Recurrence rate and lesions characteristics after cold snare polypectomy of high-grade dysplasia and T1 lesions: A multicenter analysis

Comparison of cold snare endoscopic mucosal resection and hot snare endoscopic mucosal resection for small colorectal polyps: a randomized controlled trial

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.

Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024

1:  ESGE recommends cold snare polypectomy (CSP), to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of diminutive polyps (≤ 5 mm).Strong recommendation, high quality of evidence. 2:  ESGE recommends against the use of cold biopsy forceps excision because of its high rate of incomplete resection.Strong recommendation, moderate quality of evidence. 3:  ESGE recommends CSP, to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of small polyps (6-9 mm).Strong recommendation, high quality of evidence. 4:  ESGE recommends hot snare polypectomy for the removal of nonpedunculated adenomatous polyps of 10-19 mm in size.Strong recommendation, high quality of evidence. 5:  ESGE recommends conventional (diathermy-based) endoscopic mucosal resection (EMR) for large (≥ 20 mm) nonpedunculated adenomatous polyps (LNPCPs).Strong recommendation, high quality of evidence. 6:  ESGE suggests that underwater EMR can be considered an alternative to conventional hot EMR for the treatment of adenomatous LNPCPs.Weak recommendation, moderate quality of evidence. 7:  Endoscopic submucosal dissection (ESD) may also be suggested as an alternative for removal of LNPCPs of ≥ 20 mm in selected cases and in high-volume centers.Weak recommendation, low quality evidence. 8:  ESGE recommends that, after piecemeal EMR of LNPCPs by hot snare, the resection margins should be treated by thermal ablation using snare-tip soft coagulation to prevent adenoma recurrence.Strong recommendation, high quality of evidence. 9:  ESGE recommends (piecemeal) cold snare polypectomy or cold EMR for SSLs of all sizes without suspected dysplasia.Strong recommendation, moderate quality of evidence. 10:  ESGE recommends prophylactic endoscopic clip closure of the mucosal defect after EMR of LNPCPs in the right colon to reduce to reduce the risk of delayed bleeding.Strong recommendation, high quality of evidence. 11:  ESGE recommends that en bloc resection techniques, such as en bloc EMR, ESD, endoscopic intermuscular dissection, endoscopic full-thickness resection, or surgery should be the techniques of choice in cases with suspected superficial invasive carcinoma, which otherwise cannot be removed en bloc by standard polypectomy or EMR.Strong recommendation, moderate quality of evidence.

Hot snare polypectomy vs endoscopic mucosal resection using bipolar snare for intermediate size colorectal lesions: Propensity score matching

BACKGROUND

Endoscopic resection (ER) with bipolar snare, in which the electric current only passes through the tissue between the device’s two electrodes, is a prominent method used to prevent perforation due to electricity potentially. ER using bipolar snare with or without submucosal injection enabled safe resection of colorectal lesions measuring 10–15 mm in an ex vivo porcine model. ER with bipolar snare is expected to have good treatment outcomes in 10–15 mm colorectal lesions, with high safety even without submucosal injection. However, no clinical reports have compared treatment outcomes with and without submucosal injection.

AIM

To compare the treatment outcomes of bipolar polypectomy with hot snare polypectomy (HSP) to those with endoscopic mucosal resection (EMR).

METHODS

In this single-centre retrospective study, we enrolled 10–15 mm nonpedunculated colorectal lesions (565 Lesions in 463 patients) diagnosed as type 2A based on the Japan Narrow-band Imaging Expert Team classification, resected by either HSP or EMR between January 2018 and June 2021 at the National Cancer Center Hospital East. Lesions were divided into HSP and EMR groups, and propensity score matching was performed. In the matched cohort, en bloc and R0 resection rates and adverse events were compared between the two groups.

RESULTS

Of the 565 lesions in 463 patients, 117 lesions each in the HSP and EMR groups were selected after propensity score matching. In the original cohort, there was a significant difference in antithrombotic drug use (P < 0.05), lesion size (P < 0.01), location (P < 0.01), and macroscopic type (P < 0.05) between the HSP and EMR groups. In the matched cohort, the en bloc resection rates were comparable between both groups [93.2% (109/117) vs 92.3% (108/117), P = 0.81], and there was no significant difference in the R0 resection rate [77.8% (91/117) vs 80.3% (94/117), P = 0.64]. The incidence of delayed bleeding was similar in both groups [1.7% (2/117)]. Perforation occurred in the EMR group [0.9% (1/117)] but not in the HSP group.

CONCLUSION

Using bipolar snare, ER of nonpedunculated 10–15 mm colorectal lesions may be performed safely and effectively, even without submucosal injection.

