Quality of colonoscopy and advances in detection of colorectal lesions: a current overview

Efficacy of cecal retroflexion observed on adenoma missing of ascending colon during colonoscopy: A prospective, randomized, pilot trial

BACKGROUND

Although colonoscopic retroflexion has been proved effective in reducing missed adenomas, there is still a lack of comprehensive and in-depth research focused on the ascending colon. We aimed to conduct a randomized controlled trial and tandem colonoscopy to investigate whether cecal retroflexion observed during colonoscopy can reduce missed adenomas in the ascending colon.

METHODS

Men and women required to be between 45 and 80 years of age were screened for enrollment in the trial. Patients were randomly assigned according to a 1:1 ratio to either the trial group or control group. Patients in the trial group underwent 2 forward examination and a cecal retroflexion observed in the ascending colon, while patients in the control group underwent only 2 forward examinations in the ascending colon. The primary outcome was adenoma miss rate. The secondary outcomes contained adenoma detection rate, polyp miss rate, polyp detection rate, insertion time and withdrawal time. Differences between groups in the primary outcome and in the other categorical indicators were tested using chi-squared test and Fisher exact test. For the comparison of continuous outcomes, the Student t test was applied.

RESULTS

A total of 60 subjects were eligible for the study between April to June 2020, of which 55 were randomized and eligible for analysis (26 to the control group and 29 to the trial group). The characteristics of patients were no significant differences statistically between the trial group and the control group. Similarly, the characteristics of the colonoscopy procedures included cecal insertion distance, the length of cecum and ascending colon, insertion time, withdrawal time, quality of bowel preparation, numerical rating scale for pain, polyps detected, and adenomas detected, and there were no significant differences statistically between the 2 groups (P = .864, P = .754, P = .700, P = .974, P = .585, P = .835, P = .373, P = .489). The characteristics of the polyps were also no significant differences statistically between the 2 groups.

CONCLUSION

This pilot trial failed to show benefit of cecal retroflexion observed on adenoma missing of ascending colon during colonoscopy; however, further conclusions require a prospective study with a higher level of evidence. (NCT03355443).

Indocyanine green loaded pH-responsive bortezomib supramolecular hydrogel for synergistic chemo-photothermal/photodynamic colorectal cancer therapy

Colorectal cancer is with high incidence worlwide.. Because of the heterogeneity of the tumor, combination therapy is probably of great significance to improve the prognosis of colorectal cancer patients. Herein, the pH-responsive supramolecular hydrogels mPEG-luteolin-BTZ@ICG based on bortezomib (BTZ) and indocyanine green (ICG) were prepared, and the colorectal cancer was treated with mPEG-luteolin-BTZ@ICG through the combination of photothermal/photodynamic and chemotherapy. BTZ performed drug therapy, meanwhile ICG wrapped in supramolecular hydrogels possessed higher light stability than free ICG to perform photothermal/photodynamic therapy. In vitro and in vivo assays showed excellent inhibition of tumor cells due to the combined effect of BTZ and ICG. The mPEG-luteolin-BTZ@ICG combined with laser therapy possessed exceptional biological safety and provided new candidates for advanced colon cancer therapy and important references for other tumor therapies.

Impact of photodocumentation of caecal intubation on colonoscopy outcomes

OBJECTIVES

The European and American colonoscopy guidelines recommend mandatory photodocumentation of caecal intubation to allow retrospective analysis and improve outcomes. We aim to demonstrate whether photodocumentation of caecal intubation improves colonoscopy outcomes.

METHODS

We extracted images and procedural data from 317 consecutive colonoscopies. Images were anonymised and reviewed by four expert reviewers who scored their certainty that caecal intubation was achieved. Statistical analysis correlated adequately and inadequately photodocumented cases with polyp detection rate (PDR) and adenoma detection rate (ADR).

RESULTS

The patients' mean age was 59.4 years and 52% were male. Eighty-one percent were performed by consultant endoscopists and 19% by specialist registrar. Sixty-five percent of these procedures were performed by gastroenterologists and 35% by surgical endoscopists. Fifty-three percent were deemed to have adequately demonstrated photographic evidence of caecal intubation. Statistical analysis comparing adequately and inadequately photodocumented cases: the PDR of procedures with confirmed caecal intubation was greater than procedures without photographic evidence (40% vs 34%). Similarly, the ADR of photographically confirmed cases was greater than that of inadequately photodocumented cases (25% vs 18%). The number of images taken per procedure positively correlated with photographic documentation of caecal intubation.

CONCLUSION

While failing to reach statistical significance, there was a nominal difference in ADR and PDR demonstrated between the two groups, and with predominantly positive confidence intervals, this might suggest that a larger sample size could result in significance in favour of photodocumentation of caecal intubation. Future studies would be warranted. However, endoscopists that take more images were more likely to have proven caecal intubation.

Further Defining the 2012 Multi-Society Task Force Guidelines for Surveillance of High-risk Adenomas: Is a 3-Year Interval Needed for All Patients?

GOALS

We set out to determine whether variation from this 3-year follow-up interval was associated with the finding of subsequent high-risk adenoma (HRA).

