Cold snare excision of small colorectal polyps

A case of delayed perforation after cold snare polypectomy treated conservatively by endoscopic clip closure

We present the case of a 45-year-old man who underwent a screening total colonoscopy and developed delayed perforation after a cold snare polypectomy in the descending colon and sigmoid colon. The patient developed abdominal pain and was referred to our department for further evaluation and treatment. On clinical examination, we noted lower abdominal tenderness, mild rebound pain, and elevated levels of inflammatory markers. Abdominal contrast-enhanced computed tomography confirmed the presence of free air in the abdomen. Since there were no signs of peritoneal inflammation and the vital signs were stable, we planned to perform endoscopic clip closure of the perforated area. The patient's symptoms improved with conservative management thereafter, including fasting, fluid replacement, and antibiotic administration. The patient was discharged on the 6th hospital day. In this case report, we discuss the usefulness of endoscopic clip closure in managing delayed perforation.

Phlegmonous Colitis after Cold Snare Polypectomy in an Immunosuppressed Patient: A Case Report

Introduction

Cold snare polypectomy (CSP) is a procedure with a low risk of complications. Here, we present our experience of a rare case of submucosal abscess following CSP in an immunosuppressed patient.

Case Presentation

Seventy-eight-year-old man underwent CSP, developing a fever, chills, and right lower abdominal pain 8 days later. Ultrasound and computed tomography revealed wall thickening of the ascending colon, presenting as whitening and thickening of the same region, and excretion of pus was observed after biopsy. The diagnosis was made as phlegmonous colitis, for which antibiotic therapy was commenced. The patient was diagnosed with chronic myelomonocytic leukemia (CMML) during admission. We considered the following reasons as possible causes of infectious complications after CSP: (1) the patient had a highly immunosuppressed state with comorbidities such as CMML as well as diabetes mellitus and (2) disruption of the mucosal barrier occurred during endoscopic resection.

Conclusion

Although CSP is generally considered safe, our case highlights the potential for serious complications in immunosuppressed patients. Therefore, the decision to perform CSP in such patients should be made with caution to avoid unnecessary interventions. In instances where treatment is essential, thorough bowel preparation and prophylactic antibiotic use may be necessary to mitigate the risks.

COLD SNARE POLYPECTOMY: A SAFE PROCEDURE FOR REMOVING SMALL NON-PEDUNCULATED COLORECTAL LESIONS

BACKGROUND

Polypectomy is an important treatment option for preventing colorectal cancer. Incomplete polyp resection (IPR) is re-cognized as a risk factor for interval cancer.

OBJECTIVE

The primary objective was to evaluate the complete polyp resection (CPR) rate for cold snare polypectomy (CSP) in small non-pedunculated polyps and, secondarily, specimen retrieval and complication rates.

METHODS

We prospectively evaluated 479 polyps <10 mm removed by CSP in 276 patients by an inexperienced endoscopist.

RESULTS

A total of 476 polyps (99.4%) were resected en bloc. A negative margin (classified as CPR) was observed in 435 polyps (90.8%). An unclear or positive margin (classified as IPR) was observed in 43 cases (9.0%) and 1 case (0.2%), respectively, for an overall IPR rate of 9.2% (44/479). The IPR rate was 12.2% in the first half of cases and 5.9% in the second half (P=0.02). Dividing into tertiles, the IPR rate was 15.0% in the first tertile, 6.9% in the second tertile, and 5.7% in the third tertile (P=0.01). Dividing into quartiles, the IPR rate was 15.8% in the first quartile and 5.9% in the fourth quartile (P=0.03). The IPR rate was 6.3% for type 0-IIa lesions and 14.1% for type 0-Is lesions (P=0.01). For serrated and adenomatous lesions, the IPR rate was 9.2%. Specimen retrieval failed in 3.6% of cases. Immediate bleeding (>30 s) occurred in 1 case (0.2%), treated with argon plasma coagulation. No delayed bleeding or perforation occurred.

CONCLUSION

CSP is a safe technique that provides good results for the resection of small non-pedunculated polyps, with a short learning curve.

Systematic review and meta-analysis of cold snare polypectomy and hot snare polypectomy for colorectal polyps

BACKGROUND AND AIM

Cold snare polypectomy (CSP) has become increasingly utilized to resect colorectal polyps, given its efficacy and safety. This study aims to compare CSP and hot snare polypectomy (HSP) for resecting small (< 10 mm) and large (10-20 mm) colorectal lesions.

METHODS

Relevant publications were obtained from Cochrane Library, Embase, Google Scholar, PubMed, and Web of Science databases. The publication search was limited by English-language and human studies. Pooled mean difference and odds ratios (ORs) were calculated for outcomes of interest.

RESULTS

Twenty-three studies were included in this meta-analysis. Pooled OR of delayed post-polypectomy bleeding (DPPB) in the CSP group versus the HSP group was 0.29 (P = 0.0001, I2  = 29%). Subgroup analysis according to lesion size showed a significant reduction in the DPPB rate in lesion sizes 10-20 mm (pooled OR 0.08, P = 0.003, I2  = 0%) and < 10 mm (pooled OR 0.35, P = 0.001, I2  = 27%). Pooled OR of major bleeding in the CSP group was 0.23 (P = 0.0004, I2  = 0%). Subgroup analysis by lesion size revealed a significant decrease in the rate of major bleeding in the CSP group for both lesion sizes 10-20 mm (pooled OR 0.11, P = 0.04) and < 10 mm (pooled OR 0.26, P = 0.003). Complete resection, en bloc resection, and recurrence rate were comparable in the two groups.

CONCLUSIONS

Cold snare polypectomy was associated with a lower rate of DPPB and lower risk of major bleeding compared with HSP in both small and large polyps. CSP should be considered as the polypectomy technique of choice for colorectal polyps.

Current Status of Diagnosis and Treatment of Colorectal Cancer in Asian Countries: A Questionnaire Survey

INTRODUCTION

Diagnostic and therapeutic methods for colorectal cancer (CRC) have advanced; however, they may be inaccessible worldwide, and their widespread use is challenging. This questionnaire survey investigates the current status of diagnosis and treatment of early-stage CRC in Asian countries.

METHODS

Responses to the questionnaire were obtained from 213 doctors at different institutions in 8 countries and regions. The questionnaire consisted of 39 questions on the following four topics: noninvasive diagnosis other than endoscopy (6 questions), diagnosis by magnification and image-enhanced endoscopy (IEE) including artificial intelligence (AI) (10 questions), endoscopic submucosal dissection (ESD), proper use among other therapeutic methods (11 questions), and pathologic diagnosis and surveillance (12 questions).

