence neoplasia rate (RR) after piecemeal endoscopic mucosal resection (pEMR) of 10-19 mm non-pedunculated colorectal lesions (NPL). We aimed to analyze the RR after pEMR of 10-19 mm NPL, identify risk factors for its development and compare it with RR after pEMR of ≥ 20 mm NPL.

METHODS

Retrospective cohort-study including all ≥10 mm NPL resected by pEMR in our center between 2018-2022 with an early repeat colonoscopy (ERC). RR was defined as recurrence neoplasia identified in the ERC EMR scar with virtual chromoendoscopy or histological confirmation.

RESULTS

A total of 444 NPL were assessed, 124 (27.9%) with 10-19 mm. In the ERC, performed a median of 6 months after pEMR, RR was significantly lower for 10-19 mm NPL compared to ≥ 20 mm NPL (13/124 vs 68/320, p = 0.005). In subgroup analysis, RR after pEMR of 15-19 mm NPL was significantly higher compared to 10-14 mm NPL (13/98 vs 0, p = 0.041) but not significantly different compared to ≥ 20 mm NPL (13/98 vs 68/320, p = 0.073). In multivariable analysis, size of NPL (HR 1.501, 95% CI 1.012-2.227, p = 0.044) was the only independent risk factor identified for RR for 10-19 mm NPL.

CONCLUSION

Although the early RR after pEMR of 10-19 mm NPL is significantly lower compared to ≥ 20 mm NPL, it is non-negligible (10.5%) and appears to be the highest among 15-19 mm NPL. The size of the lesion was the only independent risk factor for RR. Our findings should be accounted in the selection of the most appropriate post-polypectomy endoscopic surveillance.

Intestinal topical lidocaine spray improves the efficacy and safety of endoscopic sigmoid polypectomy

BACKGROUND AND AIMS

Endoscopic polypectomy can prevent colorectal cancer. Adequate surgical field visualization is crucial to complete resection. To prevent visual field loss caused by intestinal peristalsis, we investigated the efficacy and safety of topical lidocaine spraying during the endoscopic sigmoid polypectomy (ESP).

METHODS

Retrospective analysis was performed on 100 ESP patients admitted from July 2021 to October 2021, among which 50 patients received lidocaine (case group) and other 50 patients received normal saline (control group). Lidocaine or saline was sprayed on the colonic mucosa within 5 cm above and below the polyps before polypectomy. The en-bloc resection rate (EBRR) and complete resection rate (CRR) were primarily evaluated. Secondary outcomes included EBRR for polyps located in the 5-11 o'clock position, sigmoid colon peristalsis frequency, degree of exposure to the surgical field, operative times, and adverse events.

RESULTS

There were no significant differences in the basic demographic characteristics between the two groups. EBRR and CRR in the case group were 72.9% and 95.8%, and in the control group were 53.3% and 91.1%, respectively. The EBRR of sigmoid polyps located at the 5-11 o'clock positions was significantly higher in the case group (82.8%) than in the control group (56.7%) (P = 0.03). Sigmoid colonic peristalsis was significantly inhibited after lidocaine spraying (P < 0.01). There was no statistical difference in the operative times and adverse event rates between the two groups.

CONCLUSION

Topical spraying lidocaine around polyps can safely and effectively reduce intestinal peristalsis, thus improving the EBRR of sigmoid polypectomy.

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

INTRODUCTION

Cold snare polypectomy (CSP) is a safe and effective procedure for small colorectal polyps ≤9 mm. There are only limited data regarding CSP of larger neoplastic lesions. This study evaluated the efficacy and safety of CSP for polyps between 10 and 15 mm in size.

METHODS

In this prospective single-arm observational pilot study, patients with a least one polyp 10-15 mm were included. These polyps were preferably removed by CSP using a dedicated hybrid snare. The primary outcome was the histological complete resection rate (CRR) determined by pathologically negative margins of the specimen and no neoplastic tissue obtained from biopsies of the resection site margin. Secondary outcomes were en bloc resection rate, failure of CSP, and incidence of adverse events.

