Underwater cold snare polypectomy for colorectal adenomas

Risk factors for unclear margin in cold snare polypectomy for colorectal polyp

OBJECTIVES

Cold snare polypectomy (CSP) is a common, simple, and safe procedure; however, it has a high rate of unclear margins. We analyzed the risk factors for unclear margins of colorectal polyp.

METHODS

We retrospectively investigated colorectal polyps treated with CSP between July 2021 and July 2022, excluding those that could not be retrieved or pathologically nonneoplastic and hyperplastic polyps without margin evaluation. The clinicopathological features and risk factors for unclear margins were analyzed. Furthermore, the polyps were divided into two groups: those resected by experts and those resected by trainees. A 1 : 1 propensity score matching was performed. After matching, the risk factors for unclear margins in each group were analyzed as secondary outcomes.

RESULTS

We analyzed 237 patients with 572 polyps; the margins were negative in 58.6% (negative group) and unclear in 41.4% (unclear group). The unclear margin was significantly higher at straddling folds ( P  = 0.0001), flexure points ( P  = 0.005), and in the procedures performed by trainees ( P  < 0.0001). Altogether, 198 propensity score matched pairs were explored for secondary outcomes. There were no significant differences in risk factors for unclear margins in the expert group, while in the trainee group, the unclear margin was significantly higher at the straddling folds ( P  = 0.0004) and flexure points ( P  = 0.005).

CONCLUSIONS

We demonstrated that straddling folds, flexure points, and procedures performed by the trainees were significant risk factors for unclear margins, and we hypothesized that the rate of unclear margins will reduce as the trainees accumulate experience at difficult sites.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Protocol design for randomized clinical trial to compare underwater cold snare polypectomy to conventional cold snare polypectomy for non-pedunculated colon polyps of size 5-10 mm (COLDWATER study)

BACKGROUND

Colorectal cancer is internationally the third leading cause of death from a malignant disease. The aim of screening colonoscopy in adults > 45 years of age is early diagnosis and treatment of precancerous polyps. Endoscopic polyp removal (polypectomy) can be achieved with various techniques depending on the size, morphology, and location of the polyp. According to current guidelines, small non-pedunculated polyps should be removed with a cold snare after the colorectal lumen has been insufflated with air (conventional cold snare polypectomy).In recent years, several studies have described the benefits of water aided colonoscopy, as well as the safety and efficacy of underwater cold snare polypectomy for large colon polyps. However, there are insufficient data on conventional and underwater techniques for small polyps, the most commonly diagnosed colorectal polyps.

METHODS

We have designed a prospective randomized double-blind clinical trial to compare the safety and efficacy of conventional and underwater cold snare polypectomy for non-pedunculated polyps 5-10 mm in size. A total of 398 polyps will be randomized. Randomization will be carried out using the random numbers method of Microsoft Excel 2016. The primary endpoint is the muscularis mucosa resection rate. Secondary endpoints are the depth and percentage of R0 excisions, complications, and the recurrence rate at follow-up endoscopy 6-12 months after polypectomy.

DISCUSSION

We hypothesize underwater polypectomy will result in a higher muscularis mucosa resection rate. The results of our study will provide useful data for the development of guidelines in polypectomy techniques for non-pedunculated polyps 5-10 mm in size.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov, NCT05273697.

Polyps and Polyposis Syndromes in Children: Novel Endoscopic Considerations

Polypectomy is the most common therapeutic endoscopic intervention in children. Management of sporadic juvenile polyps is limited to polypectomy to resolve symptoms, whereas polyposis syndromes pose a multidisciplinary challenge with broader ramifications. In preparation for polypectomy, there are key patient, polyp, endoscopy unit, and provider characteristics that factor into the likelihood of success. Younger age and multiple medical comorbidities increase the risk of adverse outcomes, classified as intraoperative, immediate postoperative, and delayed postoperative complications. Novel techniques, including cold snare polypectomy, can significantly decrease adverse events but a more structured training process for polypectomy in pediatric gastroenterology is needed.

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.

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.

Underwater versus conventional cold snare polypectomy of colorectal polyps 4-9 mm in diameter: a prospective randomized controlled trial

BACKGROUND AND AIMS

Cold snare polypectomy (CSP) has been reported as safe and effective method for the removal of small colorectal polyps. However, some studies showed low R0 resection rate. Underwater endoscopic mucosal resection is an effective technique to increase the proportions of complete resection. Therefore, the aim was to compare the rate of R0 resection of colorectal polyps 4-9 mm in diameter between conventional CSP (C-CSP) and underwater CSP (U-CSP).