RESULTS

Although 101 of 213 respondents were affiliated with academic hospitals, there were disparities among countries and regions in the dissemination of advanced technologies, such as IEE, AI, and ESD. The NICE classification is widely used for the diagnosis of colorectal tumors using IEE, while the JNET classification with magnification was used in countries such as Japan (65/70, 92.9%) and China (16/22, 72.7%). Of the 211 respondents, 208 (98.6%) assumed that en bloc resection should be achieved for carcinomas, and 180 of 212 (84.9%) believed that ESD was the most suitable in cases with a diameter larger than 2 cm. However, colorectal ESD is not widespread in countries such as Thailand, the Philippines, and Indonesia.

CONCLUSION

The promotion of advanced technologies and education should be continual to enable more people to benefit from them.

Bleeding After Endoscopic Resection of Colonic Adenomatous Polyps Sized 4-10 mm

Introduction: Colonoscopy with polypectomy is an efficacious procedure in reducing the risk of colorectal cancer development, the precursor are adenomatous polyps. The most common method for resection of polyps measuring 4-10 mm are cold (CSP) and hot snare polypectomy (HSP). CSP has a lower incidence of adverse events, especially delayed post-polypectomy bleeding. Aim: To evaluate the presence of immediate and delayed bleeding in the cold snare polypectomy of sub-centimeter polyps of the colon compared with hot snare polypectomy. Materials and Methods: This prospective clinical study is comprised all patients who were incidentally detected to have adenomatous colonic polyps measuring 4-10 mm during a colonoscopy screening. Polypectomy was done with (hot snare) or without electrocautery (cold snare). After removal of polyps, immediate bleeding, delayed bleeding, and methods for were analyzed. Results: The CSP and HSP groups included 116 patients, 113 (54.4%) polyps in 61 (52.6%) patients with CSP while 95 (45.6%) polyps in 55 (47.4%) patients with HSP. 25 (22.1%) polyps after CSP had immediate bleeding. In 5 patients (20.0%), five hemostatic clips were inserted after CSP for bleeding longer than 150 sek. The average percentage difference between immediate bleeding versus total number of resected polyps using the cold snare method is not statistically significant (p<0.05) (Difference test, p=0.0000). Delayed bleeding was not registered using this method. In the second investigated group (HSP), one patient had delayed bleeding. This was stopped with 2 clips. Immediate bleeding was not registered. Conclusion: CSP is safer than HSP in resecting colon polyps sized 4-10 mm, without risk of delayed bleeding.

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.

Endoscopic resection of non-ampullary duodenal adenomas: Is cold snaring the promised land?

Due to the high risk of morbidity and mortality associated with surgical resection in this tract, endoscopic resection (ER) has taken the place of surgical resection as the first line treatment for non-ampullary duodenal adenomas. However, due to the anatomical characteristics of this area, which enhance the risk of post-ER problems, ER in the duodenum is particularly difficult. Due to a lack of data, no ER technique for superficial non-ampullary duodenal epithelial tumours (SNADETs) has yet been backed by strong, high-quality evidence; yet, traditional hot snare-based techniques are still regarded as the standard treatment. Despite having a favourable efficiency profile, adverse events during duodenal hot snare polypectomy (HSP) and hot endoscopic mucosal resection, such as delayed bleeding and perforation, have been reported to be frequent. These events are primarily caused by electrocautery-induced damage. Thus, ER techniques with a better safety profile are needed to overcome these shortcomings. Cold snare polypectomy, which has already been shown as a safer, equally effective procedure compared to HSP for treatment of small colorectal polyps, is being increasingly evaluated as a potential therapeutic option for non-ampullary duodenal adenomas. The aim of this review is to report and discuss the early outcomes of the first experiences with cold snaring for SNADETs.

Delayed perforation after cold snare polypectomy for small colonic polyps in a patient receiving oral corticosteroids

This case report describes a fatal outcome due to delayed perforation after cold snare polypectomy in a patient with bullous pemphigoid receiving oral corticosteroids. Cold snare polypectomy has become the standard treatment for small colorectal polyps because of the procedure's safety and simplicity. In this case, however, corticosteroid therapy and vasculitis may have caused local necrosis and tearing of the intestinal wall. Corticosteroids are widely used, and perforation after cold snare polypectomy is extremely rare. However, some patients on corticosteroid therapy may have special pathologies, such as in this case, and we advise physicians to use appropriate judgment and extreme caution in determining the indication for endoscopic therapy.

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.

Research trends on endoscopic mucosal resection: A bibliometric analysis from 1991 to 2021

Background

In recent years, the rapid development of digestive endoscopy technology has brought revolutionary changes to endoscopic therapy. A growing number of articles have been published annually. We aimed to explore global scientific outputs and hotspots of endoscopic mucosal resection (EMR) published by different countries, organizations, and authors.

Methods

We extracted relevant publications from the Web of Science Core Collection (WOSCC) on June 23, 2022. We examined the retrieved data by bibliometric analysis (e.g., cocited and cluster analysis, keyword co-occurrence) using the software CiteSpace and VOSviewer to analyze and predict the trends and hot spots in this field.

Results

A total of 2,695 papers were finally identified. The results showed that the number of articles fluctuated with the year and reached its peak in 2021. NATIONAL CANCER CENTER JAPAN was the most influential institution. MICHAEL J BOURKE and YUTAKA SAITO are two of the most prolific scholars. ENDOSCOPY and GASTROINTESTINAL ENDOSCOPY were the most productive journals. “Early gastric cancer” and “Barrett's esophagus” were the focus of EMR research. “Adverse events”, “cold snare polypectomy” and “outcomes” have become increasingly popular in recent years and could become hot spots in the future.

Conclusion

In this study, we summarized the characteristics of the publications; identified the most influential countries, institutions, and journals; and identified the leading topics in the EMR field.

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.

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.

Risk of Delayed Bleeding after Cold Snare Polypectomy in Patients with Antithrombotic Therapy

BACKGROUND

Cold snare polypectomy is being increasingly adopted; however, there are few reports of cold snare polypectomy regarding antithrombotic therapy.

AIMS

This study aimed to investigate the real-world safety of cold snare polypectomy during antithrombotic therapy.

METHODS

We collected data from consecutive patients undergoing cold snare polypectomy in a single hospital between 2013 and 2017. Indications for cold snare polypectomy were any ≤ 10 mm polyp. The primary outcome was delayed bleeding. We compared rates of delayed bleeding between patients with and without antithrombotic therapy and analyzed risk factors for delayed bleeding using binary logistic regression model with firth procedure.