RESULTS

A total of 61 neoplastic polyps were removed from 39 patients. Overall CRR was 80.3% (49/61). CSP was feasible in 78.7% (48/61) of polyps and the CRR in this group was 85.4% (41/48). When CSP failed (13/61; 21.3%), lesions were successfully resected by immediate HSP using the same snare with a CRR of 61.5% (8/13) in this group. One patient presented delayed hemorrhage after HSP of a polyp but successful hemostasis was achieved with two hemoclips. No other adverse events occurred. No recurrence was seen on follow-up colonoscopy in cases with incomplete resected polyps.

CONCLUSION

CSP seems to be efficient and safe in removing colorectal polyps up to 15 mm. A hybrid snare seems to be particularly advantageous for these polyps as it allows immediate conversion to HSP if CSP might fail in larger polyps. This trial is registered at ClinicalTrials.gov (NCT04464837).

Anchoring endoscopic mucosal resection versus conventional endoscopic mucosal resection for large nonpedunculated colorectal polyps: a randomized controlled trial

BACKGROUND : Colorectal polyps > 10 mm in size are often incompletely resected. Anchoring-endoscopic mucosal resection (A-EMR) is the technique of making a small incision at the oral side of the polyp using a snare tip after submucosal injection to avoid slippage during ensnaring. This study was performed to evaluate whether A-EMR could increase the complete resection rate for large colorectal polyps compared with conventional endoscopic mucosal resection (C-EMR). METHODS : Polyps with sizes of 10-25 mm were randomly allocated to either the A-EMR or the C-EMR groups. RESULTS : 105 and 106 polyps were resected using A-EMR and C-EMR, respectively. In the intention-to-treat population, the complete resection rate was 89.5 % in the A-EMR group and 74.5 % in the C-EMR group (relative risk [RR] 1.20, 95 %CI 1.04 to 1.38; P = 0.01). The en bloc resection rates for the A-EMR and C-EMR groups were 92.4 % vs. 76.4 % (RR 1.21, 95 %CI 1.06 to 1.37; P = 0.005) and R0 resection rates were 77.1 % vs. 64.2 % (RR 1.18, 95 %CI 0.98 to 1.42; P = 0.07), respectively. The median (interquartile range [IQR]) total procedure time was 3.2 (2.6-4.1) minutes in the A-EMR group and 3.0 (2.2-4.6) minutes in the C-EMR group (median difference 0.2 minutes, 95 %CI -0.22 to 0.73; P = 0.25). There was one episode of delayed bleeding and one perforation in the C-EMR group. CONCLUSIONS : A-EMR was superior to C-EMR for the complete resection of large colorectal polyps. A-EMR can be considered one of the standard methods for the removal of colorectal polyps of 10 mm or more in size.

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.

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.

Complete polyp resection with cold snare versus hot snare polypectomy for polyps of 4-9 mm: a randomized controlled trial

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Early gastric neoplasms are significant risk factor for colorectal adenoma: A prospective case-control study

Although gastric cancer patients have a high incidence and risk of colorectal cancer, evidence is lacking regarding whether early gastric neoplasms (EGNs), such as gastric adenomas and early gastric cancer, are risk factors for colorectal adenoma. This study aimed to investigate the incidence of colorectal adenomas in patients with EGN. This prospective study was conducted between January 2015 and December 2016. Of the 307 patients who underwent gastric endoscopic submucosal dissection for EGN, 110 patients were enrolled in the EGN group, and 110 age- and sex-matched healthy persons from the screening population were included in the control group in a 1:1 ratio. Demographic factors and results of colonoscopy, including quality assessment, were collected, and analyzed. No significant differences in the quality of colonoscopy, including bowel preparation, cecal intubation rate, and withdrawal time between the 2 groups, were observed. The incidence of colorectal adenoma was significantly higher in the EGN group than in the control group (55.5% vs 26.4%, P = .001). Multivariate analysis confirmed that old age (odds ratio: 1.04, 95% confidence interval: 1.01-1.08, P = .005) and a history of EGN (odds ratio: 4.99, 95% confidence interval: 2.60-9.57, P = .001) were independent risk factors for colorectal adenoma. This is the first prospective study to reflect the quality indicator of colonoscopy and confirmed that old age and a history of EGN are significant risk factors for colorectal adenomas. Therefore, more stringent colonoscopy surveillance should be considered in elderly patients with EGN.

