Introduction

Endoscopic removal of colorectal polyps is a cornerstone of colorectal cancer prevention.¹ Optimal techniques for removing small polyps (≤10mm) remain scarce,^2–4 with cold snare polypectomy (CSP), hot snare polypectomy (HSP), and cold forceps (CF) being the main options.^1–4

Aims & Methods

This systematic review and network meta-analysis aims to compare the efficacy of these techniques for removing small colorectal polyps and determine the optimal approach. We searched Web of Science, PubMed, Cochrane CENTRAL, and Scopus from inception until March 2024 for relevant randomized controlled trials and observational studies comparing CSP, HSP, and CF (including sub-techniques) for small polyp removal. Records were screened for eligible studies, and all relevant outcomes were pooled as a risk ratio (RR) with the corresponding 95% confidence intervals (CI) in a network meta-analysis (NMA) model, using R software.

Results

Our findings from 13 studies (2767 patients) showed insignificant differences among HSP versus CSP in terms of complete resection rate (CRR) and incomplete resection rate (IRR) [RR 2.00, (95% CI, 0.53 to 7.51); P = 0.74] and [RR 1.24, (95% CI, 0.20 to 7.85); P = 0.43], respectively. In addition, no significant variance was detected between the CSP and CF in terms of complete histological polyp eradication (CHPE), incomplete histological polyp eradication (IHPE), and visual polyp eradication (VPE) [RR 0.97, (95% CI, 0.87 to 1.08); P = 0.1], [RR 1.36, (95% CI, 0.57 to 3.26); P = 0.9], and [RR 0.75, (95% CI, 0.62 to 0.91); P = 0.07], respectively.

Conclusion

In conclusion, our results revealed no significant difference between any of the techniques in terms of their success rate in completely removing the polyp. These findings suggest that all three methods might be equally effective for removing small polyps. However, we recommend further studies with more participants, and longer follow-up periods might be needed to definitively determine the best approach for all situations. This could include considering factors like specific polyp characteristics or patient preferences.

References

1. Kaltenbach T, Anderson JC, Burke CA, et al. Endoscopic Removal of Colorectal Lesions—Recommendations by the US Multi-Society Task Force on Colorectal Cancer. Gastroenterology. 2020;158(4):1095-1129. doi:10.1053/j.gastro.2019.12.018

2. Abuelazm M, Mohamed I, Jaber FS, et al. Cold Versus Hot Snare Polypectomy for Colorectal Polyps: An Updated Systematic Review and Meta-analysis of Randomized Controlled Trials. J Clin Gastroenterol. 2023;57(8). https://journals.lww.com/jcge/fulltext/2023/09000/cold_versus_hot_snare_polypectomy_for_colorectal.4.aspx.

3. Niu C, Bapaye J, Zhang J, et al. Systematic review and meta-analysis of cold snare polypectomy and hot snare polypectomy for colorectal polyps. J Gastroenterol Hepatol. 2023;38(9):1458-1467. doi:https://doi.org/10.1111/jgh.16312

4. CAVASSOLA PRP, MOURA DTH de, HIRSCH BS, LANDIM DL, BERNARDO WM, MOURA EGH de. HOT VERSUS COLD SNARE FOR COLORECTAL POLYPECTOMIES SIZED UP TO 10MM: A SYSTEMATIC REVIEW AND META-ANALYSIS OF RANDOMIZED CONTROLLED TRIALS. Arq Gastroenterol. 2024;61. doi:10.1590/s0004-2803.246102023-143

Disclosure

There is no any conflict of interest to disclose.

Introduction

Hot endoscopic mucosal resection (H-EMR) is the standard of care for large non-pedunculated colorectal polyps (LNPCPs) without suspicion of submucosal invasion, achieving low recurrence rates after en bloc resection or piecemeal resection with margin ablation in expert centers.^1,2 However, electrocautery is also responsible for complications which can lead to significant morbidity and necessitate additional invasive procedures.^3,4 Cold snare polypectomy (CSP) has proven to be preferable to H-EMR for adenomas ≤10mm and non-dysplastic sessile serrated lesions, providing comparable efficacy with improved safety, shorter procedural time and lower costs.⁵ These advantages have driven interest in expanding CSP to larger polyps.