RESULTS

In 2152 patients (mean age 67.6 years; male 1411), 4433 colorectal polyps (mean diameter 5.0 mm) underwent cold snare polypectomy. Clipping during the procedure was performed for 5.8%. Delayed bleeding occurred in 0.51% (11/2152) of patients and 0.25% (11/4433) of polyps, but no major delayed bleeding occurred. A total of 244 (11%) patients received antithrombotic therapy. Patients on antithrombotic therapy were older (p < 0.001), more likely male (p < 0.001) and had cold snare polypectomy in the proximal colon (p = 0.011). The rate of delayed bleeding was higher in patients on antithrombotic therapy (1.64% vs. non-antithrombotic therapy 0.37%, p = 0.009). Larger polyp size (> 5 mm), use of clips, and antithrombotic therapy were significant risk factors for delayed bleeding. There was no clear association between specific antithrombotic agents and delayed bleeding.

CONCLUSIONS

Delayed bleeding after cold snare polypectomy was rare even in patients with antithrombotic therapy, and no major delayed bleeding occurred.

Safety and efficacy of cold versus hot snare polypectomy including colorectal polyps ≥1 cm in size

Cold snare polypectomy (CSP; polypectomy without electrocautery) has spread rapidly worldwide during the past decade in what has been called "Cold Revolution". We performed a PubMed literature search for studies investigating CSP outcomes for colorectal polyps. Five randomized controlled trials (RCTs) assessed the complete resection rates (CRRs). The CRRs were similar regardless of the presence or absence of electrocautery, and the efficacy of submucosal injection for better CRRs is still controversial. Eight RCTs assessed the adverse events. The incidence of intraprocedural bleeding with cold procedures was comparable to or higher than that of hot procedures. The incidences of delayed bleeding were comparable to or lower with cold procedures, especially in patients taking anticoagulants. Fifteen studies have been reported on CSP for large (≥1 cm) colorectal polyps (10 retrospective studies, four prospective single-arm studies, and one prospective RCT). These studies reported that the safe cold procedures (a low intra- and post-procedural bleeding rate without perforation) could be implemented for lesions ≥1 cm. However, considering the incision depth of CSP and the local recurrence rate based on the current evidence, only large sessile serrated lesions (SSLs) can be candidates for cold procedures, and large adenomas should not be candidates for this procedure. Based on the current evidence, CSP seems to be the appropriate standard procedure for sub-centimeter colorectal low-grade adenomas due to its safety and simplicity. Thus, large SSLs can be candidates for cold procedures; however, careful inspection and further prospective studies are warranted to confirm the procedure's clinical relevance.

Cold snare polypectomy vs. hot snare polypectomy vs. argon plasma coagulation for small (5-9mm) left-sided colorectal polyps: a prospective randomized trial

OBJECTIVE

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

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

Serrated polyps of the colon and rectum: a concise review

"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.

Evidence-based clinical practice guidelines for management of colorectal polyps

BACKGROUND

The Japanese Society of Gastroenterology (JSGE) published ''Daicho Polyp Shinryo Guideline 2014'' in Japanese and a part of this guideline was published in English as "Evidence-based clinical practice guidelines for management of colorectal polyps" in the Journal of Gastroenterology in 2015. A revised version of the Japanese-language guideline was published in 2020, and here we introduce a part of the contents of revised version.

METHODS

The guideline committee discussed and drew up a series of clinical questions (CQs). Recommendation statements for the CQs were limited to items with multiple therapeutic options. Items with established conclusions that had 100% agreement with previous guidelines (background questions) and items with no (or old) evidence that are topics for future research (future research questions: FRQs) were given descriptions only. To address the CQs and FRQs, PubMed, ICHUSHI, and other sources were searched for relevant articles published in English from 1983 to October 2018 and articles published in Japanese from 1983 to November 2018. The Japan Medical Library Association was also commissioned to search for relevant materials. Manual searches were performed for questions with insufficient online references.

RESULTS

The professional committee created 18 CQs and statements concerning the current concept and diagnosis/treatment of various colorectal polyps, including their epidemiology, screening, pathophysiology, definition and classification, diagnosis, management, practical treatment, complications, and surveillance after treatment, and other colorectal lesions (submucosal tumors, nonneoplastic polyps, polyposis, hereditary tumors, ulcerative colitis-associated tumors/carcinomas).

CONCLUSIONS

After evaluation by the moderators, evidence-based clinical practice guidelines for management of colorectal polyps were proposed for 2020. This report addresses the therapeutic related CQs introduced when formulating these guidelines.

Endoscopic Biopsies and Histopathological Findings in Diagnosing Chronic Gastrointestinal Disorders in Dogs and Cats

Nowadays, endoscopic examination is a diagnostic tool gaining popularity in the management of gastrointestinal disorders in dogs and cats. Direct accessibility of the lumen of gastrointestinal tract combined with the mucosal biopsy provides a great diagnostic potential. Using endoscopy and endoscopically guided biopsy, one can conduct both macro- and microscopic assessment of lesions and perform many specialist adjunct examinations. Histopathological examination of mucosal biopsy specimens collected from the stomach and intestines allows us to distinguish between types of inflammations and to diagnose ulcerative, polypoid, and cancerous lesions.

Dedicated Cold Snare vs. Traditional Snare for Polypectomy of Diminutive and Small Lesions in a Porcine Model: A Research Group for Endoscopic Instruments and Stents (REIS) Study

BACKGROUND/AIMS

The aim of this in vivo animal study was to evaluate the effectiveness and safety of dedicated cold snare (DCS) compared with those of traditional snare (TS) for cold snare polypectomy (CSP).

METHODS

A total of 36 diminutive (5 mm) and 36 small (9 mm) pseudolesions were made by electrocoagulation in the colons of mini-pigs.

RESULTS

For the diminutive lesions, there were no significant differences in technical success rate, procedure time, or complete resection rate between the DCS and TS groups; the rate of uneven resection margin in the DCS group was significantly lower than that of the TS group. For small lesions, technical success rate and complete resection rate were significantly higher in the DCS group than in the TS group (100% [18/18] vs. 55.6% [10/18], p=0.003; 94.4% [17/18] vs. 40% [4/10], p=0.006). In addition, the procedure duration was significantly shorter, and the rate of uneven resection margin was significantly lower in the DCS group (28.5 sec vs. 66.0 sec, p=0.006; 11.1% [2/18] vs. 100% [10/10], p<0.001). Two cases of perforation occurred in the DCS group. Multivariate analysis revealed that DCS use was independently associated with complete resection.

CONCLUSION

DCS is superior to TS in terms of technical success, complete resection, and reducing the duration of the procedure for CSP of small polyps.

Indications for Cold Polypectomy Stratified by the Colorectal Polyp Size: A Systematic Review and Meta-Analysis

Objectives:

Cold polypectomy (CP) is widely used because of its safety profile. This systematic review and meta-analysis aimed to clarify the indications for CP based on polyp size.

Methods:

We searched PubMed and the Cochrane Library for randomized controlled trials that compared cold snare polypectomy (CSP) and other procedures for polyps ≤10 mm. Large-scale prospective observational studies were also searched to assess delayed bleeding rates. The studies were integrated to assess the risk ratio for incomplete resection rates according to polyp size. The Cochrane risk of bias tool was used to evaluate the study bias. The certainty of cumulative evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation system.

