Oral mannitol for bowel preparation: a dose-finding phase II study

Background

Successful bowel preparation (BP) for colonoscopy depends on the instructions, diet, the laxative product, and patient adherence, which all affect colonoscopy quality. Nevertheless, there are no laxatives which combine effectiveness, safety, easy self-administration, good patient acceptance, and low cost. However, mannitol, a sugar alcohol, could be an attractive candidate for use in clinical practice if it is shown to demonstrate adequate efficacy and safety.

Aims

The present phase II dose-finding study compared three doses of mannitol (50, 100, and 150 g) to identify the best dose to be used in a subsequent phase III study.

Methods

The Boston Bowel Preparation Scale, caecal intubation rate, adherence, acceptability, and safety profile, including measurement of potentially dangerous colonic gas concentrations (CH4, H2, O2), were considered in all patients. A weighted algorithm was used to identify the best mannitol dose for use in the subsequent study.

Results

The per-protocol population included 60 patients in the 50 g group, 54 in the 100 g group, and 49 in the 150 g group. The 100 g dose was the best as it afforded optimal colon cleansing efficacy (94.4% of patients had adequate BP), adherence, acceptability, and safety, including negligible gas concentrations.

Conclusions

The present study demonstrated that the colon cleansing efficacy and safety of mannitol were dose dependent. Conversely, gas concentrations were not dose dependent and negligible in all patients. Combined evaluation of efficacy, tolerability, and safety, using a weighted algorithm, determined that mannitol 100 g was the best dose for the phase III study.

The Colon Endoscopic Bubble Scale (CEBuS): a two-phase evaluation study

BACKGROUND

To date, no scale has been validated to assess bubbles associated with bowel preparation. This study aimed to develop and assess the reliability of a novel scale - the Colon Endoscopic Bubble Scale (CEBuS).

METHODS

This was a multicenter, prospective, observational study with two online evaluation phases of 45 randomly distributed still colonoscopy images (15 per scale grade). Observers assessed images twice, 2 weeks apart, using CEBuS (CEBuS-0 - no or minimal bubbles, covering < 5 % of the surface; CEBuS-1 - bubbles covering 5 %-50 %; CEBuS-2 - bubbles covering > 50 %) and reporting the clinical action (do nothing; wash with water; wash with simethicone).

RESULTS

CEBuS provided high levels of agreement both in evaluation Phase 1 (4 experts) and Phase 2 (6 experts and 13 non-experts), with almost perfect intraobserver reliability: kappa 0.82 (95 % confidence interval 0.75-0.88) and 0.86 (0.85-0.88); interobserver agreement - intraclass correlation coefficient (ICC) 0.83 (0.73-0.89) and 0.90 (0.86-0.94). Previous endoscopic experience had no influence on agreement among experts vs. non-experts: kappa 0.86 (0.80-0.91) vs. 0.87 (0.84-0.89) and ICC 0.91 (0.87-0.94) vs. 0.90 (0.86-0.94), respectively. Interobserver agreement on clinical action was ICC 0.63 (0.43-0.78) in Phase 1 and 0.77 (0.68-0.84) in Phase 2. Absolute agreement on clinical action per scale grade was 85 % (82-88) for CEBuS-0, 21 % (16-26) for CEBuS-1, and 74 % (70-78) for CEBuS-2.

CONCLUSION

CEBuS proved to be a reliable instrument to standardize the evaluation of colonic bubbles during colonoscopy. Assessment in daily practice is warranted.

