Benefits and limitations of cap-fitted colonoscopy in screening colonoscopy

Cap-assisted colonoscopy can increase the rate of sessile serrated lesion detection at the left lateral decubitus position: A retrospective case-control study

We investigated the effectiveness of cap-assisted colonoscopy conducted with the patient in the left lateral decubitus position at both the colonoscope's insertion and withdrawal timepoints compared to the effectiveness of colonoscopy without a cap conducted in the supine position at withdrawal. This was a case-control study, based on historical comparisons of patients over 2 time periods. The first group of patients underwent colonoscopies with a transparent cap and the patient was in the left lateral decubitus position at both the insertion and withdrawal timepoints from April to June 2019. The subsequent group underwent colonoscopies without a cap and with the patient in the supine position at withdrawal from July to September 2019. The rates of successful intubation, cecal intubation time, and number, size, shape, and location of the detected adenomas and sessile serrated lesions were compared between the 2 groups. Data from 644 colonoscopies (cap-assisted colonoscopy + left lateral decubitus position, n=320; other colonoscopies, n=324) were analyzed. The demographic characteristics and technical performances were similar. The SSL detection rate was significantly higher with cap-assisted colonoscopy and the left lateral decubitus position than with other colonoscopies (3.4% vs 0.93%, P=.029). The adenoma detection rates in the 2 groups were similar (31% and 28%, respectively, P=.43).Cap-assisted colonoscopy in the left lateral decubitus position may increase the detection rate of sessile serrated lesions compared to colonoscopy without a cap and supine position at withdrawal.

Mucosal defect size predicts the adequacy of resection of ≤10 mm nonpedunculated colorectal polyps using a new cold snare polypectomy technique

OBJECTIVES

There is still room for improvement in the methods used to achieve complete polyp resection. The aim of this study was to develop a cold snare polypectomy technique that will reliably result in resections containing the muscularis mucosae and the lateral polyp margins.

MATERIALS AND METHODS

Nonpedunculated polyps ≤10 mm were resected using a dedicated cold snare with the goal of creating a mucosal defect approximately 1 cm in dia. The completeness of resection of the lateral and vertical polyp margins was examined histologically.

RESULTS

The cases of 201 patients (mean age 67 ± 13 years; 115 men) with 500 eligible polyps were enrolled. The mean polyp size was 6.1 ± 1.8 mm (range 1-10 mm). The mean mucosal defect size immediately after resection was 7.7 ± 2.5 mm (range 3-15 mm). Overall, the complete resection rate in which the lateral and vertical margins were free from the neoplasia tissue was 92% (417/454, 95% CI, 89-94); in the remaining 8% of cases, the vertical margins showed complete resection but the lateral margins could not be evaluated due to the fragmentation of resected polyps. A mucosal defect ≥7 mm predicted complete resection of the mucosal layer containing the muscularis mucosae.

CONCLUSION

Complete mucosal layer resection of nonpedunculated colorectal polyps ≤10 mm was reliably achieved using a cold snare technique that produced a mucosal defect ≥7 mm in dia.

Pedunculated colorectal polyps with heads ≤ 1 cm in diameter can be resected using cold snare polypectomy

BACKGROUND AND STUDY AIMS

Cold snare polypectomy (CSP) is not recommended for the resection of pedunculated colorectal polyp. The aim of this study was to examine the adequacy of CSP compared to hot snare polypectomy (HSP) for the complete resection of pedunculated polyps with heads ≤ 1 cm in diameter.

PATIENTS AND METHODS

This was a retrospective study of a cohort of consecutive outpatients who had resection of pedunculated polyps with heads 6-10 mm in diameter using either dedicated CSP or HSP from 2014 through 2019. The primary outcome measure was occurrence of delayed bleeding. Secondary outcome measures included total procedure time, en bloc resection rate, immediate bleeding, and number of clips used.

RESULTS

415 patients with 444 eligible polyps were enrolled; the CSP group (363 patients; 386 polyps) and HSP group (52 patients; 58 polyps). Patient characteristics, polyp characteristics and en bloc resection rate were similar between groups. The mean total procedure time and mean number (range) of hemostatic clips/ patient used were significantly lower with CSP than with HSP (18± 8 min vs. 25± 9 min, P<0.001; 1.1 ± 0.6 (1-3) vs.3.1 ± 1.6 (1-5), respectively, P<0.001). Delayed bleeding occurred significantly less frequently in the CSP, 0% (0/363 vs.3.8% (2/52) in the HSP group (P<0.001), although immediate bleeding was significantly higher in CSP than HSP (84% (325/386) vs. 12% (7/58), P<0.001).