Results:

We found 280 articles and reviewed their eligibility. We selected and extracted 12 randomized controlled trials and 3 prospective observational studies. The risk ratio of incomplete resection of polyps ≤10 mm using CSP compared with hot snare polypectomy (HSP) was 1.36 (95% confidence interval [CI], 0.92-2.01). The risk ratio for incomplete removal using CSP compared with cold forceps polypectomy (CFP) was 0.50 (95% CI, 0.31-0.82). For polyps ≤3 mm, the risk ratio of CSP compared with CFP was 1.40 (95% CI, 0.39-4.95). Certainty of cumulative evidence was considered low. No delayed bleeding after CP was reported after the treatment of 3446 polyps.

Conclusions:

CSP and HSP may result in the same complete resection rates for polyps ≤10 mm. For polyps ≤3 mm, CFP and CSP may have the same resection rates (PROSPERO registration number: CRD42019122132).

Usefulness of cold polypectomy under linked color imaging

Background and study aims  Cold polypectomy is becoming popular for treatment of colon polyps due to its safety and convenience, but there is still the problem of tumor remnants. Because linked color imaging (LCI) improves polyp visibility, cold polypectomy under LCI is anticipated to reduce the tumor remnant rate. Therefore, we investigated the usefulness of this procedure. Patients and methods  Fifty patients scheduled to undergo cold polypectomy for treatment of colon polyps < 10 mm and assumed to be adenomas were registered prospectively. After performing cold snare polypectomy (CSP) under LCI, biopsy was performed at two resection margin sites for each polyp to determine the tumor remnant rate. Results  A total of 145 lesions were treated by CSP. Of the 139 lesions in which polyps were retrievable and diagnosed as adenomas pathologically, one lesion was recognized as a remnant adenoma on biopsy (remnant rate: 0.7 % [95 % CI: 0.0-4.4]). This remnant rate was extremely low. Treatment results were extremely promising given that en bloc resection, post-procedure bleeding, and perforation rates were 100 %, 0 %, and 0 %, respectively. Conclusion  Cold snare polypectomy under LCI may be an effective treatment method capable of reducing the tumor remnant rate. This trial was approved by our Institutional Ethics Committee and registered at the University Hospital Medical Information Network (UMIN 000033690).

Biomaterials in Gastroenterology: A Critical Overview

In spite of the large diversity of diagnostic and interventional devices associated with gastrointestinal endoscopic procedures, there is little information on the impact of the biomaterials (metals, polymers) contained in these devices upon body tissues and, indirectly, upon the treatment outcomes. Other biomaterials for gastroenterology, such as adhesives and certain hemostatic agents, have been investigated to a greater extent, but the information is fragmentary. Much of this situation is due to the paucity of details disclosed by the manufacturers of the devices. Moreover, for most of the applications in the gastrointestinal (GI) tract, there are no studies available on the biocompatibility of the device materials when in intimate contact with mucosae and other components of the GI tract. We have summarized the current situation with a focus on aspects of biomaterials and biocompatibility related to the device materials and other agents, with an emphasis on the GI endoscopic procedures. Procedures and devices used for the control of bleeding, for polypectomy, in bariatrics, and for stenting are discussed, particularly dwelling upon the biomaterial-related features of each application. There are indications that research is progressing steadily in this field, and the establishment of the subdiscipline of "gastroenterologic biomaterials" is not merely a remote projection. Upon the completion of this article, the gastroenterologist should be able to understand the nature of biomaterials and to achieve a suitable and beneficial perception of their significance in gastroenterology. Likewise, the biomaterialist should become aware of the specific tasks that the biomaterials must fulfil when placed within the GI tract, and regard such applications as both a challenge and an incentive for progressing the research in this field.

Delayed hemorrhage after cold and hot snare resection of colorectal polyps: a multicenter randomized trial (interim analysis)

Background and study aims  Delayed bleeding is believed to occur less frequently after cold snare polypectomy (CSP), but this has not been validated in clinical trials. This study aimed to compare rates of delayed bleeding after CSP and hot snare polypectomy (HSP). Patients and methods  We conducted a multicenter, randomized controlled trial. Participants scheduled to undergo endoscopic resection of colorectal polyps ≤ 10 mm were enrolled and randomly assigned to CSP or HSP. Prophylactic clipping was performed at the endoscopists' discretion. The primary outcome was delayed bleeding rate. Secondary outcomes included immediate bleeding rate and clipping rate. Sample size calculation showed that 451 patients were required in each arm. Results  At the end of the study period decided in advance, 308 participants were recruited and an interim analysis was performed. A total of 273 patients (mean age 62.2 ± 8.8 years; 188 males) were analyzed, with 139 patients allocated to CSP and 134 to HSP. In total, 367 polyps were resected with CSP and 360 polyps with HSP. There were no significant differences in patient demographics or polyp characteristics. In per-patient-based analysis, delayed bleeding rates were 0.7 % after CSP and 0.7 % after HSP. Per-polyp analysis showed similar results (CSP: 0.3 % vs. HSP: 0.6 %). The immediate bleeding rate was significantly higher with CSP vs. HSP (54 % vs.14 %, P  < 0.0001), while clipping rates were 18 % and 19 %, respectively. Conclusion  This interim analysis did not demonstrate that delayed bleeding after CSP is less frequent than after HSP. The delayed bleeding rate after HSP was lower than expected. Meeting presentations: Digestive Disease Week 2017.

Cold snare polypectomy: Indications, devices, techniques, outcomes and future

Colonoscopy has been shown to reduce the risk of colon cancer by enabling the removal of precancerous lesions. Although cold snare and hot snare polypectomy have similar retrieval rates and complete resection rates, rates of delayed bleeding tend to be lower with cold snare polypectomy than with hot snare polypectomy, especially for patients taking antithrombotic agents. However, among cold snares there may be differences in terms of the completeness of polyp excision, as complete removal appears more likely with thin-wire dedicated cold snares compared to the traditional, thick-wire cold snares. Cold snare polypectomy may be especially well suited for use in patients taking antithrombotic agents, due to its minimal risk of delayed bleeding. Histological analyses suggest that cold snare polypectomy causes less damage to blood vessels in the submucosal layers, which results in a reduced incidence of hemorrhage compared to hot snare polypectomy. However, cold snare removal of small polyps may result in fragmentation of small specimens during collection and concerns as to whether the resection is complete. An endoscopy biomarker of effective cold snare polypectomy technique is needed to ensure complete removal of non-pedunculated colorectal polyps ≤10 mm. Future uses of cold snare polypectomy may include piecemeal removal of sessile serrated adenoma/polyp lesions >10 mm. Currently, cold snare polypectomy should be considered a primary method for colorectal polyps of less than 10 mm, especially those in the 4- to 10-mm range.