Aims & Methods

This meta-analysis of randomized controlled trials (RCTs) aimed to compare the risk of recurrence and adverse events between cold snare polypectomy (CSP) and hot-endoscopic mucosal resection (H-EMR) for large non-pedunculated colorectal polyps (LNPCPs).
A systematic search of Medline, Embase and Cochrane Library databases was performed through August 2024 for studies comparing recurrence, bleeding and perforation rates between CSP and H-EMR for LNPCPs ≥15mm (PROSPERO ID: CRD42024568272). RCTs were included in the quantitative analysis. A random-effects meta-analysis, with heterogeneity measured with I², was conducted to generate pooled risk ratios (RR) with 95% confidence intervals.

Results

Four RCTs comprising 1516 LNPCPs (766 CSP and 750 H-EMR) in 1442 patients were included in the quantitative analysis. CSP demonstrated a higher recurrence risk at first surveillance colonoscopy than H-EMR in the pooled analysis (22.6% vs. 10.8%; RR=1.98; 95% CI: 1.22–3.21; p=0.02; moderate-certainty evidence), corresponding to a number needed to harm of 9. Regarding adverse events, CSP demonstrated a 67% reduced risk of delayed bleeding (1.2% vs. 3.9%; RR=0.33; 95% CI: 0.12-0.89; p=0.03; high-certainty evidence), corresponding to a number needed to treat of 37. Although CSP appeared to reduce the risk of intraprocedural bleeding (10.0% vs. 19.8%; RR=0.30, 95% CI: 0-52256.34, p=0.42), the wide confidence interval from the random-effects model included 1. There were no intraprocedural or delayed perforations in the CSP group.

Author	Study design	Number of patients		Age, mean (SD), years	Female, %	Number of LNPCPs		LNPCP size, mean/median (SD/IQR), mm	Right Location, %		Adenomatous histology, %
		CSP	H-EMR			CSP	H-EMR		CSP	H-EMR	CSP	H-EMR
O’ Sullivan T. et al., 2024	Single center, RCT	87	90	68.2 (10.0)	46.9	87	90	30 (25-35)	96.5	86.7	100	100
Steinbrück et al., 2024	Multicenter, RCT	184	192	65.9 (10.5)	48.2	193	203	30.1 (10.2)	88.1	86.2	60.7	68.5
Pohl H. et al., 2024	Multicenter, RCT	336	324	65.3 (10.2)	47.7	371	343	30 (25.4)	82.5	83.4	NR	NR
Nogales et al., 2023	Multicenter, RCT	115	114	67.9 (10.6)	43.3	115	114	25 (22-30)	80.0	78.1	71.9	77.2

Table 1. Patients, LNPCPs and procedure characteristics of the randomized controlled trials included in the quantitative analysis. (List of abbreviations: CSP, cold snare polypectomy; H-EMR, hot endoscopic mucosal resection; IQR, interquartile range; LNPCPs, large non-pedunculated colorectal polyps; NR, not reported; SD, standard deviation; RCT, randomized controlled trial)

Conclusion

CSP has nearly double the recurrence risk of H-EMR for LNPCPs. However, its superior safety profile may make it a preferable option for patients where procedural safety is prioritized over radicality, such as those with extensive comorbidities.

References

1. Ferlitsch M, Hassan C, Bisschops R et al. Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024. Endoscopy 2024; 56: 516-545. doi:10.1055/a-2304-3219
2. Kaltenbach T, Anderson JC, Burke CA et al. Endoscopic Removal of Colorectal Lesions: Recommendations by the US Multi-Society Task Force on Colorectal Cancer. Am J Gastroenterol 2020; 115: 435-464. doi:10.14309/ajg.0000000000000555
3. Sidhu M, Shahidi N, Gupta S et al. Outcomes of Thermal Ablation of the Mucosal Defect Margin After Endoscopic Mucosal Resection: A Prospective, International, Multicenter Trial of 1000 Large Nonpedunculated Colorectal Polyps. Gastroenterology 2021; 161: 163-170.e163. doi:10.1053/j.gastro.2021.03.044
4. Meulen LWT, Bogie RMM, Winkens B et al. Thermal ablation of mucosal defect margins to prevent local recurrence of large colorectal polyps: a systematic review and meta-analysis. Endosc Int Open 2022; 10: E1127-e1135. doi:10.1055/a-1869-2446
5. Rex DK, Anderson JC, Pohl H et al. Cold versus hot snare resection with or without submucosal injection of 6- to 15-mm colorectal polyps: a randomized controlled trial. Gastrointest Endosc 2022; 96: 330-338. doi:10.1016/j.gie.2022.03.006