CONCLUSION

Pedunculated colorectal polyps with heads ≤ 1 cm can be removed using CSP, which has several advantages over HSP.

Linked colour imaging versus white-light colonoscopy for the detection of flat colorectal lesions: A randomized controlled trial

AIM

Linked colour imaging is an image-enhanced endoscopy system that emphasizes the red portion of the mucosa's colour. Our aim was to compare the effectiveness of linked colour imaging with white-light colonoscopy for the detection of flat-type colorectal polyps.

METHOD

This was a single-centre, randomized controlled trial. Enrolled patients were those aged ≥50 years undergoing cap-assisted colonoscopy for colorectal cancer screening. They were randomized in a 1:1 ratio for observation using linked colour imaging or white-light colonoscopy. All colorectal polyps detected were removed or biopsied. The primary outcome was the number of flat-type polyps per patient in patients in whom flat polyps were detected. Secondary outcomes included adenoma and polyp detection rates.

RESULTS

There were 302 subjects randomized: 152 to linked colour imaging and 150 to white-light colonoscopy. There were no differences in the clinical features between the two arms. The number of flat polyps detected per patient using linked colour imaging was approximately twice that with white light (2.9 ± 3.0 vs 1.2 ± 1.6, p = 0.045). Linked colour imaging also proved superior to white-light colonoscopy in terms of adenoma and polyp detection rates [adenomas 66% (101/152) vs 49% (73/150), p = 0.0024; polyps 69% (105/152) vs 55% (82/150), p = 0.013]. The ratio of polyps detected in the right colon compared with those detected in the left colon was significantly greater using linked colour than white-light imaging (168/64 vs 93/84; p < 0.001).

CONCLUSION

Compared with white-light colonoscopy, linked colour imaging improved adenoma and polyp detection rates, including detection of flat-type colorectal polyps.

Comparison of colon adenoma detection rates using cap-assisted and Endocuff-assisted colonoscopy: a randomized controlled trial

Objectives and study aim  Colonoscopy prevents colorectal cancer by removing adenomatous polyps, but missed adenomas lead to interval cancers. Different devices have been used to increase adenoma detection rates (ADR). Two such devices of interest are the transparent cap (Olympus) and Endocuff (ARC Medical). Our study aimed to compare differences in ADR between Endocuff-assisted colonoscopy (EAC), cap-assisted colonoscopy (CAC) and standard colonoscopy (SC). Patients and methods  A sample size of 126 subjects was calculated to determine an effect size of 30 %. Patients undergoing screening or surveillance colonoscopy between March 2016 and January 2017 were randomized to SC, CAC or EAC groups. Three experienced endoscopists performed all colonoscopies. Patient demographics, procedure indication, Boston Bowel Prep Score (BBPS), withdrawal time, polyp size, location, histopathology, were analyzed. Results  There was no difference in ADR (52 %, 40 % and 54 %) in the SC, CAC and EAC groups respectively ( P  = 0.4). Similar findings were also observed for proximal ADR (45 %, 35 %, and 50 %, P  = 0.4) and SSA detection rate (16 %, 14 %, and 23 %, P  = 0.5). EAC detected higher mean ADR per colonoscopy compared to CAC (1.70 vs 0.76, P  = 0.01). However, there was no significant difference in mean ADR per positive colonoscopy (2.08, 1.63, and 2.59, P  = 0.21). Conclusion  In a randomized controlled trial comparing AC to CAC and SC, neither device conferred additional benefits in ADR among high detectors. When comparing each device, EAC may be better than CAC at detecting more total adenomas.

Standards of diagnostic colonoscopy for early-stage neoplasia: Recommendations by an Asian private group

BACKGROUND AND AIM

In recent years, the incidence of colorectal cancer has been increasing, and it is now becoming the major cause of cancer death in Asian countries. The aim of the present study was to develop Asian expert-based consensus to standardize the preparation, detection and characterization for the diagnosis of early-stage colorectal neoplasia.

