Colonoscopic polypectomy: current techniques and controversies

Amphiphilic Gelator-Based Shear-Thinning Hydrogel for Minimally Invasive Delivery via Endoscopy Catheter to Remove Gastrointestinal Polyps

Injectable polymeric hydrogels delivered via endoscopic catheter have emerged as promising submucosal agents, offering durable, long-lasting cushions to enhance the efficacy of endoscopic submucosal dissection (ESD) for the removal of small, flat polyps from the gastrointestinal tract (GIT). However, polymer-based injections do not meet the easy-injectability criteria via catheter because their high viscosity tends to clog the catheter needle. To the best of knowledge, for the first time, report the fabrication of an amphiphile-based small molecule hydrogel of diglycerol monostearate (DGMS) that self-assembles to form hydrogel (DGMSH) for delivery via an endoscopic catheter. Physicochemical characterization of the hydrogel reveals its fibrous morphology, shear-thinning behaviour, and easy injectability, along with its scalability and long shelf-life (6 months). Ex vivo studies on the goat's stomach and intestine demonstrate the ease of injectability through the catheters and the development of visible submucosal cushion depots with the desired height. Moreover, the hydrogel can encapsulate both hydrophobic and hydrophilic drugs/dyes. In vivo studies in small animals have found that the hydrogel depot is durable, biocompatible, non-immunogenic, and has a hemostatic effect. Endoscopic studies in the porcine model demonstrate a safe injection and endoscopic excision of GI polyps acting as a suitable agent for ESD.

Clinical outcomes and risk factors of post-polypectomy microperforation in patients with colorectal neoplasia: a case-control study

Background

Colonoscopic polypectomy significantly reduces the incidence of colorectal cancer, but it carries potential risks, with colonic perforation being the most common and associated with significant morbidity.

Objectives

This study evaluated the clinical outcomes and risk factors of microperforation during colonoscopic polypectomy.

Design

A retrospective cohort study.

Methods

We retrospectively reviewed the patients' records who underwent colonoscopic polypectomy and subsequent plain radiographic examination to monitor perforation. Patients with pneumoperitoneum detected on plain radiography were enrolled. Patients who underwent adverse event-free colonoscopic polypectomies within 1 week of each case and were matched 2:1 by age and sex to the cases were selected as controls.

Results

Microperforations occurred in 12 patients (8 males; age: median 64.5 years). Polyps with microperforations were more frequent in the right colon (83.3% vs 33.3%). Endoscopic mucosal resection with precutting (EMR-P; 16.7% vs 0.0%) or hot-snare polypectomy (8.3% vs 0.0%) was more frequently performed in the microperforation group. Muscle fibers at the polypectomy site were more frequently visible in the microperforation group (58.3% vs 8.3%). By multivariate analysis, right colon location and visible muscle fibers were independent risk factors for microperforation. All patients with microperforation received intravenous antibiotics and were advised to fast. Patients responded well to these conservative treatments and were discharged after a median of 3 (2-6.75) days of hospital stay.

Conclusion

Our data suggest that conservative treatment is feasible and could be the primary management option for selected patients with microperforations postcolonoscopic polypectomy. Right-sided colonic polyps and visible muscle fibers predispose to microperforations.

Endoscopic Management of Complex Colorectal Polyps: Current Insights and Future Trends

Most colorectal cancers arise from adenomatous polyps and sessile serrated lesions. Screening colonoscopy and therapeutic polypectomy can potentially reduce colorectal cancer burden by early detection and removal of these polyps, thus decreasing colorectal cancer incidence and mortality. Most endoscopists are skilled in detecting and removing the vast majority of polyps endoscopically during a routine colonoscopy. Polyps can be considered “complex” based on size, location, morphology, underlying scar tissue, which are not amenable to removal by conventional endoscopic polypectomy techniques. They are technically more challenging to resect and carry an increased risk of complications. Most of these polyps were used to be managed by surgical intervention in the past. Rapid advancement in endoscopic resection techniques has led to a decreasing role of surgery in managing these complex polyps. These endoscopic resection techniques do require an expert in the field and advanced equipment to perform the procedure. In this review, we discuss various advanced endoscopic techniques for the management of complex polyps.

Effectiveness and safety of the different endoscopic resection methods for 10- to 20-mm nonpedunculated colorectal polyps: A systematic review and pooled analysis

BACKGROUND

We performed a systematic review and pooled analysis to assess the effectiveness and safety of different endoscopic resection methods for 10- to 20-mm nonpedunculated colorectal polyps.