Introduction

Colorectal cancer is the third most common cancer worldwide and the second leading cause of cancer-related death. Most colorectal cancers arise from benign polyps, especially dysplastic adenomas. Colonoscopy with polypectomy is the gold standard for preventing cancer by interrupting the adenoma-carcinoma sequence. This has led to the development of various techniques and devices for improved prevention and treatment. Hot snare endoscopic mucosal resection (HS-EMR), which combines submucosal injections with electrocautery, is commonly used for excising various colorectal polyps. However, it carries risks of diathermy-related complications, such as perforation, and bleeding. To address these issues, cold snare endoscopic mucosal resection (CS-EMR) has been proposed as an alternative. Concerns about residual adenoma/recurrence have been raised with CS-EMR. Therefore, we conducted this meta-analysis to compare the two techniques.

Aims & Methods

We searched electronic databases, including MEDLINE via PubMed, Scopus, Web of Science, and Cochrane, without restrictions on publication date or language. We included RCTs comparing CS-EMR and HS-EMR for colorectal polyp resection. Primary outcomes included the incidence of delayed bleeding and residual/recurrent adenoma (RRA).

Results

On Nov 5, 2024, our literature search across electronic databases retrieved a total of 1,888 records. Following a meticulous screening process, six studies met the eligibility criteria encompassing 1,449 patients and 1,947 polyps. Regarding safety, the overall effect estimates regarding delayed bleeding showed statistically significant results favoring CS-EMR group [OR 0.31, 95 % CI (0.12–0.76), P = 0.01] with no heterogeneity (P = 0.40; I² = 0 %). However, statistical superiority for CS-EMR could not be detected regarding early bleeding [OR 0.78, 95 % CI (0.31–1.97), P = 0.60]. Only two studies reported data on delayed perforation, showing a numerical difference favoring CS-EMR; however, statistical significance could not be obtained [OR 0.26, 95 % CI (0.03–2.41), P = 0.24]. Regarding efficacy, the overall effect estimates regarding complete resection and RRA did not favor either of the groups [OR 0.62, 95 % CI (0.25–1.53), P = 0.30], [OR 2.81, 95 % CI (0.43–18.47), P = 0.28] respectively.

Conclusion

Evidence obtained from this meta-analysis suggests that CS-EMR offers superior safety compared to HS-EMR for colorectal polyp resection. Current evidence remains limited due to the small number of studies included. Therefore, further high-quality randomized controlled trials with larger sample sizes are needed.

References

• Bray F, Ferlay J, Soerjomataram I, Siegel RL, Torre LA, Jemal A. Global cancer statistics 2018: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA Cancer J Clin. 2018;68(6):394–424.

• Winawer SJ, Zauber AG, Ho MN, O'Brien MJ, Gottlieb LS, Sternberg SS, et al. Prevention of colorectal cancer by colonoscopic polypectomy. N Engl J Med. 1993;329(27):1977–81.

• Facciorusso A, Del Prete V, Antonino M, Buccino VR, Muscatiello N. Efficacy of endoscopic polypectomy techniques for colorectal polyps: a systematic review and network meta-analysis. Gastrointest Endosc. 2020;91(4):733–745.e9.

• Pohl H, Srivastava A, Bensen SP, Anderson P, Rothstein RI, Gordon SR, et al. Incomplete polyp resection during colonoscopy—results of the complete adenoma resection (CARE) study. Gastroenterology. 2013;144(1):74–80.e1.

• Tutticci N, Hewett DG. Cold snare polypectomy: A safe, effective technique for sessile polyps. Gastrointest Endosc Clin N Am. 2015;25(2):291–301.

• Kawamura T, Takeuchi Y, Asawa S, Yokota I, Matsuno T, Omori T, et al. A comparison of cold and hot snare polypectomy for small colorectal polyps: a randomized controlled trial. Am J Gastroenterol. 2018;113(3):403–411.

