Premedication with simethicone and N-acetylcysteine for improving mucosal visibility during upper gastrointestinal endoscopy in a Western population

Use of N-acetylcysteine plus simethicone to improve mucosal visibility in upper digestive endoscopy via systematic alphanumeric-coded endoscopy: a randomized, double-blind controlled trial

Background

The use of antifoaming and mucolytic agents prior to upper gastrointestinal (GI) endoscopy and a thorough systematic review are essential to optimize lesion detection. This study evaluated the effect of simethicone and N-acetylcysteine on the adequate mucosal visibility (AMV) of the upper GI tract by an innovative systematic method.

Methods

This randomized, double-blind controlled trial included consecutive patients who underwent diagnostic upper GI endoscopy for screening for early neoplasms between August 2019 and December 2019. The upper GI tract was systematically assessed by systematic alphanumeric-coded endoscopy. Patients were divided into 4 groups: 1) water; 2) only simethicone; 3) N-acetylcysteine + simethicone; and 4) only N-acetylcysteine. The following parameters were assessed in each group: age, sex, body mass index, level of adequate mucosal visibility, and side-effects.

Results

A total of 4564 images from upper GI areas were obtained for evaluation. The mean AMV in the 4 groups was 93.98±7.36%. The N-acetylcysteine + simethicone group had a higher cleaning percentage compared with the other groups (P=0.001). There was no significant difference among the remaining groups, but several areas had better cleaning when a mucolytic or antifoam alone was used. No side-effects were found in any group.

Conclusion

The combination of N-acetylcysteine plus simethicone optimizes the visibility of the mucosa of the upper GI tract, which could potentially increase diagnostic yield.

Current status of quality control in screening esophagogastroduodenoscopy and the emerging role of artificial intelligence

Esophagogastroduodenoscopy (EGD) screening is being implemented in countries with a high incidence of upper gastrointestinal (UGI) cancer. High-quality EGD screening ensures the yield of early diagnosis and prevents suffering from advanced UGI cancer and minimal operational-related discomfort. However, performance varied dramatically among endoscopists, and quality control for EGD screening remains suboptimal. Guidelines have recommended potential measures for endoscopy quality improvement and research has been conducted for evidence. Moreover, artificial intelligence offers a promising solution for computer-aided diagnosis and quality control during EGD examinations. In this review, we summarized the key points for quality assurance in EGD screening based on current guidelines and evidence. We also outline the latest evidence, limitations, and future prospects of the emerging role of artificial intelligence in EGD quality control, aiming to provide a foundation for improving the quality of EGD screening.

Pre-medication with simethicone and N-acetyl cysteine for improving mucosal visibility during upper gastrointestinal endoscopy: A randomized controlled trial

BACKGROUND AND AIM

Diagnostic performance of esophagogastroduodenoscopy (EGD) may be compromized due to adherent mucus and foam. In this study, we aimed at assessing the impact of premedication on mucosal visibility during endoscopy.

METHODS

This is a double-blinded (patient and investigator), randomized trial conducted at a tertiary care centre. Patients were randomized into four groups: A (water), B (simethicone [S]), C (N-acetyl cysteine [NAC]), D (S + NAC). Premedication solutions were administered 10-30 minutes before endoscopy and mucosal visibility graded from 1 (best) to 4 (worst) (1 best, 4 worst). Total mucosal visibility scores (TMVS) from six sites ranged from 6 (best) to 24 (worst) points. The primary outcome of study was comparison of TMVS between simethicone and combination (S + NAC) premedication groups. Secondary outcomes were adverse events and impact of endoscopy timing on TMVS.

RESULTS

Total 800 patients (39 years, 68.8% males) were randomized into four groups. Median TMVS were significantly lower in groups B (7 [6-8]) and D (8 [6-9]) as compared to A (11 [9-13]) and C (10 [8-12]). Proportion of cases with adequate gastric mucosal visibility (score < 7) was 26% in group A, 71% in group B, 36% in group C and 79% in group D. There was no difference in TMVS in groups A and C (p = 0.137). TMVS were significantly lower in late (> 20-30 minutes) vs. early (10-20 minutes) endoscopy sub-group (8 [7-11] vs, 9 ([7-11], p = 0.001). However, TMVS were similar between group B and group D in early endoscopy group (p = 0.451). There was no significant difference in the lesion detection rate among the different premedication drugs (p > 0.05).