METHODS

Articles in PubMed, EMBASE, and the Cochrane Library related to the common endoscopic treatment of 10- to 20-mm nonpedunculated polyps published as of April 2020 were searched. Primary outcomes were the R0 resection rate and en bloc resection rate. Secondary outcomes were safety and the recurrence rate. Meta-regression and subgroup analysis were also performed.

RESULTS

A total of 36 studies involving 3212 polyps were included in the final analysis. Overall, the effectiveness of resection methods with a submucosal uplifting effect, including endoscopic mucosal resection (EMR), cold EMR and underwater EMR (UEMR), was better than that of methods without a nonsubmucosal uplifting effect [R0 resection rate, 90% (95% confidence interval (CI) 0.81-0.94, I² = 84%) vs 82% (95% CI 0.78-0.85, I² = 0%); en bloc resection rate 85% (95% CI 0.79-0.91, I² = 83%) vs 74% (95% CI 0.47-0.94, I² = 94%)]. Regarding safety, the pooled data showed that hot resection [hot snare polypectomy, UEMR and EMR] had a higher risk of intraprocedural bleeding than cold resection [3% (95% CI 0.01-0.05, I² = 68%) vs 0% (95% CI 0-0.01, I² = 0%)], while the incidences of delayed bleeding, perforation and post-polypectomy syndrome were all low.

CONCLUSIONS

Methods with submucosal uplifting effects are more effective than those without for resecting 10- to 20-mm nonpedunculated colorectal polyps, and cold EMR is associated with a lower risk of intraprocedural bleeding than other methods. Additional research is needed to verify the advantages of these methods, especially cold EMR.

The quality of colorectal polypectomy. Is it enough to have just a visual assessment of the site?

INTRODUCTION

Performing a colonoscopy allows the examination of the entire colon and the assessment of polyps.

PATIENTS, MATERIALS AND METHODS

We performed a retrospective analysis of prospectively collected data from January 2018 until February 2020 (two years), in which we enrolled a number of 210 patients performing colonoscopy in the Research Center of Gastroenterology and Hepatology, University of Medicine and Pharmacy of Craiova, Romania. We performed 326 polypectomies.

RESULTS

We classified the polyps into diminutive (n=169), small (n=103) and large polyps (n=54). Regarding the polypectomy technique, our results indicated that 40 out of 48 (83.3%) polypectomies with the biopsy forceps were complete, as well as 27 out of 31 (87.1%) cold snare polypectomies and 12 out of 14 (85.7%) hot snare polypectomies. The differences were not statistically significant (p=0.116). Regarding the number of incomplete polypectomies, our data suggests that the high expertise endoscopist had two incomplete resections (5.1% of total), the medium expertise endoscopist 1 had also two incomplete resections (11.1% of total), the medium expertise endoscopist 2 had three incomplete resections (15% of total), the limited expertise endoscopist 1 had three incomplete resections (27.27% of total) and the limited expertise endoscopist 2 had four incomplete resections (30.76% of total). Analyzing the data, the differences were statistically significant (p=0.006).

CONCLUSIONS

Our study is able to suggest that high-definition white-light endoscopy (HD-WLE) macroscopic visualization of the polyp resection site is not enough to assess complete polyp resection and follow-up colonoscopy should be performed for cases with incomplete margins of resection.

Clinical implications of decision making in colorectal polypectomy: an international survey of Western endoscopists suggests priorities for change

Introduction  Colonoscopy prevents colorectal cancer via the detection and resection of premalignant polyps. This effect may be attenuated by variations in polypectomy, with multiple techniques available and a wide range of experience amongst endoscopists. We assessed current practice against the best available contemporary evidence. Methods  An online survey was distributed to members of the gastroenterological and surgical societies of seven countries during July 2017. Images of colorectal polyps were presented and respondents requested to provide the polypectomy technique they would employ in their daily practice. Responses were compared to the evidence-based techniques in the 2017 ESGE Colorectal Polypectomy Guideline. Results  In total, 707 endoscopists (627 physicians, 71 surgeons, 9 nurse endoscopists, median practice duration 18 years) completed the survey. Of these, 3.1 % selected hot biopsy forceps and 5.2 % hot snare polypectomy (without submucosal lifting) to remove a 3 mm ascending colon polyp. Only 43.3 % selected cold snare polypectomy (CSP) to remove an 8 mm ascending colon polyp. Surgical referral was selected by 16.7 % of respondents for a 45 mm transverse colon polyp without endoscopic evidence of submucosal invasive cancer (SMIC). Endoscopic resection was selected by 12.0 % for an 80 mm sigmoid polyp with imaging consistent with deep SMIC, and a further 26.4 % selected tertiary endoscopist referral, suggesting they had not appreciated that it was endoscopically unresectable. Conclusion  CSP is underutilized for small polyp resection despite its favorable safety and efficacy. Benign polyps are commonly referred for surgery and overt SMIC is underappreciated using endoscopic imaging. Addressing these issues may reduce diathermy-related adverse events, surgery, and unnecessary colonoscopic procedures for patients and reduce rates of post-colonoscopy colorectal cancer.