Safety and efficacy of cold polypectomy compared to endoscopic mucosal resection and hot biopsy polypectomy

Backgrounds: Recently, several studies have demonstrated the usefulness of cold polypectomy (CP), a safe and simple method for the removal of small polyps. We investigated the safety and efficacy of CP compared to that of endoscopic mucosal resection (EMR) and hot biopsy polypectomy (HB). Methods: We retrospectively examined 1713 colorectal polyps (size 1-9 mm) in 731 patients. CP, EMR, and HB were performed on 476, 997, and 240 lesions, respectively. We compared the region, size, morphology, the presence of delayed bleeding as overt bleeding 24 h after operation, number of clips, pathology, the presence of antithrombotic therapy, procedure time from detection of a polyp to resection and hemostasis, device cost including device and clips, and polyp remnants. Results: The delayed bleeding in the CP group (0/476) was significantly lower compared to that in the HB group (3/240) and EMR group (7/997). There were no cases of perforations. The procedure time was significantly shorter in the CP group than in the EMR group (91.3sec vs 290.1sec, p < .0001). The CP group had a significantly lower device cost than the HB and EMR groups (49.2USD vs 58.0 USD vs 91.3 USD, p < .0001) was not inferior in terms of polyp remnants to the EMR and HB groups. (1.4% vs 0.6% vs 6.1%, p = .1599) Conclusions: CP is a safe treatment that achieves less delayed bleeding. Moreover, CP is not inferior to other groups in terms of polyp remnants and offers a cost benefit. CP can be considered useful for colonic polypectomy.

Risk of delayed bleeding before and after implementation of cold snare polypectomy in a screening colonoscopy setting

Background and study aims  Cold snare polypectomy (CSP) is considered to be effective in reducing risk of delayed bleeding but randomized trials fail to support this owing to the small sample size. The current study aimed to compare risk of delayed bleeding before and after implementation of CSP in a screening colonoscopy setting. Patients and methods  This study retrospectively analyzed a prospectively maintained screening colonoscopy database in a university hospital in Taiwan. We compared the rate of delayed bleeding before and after implementation within similar periods (18 months and 15 months) and the respective number of polypectomies (1,304 and 1,255) performed to remove small and diminutive polyps. The main outcome measurement was delayed bleeding within the two periods. Multivariate analysis was performed to adjust for major confounders. Results  A total of 1,304 and 1,225 subjects received hot snare polypectomy (HSP) and CSP in two separate periods, respectively. Compared with the HSP, the CSP had a lower rate of delayed bleeding (0.1 % vs . 1.1 %, P  < 0.001), severe bleeding (0 % vs. 0.7 %, P  < 0.01), need for second-look colonoscopy (0 % vs. 0.8 %, P  < 0.01), and emergency service visits (0.1 % vs . 1.0 %, P  < 0.01). Total procedure time (12.60 ± 11.45 vs . 16.48 ± 14.27 min/person, P  < 0.01) and duration of hospital stay (1.18 ± 0.50 vs . 1.53 ± 5.78 hour/person, P  < 0.03) were also shorter after CSP implementation. Multivariate analysis showed that HSP was an independent risk factor for delayed bleeding after adjusting for age, gender, and number of polyps (adjusted odds ratio 14.4;95 % confidence interval = 1.88 - 110.6). Conclusion  Implementation of CSP significantly reduces risk of delayed bleeding associated with removing small and diminutive polyps in screening colonoscopy.

Investigation of the Local Recurrence Rate after Colorectal Endoscopic Mucosal Resection: Is Incomplete Polyp Resection Really a Clinically Important Problem? Analysis of the Rationale for the "Resect and Discard" Strategy

BACKGROUND/AIMS

The "Resect and Discard" strategy is a potentially useful strategy. At present, only the lesion size and accuracy of diagnosis are cited as considerations for clinical adoption of this strategy. On the other hand, histopathology of the resected specimens after Endoscopic Mucosal Resection (EMR) reveals often an unclear or positive-margin status, implying Incomplete Polyp Resection (IPR). If IPR indeed increased the risk of local recurrence, histopathological evaluation of the margin would be indispensable and clinical adoption of this strategy is difficult. The aim of this study is to verify the association between IPR and the risk of local recurrence.

METHODS

The 1872 polyps and 603 EMR cases in 597 patients who had EMR between May 2013 and May 2014 were enrolled. The local recurrence rate until 3 years after the EMR in cases with the target lesions of the "Resect and Discard" strategy was determined in the negative-margin and IPR groups.

RESULTS

The final analysis was performed using the data of 1092 polyps, and 222 were categorized into the IPR group. There were no cases of recurrence in either of the groups.

CONCLUSION

This is the world's first report conducted to examine the correlation of IPR and the local recurrence rate for clinical practice of "Resect and Discard" strategy. There is the possibility that pathological evaluation of the margins after EMR in patients with small polyps can be skipped.

Postpolypectomy Bleeding Prevention and More Complete Precancerous Colon Polyp Removal With Endoscopic Mucosal Stripping (EMS)

Background and Aims: Postpolypectomy bleeding and incomplete polyp removal are important complication and quality concerns of colonoscopy for colon cancer prevention. We investigated if endoscopic mucosal stripping (EMS) as a technical modification of traditional cold snare polypectomy to avoid submucosal injury during removal of non-pedunculated colon polyps could prevent postpolypectomy bleeding and facilitate complete polyp removal.

Methods: This is an Internal Review Board exemption-granted retrospective analysis of 5,142 colonoscopies with snare polypectomy performed by one of the authors (ZJC) at Minnesota Gastroenterology ambulatory endoscopy centers during a 12-year period divided into pre-EMS era (2005–2012, n = 2,973) and EMS era (2013–2016, n = 2169) with systemic adoption of EMS starting 2013. Change in postpolypectomy bleeding rate before and after EMS adoption and EMS polypectomy completeness were evaluated.

Results: Zero postpolypectomy bleeding case was found during EMS era (rate 0%) compared with 10 bleeding cases during pre-EMS era (rate 0.336%). This difference was statistically significant (P = 0.0055) and remained so after excluding 2 bleeding cases of pedunculated polyps (P = 0.012). All bleeding cases involved hot snare polypectomy. Histological examination of the involved polyps showed substantial submucosal vascular damage in contrast to a remarkable paucity of submucosa in comparable advanced polyps removed using EMS. Both biopsy and follow-up colonoscopy examination of the polypectomy sites confirmed that EMS more completely removed non-pedunculated advanced polyps.

Conclusions: EMS polypectomy was effective in preventing postpolypectomy bleeding and facilitated complete polyp removal.