CONCLUSIONS

Premedication with simethicone or combination (simethicone and NAC) significantly improves mucosal visibility during EGD. If early endoscopy is indicated, simethicone provides similar mucosal visibility and may be an effective alternative to combined premedication.

TRIAL REGISTRATION

NCT05951712.

Optimal timing of simethicone administration prior to upper endoscopy: A multicenter, single-blind, randomized controlled trial

Background and study aims Simethicone is useful as premedication for upper endoscopy because of its antifoaming effects. We aimed to evaluate the effect of timing of simethicone administration on mucosal visibility. Patients and methods In this multicenter, randomized, endoscopist-blinded study, patients scheduled for upper endoscopy were randomized to receive 40 mg simethicone at the following time points prior to the procedure: 20 to 30 minutes (early group), 0 to 10 minutes (late group) or 20 mg simethicone at both time points (split-dose group). Images were taken from nine predefined locations in the esophagus, stomach, and duodenum before endoscopic flushing. Each image was scored on mucosal visibility by three independent endoscopists on a 4-point scale (lower scores indicating better visibility), with adequate mucosal visibility defined as a score ≤ 2. Primary outcome was the percentage of patients with adequate total mucosal visibility (TMV), reached if all median subscores for each location were ≤ 2. Results A total of 386 patients were included (early group: 132; late group: 128; split-dose group: 126). Percentages of adequate TMV were 55%, 42%, and 61% in the early, late, and split-dose group, respectively ( P < 0.01). Adequate TMV was significantly higher in the split-dose group compared to the late group ( P < 0.01), but not compared to the early group ( P = 0.29). Differences between groups were largest in the stomach, where percentages of adequate mucosal visibility were higher in the early (68% vs 53%, P = 0.03) and split-dose group (69% vs 53%, P = 0.02) compared to the late group. Conclusions Mucosal visibility can be optimized with early simethicone administration, either as a single administration or in a split-dose regimen.

Computer-Based Diagnosis of Celiac Disease by Quantitative Processing of Duodenal Endoscopy Images

Celiac disease (CD) is a lifelong chronic autoimmune systemic disease that primarily affects the small bowel of genetically susceptible individuals. The diagnostics of adult CD currently rely on specific serology and the histological assessment of duodenal mucosa on samples taken by upper digestive endoscopy. Because of several pitfalls associated with duodenal biopsy sampling and histopathology, and considering the pediatric no-biopsy diagnostic criteria, a biopsy-avoiding strategy has been proposed for adult CD diagnosis also. Several endoscopic changes have been reported in the duodenum of CD patients, as markers of villous atrophy (VA), with good correlation with serology. In this setting, an opportunity lies in the automated detection of these endoscopic markers, during routine endoscopy examinations, as potential case-finding of unsuspected CD. We collected duodenal endoscopy images from 18 CD newly diagnosed CD patients and 16 non-CD controls and applied machine learning (ML) and deep learning (DL) algorithms on image patches for the detection of VA. Using histology as standard, high diagnostic accuracy was seen for all algorithms tested, with the layered convolutional neural network (CNN) having the best performance, with 99.67% sensitivity and 98.07% positive predictive value. In this pilot study, we provide an accurate algorithm for automated detection of mucosal changes associated with VA in CD patients, compared to normally appearing non-atrophic mucosa in non-CD controls, using histology as a reference.