The Impact of Hospital Teaching Status on Colonoscopy Perforation Risk: A National Inpatient Sample Study

Background

Colonoscopy has been widely used as a diagnostic tool for many conditions, including inflammatory bowel disease and colorectal cancer. Colonoscopy complications include perforation, hemorrhage, abdominal pain, as well as anesthesia risk. Although rare, perforation is the most dangerous complication that occurs in the immediate post-colonoscopy period with an estimated risk of less than 0.1%. Studies on colonoscopy perforation risk between teaching hospitals and non-teaching hospitals are scarce.

Methods

The National Inpatient Sample database was queried for patients who underwent inpatient colonoscopy between January 2010 and December 2014 in teaching versus non-teaching facilities in order to study their perforation rates. Our study population included 257,006 patients. Univariate regression was performed, and the positive results were analyzed using a multivariate regression module.

Results

Teaching hospitals had a higher risk of perforation (odds ratio 1.23, confidence interval 1.07 - 1.42, P = 0.004). Perforation rates were higher in females, patients with inflammatory bowel disease and dilatation of strictures. Polypectomy did not yield any statistical difference between the study groups. Other factors such as African-American ethnicity appeared to have a lower risk.

Conclusion

Perforation rates are higher in teaching hospitals. More studies are needed to examine the difference and how to mitigate the risks.

Risk of Delayed Bleeding after a Colorectal Endoscopic Mucosal Resection without Prophylactic Clipping: Single Center, Observational Study

BACKGROUND/AIMS

Bleeding is one of the major complications of a colorectal polypectomy. The aim of this study was to identify the risk of delayed bleeding, particularly after a colorectal endoscopic mucosal resection (EMR) without prophylactic clipping.

METHODS

Between April 2014 and August 2014, patients who underwent colorectal EMR (≥6 mm and <2 cm) without prophylactic clipping were included. This study evaluated the incidence of delayed bleeding and the associated factors after colorectal EMR without prophylactic clipping.

RESULTS

A total of 717 colorectal polyps (≥6 mm and <2 cm) of 243 patients resected by colorectal EMR in the study period were evaluated. The mean age of the patients was 63 years; 165 patients were men and 78 patients were women. The mean polyp size removed by colorectal EMR was 9.0 mm (range 6.0-19.0), and the number of polyps larger than 1 cm was 212 (29.6%). Delayed bleeding after colorectal EMR occurred in 12 polyps (1.7%) in eight patients (3.3%), and there were no significant risk factors affecting delayed bleeding.

CONCLUSIONS

This study identified that the incidence of delayed bleeding on colorectal polyps (≥6 mm and <2 cm) after EMR without prophylactic clipping was 3.3%, but no significant risk factors affecting delayed bleeding were found.

The Cold Revolution: How Far Can It Go?

Cold resection for small colonic polyps, and larger lesions, is being rapidly and widely adopted. Driven by an impressive safety and cost profile compared with conventional polypectomy, these advantages are offset by the limitations of smaller and shallower resection, and absent thermal effects that may permit persistence of residual neoplasia. To overcome this, optimal cold snare technique requires inclusion of a margin of normal mucosa and a piecemeal resection technique for larger polyps. This article examines the fundamentals of cold snare resection and evidence for its application, theorizes on limits to its application, and identifies areas for further research.

Assessing the Quality of Polypectomy and Teaching Polypectomy

Ineffective polypectomy technique may lead to incomplete polyp resection, high complication rates, interval colorectal cancer, and costly referral to surgery. Despite its central importance to endoscopy, training in polypectomy is not standardized nor has the most effective training approach been defined. Polypectomy competence is rarely reported and quality metrics for this skill are lacking. Use of tools and measurements to assess polypectomy outcomes is low. There is a need for standardization of training and remediation in polypectomy; defining standards of competent polypectomy and how it is feasibly measured; and integration of polypectomy quality metrics into training programs and the accreditation process.

