Faculty Bibliography

Colonoscopy is the most commonly performed endoscopic procedure and overall is considered a low-risk procedure. However, adverse events (AEs) related to this routinely performed procedure for screening, diagnostic, or therapeutic purposes are an important clinical consideration. The purpose of this document from the American Society for Gastrointestinal Endoscopy's Standards of Practice Committee is to provide an update on estimates of AEs related to colonoscopy in an evidence-based fashion. A systematic review and meta-analysis of population-based studies was conducted for the 3 most common and important serious AEs (bleeding, perforation, and mortality). In addition, this document includes an updated systematic review and meta-analysis of serious AEs (bleeding and perforation) related to EMR and endoscopic submucosal dissection for large colon polyps. Finally, a narrative review of other colonoscopy-related serious AEs and those related to specific colonic interventions is included.

BACKGROUND & AIMS:Accurate sizing of polyps and improving adenoma detection rates (ADR) are important goals for high-quality colonoscopy. Surveillance intervals are based on accurate sizing of polyps. There are no clinical tools or interventions that have demonstrated improvement in both these metrics. We investigated the efficacy of a simple, low-cost intervention, based on use of polyp sizing posters to improve measurements of polyps and increase ADRs during colonoscopy at a large gastroenterology community practice. METHODS:We collected data on polyp measurements and ADRs by 62 gastrointestinal endoscopists at a large multi-site community practice, from January to November 2015 (baseline). In a prospective study, endoscopy units were given a polyp sizing poster to be hung above the endoscopy video monitor (intervention group, for 33 endoscopists) or for usual care (control group, for 29 endoscopists) in December 2015, and we collected data on polyp measurements and ADRs over the following 6 months (January-June 2016). We compared the endoscopists' assessment of polyp size and their ADRs before and after the intervention using a mixed effects proportional odds model, controlling for provider age and sex and patient and indication for colonoscopy. Our primary aim was to assess the effect of the snare and forcep-based polyp sizing poster on change in polyp size. The secondary aim was to study the effect of the polyp sizing poster on ADR. RESULTS:Our final analysis included 85,657 polyps from 38,307 colonoscopies. The characteristics of patients who underwent colonoscopy were similar between the control and intervention group (median age, 61 years; 48.1% female; 53.9% undergoing screening; 31.4% undergoing surveillance; 14.7% receiving a diagnostic colonoscopy). The endoscopists' median age was 51 years (range, 33-76) years, and 15 were women (24.2%). During the baseline period, male endoscopists were more likely to size polyps larger than measurements made by female endoscopists (odds ratio [OR], 1.78; 95% CI, 1.24-2.55; P = .002). For the intervention group, 78.6% of polyps were assigned to the 1-5 mm category during the baseline period compared to 76.0% after the intervention, whereas the proportions of polyps assigned to the 6-10 mm category increased from 16.9% during the baseline period to 18.3% after the intervention. In the control group, 78.9% of polyps were assigned to the 1-5 mm category during the baseline period and 78.3% were assigned to this group in the prospective study; 16.5% of polyps were assigned to the 6-10 mm during the baseline period and 17.5% were assigned to this group in the prospective study. The interaction between intervention group and timing (baseline vs after the intervention) was statistically significant, with an increase in the odds of larger polyp sizing after the intervention (OR, 1.15; 95% CI, 1.08-1.23; P < .001). The odds of larger polyp measurement during the intervention period, compared to the baseline period, increased for male endoscopists (OR, 1.17; 95% CI, 1.09-1.27; P < .001) and female endoscopists (OR, 1.18; 95% CI, 1.01-1.36; P = .04), as well as for younger physicians (<50 years; OR, 1.32; 95% CI, 1.20-1.46; P < .001) but not for older physicians (>50 years; OR, 0.96; 95% CI, 0.88-1.06; P = .44). The average ADR for male and female endoscopists combined during the baseline period was 42%. The change in ADR from the baseline vs the post-intervention was an increase of 2.6% in the control group compared to 5.7% in the intervention group (P = .39) CONCLUSIONS: Placement of a polyp sizing poster above the endoscopy video monitor increases the odds of polyps being assigned a larger size but does not affect ADRs.

Colorectal cancer is defined clinically as invasion of dysplastic cells into the submucosa. Lesions with submucosal invasion but without invasion into the muscularis propria are generally called malignant polyps. A stepwise approach produces optimal management of malignant polyps (including polypoid and flat/depressed lesions). The first step is to avoid endoscopic resection of non-pedunculated lesions with endoscopic features that predict deep submucosal invasion. Lesions without such features are candidates for endoscopic resection. The second step is to assess candidates for endoscopic resection for features that predict an increased risk of superficial submucosal invasion. Such lesions should be considered for en bloc endoscopic excision if feasible. The third step is giving patients with endoscopically resected malignant polyps good advice regarding whether to undergo adjuvant therapy, usually surgery. We review the endoscopic and histologic criteria that guide clinicians through these steps.

Irritable bowel syndrome (IBS) is a common disorder of heterogeneous pathogenesis, and alterations in the gut microbiome/dysbiosis play a role in the development of symptoms in a subset of individuals with IBS. Consequently, it stands to reason that modulation of the microbiome via fecal microbial transplant (FMT) may serve as an effective treatment strategy because this has proven effective for treating other illnesses such as Clostridium difficile colitis. Small studies completed to date have offered conflicting results and the strains used, route of administration, and IBS subtypes may all play a role in treatment outcomes. A better understanding of the altered microbiome of patients with IBS and more rigorous trials are warranted before the utility of fecal microbial transplant for IBS symptoms can be determined.