Computer-Based Diagnosis of Celiac Disease by Quantitative Processing of Duodenal Endoscopy Images

Celiac disease (CD) is a lifelong chronic autoimmune systemic disease that primarily affects the small bowel of genetically susceptible individuals. The diagnostics of adult CD currently rely on specific serology and the histological assessment of duodenal mucosa on samples taken by upper digestive endoscopy. Because of several pitfalls associated with duodenal biopsy sampling and histopathology, and considering the pediatric no-biopsy diagnostic criteria, a biopsy-avoiding strategy has been proposed for adult CD diagnosis also. Several endoscopic changes have been reported in the duodenum of CD patients, as markers of villous atrophy (VA), with good correlation with serology. In this setting, an opportunity lies in the automated detection of these endoscopic markers, during routine endoscopy examinations, as potential case-finding of unsuspected CD. We collected duodenal endoscopy images from 18 CD newly diagnosed CD patients and 16 non-CD controls and applied machine learning (ML) and deep learning (DL) algorithms on image patches for the detection of VA. Using histology as standard, high diagnostic accuracy was seen for all algorithms tested, with the layered convolutional neural network (CNN) having the best performance, with 99.67% sensitivity and 98.07% positive predictive value. In this pilot study, we provide an accurate algorithm for automated detection of mucosal changes associated with VA in CD patients, compared to normally appearing non-atrophic mucosa in non-CD controls, using histology as a reference.

Administration of maximum dose of mucolytic solution before upper endoscopy - a double-blind, randomized trial

OBJECTIVE

The aim of the study was to demonstrate that an administration of mucolytic solution with a maximum dose of simethicone and n -acetylcysteine before upper endoscopy improves mucosal visibility compared to a group without administration of mucolytic solution or water.

METHODS

This study was a double-blind, randomized controlled trial. Patients were randomized into four groups, with the administration of 100 ml of water + 600 mg n -acetylcysteine + 400 mg simethicone, 100 ml of water + 400 mg n -acetylcysteine + 20 mg simethicone, 100 ml of water, and without any water or mucolytic solution. During the examination, a total of 10 images were taken in the defined areas. The overall visibility score was given by the sum of the 0-5 scores of the five areas and was assessed by the endoscopist performing the procedure and the blinded endoscopists using static images.

RESULTS

A total of 129 patients were randomized. The group of patients did not differ in age, sex distribution, and indications significantly. The overall visibility score as assessed by the endoscopist performing the procedure was significantly higher in the group with the maximum dose of mucolytic solution compared to the group without solution or water (18.9 ± 2.9 vs. 16.6 ± 3.3, P  = 0.023). This difference was not evident by the blinded evaluation of static photographs.

CONCLUSION

Administration of mucolytic solution with a maximum dose of n -acetylcysteine and simethicone before upper endoscopy improved mucosal visibility in the upper gastrointestinal tract compared with the group without any preparation while evaluated by performing endoscopist.

Impact of improved upper endoscopy quality on detection of gastric precancerous lesions

OBJECTIVE

Intestinal metaplasia (IM) is the point of no return in gastric carcinogenesis, and patients with extensive (antrum plus corpus) IM are at high risk of developing gastric cancer. We evaluated the impact of improved gastroscopy quality on the detection of gastric IM in an Italian area at high risk for gastric cancer.

METHODS

Data of consecutive patients with gastric biopsies according to the updated Sydney System observed in 2013, 2016 and 2019 resulting in IM diagnosis were retrieved. In the first period, endoscopy was performed with standard white light instruments. In the second period, preendoscopic gastric preparation was administered, and the examinations lasting at least 7 min with standard endoscopes were performed. In the third period, the latter procedure was followed, with virtual chromoendoscopy equipped instruments. The prevalence of IM in any gastric site and that of extensive IM were compared among the three periods.

RESULTS

Data of 3485 patients were available. The detection of IM in at least one gastric site increased from 29.9 to 33.6% and 34.5% (95% CI, 32.1-36.8) in the first, second and third period, respectively. The difference was statistically significant between the first and last (P = 0.02; OR, 1.24; 95% CI, 1.04-1.48) period. When considering extensive IM, the detection increased from 4.28 to 6.1% and 5.44%, although the difference failed to reach statistical significance (P = 0.076).

CONCLUSION

Our data showed that implementation of a quality protocol increased the probability to detect IM in the stomach, allowing us to select patients deserving stricter follow-up.