Colon polypectomy report card improves polypectomy competency: results of a prospective quality improvement study (with video)

BACKGROUND AND AIMS

Polypectomy competency varies significantly among providers. Poor polypectomy technique may lead to interval cancer and/or adverse events. Our aim was to determine the effect of a polypectomy skills report card on subsequent polypectomy performance.

METHODS

We conducted a 3-phase, prospective, single-blinded study. In phase 1 ("baseline"), we graded 10 polypectomies per endoscopist using the Direct Observation of Polypectomy Skills (DOPyS) tool (scores 1-4); mean overall scores ≥3 are competent. In phase 2 ("pre-report card"), we selected 10 additional polypectomies per endoscopist. We subsequently gave endoscopists a report card with baseline scores and instructional videos demonstrating optimal polypectomy technique. In phase 3 ("post-report card"), 10 additional polypectomies per endoscopist were selected. Raters, blinded to study phase, graded 10 pre- and 10 post-report card polypectomies per endoscopist. We compared mean DOPyS scores and rate of competent polypectomy in the pre- and post-report card phases.

RESULTS

We graded 110 pre- and 110 post-report card polypectomies performed by 11 endoscopists. The mean DOPyS score increased between the pre- and post-report card phases (2.7 ± .9 vs 3.0 ± .8, P = .01); this improvement was seen for diminutive (P < .0001) but not for small-to-large polyps. Rate of competent polypectomy significantly improved from the pre- to post-report card phase (56% vs 69%, P = .04); this improvement was seen for diminutive (57% vs 81%, P = .001) but not for small-to-large polyps (55% vs 36%, P = .2).

CONCLUSIONS

Report cards with educational videos effectively improved polypectomy technique, primarily because of improvements in resecting diminutive polyps. The improved competency and decreased piecemeal resection may reduce the risk of polyp recurrence. Further education is needed to improve larger polyp resection.

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.

Cold EMR of large sessile serrated polyps at colonoscopy (with video)

BACKGROUND AND AIMS

The optimal technique for the resection of sessile serrated polyps (SSPs) is unknown, with established limitations and risks with conventional polypectomy. Although cold snare polypectomy is safe, the efficacy of piecemeal resection for large lesions is untested. In this study we evaluate the safety and efficacy of cold EMR for large SSPs.

METHODS

Patients presenting for elective colonoscopy at an academic endoscopy center with 1 or more SSPs ≥10 mm in size were enrolled, excluding those on anticoagulant or antiplatelet therapy other than aspirin. Lesions were resected with a cold EMR technique comprising submucosal injection of succinylated gelatin and dilute methylene blue before piecemeal cold snare resection of all visible polyp with a margin of normal tissue. Outcomes were the presence of residual serrated neoplasia in biopsy specimens from the defect margin and findings on surveillance colonoscopy.

RESULTS

Cold EMR was performed on 163 SSPs during 105 procedures in 99 patients (97% women; median age, 57 years). The mean size was 17.5 mm: 61 SSPs were ≥20 mm and 13 SSPs ≥30 mm, and 97.5% were in the proximal colon. Cytologic dysplasia was present in 2 (1.2%). Margin biopsy specimens were positive in 2 lesions (1.2%). Surveillance colonoscopy for 82% of lesions (median, 5 months) showed residual serrated tissue in 1, treated with cold snare, but no evidence of recurrence in the remainder. Minor adverse events were seen in 3 patients; no delayed bleeding was observed.

CONCLUSIONS

Cold EMR is a safe and effective method for the removal of large SSPs.

Assessing colon polypectomy competency and its association with established quality metrics

BACKGROUND AND AIMS

Inadequate polypectomy leads to incomplete resection, interval colorectal cancer, and adverse events. However, polypectomy competency is rarely reported, and quality metrics are lacking. The primary aims of this study were to assess polypectomy competency among a cohort of gastroenterologists and to measure the correlation between polypectomy competency and established colonoscopy quality metrics (adenoma detection rate and withdrawal time).

METHODS

We conducted a prospective observational study to assess polypectomy competency among 13 high-volume screening colonoscopists at an academic medical center. Over 6 weeks, we made video recordings of ≥28 colonoscopies per colonoscopist and randomly selected 10 polypectomies per colonoscopist for evaluation. Two raters graded the polypectomies by using the Direct Observation of Polypectomy Skills, a polypectomy competency assessment tool, which assesses individual polypectomy skills and overall competency.

