Impact of retroflexion in the right colon after repeated forward-view examinations

What are the priority quality indicators for colonoscopy in real-world clinical practice?

Colonoscopy is widely used as a colorectal cancer (CRC) screening tool. The effectiveness of a screening colonoscopy is associated with a decreased risk of CRC. However, colonoscopy is an operator-dependent procedure, and endoscopists' quality performance varies widely. This article reviewed the priority metrics and practices that contribute to high-quality screening colonoscopy in real-world clinical practice. With growing evidence, quality indicators have been subject to intense research and associated with reducing postcolonoscopy CRC incidence and mortality. Some quality metrics can reflect an endoscopy unit-based practice (i.e. quality of bowel preparation and withdrawal time). Other quality indicators primarily reflect individuals' skill and knowledge (i.e. cecal intubation rate, adenoma detection rate, and appropriately assigned follow-up colonoscopy interval). Measurement and improvement of priority quality indicators for colonoscopy should be made at both the endoscopist and unit levels. Substantial evidence supports the impact of high-quality colonoscopy in reducing the incidence of postcolonoscopy CRC.

Multicenter propensity score-matched analysis comparing short versus long cap-assisted colonoscopy for acute hematochezia

Background and Aim

While short and long attachment caps are available for colonoscopy, it is unclear which type is more appropriate for stigmata of recent hemorrhage (SRH) identification in acute hematochezia. This study aimed to compare the performance of short versus long caps in acute hematochezia diagnoses and outcomes.

Methods

We selected 6460 patients who underwent colonoscopy with attachment caps from 10 342 acute hematochezia cases in the CODE BLUE-J study. We performed propensity score matching (PSM) to balance baseline characteristics between short and long cap users. Then, the proportion of definitive or presumptive bleeding etiologies found on the initial colonoscopy and SRH identification rates were compared. We also evaluated rates of blood transfusions, interventional radiology, or surgery, as well as the rate of rebleeding and mortality within 30 days after the initial colonoscopy.

Results

A total of 3098 patients with acute hematochezia (1549 short cap and 1549 long cap users) were selected for PSM. The rate of colonic diverticular bleeding (CDB) diagnosis was significantly higher in long cap users (P = 0.006). While the two groups had similar rates of the other bleeding etiologies, the frequency of unknown etiologies was significantly lower in long cap users (P < 0.001). The rate of SRH with active bleeding was significantly higher in long cap users (P < 0.001). Other clinical outcomes did not differ significantly.

Conclusion

Compared to that with short caps, long cap-assisted colonoscopy is superior for the diagnosis of acute hematochezia, especially CDB, and the identification of active bleeding.

Improving polyp detection at colonoscopy: Non-technological techniques

Colonoscopy and polypectomy remain the gold standard investigation for the detection and prevention of colorectal cancer. Halting the progression of colonic adenoma through adequate detection of pre-cancerous lesions interrupts the progression to carcinoma. The adenoma detection rate is a key performance indicator. Increasing adenoma detection rates are associated with reducing rates of interval colorectal cancer. Endoscopists with high baseline adenoma detection rate have a meticulous technique during colonoscopy withdrawal that improves their adenoma detection. This minireview article summarizes the evidence on the following simple operator techniques and their effects on the adenoma detection rate; minimum withdrawal times, dynamic patient position change and proximal colon retroflexion.

Unlocking quality in endoscopic mucosal resection

A review of the development of the key performance metrics of endoscopic mucosal resection (EMR), learning from the experience of the establishment of widespread colonoscopy quality measurements. Potential future performance markers for both colonoscopy and EMR are also evaluated to ensure continued high quality performance is maintained with a focus service framework and predictors of patient outcome.

Negative effect of prolonged cecal intubation time on adenoma detection in female patients

Background and Aim

Withdrawal time of the colonoscope is associated with adenoma detection. However, the association between cecal intubation time and adenoma detection remains unclear. This study aimed to evaluate the association between cecal intubation time and adenoma detection.

Methods

This retrospective study analyzed prospectively collected data from a randomized controlled trial on female patients who underwent colonoscopy in an academic hospital. The primary outcome was the mean number of all adenomas detected per patient. Secondary outcomes included the mean number of advanced, diminutive, small/large, right-sided colonic, and left-sided colonic adenomas detected per patient. Furthermore, the detection rates of all categories of adenoma were evaluated.

Results

The analysis included 216 female patients aged ≥20 years. The correlation analysis did not reveal a significant relationship (P = 0.473) between cecal intubation and withdrawal times. The mean number of all adenomas detected per patient declined by approximately 30% (1.05-0.70) from the fastest to the slowest insertion time quartile. Adjusted regression analysis showed a significant decrease in the mean number of all adenomas detected per patient with increased intubation time (relative risk, RR = 0.87; 95% confidence interval, 0.76-0.99, P = 0.045), whereas the mean number of other categories of adenomas detected per patient and the detection rates of all categories of adenoma were not associated with the cecal intubation time.