METHODS

A professional group was formed by 36 experts of the Asian Novel Bio-Imaging and Intervention Group (ANBI2 G) members. Representatives from 12 Asia-Pacific countries participated in the meeting. The group organized three consensus meetings focusing on diagnostic endoscopy for gastrointestinal neoplasia. The Delphi method was used to develop the consensus statements.

RESULTS

Through the three consensus meetings with debating, reviewing the literature and regional data, a consensus was reached at third meeting in 2016. The consensus was reached on a total of 10 statements. Summary of statements is as follows: (i) Adequate bowel preparation for high-quality colonoscopy; (ii) Antispasmodic agents for lesion detection; (iii) Image-enhanced endoscopy (IEE) for polyp detection; (iv) Adenoma detection rate for quality indicators; (v) Good documentation of colonoscopy findings; (vi) Complication rates; (vii) Cecal intubation rate; (viii) Cap-assisted colonoscopy (CAC) for polyp detection; (ix) Macroscopic classification using indigocarmine spray for characterization of colorectal lesions; and (x) IEE and/or magnifying endoscopy for prediction of histology.

CONCLUSION

This consensus provides guidance for carrying out endoscopic diagnosis and characterization for early-stage colorectal neoplasia based on the evidence. This will enhance the quality of endoscopic diagnosis and improve detection of early-stage colorectal neoplasia.

To cap/cuff or ring: do distal attachment devices improve the adenoma detection?

Colonoscopy reduces the risk of colorectal cancer, by interrupting the adenoma-carcinoma sequence enabling the detection and removal of adenomas before they turn into colorectal cancer. Colonoscopy has its limitations as adenoma miss rates as high as 25% have been reported. The reasons for missed pathology are complicated and multi-factorial. The recent drive to improve adenoma detection rates has led to a plethora of new technologies. Areas covered: An increasing number of advanced endoscopes and distal attachment devices have appeared in the market. Advanced endoscopes aim to improve mucosal visualization by widening the field of view. Distal attachment devices aim to increase adenoma detection behind folds by flattening folds on withdrawal. In this review article, we discuss the three following distal attachment devices: the transparent cap, the Endocuff, and the Endoring. Expert commentary: The authors believe that the distal attachment devices will have a greater benefit for endoscopists with low baseline adenoma detection rates.

Cap-assisted endoscopy: Do we have enough evidence?

So, is there enough evidence to incorporate CC in clinical practice? If we interpret the literature and the meta-analysis by Nutalapati et al., the answer for the clinically-focused endoscopist, with regard to adenoma detection rate (ADR), at present, may be "no". Significant differences do not necessarily imply clinical benefits and translation into clinical practice. The answer for the improvement of cecal intubation frequency and intubation time by the cap depends on the focus of training commitment, because these effects of the cap may be beneficial, especially for unexperienced endoscopists. It is obvious that further studies are needed. In this line, it is interesting to know, that in a recent meta-analysis of prospective studies, the length of the transparent cap had opposite effects on investigation time and polyp detection rate. Whereas, the anal to cecal time was significantly shortened by a cap length of > 7 mm and a polyp detection rate was significantly improved by a cap length of < 4 mm.

Delayed Bleeding Following Cold Snare Polypectomy for Small Colorectal Polyps in Patients Taking Antithrombotic Agents

BACKGROUND

This study compared the incidence of delayed bleeding following 2 methods of cold snare polypectomy for colorectal polyps in patients taking antithrombotic agents.

METHODS

Patients undergoing cold snare polypectomy for colorectal polyps ≤10 mm without discontinuation of antithrombotic agents were enrolled. This was a retrospective study of a prospectively collected cohort based on a historical comparison of 2 time periods. A traditional cold snare was used between January 2012 and December 2013 and a dedicated cold snare was used between January 2014 and December 2015. Patients' and polyps' characteristics, antithrombotic agents used, the snare used, the number of clips used, and adverse events were documented from a hospital online database. Delayed bleeding was defined as bleeding that required endoscopic treatment within 2 weeks after polypectomy. The submucosal layer of the resected polyps (6 to 10 mm) was histologically examined for the presence of injured arteries.