Minimizing the Risks of Simethicone in Endoscope Reprocessing

This statement was written under the auspices of the World Gastroenterology Organization's Guidelines Committee. The authors are members of the Review Team of the WGO Endoscope Disinfection Guideline and have experience in endoscopy, endoscope reprocessing, and microbiology, including biofilms. During the preparation of the WGO Update on Endoscope Disinfection Guidelines, concerns about simethicone on endoscope channel surfaces compromising cleaning and disinfection were raised. Publications on simethicone, including modes of delivery, effectiveness, and risks, have been reviewed. The paper was written as a companion to the new guidelines with a focus on minimizing the risks of simethicone in endoscope reprocessing.

Prospective cohort study to evaluate premedication with simethicone and n-acetilcysteine for upper diagnostic gastrointestinal endoscopy

INTRODUCTION

The use of premedication for upper gastrointestinal endoscopy (UGE) is not widely established in western countries. The primary aim of the study was to compare gastric visibility according to the total visibility score (TVS). The secondary aim was to assess complications, diagnostic yield, endoscopic procedure time, sedation dose and patient satisfaction.

METHODS

A single center prospective cohort study was performed of consecutive adults undergoing an UGE in the afternoon working shift. After completing enrolment in the control group, patients were administered 200 mg simethicone and 500 mg N-acetylcysteine diluted in 100 ml of water >15 minutes before the procedure. All procedures were recorded and a single, blinded endoscopist evaluated the TVS after recruitment of both cohorts. Patient satisfaction was evaluated using the Spanish translation of the American Society of Gastrointestinal Endoscopy satisfaction questionnaire.

RESULTS

205 patients were included in the study, 103 females (50.2%) with a median age of 54.8-years (IQR: 41.2-65.2). 104 were enrolled to the control group and 101 to the intervention group. Patients receiving premedication presented a higher rate of adequate (74.3% vs 45.2; difference 95% CI: 16,3-41,9%, p<0.001) and excellent gastric visibility (23.8% vs 7.7%; difference 95% CI: 6,3-25,8%, p=0.002). Propofol dose was similar, although the median procedure time was lower in the group of no intervention [5 (IQR: 4-7) vs 6 minutes (IQR: 5-7); p=0.03]. Procedure related adverse events were similar, except that patient without premedication experienced more nausea episodes. Major and minor endoscopic findings and the satisfaction questionnaire showed no differences between both groups.

CONCLUSION

Patients receiving premedication with simethicone and N-acetylcysteine had a better gastric visibility score, without any increase in adverse events or affecting the patients' satisfaction.

Quality performance measures in upper gastrointestinal endoscopy for lesion detection: Italian AIGO-SIED-SIGE joint position statement

Esophagogastroduodenoscopy (EGD) plays a crucial role in the management of gastroduodenal diseases by allowing a direct and accurate evaluation of the mucosa and the execution of several operative maneuvers. Despite a constant development of new imaging tools and operative devices, the widespread use of EGD has not resulted in a significant reduction of mortality for patients affected by esophageal/gastric cancer during the last three decades in Western countries. Evidence indicates that this disheartening scenario derives from a high variability of execution of EGD which determines its quality and diagnostic yield, delaying the diagnosis of neoplastic diseases. Based on this evidence, in recent years many scientific societies have produced different position papers aimed at defining quality performance measures in EGD. Thus, the Italian Association of Gastroenterologists and Endoscopists, the Italian Society of Digestive Endoscopy and the Italian Society of Gastroenterology have produced this joint document based on the review of ASGE, ACG, BSG, ESGE and Asian Consensus EGD position papers with the aim of indicating the quality standards of EGD (pre-, intra- and post-procedure) focused on lesion detection to be adopted in the Italian context.