RESULTS

We evaluated 130 polypectomies. A total of 83 polypectomies (64%) were rated as competent, which was more likely for diminutive (70%) than small and/or large polyps (50%, P = .03). Overall Direct Observation of Polypectomy Skills competency scores varied significantly among colonoscopists (P = .001), with overall polypectomy competency rates ranging between 30% and 90%. Individual skills scores, such as accurately directing the snare over the lesion (P = .02) and trapping an appropriate amount of tissue within the snare (P = .001) varied significantly between colonoscopists. Polypectomy competency rates did not significantly correlate with the adenoma detection rate (r = 0.4; P = .2) or withdrawal time (r = 0.2; P = .5).

CONCLUSIONS

Polypectomy competency varies significantly among colonoscopists and does not sufficiently correlate with established quality metrics. Given the clinical implications of suboptimal polypectomy, efforts to educate colonoscopists in polypectomy techniques and develop a metric of polypectomy quality are needed.

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.

The Difficult Colorectal Polyp

Difficult colorectal polyps represent lesions that pose a challenge to traditional endoscopic snare polypectomy. These polyps have historically been managed by surgical resection. Currently, several less invasive options are available to avoid colectomy. Repeat colonoscopy and snare polypectomy by an expert endoscopist, endoscopic mucosal resection, endoscopic submucosal dissection, and combined endoscopic and laparoscopic surgery have been developed to remove difficult polyps without the need for formal surgical resection. Patients with rectal polyps have the advantage of additional transanal minimally invasive techniques to enhance their resectability. Today, most colorectal polyps can be managed without the need for formal surgical resection.

Complications of endoscopic polypectomy, endoscopic mucosal resection and endoscopic submucosal dissection in the colon

Endoscopic resection (ER), including endoscopic polypectomy (EP), endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) are used to remove superficial neoplasms from the colon. Snare resection is used for EP and EMR, whereas endoscopic knives are used to perform dissection in the submucosal space in ESD. 80-90% colonic polyps are <10 millimetres (mm) and are effectively managed by conventional EP. Increasingly cold snare polypectomy is preferred. Large laterally spreading lesions (LSLs) and sessile polyps ≥20 mm are primarily removed by EMR. ESD may be used when superficial invasive disease is suspected and for some LSLs, particularly non-granular subtypes. Resection of colonic lesions by ER is associated with a small but definite incidence of significant complications, most commonly bleeding and perforation. This review discusses complications of ER with a particular focus on their prevention, early recognition and management. In many cases, complications from all three procedures share similar mechanisms and management principles and these are described at the start of each section, followed by a description of specific aspects for individual procedures.

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.

Is forceps more useful than visualization for measurement of colon polyp size?

AIM

To identify whether the forceps estimation is more useful than visual estimation in the measurement of colon polyp size.

METHODS

We recorded colonoscopy video clips that included scenes visualizing the polyp and scenes using open biopsy forceps in association with the polyp, which were used for an exam. A total of 40 endoscopists from the Busan Ulsan Gyeongnam Intestinal Study Group Society (BIGS) participated in this study. Participants watched 40 pairs of video clips of the scenes for visual estimation and forceps estimation, and wrote down the estimated polyp size on the exam paper. When analyzing the results of the exam, we assessed inter-observer differences, diagnostic accuracy, and error range in the measurement of the polyp size.

RESULTS

The overall intra-class correlation coefficients (ICC) of inter-observer agreement for forceps estimation and visual estimation were 0.804 (95%CI: 0.731-0.873, P < 0.001) and 0.743 (95%CI: 0.656-0.828, P < 0.001), respectively. The ICCs of each group for forceps estimation were higher than those for visual estimation (Beginner group, 0.761 vs 0.693; Expert group, 0.887 vs 0.840, respectively). The overall diagnostic accuracy for visual estimation was 0.639 and for forceps estimation was 0.754 (P < 0.001). In the beginner group and the expert group, the diagnostic accuracy for the forceps estimation was significantly higher than that of the visual estimation (Beginner group, 0.734 vs 0.613, P < 0.001; Expert group, 0.784 vs 0.680, P < 0.001, respectively). The overall error range for visual estimation and forceps estimation were 1.48 ± 1.18 and 1.20 ± 1.10, respectively (P < 0.001). The error ranges of each group for forceps estimation were significantly smaller than those for visual estimation (Beginner group, 1.38 ± 1.08 vs 1.68 ± 1.30, P < 0.001; Expert group, 1.12 ± 1.11 vs 1.42 ± 1.11, P < 0.001, respectively).

