[Additional polyp detection rate using colonoscopic retroflexion in right colon]

Retroflexion, a costless endoscopic maneuver, increases adenoma detection rate in the ascending colon

Background

Missed polyps during colonoscopy are considered an important factor for interval cancer appearance, especially in the ascending colon (AC). We evaluated the contribution of retroflexion to polyp and adenoma detection in the AC.

Methods

This prospective observational study included consecutive patients who underwent a complete colonoscopy between 06/2017 and 06/2018. The AC was examined in 2 phases: the first included 2 forward views from the hepatic flexure to the cecum; the second involved a retroflexion in the cecum, inspection up to the hepatic flexure and reinsertion to the cecum.

Results

The study included 655 patients, 628 (95.88%) with successful retroflexion (mean age: 62.5±10.8 years, 332 male). Indications for colonoscopy were screening in 33.28%, follow up in 36.03%, and diagnostic assessment in 30.69%. In total, 286 polyps and 220 adenomas were detected in the AC. Phase 1 identified 119 adenomas, yielding an adenoma detection rate (ADR) in the AC of 14.2% (95% confidence interval [CI] 11.52-16.84%) while phase 2 identified 86 additional adenomas, improving the ADR in the AC to 22.75% (95%CI 19.54-25.96%; P<0.01). Adenoma miss rate was 39.1% (86/225) and per-patient adenoma miss rate was 11.15% (73/655). Retroflexion proved beneficial mainly in the upper third of the AC (odds ratio [OR] 4.29, 95%CI 1.84-11.56; P<0.01) and for small (<5 mm) adenomas (OR 1.61, 95%CI 1.02-2.56; P=0.04). Multivariate analysis showed that age >60 years, detection of adenomas in forward views and the indication “follow up” influenced ADR during retroflexion.

Conclusion

Retroflexion is a simple and safe maneuver that increases the ADR in the AC and should complete a second forward view.

Success, safety, and usefulness of right colon retroflexion for the detection of additional colonic lesions not visualized with standard frontal view

BACKGROUND

Missed adenomas are the main concern for endoscopists. Right colon retroflexion (RCR) seems to increase the adenoma detection rate (ADR), but important variation in success and usefulness of this maneuver has been reported in the literature AIMS: Primary objective: to assess additional adenoma detection rate (AADR) detected during the RCR attempt. Secondary objectives: to assess success rates of RCR, variables associated with it, and safety of RCR.

METHODS

This is a prospective, unicentric, non-randomized study. Consecutive colonoscopies done by six endoscopists (3 of them with < 3 years of experience and 3 with > 3 years) from March to May 2017 were included. Olympus colonoscopes were used (CF-H190, CF-H180) Demographic, clinical, and endoscopic variables were collected.

RESULTS

463 colonoscopies were included. RCR success rate was 93.1% (431/463 colonoscopies). Forty additional lesions were visualized during RCR in 34/463 colonoscopies (7.3%). Additional adenomas were detected in 31/463 colonoscopies (6.7%; OR 0.07).

HISTOLOGY

low-grade dysplasia adenomas in 29/40 (72.5%) lesions; 3/40 (7.5%), adenomas with high-grade dysplasia; and 7/40 (17.5%) sessile serrated lesions. Additional adenoma detection contributed to modify the colonoscopy surveillance interval in 25 patients (5.4% of the cohort). Variables associated with RCR success in multivariate analysis were no previous abdominal surgery, length of colonoscope insertion in cecum < 80 cm, and use of Olympus 190 series colonoscopes. No differences between endoscopists' experience were found. RCR was a safe maneuver, with no adverse events in our study.

CONCLUSIONS

RCR is a feasible and safe maneuver that can increase ADR, so its routine inclusion in colonoscopy practice should be considered.

The Role of Behind Folds Visualizing Techniques and Technologies in Improving Adenoma Detection Rate

PURPOSE OF REVIEW

Colorectal cancer is one of the most common malignancies in the Western world and is thought to develop from premalignant polyps. Over the past decade, several behind folds visualizing techniques (BFTs) have become available to improve polyp detection. This systematic review and meta-analysis aims to compare BFTs with conventional colonoscopy (CC).

RECENT FINDINGS

In the past five years, 14 randomized controlled trials (RCTs) including 8384 patients comparing different BFTs with CC were published. The overall relative risks for adenoma detection rate, polyp detection rate, and adenoma miss rate comparing BFTs with CC were 1.04 (95% confidence interval [CI] 0.98-1.10; P = 0.15), 1.03 (95% CI 0.98-1.09; P = 0.28), and 0.70 (95% CI 0.46-1.05; P = 0.08), respectively. Other quality metrics for colonoscopy were not significantly different between BFT-assisted colonoscopy and CC either. This meta-analysis of RCTs published in the past five years does not show a significant benefit of BFTs on any of the important quality metrics of colonoscopy. The lack of additional effect of BFTs might be due to improved awareness of colonoscopy quality metrics and colonoscopy skills among endoscopists combined with improvements of conventional colonoscope technology.

The Effect of Right Colon Retroflexion on Adenoma Detection: A Systematic Review and Meta-analysis

BACKGROUND

Although colonoscopy with polypectomy can prevent up to 80% of colorectal cancers, a significant adenoma miss rate still exists, particularly in the right colon. Previous studies addressing right colon retroflexion have revealed discordant evidence regarding the benefit of this maneuver on adenoma detection with concomitant concerns about safety and rates of maneuver success. In this meta-analysis, we sought to determine the effect of right colon retroflexion on improving adenoma detection compared with conventional colonoscopy without retroflexion, as well as determine the rates of retroflexion maneuver success and adverse events.

METHODS

Multiple databases including MEDLINE, Embase, and Web of Science were searched for studies on right colon retroflexion and its impact on adenoma detection compared with conventional colonoscopy. Pooled analyses of adenoma detection and retroflexion success were based on mixed-effects and random-effects models with heterogeneity analyses.

RESULTS

Eight studies met the inclusion criteria (N=3660). The primary analysis comparing colonoscopy with right-sided retroflexion versus conventional colonoscopy to determine the per-adenoma miss rate in the right colon was 16.9% (95% confidence interval, 12.5%-22.5%). The overall rate of successful retroflexion was 91.9% (95% confidence interval, 86%-95%) and rate of adverse events was 0.03%.

CONCLUSIONS

Colonoscopy with right-sided retroflexion significantly increases the detection of adenomas in the right colon compared with conventional colonoscopy with a high rate of maneuver success and small risk of adverse events. Thus, reexamination of the right colon in retroflexed view should be strongly considered in future standard of care colonoscopy guidelines for quality improvement in colon cancer prevention.