Conclusions

This study showed a significant association between prolonged cecal intubation time and decreased adenoma detection. The cecal intubation time may be a significant quality indicator for colonoscopy.

Establishment and evaluation of a nomogram predicting risks of missed diagnoses of colorectal polyps

Background

A missed diagnosis of colorectal polyps during colonoscopy may be associated with the occurrence of interval colorectal cancer. The risk factors for a missed diagnosis or a method to predict the risk of a missed diagnosis of colorectal polyps during colonoscopy remain unidentified.

Methods

The clinical data of patients who underwent two colonoscopies within three months at the Affiliated Hospital of North Sichuan Medical College between February 2017 and August 2019 were retrospectively reviewed. Independent risk factors for missed diagnoses were identified, and a nomogram was established to predict the risk of missed diagnoses. The prediction performance of the nomogram was evaluated using C-index and calibration curves, and its clinical application value was assessed using the Youden index and decision curve analysis.

Results

Independent influencing factors for missed diagnoses included age, endoscopist experience, bowel preparation, retroflected view, withdrawal time, number of polyps in the right colon, and number of polyps ≥ 6 mm. The C-index of the nomogram in the training and validation cohorts was 0.763 (95% confidence interval [CI]: 0.724 − 0.807) and 0.726 (95%CI: 0.657 − 0.794), respectively. The optimal cut-off value of the nomogram calculated using the Youden index was 152.2 points. Under the cut-off value, the sensitivity, specificity, positive predictive value, and negative predictive value were 67.1%, 75.7%, 45.8%, and 88.2%, respectively, in the training cohort, and 57.1%, 79.9%, 53.3%, and 82.3%, respectively, in the validation cohort.

Conclusions

The nomogram provides a reference value for clinicians to analyse the risk of a missed diagnosis of colorectal polyps in individuals, identify high-risk groups, and formulate appropriate follow-up strategies.

Gadus morhua Eggs Sialoglycoprotein Prevent Estrogen Deficiency-Induced High Bone Turnover by Controlling OPG/RANKL/TRAF6 Pathway and Serum Metabolism

In recent years, the development of safe and effective anti-osteoporosis factors has attracted extensive attention. In this study, an estrogen-deficient osteoporosis rat model was employed to study the improving mechanism of sialoglycoprotein isolated from Gadus morhua eggs (Gds) against osteoporosis. The results showed that compared with OVX, Gds ameliorated the trabecular microstructure, especially the increased trabecular thickness, decreased trabecular separation, and enhanced the trabecular number. The analysis of qRT-PCR and western blotting found that Gds reduced bone resorption by inhibiting RANKL-induced osteoclastogenesis. The LC-MS/MS was used to investigate serum metabolism, and the enrichment metabolites were analyzed by the KEGG pathway. The results revealed that the Gds significantly altered the fat anabolism pathway, which includes ovarian steroidogenesis pathway and arachidonic acid metabolism pathway. Altogether, Gds could improve osteoporosis by suppressing high bone turnover via controlling OPG/RANKL/TRAF6 pathway, which is implicated with ovarian steroidogenesis pathway and arachidonic acid metabolism pathway. These findings indicated that Gds could be a candidate factor for anti-osteoporosis.

Detection of colorectal lesions during colonoscopy

Owing to its high mortality rate, the prevention of colorectal cancer is of particular importance. The resection of colorectal polyps is reported to drastically reduce colorectal cancer mortality, and examination by endoscopists who had a high adenoma detection rate was found to lower the risk of colorectal cancer, highlighting the importance of identifying lesions. Various devices, imaging techniques, and diagnostic tools aimed at reducing the rate of missed lesions have therefore been developed to improve detection. The distal attachments and devices for improving the endoscopic view angle are intended to help avoid missing blind spots such as folds and flexures in the colon, whereas the imaging techniques represented by image‐enhanced endoscopy contribute to improving lesion visibility. Recent advances in artificial intelligence‐supported detection systems are expected to supplement an endoscopist's eye through the instant diagnosis of the lesions displayed on the monitor. In this review, we provide an outline of each tool and assess its impact on the reduction in the incidence of missed colorectal polyps by summarizing previous clinical research and meta‐analyses. Although useful, the many devices, image‐enhanced endoscopy, and artificial intelligence tools exhibited various limitations. Integrating these tools can improve their shortcomings. Combining artificial intelligence‐based diagnoses with wide‐angle image‐enhanced endoscopy may be particularly useful. Thus, we hope that such tools will be available in the near future.