CONCLUSION

Application of the open biopsy forceps method when measuring colon polyp size could help reduce inter-observer differences and error rates.

Improving the utility of colonoscopy: Recent advances in practice

Colonoscopy is a frequently performed diagnostic and therapeutic test and the primary screening tool in several nationalized bowel cancer screening programs. There has been a considerable focus on maximizing the utility of colonoscopy. This has occurred in four key areas: Optimizing patient selection to reduce unnecessary or low yield colonoscopy has offered cost-benefit improvements in population screening. Improving quality assurance, through the development of widely accepted quality metrics for use in individual practice and the research setting, has offered measurable improvements in colonoscopic yield. Significant improvements have been demonstrated in colonoscopic technique, from the administration of preparation to the techniques employed during withdrawal of the colonoscope. Improved techniques to avoid post-procedural complications have also been developed-further maximizing the utility of colonoscopy. The aim of this review is to summarize the recent evidence-based advances in colonoscopic practice that contribute to the optimal practice of colonoscopy.

Prospective, randomized comparison of 2 methods of cold snare polypectomy for small colorectal polyps

BACKGROUND

Both cold-only snare and hot polypectomy snare are used for the removal of small colorectal polyps.

OBJECTIVE

To compare the outcome of cold snare polypectomy of small colorectal polyps with a snare exclusively designed as a cold snare versus cold snare polypectomy by using a traditional polypectomy snare.

DESIGN

Prospective, randomized, controlled study.

SETTING

Municipal hospital in Japan.

INTERVENTIONS

Patients with colorectal polyps 10 mm or smaller in diameter were randomized to dedicated cold snare (dedicated cold snare group) or traditional cold snare (traditional cold snare group). The primary outcome measure was complete resection rates by cold snaring based on pathological examination. Secondary outcomes included bleeding within 2 weeks after polypectomy and identification of submucosal arteries and injured arteries in the resected specimens.

RESULTS

Seventy-six patients having 210 eligible polyps were randomized: dedicated cold snare group, N = 37 (98 polyps) and traditional cold snare group, N = 39 (112 polyps). Patient demographic characteristics including the number, size, and shape of the polyps removed were similar in the 2 groups. The complete resection rate was significantly greater with the dedicated cold than with the traditional cold snare (91% [89/98] vs 79% [88/112], P = .015), with a marked difference with 8- to 10-mm polyps, both flat and pedunculated. Immediate bleeding and hematochezia rates were similar (19% vs 21%, P = .86; 5.4% vs 7.7%, P = .69). No delayed bleeding occurred. Histology demonstrated a similar prevalence of arteries and injured arteries in the submucosa (33% [32/96] vs 30% [31/104], P = .59; 3.1% [3/96] vs 6.7% [7/104], P = .24).

LIMITATIONS

Small sample size, single-center study.

CONCLUSION

Polypectomy by using a dedicated cold snare resulted in complete polyp removal more often than did cold snaring with a traditional snare, especially polyps 8 to 10 mm in diameter, whether flat or pedunculated. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT02036047.)

Cold snare polypectomy: does snare type influence outcomes?

BACKGROUND AND AIM

Cold snare techniques are widely used for the removal of small and diminutive polyps. The influence of snare type on the effectiveness of cold snare polypectomy is unknown.

METHODS

Cold snare polypectomy of 3-7-mm polyps was undertaken using either a thin wire mini-snare (0.30 mm) or a thick wire mini-snare (0.47 mm). Primary outcome was endoscopic completeness of excision. Consensus regarding endoscopic assessment of completeness of excision was standardized and aided by chromoendoscopy. Secondary outcomes included: completeness of histological excision, polyp 'fly away', polyp retrieval rate, early or delayed bleeding and perforation.

RESULTS

One hundred and fifty-seven polyps were removed ranging from 3 to 7 mm, 62% were situated in the left side of the colon and 89.4% were sessile. Endoscopic completeness of excision was significantly higher with the thin wire snare compared to the thick wire snare (90.2% vs 73.3%, P < 0.05). There was a numerical trend towards a higher complete histological excision rate with the thin wire snare, but this did not reach statistical significance (73.3% vs 65.2%, P = 0.4). There was a fair level of agreement (kappa = 0.36) between endoscopic and histological completeness of excision. Polyp 'fly away' occurred less often with the thin wire snare (14.6% vs 35.3%, P = 0.002), but there was no significant difference in polyp retrieval rate (84.3% vs 83.8%, P = 0.94). There were no complications with either snare.