Common bile duct size in malignant distal obstruction and lumen-apposing metal stents: a multicenter prospective study

Background and study aims  Feasibility of EUS-guided choledochoduodenostomy (EUS-CDS) using available lumen-apposing stents (LAMS) is limited by the size of the common bile duct (CBD) (≤ 12 mm, cut-off for experts; 15 mm, cut-off for non-experts). We aimed to assess the prevalence and predictive factors associated with CBD size ≥ 12 and 15 mm in naïve patients with malignant distal biliary obstruction (MDBO). Patients and methods  This was a prospective cohort study involving 22 centers with assessment of CBD diameter and subjective feasibility of the EUS-CDS performance in naïve jaundiced patients undergoing EUS evaluation for MDBO. Results  A total of 491 patients (mean age 69 ± 12 years) with mean serum bilirubin of 12.7 ± 6.6 mg/dL entered the final analysis. Dilation of the CBD ≥ 12 and 15 mm was detected in 78.8 % and 51.9 % of cases, respectively. Subjective feasibility of EUS-CDS was expressed by endosonographers in 91.2 % for a CBD ≥ 12 mm and in 96.5 % for a CBD ≥ 15 mm. On multivariate analysis, age ( P  < 0.01) and bilirubin level ( P  ≤ 0.001) were the only factors associated with both CBD dilation ≥ 12 and ≥ 15 mm. These variables were poorly associated with the extent of duct dilation; however, based on them a prediction model could be constructed that satisfactorily predicted CBD size ≥ 12 mm in patients at least 70 years and a bilirubin level ≥ 7 mg/dL. Conclusions  Our study showed that at presentation in a large cohort of patients with MDBO, EUS-CDS can be potentially performed in three quarters to half of cases by expert and less experienced endosonographers, respectively. Dedicated stents or devices with different designs able to overcome the limitations of existing electrocautery-enhanced LAMS for EUS-CDS are needed.

Novel 1-L polyethylene glycol + ascorbate versus high-volume polyethylene glycol regimen for colonoscopy cleansing: a multicenter, randomized, phase IV study

BACKGROUND AND AIMS

Adequate bowel cleansing is critical to ensure quality and safety of a colonoscopy. A novel 1-L polyethylene glycol plus ascorbate (1L-PEG+ASC) regimen was previously validated against low-volume regimens but was never compared with high-volume regimens.

METHODS

In a phase IV study, patients undergoing colonoscopy were randomized 1:1 to receive split-dose 1L PEG+ASC or a split-dose 4-L PEG-based regimen (4L-PEG) in 5 Italian centers. Preparation was assessed with the Boston Bowel Preparation Scale (BBPS) by local endoscopists and centralized reading, both blinded to the randomization arm. The primary endpoint was noninferiority of 1L-PEG+ASC in colon cleansing. Secondary endpoints were superiority of 1L-PEG+ASC, patient compliance, segmental colon cleansing, adenoma detection rate, tolerability, and safety.

RESULTS

Three hundred eighty-eight patients (median age, 59.8 years) were randomized between January 2019 and October 2019: 195 to 1L-PEG+ASC and 193 to 4L-PEG. Noninferiority of 1L-PEG+ASC was demonstrated for cleansing in both the entire colon (BBPS ≥ 6: 97.9% vs 93%; relative risk [RR], 1.03; 95% confidence interval [CI], 1.001-1.04; P superiority = .027) and in the right-sided colon segment (98.4% vs 96.0%; RR, 1.02; 95% CI, .99-1.02; P noninferiority = .013). Compliance was higher with 1L-PEG+ASC than with 4L-PEG (178/192 [92.7%] vs 154/190 patients [81.1%]; RR, 1.10; 95% CI, 1.05-1.12), whereas no difference was found regarding safety (moderate/severe side effects: 20.8% vs 25.8%; P = .253). No difference in adenoma detection rate (38.8% vs 43.0%) was found.

CONCLUSIONS

One-liter PEG+ASC showed noninferiority compared with 4L-PEG in achieving adequate colon cleansing and provided a higher patient compliance. No differences in tolerability and safety were detected. (Clinical trial registration number: NCT03742232.).