Premedication with simethicone for improving the quality of gastric mucosal visualization: a double-blind randomized controlled trial

Background and study aims  Saliva, bubbles, or mucus can limit gastric mucosal visualization (GMV), increasing the risk of missed lesions such as gastric cancer. Several studies using endoscopy photodocumentation-based scores have reported increased quality of GMV when mucolytic and/or defoaming agents are administered. This single-center, prospective, double-blind, randomized, placebo-controlled trial aimed to evaluate whether simethicone administration could improve GMV. Patients and methods  Patients were randomly assigned (1:1) to receive either 200 mg of simethicone (Group A) or placebo (Group B). Two independent endoscopists reviewed the entire video recording from each examination to assess the quality of GMV. The primary outcome was the rate of adequate GMV, defined as the percentage of patients in each group with a video score scale < 7 based on gastric visualization of five gastric landmarks. Secondary outcomes included procedure duration, patient satisfaction, and side effects. Results  A total of 110 consecutive outpatients were randomly assigned to one of the two study groups (11 were excluded for various reasons). For the primary endpoint, 32 patients (61.5 %) in group A achieved adequate GMV compared to one of 47 (2.1 %) in group B (odds ratio [95 % confidence interval]: 73.6 [9.4-576.6]; P  < 0.001). Median procedure time did not differ between the groups ( P  = 0.55), and no differences were detected in patient satisfaction ( P  = 0.18) or side effects ( P  = 0.58). No serious adverse events were documented. Conclusions  Premedication with simethicone before upper gastrointestinal endoscopy significantly improves the quality of GMV without affecting the duration of the examination, patient satisfaction, and the rate of side effects.

Scoring system assessing mucosal visibility of upper gastrointestinal tract: The POLPREP scale

BACKGROUND AND AIM

The proper visibility of mucosa during esophagogastroduodenoscopy (EGD) is crucial for the detection of early upper gastrointestinal tract lesions. In contrast to colonoscopy, no validated scoring system for the assessment of upper gastrointestinal mucosal cleanliness has been developed so far. The aim of the study was to create and validate standardized grading system (POLPREP) to assess the mucosal cleanliness during EGD.

METHODS

To assess the visibility of mucosa during EGD, 4-point scale was developed (0-3). Twelve operators assessed 18 images of esophagus, stomach, and duodenum twice (in 2 weeks interval). In validation round, the images and endoscopy reports of 443 EGDs performed in six centers were assessed.

RESULTS

The inter-observer accordance of POLPREP was 0.8 (intra-class correlation coefficient; 0.79 consultants, 0.85 trainees). The intra-observer repeatability was 0.64 (Fleiss kappa value; 0.64 consultants, 0.64 trainees). The lesions detection rate was significantly higher in clean (scores 2 and 3; 19.7%) than in "unclean" segments (score 1; 7.7%, P = 0.049). Score 3 was associated with over three-fold higher lesion detection than score 1 (odds ratio 3.2, 95% confidence interval 1.1-9; P = 0.03).

CONCLUSIONS

The proposed POLPREP scale allows for unified assessment of upper gastrointestinal tract mucosal cleanliness. The higher cleanliness scores are related with greater upper gastrointestinal pathologies detection.

N-Acetylcysteine (NAC): Impacts on Human Health

N-acetylcysteine (NAC) is a medicine widely used to treat paracetamol overdose and as a mucolytic compound. It has a well-established safety profile, and its toxicity is uncommon and dependent on the route of administration and high dosages. Its remarkable antioxidant and anti-inflammatory capacity is the biochemical basis used to treat several diseases related to oxidative stress and inflammation. The primary role of NAC as an antioxidant stems from its ability to increase the intracellular concentration of glutathione (GSH), which is the most crucial biothiol responsible for cellular redox imbalance. As an anti-inflammatory compound, NAC can reduce levels of tumor necrosis factor-alpha (TNF-α) and interleukins (IL-6 and IL-1β) by suppressing the activity of nuclear factor kappa B (NF-κB). Despite NAC's relevant therapeutic potential, in several experimental studies, its effectiveness in clinical trials, addressing different pathological conditions, is still limited. Thus, the purpose of this chapter is to provide an overview of the medicinal effects and applications of NAC to human health based on current therapeutic evidence.