CONCLUSION

Snare type appears to be an important determinant of completeness of excision when removing small polyps by the cold snare technique.

Accuracy of i-Scan for Optical Diagnosis of Colonic Polyps: A Meta-Analysis

Background

i-Scan is a novel virtual chromoendoscopy system designed to enhance surface and vascular patterns to improve optical diagnostic performance. Numerous prospective studies have been done to evaluate the accuracy of i-Scan in differentiating colonic neoplasms from non-neoplasms. i-Scan could be an effective endoscopic technique for optical diagnosis of colonic polyps.

Objective

Our aim of this study was to perform a meta-analysis of published data to establish the diagnostic accuracy of i-Scan for optical diagnosis of colonic polyps.

Methods

We searched PubMed, Medline, Elsevier ScienceDirect and Cochrane Library databases. We used a bivariate meta-analysis following a random effects model to summarize the data and plotted hierarchical summary receiver-operating characteristic (HSROC) curves. The area under the HSROC curve (AUC) serves as an indicator of the diagnostic accuracy.

Results

The meta-analysis included a total of 925 patients and 2312 polyps. For the overall studies, the area under the HSROC curve was 0.96. The summary sensitivity was 90.4% (95%CI 85%-94.1%) and specificity was 90.9% (95%CI 84.3%-94.9%). In 11 studies predicting polyps histology in real-time, the summary sensitivity and specificity was 91.5% (95%CI 85.7%-95.1%) and 92.1% (95%CI 84.5%-96.1%), respectively, with the AUC of 0.97. For three different diagnostic criteria (Kudo, NICE, others), the sensitivity was 86.3%, 93.0%, 85.0%, respectively and specificity was 84.8%, 94.4%, 91.8%, respectively.

Conclusions

Endoscopic diagnosis with i-Scan has accurate optical diagnostic performance to differentiate neoplastic from non-neoplastic polyps with an area under the HSROC curve exceeding 0.90. Both the sensitivity and specificity for diagnosing colonic polyps are over 90%.

Right-sided adenoma detection with retroflexion versus forward-view colonoscopy

BACKGROUND

Colonoscopy and polypectomy can prevent up to 80% of colon cancer; however, a significant adenoma miss rate still exists, particularly in the right side of the colon.

OBJECTIVE

To assess whether retroflexion in the right side of the colon significantly improves the adenoma detection rate (ADR) over forward-view assessment.

DESIGN

Multicenter prospective cohort study.

SETTING

Three tertiary care public and 2 private hospitals.

PATIENTS

A total of 1351 consecutive adult patients undergoing elective colonoscopy.

INTERVENTION

Withdrawal from the cecum was performed in the forward view initially and identified polyps removed. Once the hepatic flexure was reached, the cecum was reintubated and the right side of the colon was assessed in the retroflexed view to the hepatic flexure.

MAIN OUTCOME MEASUREMENTS

ADR in the retroflexed view when compared with forward-view examination of the right side of the colon.

RESULTS

Retroflexion was successful in 95.9% of patients, with looping the predominant (69.6%) reason for failure. Forward-view assessment of the right side of the colon identified 642 polyps, of which 531 were adenomas yielding a polyp and ADR of 28.57% and 24.64%, respectively. Retroflexion identified a further 84 polyps of which 75 were adenomas, improving the polyp and ADR to 30.57% and 26.4%, respectively.

LIMITATIONS

Observational study.

CONCLUSION

Right-sided retroflexion was successful in most of our cohort with a statistically significant but small increase in ADR. Right-sided retroflexion is safe when performed by experienced endoscopists with no adverse events observed in this cohort. (

CLINICAL TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry, ACTRN12613000424707.).

Advances in the removal of diminutive colorectal polyps

Diminutive polyps (<5 mm in diameter) represent the majority of polyps found during colonoscopy; about a half of them are adenomatous, with low risk of advanced neoplasia. Recent studies have demonstrated that cold polypectomy should be considered the recommended approach for resecting diminutive polyps and that cold snaring may be superior to cold forceps biopsy, at least for polyps of 4-5 mm. Recently, electronic chromoendoscopy has been applied to characterization of diminutive polyps to discriminate adenomatous from nonadenomatous lesions. Optical diagnosis of polyp histology could potentially exert huge cost savings by the 'resect and discard' strategy for diminutive polyps and 'leaving-in' for diminutive hyperplastic polyps in the recto-sigmoid colon. These policies represent the mainstay for adopting endoscopy-directed post-polypectomy surveillance strategies, endorsed by both American and European Endoscopy Societies. Accuracy of both histology and surveillance intervals predictions from academic centers have been encouraging, although the same performance has not been replicated in community practices.