A multicenter survey on endoscopic retrograde cholangiopancreatography during the COVID-19 pandemic in northern and central Italy

Background and study aims  COVID-19 has dramatically impacted endoscopy practice because upper endoscopy procedures can be aerosol-generating. Most elective procedures have been rescheduled. Endoscopic retrograde cholangiopancreatography (ERCP) is frequently performed in emergency or urgent settings in which rescheduling is not possible. We evaluated the impact of the COVID-19 pandemic on ERCP in Italy during the SARS-CoV-2 lockdown, in areas with high incidence of COVID-19. Patients and methods  We performed a retrospective survey of centers performing ERCP in high COVID-19 prevalence areas in Italy to collect information regarding clinical data from patients undergoing ERCP, staff, case-volume and organization of endoscopy units from March 8, 2020 to April 30, 2020. Results  We collected data from 31 centers and 804 patients. All centers adopted a triage and/or screening protocol for SARS-CoV-2 and performed follow-up of patients 2 weeks after the procedure. ERCP case-volume was reduced by 44.1 % compared to the respective 2019 timeframe. Of the 804 patients undergoing ERCP, 22 (2.7 %) were positive for COVID-19. Adverse events occurred at a similar rate to previously published data. Of the patients, endoscopists, and nurses, 1.6 %, 11.7 %, and 4.9 %, respectively, tested positive for SARS-CoV-2 at follow up. Only 38.7 % of centers had access to a negative-pressure room for ERCP. Conclusion  The case-volume reduction for ERCP during lockdown was lower than for other gastrointestinal endoscopy procedures. No definitive conclusions can be drawn about the percentage of SARS-CoV-2-positive patients and healthcare workers observed after ERCP. Appropriate triage and screening of patients and adherence to society recommendations are paramount.

Artificial Intelligence in Lower Gastrointestinal Endoscopy: The Current Status and Future Perspective

The present manuscript aims to review the history, recent advances, evidence, and challenges of artificial intelligence (AI) in colonoscopy. Although it is mainly focused on polyp detection and characterization, it also considers other potential applications (i.e., inflammatory bowel disease) and future perspectives. Some of the most recent algorithms show promising results that are similar to human expert performance. The integration of AI in routine clinical practice will be challenging, with significant issues to overcome (i.e., regulatory, reimbursement). Medico-legal issues will also need to be addressed. With the exception of an AI system that is already available in selected countries (GI Genius; Medtronic, Minneapolis, MN, USA), the majority of the technology is still in its infancy and has not yet been proven to reach a sufficient diagnostic performance to be adopted in the clinical practice. However, larger players will enter the arena of AI in the next few months.

Usefulness of virtual chromoendoscopy in the evaluation of subtle small bowel ulcerative lesions by endoscopists with no experience in videocapsule

BACKGROUND AND STUDY AIMS

In videocapsule endoscopy examination (VCE), subtle variations in mucosal hue or pattern such as those seen in ulcerations can be difficult to detect, depending on the experience of the reader. Our aim was to test whether virtual chromoendoscopy (VC) techniques, designed to enhance the contrast between the lesion and the normal mucosa, could improve the characterization of ulcerative mucosal lesions.

PATIENTS AND METHODS

Fifteen trainees or young gastroenterologists with no experience in VCE were randomly assigned to evaluate 250 true ulcerative and 100 false ulcerative, difficult-to-interpret small bowel lesions, initially as white light images (WLI) and then, in a second round, with the addition of one VC setting or again as WLI, labeling them as real lesions or artifacts.

RESULTS

On the overall image evaluation, an improvement in lesion characterization was observed by adding any chromoendoscopy setting, especially Blue mode and FICE 1, with increases in accuracy of 13 % [95 %CI 0.8, 25.3] and 7.1 % [95 %CI - 17.0, 31.3], respectively. However, when only false ulcerative images were considered, with the same presets (Blue mode and FICE 1), there was a loss in accuracy of 10.7 % [95 %CI - 10.9, 32.3] and 7.3 % [95 %CI - 1.3, 16.0], respectively. The interobserver agreement was poor for both readings.