Resection depth and layer of cold snare polypectomy versus endoscopic mucosal resection

BACKGROUND

Cold snare polypectomy (CSP) has not undergone sufficient histopathological evaluation. This study aimed to clarify the histopathological features of CSP specimens, including resection depth and layer, as compared with endoscopic mucosal resection (EMR).

METHODS

Polyps were recruited retrospectively. Sessile, semi-pedunculated, and 0-IIa polyps of ≤ 9 mm were selected by propensity score matching and classified as either a complete resection or one with an unevaluable/positive (X/+) margin. Resection depth and layer were estimated and the risk factors for an X/+ margin were evaluated.

RESULTS

A total of 1072 polyps were enrolled. After matching, 184 polyp pairs were selected. An X/+ margin was seen in 105/184 (57%) vs. 70/184 (38%) CSP vs. EMR specimens (p < 0.001): specimen damage was 53/184 (29%) vs. 30/184 (16%) (p < 0.01) and vertical margin (VM) X/+ was 11/184 (6%) vs. 2/184 (1%) (p < 0.05). Among 193 completely resected specimens, resection depth from the muscularis mucosae in CSP vs. EMR was 76 vs. 338 µm (p < 0.001) and resection layer was the submucosa in 7/79 (9%) vs. 105/114 (92%) (p < 0.001). In multivariate analysis, CSP was a risk factor for procedure-associated VMX/+ [odds ratio (OR) 6.80, 95% confidence interval (CI) 1.33-34.69, p < 0.05]. Sessile serrated adenoma/polyp (SSA/P) was a risk factor for VMX/+ margin in CSP specimens (OR 58.36, 95% CI 7.45-456.96, p < 0.001).

CONCLUSIONS

SSA/P and colorectal cancer may not be suitable for CSP adoption.

Validation of treatment algorithm based on the Japan narrow-band imaging expert team classification for sub-centimeter colorectal polyps

BACKGROUND AND STUDY AIMS

 Although cold polypectomy (CP) is widely used for colorectal polyps < 10 mm, appropriateness of indications for CP or endoscopic mucosal resection (EMR) are still unclear. The aim of this study was to validate the endoscopic treatment algorithm based on the Japan NBI Expert Team (JNET) classification.

PATIENTS AND METHODS

 Consecutive patients with at least one colorectal non-pedunculated polyp < 10 mm between July 2014 and October 2016 were included in this retrospective study. During the period, EMR was performed for JNET ≥ 2B lesions and CP for JNET < 2A. Among a total of 3966 lesions, 3368 lesions with JNET ≤ 2A were resected by CP in compliance with the treatment algorithm but 565 resections for JNET ≤ 2A were not compliant (by EMR), while all 24 JNET > 2B lesions were removed by EMR in compliance with the algorithm. Polypectomy outcomes were compared between the compliant and non-compliant groups. Histological outcomes were analyzed in accordance with JNET classification.

RESULTS

 Post-polypectomy bleeding rate in the compliant group (0 %) was lower than that in the non-compliant group (0.53 %, P  < 0.01). Proportion of lesions diagnosed as cancer (38 % vs 0.36 %, P  < 0.01) or submucosal cancer (4.2 % vs 0.03 %, P  = 0.012), and the lesion with free resection margin (91 % vs 64 %, P  < 0.01) was higher in the JNET ≥ 2B than JNET ≤ 2A.

CONCLUSION

 This study indicated our algorithm would be valid: CP is suitable for most polyps < 10 mm as incidence of post-polypectomy bleeding is low, whereas EMR is recommended for JNET ≥ 2B lesions for histological complete removal.

Usefulness of close observation with non-magnified blue laser imaging for determining cold polypectomy indications

PURPOSE

To examine the usefulness of non-magnified close observation with blue laser imaging (BLI) using a colonoscope with close observation capability in determining indications for cold polypectomy.

METHODS

We conducted an image evaluation study on 100 consecutive colorectal lesions of 10 mm or less which were observed endoscopically without magnification using BLI mode prior to treatment. Two experts and two non-experts reviewed the images using the Japan NBI expert team (JNET) classification and the diagnostic accuracy was analyzed.

RESULTS

The final pathological diagnoses of the 100 lesions were hyperplastic/sessile serrated polyp (HP/SSP), low grade dysplasia (LGD), high grade dysplasia (HGD) and deep submucosal invasive cancer (dSM), respectively, in 12, 79, 9 and 0 lesions. When JNET classification type 1 corresponds to HP/SSP; 2A to LGD; 2B to HGD; and 3 to dSM; the overall diagnostic accuracy was 84.3%. Accuracy was 90.5% for experts and 78.0% for non-experts. High confidence rate was 67.5% for experts and 48.0% for non-experts. In diagnostic accuracy for HGD, the sensitivity, specificity, PPV and NPV were, respectively, 77.8%, 98.9%, 87.5% and 97.8% for experts; and 66.6%, 92.3%, 46.2% and 96.6% for non-experts.

CONCLUSIONS

The diagnostic accuracy of unmagnified close observation with BLI using a colonoscope with close observation capability is similar to that reported for magnifying endoscopy and is useful in predicting the histological diagnosis of colorectal polyps of 10 mm or less although the effectiveness may be limited for non-experts. This modality is a potentially useful tool in deciding indications for cold polypectomy.

Histological Comparison of Cold versus Hot Snare Resections of the Colorectal Mucosa

BACKGROUND

Delayed postpolypectomy bleeding occurs more frequently after hot resection than after cold resection.

OBJECTIVE

To elucidate the underlying mechanism, we performed a histological comparison of tissue after cold and hot snare resections.

DESIGN

This is a prospective study, registered in the University Hospital Medical Information Network (UMIN000020104).

SETTING

This study was conducted at Aizu Medical Center, Fukushima Medical University, Japan.

PATIENTS

Fifteen patients scheduled to undergo resection of colorectal cancer were enrolled.

INTERVENTION

On the day before surgery, 2 mucosal resections (hot and cold) of normal mucosa were performed on each patient using the same snare without saline injection. The difference was only the application of electrocautery or not. Resection sites were placed close to the cancer to be included in the surgical specimen.

MAIN OUTCOME MEASURES

The primary outcome measure was the depth of destruction. Secondary outcome measures included the width of destruction, depth of the remaining submucosa, and number of vessels remaining at the resection sites. The number and diameter of vessels in undamaged submucosa were also evaluated.

RESULTS

All cold resections were limited to the shallow submucosa, whereas 60% of hot resections advanced to the deep submucosa and 20% to the muscularis propria (p < 0.001). There was no significant difference in the width of destruction. The number of remaining large vessels after hot resections trended toward fewer (p = 0.15) with a decreased depth of remaining submucosa (p = 0.007). In the deep submucosa, the vessel diameter was larger (p < 0.001) and the number of large vessels was greater (p = 0.018).

LIMITATIONS

Histological assessment was not blinded to the 2 reviewers. Normal mucosa was used instead of adenomatous tissue.

