What Influences the Quality of Prevention Colonoscopy?

Does the withdrawal time affect adenoma detection in non-screening colonoscopies?

AIMS

There are no studies looking at the relationship between colonoscopy withdrawal time (CWT) and adenoma detection rate (ADR) in non-screening patients. Our aim is to explore the relationship between CWT and ADR, particularly in the proximal colon where colonoscopy is shown to be less protective for the development of cancers.

METHODS

This is a retrospective study during November 2015 to December 2016 of non-screening colonoscopies done at a large teaching hospital. Incomplete and therapeutic procedures were excluded. The 39 endoscopists included were 15 gastroenterologists, 10 colorectal surgeons and 14 trainee colonoscopists. CWT was calculated by reviewing caecal intubation and rectal retroflexion images.

RESULTS

783 colonoscopies were included, with mean patient age of 58.51 years (SD 15.5). The mean ADR was 21.45% in the study. The CWT could be calculated for 62.83% of the cases (n=492). 80% (393) of colonoscopies had CWT of ≥6 min. Mean CWT was 9.15 min (SD 4.4). The ADR positively correlated with longer CWT (r=0.31, p=0.0001). The ADR was significantly higher when CWT was ≥8 min compared with CWT <6 min or CWT of 6-8 min (p=0.0001). More polyps were detected in the proximal colon when CWT ≥8 min (p=0.078). Mean CWT of gastroenterologists was 9.8 min (SD 4.5), similar to the trainee group (10.3 min, SD 3.8), while mean CWT for colorectal surgeons was 5.7 min (SD 3.2). The ADR for gastroenterologists was 25.9% versus 17.5% for colorectal surgeons and 17.8% for trainees.

CONCLUSIONS

There is a moderately strong positive correlation between longer CWT and ADR in non-screening colonoscopies. CWT can differ between different endoscopists. Meticulous colonoscopy withdrawal may improve polyp detection in the proximal colon.

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.