Polypectomy practices of sub-centimeter polyps in the English Bowel Cancer Screening Programme

BACKGROUND

Most colonic polyps are small, and several polypectomy techniques are available. We aimed to describe the variation in polypectomy techniques employed for the removal of sub-centimeter polyps in relation to polyp characteristics, completeness of histological excision and safety.

METHODS

Prospectively collected data relating to the removal of sub-centimeter polyps over a 3-year period (between January 2010 and December 2012) were retrieved from the English Bowel Cancer Screening Programme.

RESULTS

A total of 147,174 sub-centimeter polyps were removed during 62,679 procedures. For pedunculated polyps, hot snare was most common in the left (median 92 %, IQR 83.3-97.0 %) and right colon (median 75 %, IQR 3-92 %). For non-pedunculated polyps, cold snare was most common in the right colon (median 24 %, IQR 9-47 %); whereas hot snare remained most common in the left colon (median 32 %, IQR 19-49 %). Surgeons were more likely than physicians to use diathermy-assisted techniques (65.6 vs. 56.5 %, p < 0.001). Twelve (0.03 %) bleeding episodes required transfusion with no polypectomy technique dominating and 16 (0.04 %) perforations with 81 % of polypectomies performed using diathermy-assisted techniques. There was substantial variation between screening centers for the completeness of histological excision. For non-pedunculated polyps, histologically confirmed complete excision was more after EMR (23.4 %) compared with other techniques (cold biopsy forceps 17.7 %, cold snare 15.1 %, hot biopsy forceps 19.1 %, hot snare 21.5 %). The use of cold techniques and EMR has increased over time, whereas the use of hot biopsy forceps and hot snare has decreased (p < 0.001).

CONCLUSIONS

The removal of sub-centimeter polyps within the BCSP is safe despite wide variations in practice. The use of cold resection techniques and EMR has increased over time. The histological assessment for completeness of excision is limited and should be confirmed endoscopically at the time of polypectomy.

Advances, problems, and complications of polypectomy

The major role of colonoscopy with polypectomy in reducing the incidence of and mortality from colorectal cancer has been firmly established. Yet there is cause to be uneasy. One of the most striking recent findings is that there is an alarmingly high incomplete polyp removal rate. This phenomenon, together with missed polyps during screening colonoscopy, is thought to be responsible for the majority of interval cancers. Knowledge of serrated polyps needs to broaden as well, since they are quite often missed or incompletely removed. Removal of small and diminutive polyps is almost devoid of complications. Cold snare polypectomy seems to be the best approach for these lesions, with biopsy forcep removal reserved only for the tiniest of polyps. Hot snare or hot biopsy forcep removal of these lesions is no longer recommended. Endoscopic mucosal resection and endoscopic submucosal dissection have proven to be effective in the removal of large colorectal lesions, avoiding surgery in the majority of patients, with acceptably low complication rates. Variants of these approaches, as well as new hybrid techniques, are being currently tested. In this paper, we review the current status of the different approaches in removing polypoid and nonpolypoid lesions of the colon, their complications, and future directions in the prevention of colorectal cancer.

Cold polypectomy techniques for diminutive polyps in the colorectum

Adequate colonoscopic polypectomy is a very important intervention for the prevention of colorectal cancer progression during screening and surveillance colonoscopy. Whereas various techniques are used for the removal of diminutive polyps, including cold biopsy forceps, hot biopsy forceps, hot snare, and cold snare, hot polypectomy techniques with electrocautery have been associated with an increased risk of electrocautery-related complications, including immediate and/or delayed bleeding or perforation. In contrast, recent studies have found a polypectomy technique without electrocautery, so-called cold polypectomy, to be a safer and more efficacious technique. The present article discusses the use of cold polypectomy techniques and describes how cold biopsy forceps polypectomy using jumbo biopsy forceps designed with a greater capacity for removing larger tissue samples, and cold snare polypectomy, are adequate for removing diminutive polyps completely and safely and shorten withdrawal time of the colonoscopy procedure.