RESULTS

A total of 172 patients having 370 eligible polyps were enrolled; traditional cold snare group, N=100 (212 polyps) and dedicated cold snare group, N=72 (158 polyps). The patients' and polyps' characteristics were similar between the 2 groups. Hemostatic clips were used more often with the traditional than dedicated cold snares [33/100 (33%) vs. 13/72 (18%), P=0.044]. Delayed bleeding following cold snare polypectomy occurred in 1.2% (2/172); 0% (0/72) with dedicated snare versus 2% (2/100) with the traditional snare (P=0.63). The presence of histologically demonstrated injured submucosal arteries with the dedicated cold snare was significantly less than with the traditional cold snare [4.1% (4/98) vs. 16% (17/105), P=0.009].

CONCLUSIONS

Colorectal polyps ≤10 mm can be removed without an increase in delayed bleeding using dedicated cold snare polypectomy in patients taking antithrombotic agents.

Impact of cap-assisted colonoscopy on detection of proximal colon adenomas: systematic review and meta-analysis

BACKGROUND AND AIMS

Proximal colon adenomas can be missed during routine colonoscopy. Use of a cap or hood on the tip of the colonoscope has been shown to improve overall adenoma detection with variable rates. However, it has not been systematically evaluated for detection of proximal colon or right-sided adenomas where the cap may have maximum impact on adenoma detection rate (ADR). Our aim was to perform a systematic review and meta-analysis to evaluate the impact of cap-assisted colonoscopy (CC) on right-sided ADRs (r-ADRs) compared with standard colonoscopy (SC).

METHODS

PubMed, EMBASE, SCOPUS, and Cochrane databases as well as secondary sources (bibliographic review of selected articles and major GI proceedings) were searched through October 1, 2016. Primary outcome was the pooled rate of r-ADR. Detection of flat adenoma, sessile serrated adenoma/polyp (SSA/P), and number of right-sided adenomas per patient were also assessed. Pooled odds ratio (OR) and 95% confidence intervals (CIs) were calculated using random-effect models.

RESULTS

We screened 686 records and analyzed data from 4 studies (CC group, 2546 patients; SC group, 2547 patients) that met criteria for determination of r-ADRs, whereas 6 studies (CC group, 3159 patients; SC group, 3137 patients) were analyzed to estimate right-sided adenomas per patient. r-ADR was significantly higher with CC compared with SC (23% vs 17%; OR, 1.49; 95% CI, 1.08-2.05; I² = 79%; P = .01). CC also improved detection rates of flat adenoma (OR, 2.08; 95% CI, 1.35-3.20; P < .01) and SSA/P (OR, 1.33; 95% CI, 1.01-1.74; P = .04). The total number of right-sided adenomas (CC: 1428 [60%] vs SC: 1127 [58%]) and number of right-sided adenomas per patient (CC, .71 ± .5, vs SC, .65 ± .62 [mean ± standard deviation]) were numerically higher for CC but were not statistically significant (P = .43). Approximately 17 CCs would be required to detect an additional patient with right-sided adenoma.

CONCLUSIONS

Use of CC significantly improves the proximal colon ADR. In addition, flat adenoma and serrated colonic lesion detection rates are also significantly higher as compared with SC.

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.)

Efficacy of cap-assisted colonoscopy according to lesion location and endoscopist training level

AIM: To evaluate the efficacy of cap-assisted colonoscopy (CAC) for detection of colorectal polyps and adenomas according to the lesion location and endoscopist training level.

METHODS: Patients 20 years or older, who underwent their first screening colonoscopy in a single tertiary center from May 2011 to December 2012 were enrolled in this study. All patients underwent either CAC or standard colonoscopy (SC), and all of the procedures were performed by 11 endoscopists (8 trainees and 3 experts). All procedures were performed with high-definition colonoscopes and narrow band imaging. The eight trainees had experiences of performing 150 to 500 colonoscopies, and the three experts had experiences of performing more than 3000 colonoscopies. A 4-mm-long transparent cap was attached to the end of a colonoscope in the CAC group. We retrospectively evaluated the number of polyps and adenomas, polyp detection rate (PDR), and the number of adenomas and adenoma detection rate (ADR) according to the lesion location and endoscopist training level between CAC and SC. We also evaluated the number of polyps and adenomas according to their size between CAC and SC.