CONCLUSIONS

VC helps beginner VCE readers correctly categorize difficult-to-interpret small bowel mucosal ulcerative lesions. However, false lesions tend to be misinterpreted as true ulcerative with the same presets. Therefore care is advised in using VC especially under poor bowel preparation.

Colon capsule versus CT colonography in patients with incomplete colonoscopy: a prospective, comparative trial

OBJECTIVE

In case of incomplete colonoscopy, several radiologic methods have traditionally been used, but more recently, capsule endoscopy was also shown to be accurate. Aim of this study was to compare colon capsule endoscopy (CCE) and CT colonography (CTC) in a prospective cohort of patients with incomplete colonoscopy.

DESIGN

Consecutive patients with a previous incomplete colonoscopy underwent CCE and CTC followed by colonoscopy in case of positive findings on either test (polyps/mass lesions ≥6 mm). Clinical follow-up was performed in the other cases to rule out missed cancer. CTC was performed after colon capsule excretion or 10-12 h postingestion. Since the gold standard colonoscopy was performed only in positive cases, diagnostic yield and positive predictive values of CCE and CTC were used as study end-points.

RESULTS

100 patients were enrolled. CCE and CTC were able to achieve complete colonic evaluation in 98% of cases. In a per-patient analysis for polyps ≥6 mm, CCE detected 24 patients (24.5%) and CTC 12 patients (12.2%). The relative sensitivity of CCE compared to CTC was 2.0 (95% CI 1.34 to 2.98), indicating a significant increase in sensitivity for lesions ≥6 mm. Of larger polyps (≥10 mm), these values were 5.1% for CCE and 3.1% for CTC (relative sensitivity: 1.67 (95% CI 0.69 to 4.00)). Positive predictive values for polyps ≥6 mm and ≥10 mm were 96% and 85.7%, and 83.3% and 100% for CCE and CTC, respectively. No missed cancer occurred at clinical follow-up of a mean of 20 months.

CONCLUSIONS

CCE and CTC were of comparable efficacy in completing colon evaluation after incomplete colonoscopy; the overall diagnostic yield of colon capsule was superior to CTC.

TRIAL REGISTRATION NUMBER

NCT01525940.

Colon capsule endoscopy: What we know and what we would like to know

Colonoscopy is usually perceived as an invasive and potentially painful procedure, being also affected by a small, but definite, risk of major complications (cardiopulmonary complications, perforation, hemorrhage) and even mortality. To improve both acceptability and safety, PillCam Colon Capsule Endoscopy (CCE) (Given Imaging Ltd, Yoqneam, Israel) has been developed. CCE represents a non-invasive technique that is able to explore the colon without sedation and air insufflation. The Second Generation of Colon Capsule Endoscopy (PillCam Colon 2) (CCE-2) was proven to be an accurate tool to detect colonic neoplastic lesions when used in average risk individuals. To date, the evidence supports the use of CCE-2 in case of colonoscopy failure, in patients unwilling to perform colonoscopy and when colonoscopy is contraindicated. Other potential applications, such as colorectal cancer screening or diagnostic surveillance of inflammatory bowel disease need to be clarified. In this paper, the current “state of the art”, potential application of CCE and future needs are evaluated.

Accuracy and safety of second-generation PillCam COLON capsule for colorectal polyp detection

PillCam COLON capsule endoscopy (CCE) (Given Imaging Ltd, Yoqneam, Israel) is one of the most recent diagnostic, endoscopic technologies designed to explore the colon. CCE is a noninvasive, patient-friendly technique that is able to explore the colon without requiring sedation and air insufflation. The first generation of CCE was released onto the market in 2006 and although it generated great enthusiasm, it showed suboptimal accuracy. Recently, a second-generation system (PillCam COLON 2) (CCE-2) has been developed to increase sensitivity for colorectal polyp detection. In this review, accuracy and safety data for CCE-2 are analyzed.