Introduction

The Resect and Discard strategy allows endoscopists to replace post-polypectomy pathology with real-time prediction of polyp histology during colonoscopy (optical diagnosis). The present systematic review and meta-analysis investigated how implementation of computer-aided diagnosis (CADx) for polyp pathology affected this optical diagnosis procedure.

Aims & Methods

We conducted a search of MEDLINE, EMBASE, and Scopus databases, covering studies published from inception to February 20, 2024. We included histologically verified accuracy diagnostic studies that evaluated the real-time optical diagnosis performance of CADx systems for polyps ≤5mm in the entire colon. The aim was to estimate the potential benefits and harms associated with integrating CADx assistance into the endoscopist optical diagnosis, both before and after its implementation. The primary outcomes were the proportion of polyps that would have avoided pathological assessment (main benefit) and the proportion of polyps incorrectly predicted (main harm) due to false-positive or -negative optical diagnosis. Only diagnosis with a high-level of confidence were considered.

Results

A total of 11 studies with 7,400 polyps were eligible for analysis, providing stand-alone performance of CADx with sensitivity and specificity in identifying adenomatous histology of 87% (95% confidence interval [CI]: 0.82, 0.91) and 75% (95% CI: 0.68, 0.82), respectively. Three studies (4,086 polyps) were included to analyze the primary benefit/harm outcome measures. There was no significant difference between the CADx-unassisted and CADx-assisted strategies for the proportion of polyps that would have avoided pathological assessment (90% vs. 90%; risk ratio: 1.01; 95% CI: 0.99, 1.04; I²=53.49%; moderate certainty evidence). CADx-assisted strategy reduced the proportion of incorrectly predicted polyps as compared with CADx-unassisted (13% vs. 12%; risk ratio: 0.88; 95% CI: 0.79, 0.98; I²=0%; moderate certainty evidence) mainly due to a decrease in false-positive diagnosis.

Conclusion

CADx implementation did not result in clinically relevant benefits for the Resect-and-Discard strategy.

Disclosure

Cesare Hassan: Fujifilm Co. (consultancy); Medtronic Co. (consultancy), Yuichi Mori: Olympus Corp (consultancy, speaking honorarium, equipment loan); Cybernet System (ownership interest), Alessandro Repici: Fujifilm Co. (consultancy); Olympus Corp (consultancy); Medtronic Co. (consultancy).

Introduction

Familial adenomatous polyposis (FAP) is an inherited colorectal cancer syndrome characterized by the development of numerous adenomatous polyps in the colon and rectum, with prophylactic colectomy being the standard treatment to prevent disease progression. Recently, endoscopic intensive downstaging polypectomy (IDP) has attracted attention as a novel disease management strategy, particularly for patients with non-dense FAP who refuse or delay surgery. Since IDP requires the resection of numerous polyps, simpler and safer techniques such as hot snare polypectomy (HSP), cold snare polypectomy (CSP), and hot biopsy (HB) are commonly used. However, the effectiveness of these techniques for the treatment of small adenomas in the context of IDP has not been fully evaluated.

Aims & Methods

This study aimed to evaluate the safety and efficacy of CSP compared with HSP and HB in patients with FAP undergoing IDP. This retrospective study included patients with FAP who underwent IDP using only CSP, HSP, or HB at Hiroshima University Hospital between September 2012 and March 2024. Patients were divided into two groups: the CSP group, treated with CSP from October 2022 onward, and the HOT group, treated with HSP and HB between 2012 and September 2022. The primary endpoints were the incidence of adverse events and the treatment duration per polyp. Secondary endpoints included the incidence of immediate and delayed bleeding, perforation, total treatment duration per session, number of polyps removed per procedure, R0 resection rate, and the rate of missed polyps ≥10 mm.