CONCLUSIONS

Hot resection caused damage to deeper layers involving more large vessels. This may explain the mechanism for the reduced incidence of hemorrhage after cold snare polypectomy. See Video Abstract at http://links.lww.com/DCR/A631.

Comparison of cold and hot snaring polypectomy for small colorectal polyps: study protocol for a randomized controlled trial

Background

Colorectal cancer remains a considerable challenge in healthcare nowadays. Most patients’ disease develops via the adenoma–carcinoma sequence; colonoscopy with polypectomy effectively reduces both mortality and incidence by removing precancerous adenomas. Previous studies showed that polypectomy without electrocautery (cold snaring polypectomy) is a safe and time-saving procedure to manage polyps < 10 mm. However, randomized controlled trials have failed to prove the superiority of cold snaring polypectomy for reducing the risk of delayed bleeding in comparison with hot snaring polypectomy, generally because of their low statistical power that was limited by sample sizes. In this study, we aim to compare the risk of delayed bleeding following cold and hot snaring polypectomy based on a large sample size.

Methods

This is a prospective multicentre randomized controlled trial to compare cold and hot snaring polypectomy for the treatment of small colorectal polyps. A total of 4258 patients with small polyps (4–10 mm) will be randomized 1:1 to each group. Colonoscopy and polypectomy will be performed by 17 experienced endoscopists at six study sites. The randomization will be performed via an online website. Pathological examination using image-enhanced endoscopy with either narrow-band imaging or chromoendoscopy will be conducted to confirm optically and histologically that complete resections have been achieved, respectively. The primary outcome measurement is the risk of delayed bleeding. The secondary outcome measurements include the number of hemoclip applications, complete eradication confirmed optically and histologically, tissue retrieval rate, procedure time, emergency unit visits, and any adverse events such as immediate bleeding or perforation.

Discussion

We hypothesize that cold snaring polypectomy can reduce the risk of delayed bleeding by avoiding thermal injury. In addition, this study will also compare cold and hot snaring polypectomy in terms of the complete eradication rate and procedure time. Based on data collected, we will demonstrate that cold snaring polypectomy is a safe, effective, and economic procedure for small colorectal polyps. The results will also provide additional data on which to develop recommendations for treating small colorectal polyps.

Trial registration

ClinicalTrials.gov, NCT03373136. Registered on 29 November 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2743-z) contains supplementary material, which is available to authorized users.

A case of colonic stenosis caused by cold snare polypectomy for the removal of a colonic polyp

A 78-year-old woman with hypertension had a positive fecal immunochemical test and underwent colonoscopy, which revealed a 4 mm sessile polyp (Paris type; 0-Is) in the transverse colon. Based on low magnification colonoscopy with narrow band imaging, the polyp was Type 2 according to the NBI International Colorectal Endoscopic classification, diagnosed as an adenoma, and then resected via cold snare polypectomy (CSP). Five days after CSP, she complained of right-sided abdominal pain. Abdominal CT showed focal wall thickening of the transverse colon and focal infiltration of tissues surrounding the transverse colon. The inflammatory lesion was considered to coincide with the location of the polyp resected with CSP. However, no inflammatory findings were seen in other parts of the colon, and intraperitoneal free air and ascites were not identified. Moreover, no inflammatory findings and no infectious signs in other organs were present. She was administered intravenous antibiotics and, 19 days later, she was discharged from our hospital. Approximately 3 months later, colonoscopy revealed colonic stenosis associated with red mucosa and ulceration in the transverse colon where the polyp had been resected with CSP. Contrast-enhanced X-ray revealed an approximately 1 cm-long colonic stenosis in the transverse colon near the hepatic flexure.

Cold snare polypectomy reduced delayed postpolypectomy bleeding compared with conventional hot polypectomy: a propensity score-matching analysis

BACKGROUND AND STUDY AIMS

 Cold snare polypectomy (CSP) for small colorectal polyps has lower incidence of adverse events, especially delayed postpolypectomy bleeding (DPPB). However, few data are available on comparisons of the incidence of DPPB of CSP and hot polypectomy (HP). The aim of this study was to evaluate the incidence of DPPB after CSP and compare it with that of HP. A propensity score model was used as a secondary analysis.

PATIENTS AND METHODS

 This was a retrospective cohort study conducted in a single municipal hospital. We identified 539 patients with colorectal polyps from 2 mm to 11 mm in size who underwent CSP (804 polyps in 330 patients) or HP (530 polyps in 209 patients) between July 2013 and June 2015.

RESULTS

 There were no cases of DPPB in the CSP group. Conversely, DPPB occurred in 4 patients (1.9 %) after HP, resulting in a significant difference between the CSP and HP groups (0.008 % vs 0 %, P  = 0.02). Propensity score-matching analysis created 402 matched pairs, yielding a significantly higher DPPB rate in the HP group than CSP group (0.02 % vs 0 %, P  = 0.04). However, significantly more patients in the CSP group had unclear horizontal margins that precluded assessment (83 vs 38 cases, P  < 0.001). The retrieval failure rate was significantly higher in the CSP group than in the HP group (3 % vs 0.7 %, P  = 0.01).

CONCLUSIONS

DPPB was less frequent with CSP than HP, as selected by the propensity score-matching model. Our findings indicate that CSP is recommended polypectomy in daily clinical setting. However, special care should be taken during polyp retrieval and horizontal margin assessment, and these issues could be taken into account in follow-up after CSP.

Efficacy and safety of cold snare resection in preventive screening colonoscopy

BACKGROUND AND AIM

 Removal of polyps during colonoscopy effectively prevents the development of colorectal cancer. So far, snare resection with high frequency current with or without prior submucosal saline injection is the method of choice. The aim of this study was to evaluate the feasibility, safety, and outcome of cold snare resection during routine endoscopy.

METHODS

 In this prospective study, 522 patients undergoing outpatient colonoscopy were included. Cold snare resection for diminutive (< 6 mm), small (6 - 9 mm), and larger polyps (> 9 - 15 mm) was performed using a dedicated cold snare device (Exacto ^® ) without prior submucosal injection. Outcome parameters included bleeding rate, perforation rate, procedure time, histologic evaluation of polyp margins, and success rates. The data were compared to a group of patients undergoing hot snare resection.

RESULTS

 Overall, 1233 polyps were removed using cold snare resection with an overall success rate of 99.4 %. All failures of cold snare resection occurred in the cecum (8/82, failure rate 9.8 %). In the remaining colon, the success rate was 100 %. Immediate post-polypectomy bleeding occurred in 0.49 % of all patients and was most frequently seen in polyps larger than 9 mm. The procedure time was significantly shorter using cold snare resection compared with hot snare resection (27.6 min vs. 35.7 min, P  < 0.01).