BACKGROUND

HRAs include the following: (1) an adenoma measuring ≥10 mm, (2) ≥3 adenomas found during a single procedure, and (3) an adenoma with high-grade dysplasia or villous architecture. The current Multi-Society Task Force guideline for timing of surveillance colonoscopy after removal of a HRA is 3 years.

STUDY

In 2016, we analyzed 495 patients who had a HRA removed during a 2008 colonoscopy. We compared the frequency of finding another HRA at follow-up intervals. We used the current guidelines as our referent group and performed logistical regression to identify whether any patient characteristics, procedural factors, or type of HRA predicted the development of HRAs on follow-up colonoscopy.

RESULTS

Individuals who followed-up at a median of 4.5 years did not have more HRA on follow-up compared with those who followed-up at 3 years (25.2% vs. 21.0%, P=0.062). These groups had similar baseline characteristics. Older individuals, male gender, having a history of polyps, and piecemeal resection of an HRA predicted future HRAs. The removal of ≥3 adenomas in 2008 as well as a combination of multiple, large, and advanced polyps showed a higher risk of future HRAs.

CONCLUSIONS

The 2012 Multi-Society Task Force recommendation of 3-year follow-up after removal of HRAs may not apply to all patients. We showed that a combination of patient demographics, procedural factors, and pathology best determines the surveillance colonoscopy interval.

New technologies improve adenoma detection rate, adenoma miss rate, and polyp detection rate: a systematic review and meta-analysis

BACKGROUND AND AIMS

The need to increase the adenoma detection rate (ADR) for colorectal cancer screening has ushered in devices that mechanically or optically improve conventional colonoscopy. Recently, new technology devices (NTDs) have become available. We aimed to compare the ADR, polyp detection rate (PDR), and adenoma miss rate (AMR) between NTDs and conventional colonoscopy and between mechanical and optical NTDs.

METHODS

MEDLINE and Embase databases were searched from inception through September 2017 for articles or abstracts reporting ADR, PDR, and AMR with NTDs. Randomized controlled trials and case-control studies with >10 subjects were included. Primary outcomes included ADR, PDR, and AMR odds ratio (OR) between conventional colonoscopy and NTDs. Secondary outcomes included cecal intubation rates, adverse events, cecal intubation time, and total colonoscopy time.

RESULTS

From 141 citations, 45 studies with 20,887 subjects were eligible for ≥1 analyses. Overall, the ORs for ADR (1.35; 95% confidence interval [CI] 1.24-1.47; P < .01) and PDR (1.51; 95% CI, 1.37-1.67; P < .01) were higher with NTDs. Higher ADR (OR, 1.52 vs 1.25; P = .035) and PDR (OR, 1.63 vs 1.10; P ≤ .01) were observed with mechanical NTDs. The overall AMR with NTDs was lower compared with conventional colonoscopy (OR, .19; 95% CI, .14-.26; P < .01). Mechanical NTDs had lower AMRs compared with optical NTDs (OR, .10 vs .33; P < .01). No differences in cecal intubation rates, cecal intubation time, or total colonoscopy time were found.

CONCLUSIONS

Newer endoscopic technologies are an effective option to improve ADR and PDR and decrease AMR, particularly with mechanical NTDs. No differences in operability and safety were found.

Multiple, zonal and multi-zone adenoma detection rates according to quality of cleansing during colonoscopy

BACKGROUND

The safety and diagnostic accuracy of colonoscopy depend on the quality of colon cleansing. The adenoma detection rate is usually used as a quality measurement score.

OBJECTIVE

We aimed to introduce and evaluate three new parameters to determine polyps and adenomas segmental localization and their distribution in association with different bowel preparation levels during colonoscopy. We introduce the multiple adenoma detection rate (the percentage of patients with >2 adenomas diagnosed during colonoscopy), the zonal adenoma detection rate (the percentage of patients with >2 adenomas diagnosed during colonoscopy in different colon areas (rectum, sigmoid, descending, transverse, ascending and cecum colon)), and multi-zone adenoma detection rate (the percentage of patients with >2 adenomas diagnosed during colonoscopy in different colon areas with at least a segment between them with or without lesions (i.e. rectum and descending colon with or without lesions in the sigmoid)).

METHODS

We prospectively enrolled outpatients who underwent colonoscopy from January 2013 to October 2014. The bowel preparation quality, according to the Aronchick modified scale, number and location of lesions, Paris classification and histology, were recorded. The multiple adenoma/polyp detection rate, zonal adenoma/polyp detection rate, and multi-zone adenoma/polyp detection rate were determined.

RESULTS

In total, 519 consecutive patients (266/253 M/F; mean age 55.3 ± 12.8 years) were enrolled. The adenoma and polyp detection rates were 21% and 35%, respectively. Multiple adenomas were detected in 28 patients. Adenoma and polyp detection rate and new parameters were statistically significantly higher in the optimal as compared with the adequate bowel preparation.

CONCLUSIONS

An optimal level of bowel preparation was strongly associated not only with a higher adenoma detection rate, but also with a higher chance of detecting multiple clinically relevant lesions in adjacent or discrete segments of the colon.