Colorectal cold snare polypectomy: Current standard technique and future perspectives

It has been shown that resection of adenomatous colorectal polyps can reduce mortality due to colorectal cancer. In daily clinical practice, simpler and safer methods of colorectal polypectomy have been sought to enable endoscopists to resect all detected lesions. Among these, cold snare polypectomy (CSP) is widely used in clinical practice because of its advantages in shortening procedure time, reducing delayed bleeding risk, and lowering treatment costs, while maintaining a similar complete resection rate for lesions smaller than 10 mm when compared to conventional hot snare polypectomy. This review introduces the findings of previous studies that investigated the efficacy and safety of the CSP procedure for nonpedunculated polyps smaller than 10 mm, and describes technical points to remember when practicing CSP based on the latest evidence, including using a thin wire snare specifically designed for CSP, and observing the surrounding mucosa of the resection site with chromoendoscopy or image-enhanced endoscopy to ensure that there is no residual lesion. This review also describes the potential of expanding the indication of CSP as a treatment for lesions larger than 10 mm, those with pedunculated morphology, those located near the appendiceal orifice, and for patients under continuous antithrombotic agent therapy. Finally, the perspective on optimal treatments for recurrent lesions after CSP is also discussed, despite the limited related evidence and data.

Endoscopic features and clinical course of colorectal carcinoma resected by cold snare polypectomy

BACKGROUND AND AIM

Cold snare polypectomy is commonly performed to remove small colorectal polyps. Accidental resection of carcinomas during this procedure has been reported. Herein, we aimed to clarify the clinicopathological features and clinical course of colorectal carcinomas resected by cold snare polypectomy.

METHODS

This multicenter retrospective cohort study was conducted at 10 Japanese healthcare centers. Of the colorectal lesions resected by cold snare polypectomy between April 2016 and March 2020, lesions pathologically diagnosed as carcinoma were reviewed. Centralized histology (based on the Vienna classification) and endoscopic reviews were performed. The study endpoints were endoscopic features and clinical outcomes of cold snare polypectomy-resected colorectal carcinomas (Vienna category ≥4.2).

RESULTS

We reviewed 74 of the 70 693 lesions resected by cold snare polypectomy. After a central pathological review, 68 lesions were diagnosed as carcinomas. The Japan Narrow-band imaging Expert Team (JNET) classification type 2B, lesion size ≥6 mm, and multinodular morphology were the significant endoscopic predictors of carcinoma resected by cold snare polypectomy. No adverse events related to the procedure occurred. Sixty-three lesions were diagnosed as carcinomas within the mucosal layer, and 34 were curative resections. Of the five carcinoma lesions with submucosal invasion, additional surgery revealed remnant cancer tissues in one lesion. No local or metastatic recurrence was observed during follow-up.

CONCLUSIONS

Although most of the carcinomas resected by cold snare polypectomy were within the mucosal layer, few lesions invading the submucosa were identified. Careful pre-procedural endoscopic evaluation, especially focusing on the JNET classification and multinodular morphology, is recommended.

Invasive Colon Cancer Inadvertently Resected by Cold Snare Polypectomy

A 74-year-old man with anemia underwent colonoscopy, which revealed a 4-mm polyp in the ascending colon. The polyp was subsequently diagnosed as an adenomatous lesion according to the narrow-band imaging (NBI) International Colorectal Endoscopic classification/Japan NBI Expert Team classification and resected via cold snare polypectomy (CSP). However, a pathological examination revealed a well-differentiated adenocarcinoma with a positive vertical margin. We performed additional endoscopic resection at the CSP scar area, revealing residual submucosal cancer with lymphatic involvement. The patient then underwent additional surgical resection. In such cases, additional endoscopic resection might be a treatment option.

Comparison of complete resection rates in cold snare polypectomy using two different wire diameter snares: A randomized controlled study

BACKGROUND AND AIM

Cold snare polypectomy (CSP) is a standard treatment for small colorectal polyps. This study examined the effect of different snare wire diameters on complete histological resection rate, resection depth, and CSP safety.

METHODS

This randomized controlled trial was conducted at two institutions between June 2019 and March 2021. Eligible colorectal polyps (≤10 mm) were randomly assigned in a 1:1 ratio to receive either CSP with a conventional snare made of normal-diameter wire (0.40 mm) or CSP with a dedicated snare made of thin wire (0.23 mm). The primary endpoint was the complete resection rate determined on histological assessment of the resected specimen.

RESULTS

In total, 254 lesions in 152 patients were included, with 128 and 126 lesions assigned to the normal-diameter wire snare group and the thin-wire snare group, respectively. No significant differences were observed in patient characteristics between the two groups. The histological complete resection rate was significantly higher in the thin-wire snare group than in the normal-diameter wire snare group (70.0% vs 81.0%, P = 0.04). The normal-diameter wire snare group had significantly more cases of unclear horizontal margin evaluation than the thin-wire snare group (28.1% vs 15.9%, P = 0.02). No significant differences were observed between the two groups in the muscularis mucosa and submucosa of the resected specimens or the thickness of the submucosa in the resected specimens.

CONCLUSIONS

CSP with a dedicated thin-wire snare provides more specimens that can be evaluated at the horizontal end and increases the histological complete resection rate.