CONCLUSION

 Cold snare resection can be performed safely in outpatients for removal of small polyps in screening colonoscopy. It does not require prior saline injection and reduces procedure time without an increased risk of bleeding.

Histopathological analysis of cold snare polypectomy and its indication for colorectal polyps 10-14 mm in diameter

BACKGROUND AND AIM

Cold snare polypectomy (CSP) is commonly used for treating colorectal polyps <10 mm in diameter. We evaluated the analysis and safety of CSP for larger polyps.

METHODS

We retrospectively analyzed 1006 colorectal polyps resected with CSP. Indication for CSP was polyps 2-14 mm that were diagnosed as benign neoplastic polyp by magnifying endoscopy. Various clinicopathological characteristics were analyzed. Multivariate analyses were used to determine the independent risk factors for failure of complete CSP resection. With respect to polyp size, we compared the therapeutic outcomes between polyps <10 mm and ≥10 mm. Additionally, the presence of muscularis mucosa in resected specimens was analyzed.

RESULTS

Rates of en bloc resection and postoperative hemorrhage were 98.8% and 0.1%, respectively. Seven hundred and ninety-one neoplastic lesions were analyzed and negative margins were found in 70.5% of the lesions, Multivariate analysis showed that non-polypoid morphology, histology of intramucosal cancer + high-grade adenoma and sessile serrated adenoma and polyp were significant factors for incomplete resection. With respect to the difference between lesions ≥10 mm than in those <10 mm, rates of cancer and positive/unclear margins were significantly higher (5.0% vs 0.9%, P < 0.001; 40.6% vs 27.7%, P = 0.007) in the ≥10 mm with rates of postoperative hemorrhage not significantly different (0.8% vs 0.0%). Additionally, the loss of muscularis mucosa was found in 27.8% of all lesions.

CONCLUSION

CSP is a safe procedure for polyps 2-14 mm. However, CSP has limitations in terms of the histopathological margin and loss of muscularis mucosa in specimens.

The clinical impact of serrated colorectal polyps

Serrated polyps (SPs) of the colorectum pose a novel challenge to practicing gastroenterologists. Previously thought benign and unimportant, there is now compelling evidence that SPs are responsible for a significant percentage of incident colorectal cancer worldwide. In contrast to conventional adenomas, which tend to be slow growing and polypoid, SPs have unique features that undermine current screening and surveillance practices. For example, sessile serrated polyps (SSPs) are flat, predominately right-sided, and thought to have the potential for rapid growth. Moreover, SSPs are subject to wide variations in endoscopic detection and pathologic interpretation. Unfortunately, little is known about the natural history of SPs, and current guidelines are based largely on expert opinion. In this review, we outline the current taxonomy, epidemiology, and management of SPs with an emphasis on the clinical and public health impact of these lesions.

Complications of diagnostic colonoscopy, upper endoscopy, and enteroscopy

Endoscopy is an inherent and an invaluable tool in every gastroenterologist's armamentarium. The prerequisite for quality and safety remains foremost. Adverse events should be minimized and proactive steps should taken before, during and after the endoscopic procedure. Upper endoscopy and colonoscopy are part of basic endoscopy and their major complications will be reviewed here, together with those of enteroscopy. The most common of all endoscopy related complications are cardiopulmonary and thus they will be addressed in detail first. Colonoscopy's major complications are bleeding and perforation. Their epidemiology, mechanisms/risk factors, diagnosis, treatment and prevention will be addressed. The incidence of both of these complications increases significantly with polypectomy. Thus clinical judgment and experience in both polypectomy techniques and the ways to treat these complications, especially with the advanced endoscopic options advanced in the last decade, are of paramount importance. Post-polypectomy syndrome, infection and gas explosion are less frequent and will be reviewed briefly. Bleeding and perforation are upper endoscopy's major complications as well. Advances in endoscopic techniques in recent years offer endoscopic treatment instead of directly resorting to surgery, as was used to be the case and still is if the first fails. Enteroscopy is generally a more advanced procedure and overall complication rate is often quoted as 1%, most of them have been attributed to the passage of the overtube. Perforation and bleeding are the major complications, and a unique upper enteroscopy-associated complication is pancreatitis.

The Influence of Snare Size on the Utility and Safety of Cold Snare Polypectomy for the Removal of Colonic Polyps in Japanese Patients

Background

Cold snare polypectomy (CSP) has been recently reported to be useful for the removal of small colonic polyps. However, the relationship between the histologically complete resection rate and snare size used during CSP has not been reported. Our aim was to assess the utility of CSP.

Methods

We analyzed the histologically complete resection rates and the frequency of complications for 175 colon polyps removed by CSP. Moreover, we examined the histologically complete resection rate associated with different snare sizes used during CSP.

Results

There was no significant difference in the histologically complete resection rate between endoscopic mucosal resection (EMR) (60.9%) and CSP (53.1%). There were also no significant differences in the frequency of complications including perforation and postoperative bleeding between EMR (perforation: none; postoperative bleeding: two patients) and CSP (perforation: none; postoperative bleeding: none). Histological examination revealed that the complete resection rate of CSP using a short snare (61.6%) was significantly higher than that of CSP using a long snare (44.9%; P < 0.05). There were no significant differences in the frequency of complications between CSP using the short snare and that using the long snare.

Conclusions

CSP is a safe, useful method for the removal of colonic polyps. CSP using the short snare improved the histologically complete resection rates compared to the long snare. Future studies to further assess the utility of CSP are required.

Efficacy and adverse events of cold vs hot polypectomy: A meta-analysis

AIM: To compare previously reported randomized controlled studies (RCTs) of cold and hot polypectomy, we systematically reviewed and clarify the utility of cold polypectomy over hot with respect to efficacy and adverse events.

METHODS: A meta-analysis was conducted to evaluate the predominance of cold and hot polypectomy for removing colon polyps. Published articles and abstracts from worldwide conferences were searched using the keywords “cold polypectomy”. RCTs that compared either or both the effects or adverse events of cold polypectomy with those of hot polypectomy were collected. The patients’ demographics, endoscopic procedures, No. of examined lesions, lesion size, macroscopic and histologic findings, rates of incomplete resection, bleeding amount, perforation, and length of procedure were extracted from each study. A forest plot analysis was used to verify the relative strength of the effects and adverse events of each procedure. A funnel plot was generated to assess the possibility of publication bias.

RESULTS: Ultimately, six RCTs were selected. No significant differences were noted in the average lesion size (less than 10 mm) between the cold and hot polypectomy groups in each study. Further, the rates of complete resection and adverse events, including delayed bleeding, did not differ markedly between cold and hot polypectomy. The average procedural time in the cold polypectomy group was significantly shorter than in the hot polypectomy group.

CONCLUSION: Cold polypectomy is a time-saving procedure for removing small polyps with markedly similar curability and safety to hot polypectomy.