METHODS

This study was a prospective randomized controlled trial. A total of 198 polyps (4-9 mm) in 110 patients were enrolled between December 2019 and June 2020. The polyps were randomized to be treated with either C-CSP (100 polyps) or U-CSP (98 polyps).

RESULTS

The R0 resection rate was significantly higher in U-CSP group than in C-CSP groups (84.7% vs. 59.0%; p < 0.001). The polyp retrieval rate of C-CSP and U-CSP was 94.5% and 100% (p = 0.030). The rate of polyp fragmentation of C-CSP and U-CSP group was 5.3% and 0% (p = 0.027). The resection time and retrieval time were longer in C-CSP than U-CSP (45.0 ± 37.7 s vs. 34.1 ± 21.2 s, p = 0.032 and 51.9 ± 67.7 s vs. 12.7 ± 12.4 s, p < 0.001). No clinically significant bleeding or perforation occurred in either group.

CONCLUSIONS

The results of this study were excellent with U-CSP of 4-9 mm colorectal polyps in terms of R0 resection, polyp retrieval and fragmentation rate, and procedure/retrieval time. Therefore, U-CSP is a safe and effective technique for removing colorectal polyps 4-9 mm in diameter. KCT (0004530).

Effect of cold snare polypectomy for small colorectal polyps

BACKGROUND

Colorectal cancer remains a considerable challenge in healthcare nowadays. Approximately 60%-80% of colorectal cancer is caused by intestinal polyps, and resection of intestinal polyps has been proved to reduce the incidence of colorectal cancer. The vast majority of intestinal polyps can be found during colonoscopy and removed endoscopically. Therefore, more attention has been paid to the development of endoscopic resection of intestinal polyps. In this study, we compared the efficacy and safety of cold snare polypectomy (CSP) and hot snare polypectomy (HSP).

AIM

To investigate the efficacy and safety of CSP and HSP for colorectal polyps.

METHODS

Between January and December 2020, 301 patients with colorectal polyps 4-9 mm in diameter were treated with endoscopic therapy in our hospital, and were divided into the CSP group (n = 154) and HSP group (n = 147). The operating time, incidence of bleeding and perforation, use of titanium clips, and complete resection rate were compared between the two groups.

RESULTS

We included 249 patients (301 polyps). No differences in gender, age, and polyp size, location, shape and type were observed between the CSP and HSP groups, and the resection rates in these two groups were 93.4% and 94.5%, respectively, with no significant difference. The use of titanium clips was 15.6% and 95.9%, the operating time was 3.2 ± 0.5 min and 5.6 ± 0.8 min, the delayed bleeding rate was 0% and 2.0%, and delayed perforation was 0% and 0.7%, in the CSP and HSP groups, respectively.

CONCLUSION

For sessile colorectal polyps < 10 mm, CSP had the same resection rate of impaired tissue integrity as traditional HSP had. The rate of complications was lower in the CSP group. CSP is a safe and effective method for polypectomy.

Impact of submucosal saline solution injection for cold snare polypectomy of small colorectal polyps: a randomized controlled study

BACKGROUND AND AIMS

Cold snare polypectomy (CSP) of small colorectal polyps is widely used. However, the technique is still troubled by insufficient resection depth, which may prevent precise pathologic evaluation. In this study, we investigated whether submucosal injection of saline solution helps to achieve deeper resection in CSP.

METHODS

The study was a single-center, prospective, randomized trial. Patients with small (3- to 10-mm diameter) nonpedunculated adenomatous or sessile serrated colorectal polyps were randomly allocated to either conventional CSP (C-CSP) or CSP with submucosal injection (CSP-SI). Primary outcome was the rate of complete muscularis mucosae (MM) resection, defined by the proportion of MM under the tumor more than 80% of the tumor's horizontal dimension. Secondary outcomes were the rates of negative lateral and vertical margins, fragmentation of resected specimens, conversion to hot snare mucosal resection, intraprocedural bleeding, delayed bleeding, and perforation.

RESULTS

Two hundred fourteen patients were randomly assigned to the CSP-SI (n = 107) or C-CSP (n = 107) group. The rate of complete MM resection was 43.9% in the CSP-SI group and 53.3% in the C-CSP group, a statistically insignificant difference. The rates of negative lateral margin and vertical margin (42.3% and 56.7%, respectively) in the CSP-SI group were significantly lower than those (58% and 76%) in the C-CSP group (P = .03 and P = .006, respectively). There was no polypectomy-related major bleeding or perforation.

CONCLUSIONS

Saline solution injection into the submucosa did not improve the resection depth of CSP of small colorectal polyps, and the method resulted in lower rates of negative lateral and vertical margins of resected lesions. (Clinical trial registration number: UMIN000037980.).