Results

Variables	Total (n=185)	CSP (n=46)	HOT (n=139)	p-value
Treatment duration per procedure (min)	45.9 (22.1)	51.1 (23.2)	44.3 (21.7)	0.06
Polyps removed per procedure	51.6 (52.1)	80.5 (56.8)	42.1 (46.9)	< 0.01
Treatment duration per lesion (min)	1.7 (1.4)	1.3 (1.4)	1.8 (1.3)	0.01
Maximum tumor size per procedure (mm)	5.2 (2.4)	6.0 (2.5)	4.9 (2.4)	< 0.01
Overall adverse events (n (%)) Immediate bleeding (n (%)) Delayed bleeding (n (%)) Perforation (n (%))	14 (7.6) 10 (5.4) 2 (1.1) 2 (1.1)	0 (0) 0 (0) 0 (0) 0 (0)	14 (10.1) 10 (7.2) 2 (1.1) 2 (1.1)	0.03 0.06 0.41 0.41

During the study period, 46 treatment sessions were performed in 24 patients in the CSP group, resulting in the removal of a total of 3,689 polyps. In contrast, 139 treatment sessions were performed in 27 patients in the HOT group, with a total of 5,912 polyps removed. The average number of polyps removed per session was significantly higher in the CSP group (80.5 polyps) than in the HOT group (42.1 polyps) (p < 0.01). Additionally, the treatment duration per polyp was significantly shorter in the CSP group (1.3 minutes) than in the HOT group (1.8 minutes) (p = 0.01). The total treatment duration per session was slightly longer in the CSP group (51.1 minutes) compared to the HOT group (44.3 minutes), although the difference was not statistically significant (p = 0.06). The maximum polyp size was significantly larger in the CSP group (6.0 mm) than in the HOT group (4.91 mm) (p < 0.01). The overall incidence of adverse events was significantly lower in the CSP group. Immediate bleeding occurred in 10 cases (7.2%) in the HOT group but was not observed in the CSP group. Delayed bleeding and perforation were also observed only in the HOT group; however, there were no statistically significant differences between the groups.

Conclusion

This study demonstrated that CSP is a safe and effective option for intensive polyp reduction in patients with FAP. Compared with HSP and HB, CSP enabled the removal of more polyps in a shorter duration and reduced the risk of adverse events.

Introduction

Colorectal cancer (CRC) is the third most common cancer and the second cause of cancer-related deaths worldwide [1]. Although the biological pathways that transform the normal colon tissue into malignant tissue are different, polyps are presumed to be the precursor lesions for malignant tumors in all cases[2]. Colorectal polyps (CRP) can be seen in various forms or shapes on colonoscopy. Convolutional neural networks (CNNs) are a class of deep neural networks used for different clinical purposes, including improving the detection rate of colorectal lesions.

Aims & Methods

This systematic review and meta-analysis aimed to assess the performance of CNN-based models in the detection or classification of colorectal polyps (CRP) and colorectal cancer (CRC). A systematic search was performed in MEDLINE, SCOPUS, Web of Science, and other related databases. The performance measures of the CNN models in the detection of CRP and CRC were calculated in the two scenarios of the best and worst accuracy. Stata and R software were used for conducting the meta-analysis.

Results

From 3368 searched records, 24 primary studies were included. The sensitivity and specificity of CNN models in predicting CRP in worst and best scenarios ranged fr3om 84.7-91.6% and 86.0-93.8%, respectively. These values in predicting CRC varied between 93.2-94.1% and 94.6-97.7%. The positive and negative likelihood ratios varied between 6.2-14.5 and 0.09-0.17 in these scenarios, respectively, in predicting CRP, and 17.1-41.2 and 0.07-0.06 in predicting CRP. The diagnostic OR and accuracy measures of CNN models in predicting CRP in worst and best scenarios ranged between 36-162 and 80.5-88.6%, respectively. These values in predicting CRC in the worst and the best scenarios varied between 239.63-677.47 and 88.2-96.4%. The area under the ROC varied between 0.92 to 0.97 in the worst and the best scenarios in CRP, respectively, and 0.98 to 0.99 in CRP prediction.

Conclusion

CNN-based models showed an acceptable accuracy in detecting CRP and CRC.

References

1. Keum NN, Giovannucci E. Global burden of colorectal cancer: emerging trends, risk factors and prevention strategies. Nat Rev Gastroenterol Hepatol 2019;16:713-732.
2. Øines M, Helsingen LM, Bretthauer M, Emilsson L. Epidemiology and risk factors of colorectal polyps. Best Pract Res Clin Gastroenterol 2017;31: 419–24.

Disclosure

Not to declare