RESULTS: Overall, PDR and ADR using CAC were significantly higher than those using SC for both whole colon (48.5% vs 40.7%, P = 0.012; 35.7% vs 28.3%, P = 0.012) and right-side colon (35.3% vs 26.6%, P = 0.002; 27.0% vs 16.9%, P < 0.001). The number of polyps and adenomas per patient using CAC was significantly higher than that using SC for both the whole colon (1.07 ± 1.59 vs 0.82 ± 1.31, P = 0.008; 0.72 ± 1.32 vs 0.50 ± 1.01, P = 0.003) and right-side colon (0.66 ± 1.18 vs 0.41 ± 0.83, P < 0.001; 0.46 ± 0.97 vs 0.25 ± 0.67, P < 0.001). In the trainee group, the PDR and ADR using CAC were significantly higher than those using SC for both the whole colon (46.7% vs 39.7%, P = 0.040; 33.9% vs 26.0%, P =0.012) and right-side colon (34.2% vs 26.5%, P = 0.015; 25.3% vs 15.9%, P = 0.001). In the expert group, the PDR and ADR using CAC were significantly higher than those using SC only for the right-side colon (42.1% vs 27.0%, P =0.035; 36.8% vs 21.0%, P = 0.020).

CONCLUSION: CAC is more effective than SC for detection of colorectal polyps and adenomas, especially when performed by trainees and when the lesions are located in the right-side colon.

Improving quality measures in colonoscopy and its therapeutic intervention

Colonoscopy with polypectomy has been shown to reduce the risk of colon cancer. The critical element in the quality of colonoscopy in terms of polyp detection and removal continues to be the performance of the endoscopist, independent of patient-related factors. Improved results in terms of polyp detection and complete removal have implications regarding the development of screening and surveillance intervals and the reduction of interval cancers after negative colonoscopy. Advances in colonoscopy techniques such as high-definition colonoscopy, hood-assisted colonoscopy and dye-based chromoendoscopy have improved the detection of small and flat-type colorectal polyps. Virtual chromoendoscopy has not proven to improve polyp detection but may be useful to predict polyp pathology. The majority of polyps can be removed endoscopically. Available polypectomy techniques include cold forceps polypectomy, cold snare polypectomy, conventional polypectomy, endoscopic mucosal resection and endoscopic submucosal dissection. The preferred choice depends on the polyp size and characteristics. Other useful techniques include colonoscopic hemostasis for acute colonic diverticular bleeding, endoscopic decompression using colonoscopic stenting, and transanal tube placement for colorectal obstruction. Here we review the current knowledge concerning the improvement of quality measures in colonoscopy and colonoscopy-related therapeutic interventions.

Removal of small colorectal polyps in anticoagulated patients: a prospective randomized comparison of cold snare and conventional polypectomy

BACKGROUND

The bleeding risk after cold snare polypectomy in anticoagulated patients is not known.

OBJECTIVE

To compare the bleeding risk after cold snare polypectomy or conventional polypectomy for small colorectal polyps in anticoagulated patients.

DESIGN

Prospective randomized controlled study.

SETTING

Municipal hospital in Japan.

INTERVENTIONS

Anticoagulated patients with colorectal polyps up to 10 mm in diameter were enrolled. Patients were randomized to polypectomy with either cold snare technique (Cold group) or conventional polypectomy (Conventional group) without discontinuation of warfarin. The primary outcome measure was delayed bleeding (ie, requiring endoscopic intervention within 2 weeks after polypectomy). Secondary outcome measures were immediate bleeding and retrieval rate of colorectal polyps.

RESULTS

Seventy patients were randomized (159 polyps): Cold group (n = 35, 78 polyps) and Conventional group (n = 35; 81 polyps). The patients' demographic characteristics including international normalized ratio and the number, size, and shape of polyps removed were similar between the 2 techniques. Immediate bleeding during the procedure was more common with conventional polypectomy (23% [8/35]) compared with cold polypectomy (5.7% [2/35]) (P = .042). No delayed bleeding occurred in the Cold group, whereas 5 patients (14%) required endoscopic hemostasis in the Conventional group (P = .027). Complete polyp retrieval rates were identical (94% [73/78] vs 93% [75/81]). The presence of histologically demonstrated injured arteries in the submucosal layer with cold snare was significantly less than with conventional snare (22% vs 39%, P = .023).

LIMITATION

Small sample size, single-center study.

CONCLUSIONS

Delayed bleeding requiring hemostasis occurred significantly less commonly after cold snare polypectomy than conventional polypectomy despite continuation of anticoagulants. Cold snare polypectomy is preferred for removal of small colorectal polyps in anticoagulated patients. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT 01553565.).