Increased Colorectal Neoplasia Risk in Patients with Inflammatory Bowel Disease and Serrated Polyps with Dysplasia

BACKGROUND

The impact of serrated polyps on the advanced colorectal neoplasia (CRN) risk in inflammatory bowel disease (IBD) patients is unknown. Serrated polyps are histologically categorized as hyperplastic polyps (HPs), sessile serrated lesions (SSLs), and traditional serrated adenomas (TSAs).

AIMS

We aimed (1) to characterize the serrated polyps in IBD patients, (2) to identify factors associated with the presence of serrated polyps in IBD, and (3) to assess the CRN risk in IBD patients with serrated polyps.

METHODS

We established a retrospective cohort of IBD patients with and without colonic serrated polyps. Cox-regression analysis with time-dependent variables was used to compare advanced CRN risk in IBD patients with and without serrated polyps.

RESULTS

Of the 621 enrolled IBD patients, 198 had a serrated polyp (92 HPs, 88 SSLs without dysplasia, 13 SSLs with dysplasia, and 5 TSAs). Independent factors associated with serrated polyps were ulcerative colitis (UC) (odds ratio (OR) 1.77, 95% confidence interval (CI) 1.19-2.62, p = 0.005), male gender (OR 1.63, 95% CI 1.11-2.40, p = 0.013), and older age (per year increase, OR 1.06, 95%CI 1.05-1.08, p < 0.001). TSAs and SSLs with dysplasia were risk factors for subsequent advanced CRN (HR 13.51, 95% CI 3.11-58.68, p < 0.001), while HPs (HR 1.98, 95% CI 0.46-8.60, p = 0.36) and SSLs without dysplasia (HR 0.87, 95% CI 0.11-6.88, p-0.89) did not impact the subsequent advanced CRN risk.

CONCLUSIONS

UC, male gender and older age were associated with the presence of serrated polyps. The majority of serrated polyps (91%) were HPs and SSL without dysplasia and did not affect the CRC risk. However TSAs and SSLs with dysplasia, representing a small subgroup of serrated polyps (9%), were associated with subsequent advanced CRN.

Simulation-based training improves polypectomy skills among practicing endoscopists

Background and study aims  Practicing endoscopists have variable polypectomy skills during colonoscopy and limited training opportunities for improvement. Simulation-based training enhances procedural skill, but its impact on polypectomy is unclear. We developed a simulation-based polypectomy intervention to improve polypectomy competency. Methods  All faculty endoscopists at our tertiary care center who perform colonoscopy with polypectomy were recruited for a simulation-based intervention assessing sessile and stalked polypectomy. Endoscopists removed five polyps in a simulation environment at pretest followed by a training intervention including a video, practice, and one-on-one feedback. Within 1-4 weeks, endoscopists removed five new simulated polyps at post-test. We used the Direct Observation of Polypectomy Skills (DOPyS) checklist for assessment, evaluating individual polypectomy skills, and global competency (scale: 1-4). Competency was defined as an average global competency score of ≥ 3. Results  83 % (29/35) of eligible endoscopists participated and 95 % (276/290) of planned polypectomies were completed. Only 17 % (5/29) of endoscopists had average global competency scores that were competent at pretest compared with 52 % (15/29) at post-test ( P  = 0.01). Of all completed polypectomies, the competent polypectomy rate significantly improved from pretest to post-test (55 % vs. 71 %; P  < 0.01). This improvement was significant for sessile polypectomy (37 % vs. 65 %; P  < 0.01) but not for stalked polypectomy (82 % vs. 80 %; P  = 0.70). Conclusions  Simulation-based training improved polypectomy skills among practicing endoscopists. Further studies are needed to assess the translation of simulation-based education to clinical practice.