Yield of a second right colon examination during colonoscopy after a first examination using a mucosal exposure device

BACKGROUND AND AIMS

Double right colon examination during colonoscopy has been advocated to reduce the risk of interval cancer in the right colon. Whether 2 examinations are necessary when the first examination is performed with a mucosal exposure device is uncertain. We documented the rates of missed adenomas, sessile serrated lesions, and hyperplastic polyps after an initial right colon examination by a high-level detector using a mucosal exposure device.

METHODS

At a single tertiary hospital outpatient practice, we prospectively collected data on the yield of a second examination of the right colon after an initial examination by a single high-detecting colonoscopist using a mucosal exposure device.

RESULTS

During the study period, 1331 eligible consecutive patients underwent colonoscopy. Right colon adenoma, sessile serrated lesion, and hyperplastic polyp miss rates were 15.8%, 14.1%, and 16.7%, respectively. Four percent of patients had adenomas detected in the right colon only with a second examination.

CONCLUSIONS

A second examination of the right colon is warranted, even when using a distal mucosal exposure device to perform colonoscopy.

Retroflexed view for reexamination of the right colon after forward view examination: Systematic review and meta-analysis

BACKGROUND

The effect of retroflexed view (RV) for the reexamination of the right colon after forward view (FV) examination has not been fully understood.

METHODS

We searched multiple databases including PubMed, Embase, and the Cochrane Library for prospective studies exploring the role of RV for reexamination of the right colon. A meta-analysis was performed on outcomes including lesion detection rates, lesion miss rates, and withdrawal time.

RESULTS

Four randomized controlled trials aimed to compare the impact of the second withdrawal from the right colon in RV vs. FV following a standard colonoscopy. Both the additional adenoma detection rate (AADR) and additional polyp detection rate (APDR) of the right colon were lower in the RV group compared with the FV group (risk ratio [RR] 0.73 for AADR; RR 0.76 for APDR); similar results were noted in comparisons of the adenoma miss rate and polyp miss rate. Six prospective cohort studies aimed to describe the effect of the RV examination of the right colon after one or two rounds of FV examination. Both the adenoma detection rate (ADR) and polyp detection rate (PDR) of the right colon were slightly higher in combined examinations with RV examination than single FV examination (RR 1.11 for ADR; RR 1.16 for PDR) or two FV examinations (RR 1.21 for ADR; RR 1.22 for PDR).

CONCLUSIONS

FV may detect more adenomas and polyps than RV during the second withdrawal from the right colon. RV may detect additional adenomas and polyps in the right colon after two FV examinations.

Diagnosis, epidemiology and management of serrated polyposis syndrome: a comprehensive review of the literature

Serrated polyp associated colorectal cancer (CRC) develops from an alternative mechanism of colorectal carcinogenesis and accounts for 10-15% of all CRC. Serrated polyposis syndrome (SPS) occurs infrequently and is characterized by the occurrence of multiple serrated polyps (hyperplastic polyps, sessile serrated lesions and traditional serrated adenomas) throughout the colon and/or rectum and has been strongly associated with development of CRC. However, SPS is frequently unrecognized, due to application failure of the WHO criteria regarding diagnosis and/or missed serrated polyps during endoscopy. The management of SPS requires surveillance at regular intervals and removal of large serrated polyps. Endoscopic resection suitability and technique depends on lesion size and the endoscopist's experience. In this manuscript, we present an update regarding SPS epidemiology, molecular characteristics, management, surveillance strategies and endoscopic resection techniques.

Colonoscopy screening and surveillance guidelines

The Colonoscopy Screening and Surveillance Guidelines were developed by the Japan Gastroenterological Endoscopy Society as basic guidelines based on the scientific methods. The importance of endoscopic screening and surveillance for both detection and post-treatment follow-up of colorectal cancer has been recognized as essential to reduce disease mortality. There is limited high-level evidence in this field; therefore, we had to focus on the consensus of experts. These clinical practice guidelines consist of 20 clinical questions and eight background knowledge topics that have been determined as the current guiding principles.

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.

State of the Science on Quality Indicators for Colonoscopy and How to Achieve Them

Colonoscopy is a safe and effective tool, but operator dependent. Room for improvement in the quality of colonoscopy is the impetus for the development and measurement of colonoscopy quality indicators and the focus of many efforts to improve colonoscopy quality indicator prevention and control in provider practices and health systems. We present the preprocedural, intraprocedural, and postprocedural quality indicators and benchmarks for colonoscopy. Every provider and practice must make a commitment to performing high-quality colonoscopy and implement and monitor quality metrics. There are a variety of tools available to assist in improving quality indicators that range from distal attachment devices to education and feedback. Although technology can help, it is not a substitute for proper technique. The commitment also requires provider feedback through audits and report cards. The impact of these efforts on patient outcomes is an important area of further research.