The anti-spasmodic effect of peppermint oil during colonoscopy: a systematic review and meta-analysis

Optimizing adenoma detection in screening-related colonoscopy

INTRODUCTION

Screening-related colonoscopy is a vital component of screening initiatives to both diagnose and prevent colorectal cancer (CRC), with prevention being reliant upon early and accurate detection of pre-malignant lesions. Several strategies, techniques, and interventions exist to optimize endoscopists' adenoma detection rates (ADR).

AREAS COVERED

This narrative review provides an overview of the importance of ADR and other colonoscopy quality indicators. It then summarizes the available evidence regarding the effectiveness of the following domains in terms of improving ADR: endoscopist factors, pre-procedural parameters, peri-procedural parameters, intra-procedural strategies and techniques, antispasmodics, distal attachment devices, enhanced colonoscopy technologies, enhanced optics, and artificial intelligence. These summaries are based on an electronic search of the databases Embase, Pubmed, and Cochrane performed on December 12, 2022.

EXPERT OPINION

Given the prevalence and associated morbidity and mortality of CRC, the quality of screening-related colonoscopy quality is appropriately prioritized by patients, endoscopists, units, and payers alike. Endoscopists performing colonoscopy should be up to date regarding available strategies, techniques, and interventions to optimize their performance.

Menthol: An underestimated anticancer agent

Menthol, a widely used natural, active compound, has recently been shown to have anticancer activity. Moreover, it has been found to have a promising future in the treatment of various solid tumors. Therefore, using literature from PubMed, EMBASE, Web of Science, Ovid, ScienceDirect, and China National Knowledge Infrastructure databases, the present study reviewed the anticancer activity of menthol and the underlying mechanism. Menthol has a good safety profile and exerts its anticancer activity via multiple pathways and targets. As a result, it has gained popularity for significantly inhibiting different types of cancer cells by various mechanisms such as induction of apoptosis, cell cycle arrest, disruption of tubulin polymerization, and inhibition of tumor angiogenesis. Owing to the excellent anticancer activity menthol has demonstrated, further research is warranted for developing it as a novel anticancer agent. However, there are limitations and gaps in the current research on menthol, and its antitumor mechanism has not been completely elucidated. It is expected that more basic experimental and clinical studies focusing on menthol and its derivatives will eventually help in its clinical application as a novel anticancer agent.

Does i-scan improve adenoma detection rate compared to high-definition colonoscopy? A systematic review and meta-analysis

Background and study aims  Recent studies evaluated the impact of i-scan in improving the adenoma detection rate (ADR) compared to high-definition (HD) colonoscopy. We aimed to systematically review and analyze the impact of this technique. Methods  A thorough search of the following databases was undertaken: PubMed/Medline, EMBASE, Cochrane and Web of Science. Full-text RCTs and cohort studies directly comparing i-scan and HD colonoscopy were deemed eligible for inclusion. Dichotomous outcomes were pooled and compared using random effects model and DerSimonian-Laird approach. For each outcome, relative risk (RR), 95 % confidence interval (CI), and P value was generated. P  < 0.05 was considered statistically significant. Results  A total of five studies with six arms were included in this analysis. A total of 2620 patients (mean age 58.6 ± 7.2 years and female proportion 44.8 %) completed the study and were included in our analysis. ADR was significantly higher with any i-scan (RR: 1.20, [CI: 1.06-1.34], P  = 0.003) compared to HD colonoscopy. Subgroup analysis demonstrated that ADR was significantly higher using i-scan with surface and contrast enhancement only (RR: 1.25, [CI: 1.07-1.47], P  = 0.004). Conclusions  i-scan has the potential to increase ADR using the surface and contrast enhancement method. Future studies evaluating other outcomes of interest such as proximal adenomas and serrated lesions are warranted.

L-Menthol for Gastrointestinal Endoscopy: A Systematic Review and Meta-Analysis

In randomized controlled trials, L-menthol inhibits gastrointestinal peristalsis during endoscopy. Our goal was to quantitatively synthesize the available evidence to evaluate the efficacy and safety of L-menthol for gastrointestinal endoscopy.

Do Water-aided Techniques Improve Serrated Polyp Detection Rate During Colonoscopy?: A Systematic Review With Meta-Analysis

BACKGROUND AND STUDY AIMS

The utility of water-aided techniques (WT): water exchange (WE) and water immersion (WI) have been studied extensively in the literature for improving colonoscopy outcome metrics such as adenoma detection rate. Serrated polyps owing to their location and appearance have a high miss rate. The authors performed a systematic review and meta-analysis of studies comparing WT with the standard gas-assisted (GA) method to determine if there was any impact on serrated polyp detection rate (SPDR) and sessile serrated polyp detection rate.

METHODS

The following databases were queried for this systematic review: Medline, EMBASE, Cochrane Library, CINAHL, and Web of Sciences. The authors only included randomized controlled trials (RCTs). The primary outcome was SPDR and secondary outcomes were sessile serrated polyp detection rate and cecal intubation rate. Risk ratios (RRs) were calculated for each outcome. A P-value <0.05 was considered to be statistically significant.

RESULTS

A total of 4 RCTs (5 arms) with 5306 patients (2571 in the GA group and 2735 in the WT group) were included. The SPDR was significantly increased for the WT group compared with GA (6.1% vs. 3.8%; RR, 1.63; 95% confidence interval, 1.24-2.13; P<0.001; I2=22.7%). A subgroup analysis for WE technique also demonstrated improved SPDR compared with the GA method (4.9% vs. 3.2%; RR, 1.57; 95% confidence interval, 1.15-2.14; P=0.004; I2=6.1%).

CONCLUSIONS

WT, particularly, the WE method results in improved SPDR. This technique should be encouraged in a clinical setting to detect these polyps to prevent interval colorectal cancer.

Efficacy of Endocuff Vision compared to first-generation Endocuff in adenoma detection rate and polyp detection rate in high-definition colonoscopy: a systematic review and network meta-analysis

Background and study aims  Recently, the newer Endocuff Vision (ECV) has been evaluated for improving colonoscopy outcome metrics such as adenoma detection rate (ADR) and polyp detection rate (PDR). Due to lack of direct comparative studies between ECV and original Endocuff (ECU), we performed a systematic review and network meta-analysis to evaluate these outcomes. Methods  The following databases were searched: PubMed, Embase, Cochrane, and Web of Sciences to include randomized controlled trials (RCTs) comparing ECV or ECU colonoscopy to high-definition (HD) colonoscopy. Direct as well as network meta-analyses comparing ADR and PDR were performed using a random effects model. Relative-risk (RR) with 95 % confidence interval (CI) was calculated. Results  A total of 12 RCTs with 8638 patients were included in the final analysis. On direct meta-analysis, ECV did not demonstrate statistically improved ADR compared to HD colonoscopy (RR: 1.12, 95 % CI 0.99-1.27). A clinically and statistically improved PDR was noted for ECV compared to HD (RR: 1.15, 95 % CI 1.03-1.28) and ECU compared to HD (RR: 1.26, 95 % CI 1.09-1.46) as well as improved ADR (RR: 1.22, 95 % CI 1.05-1.43) was observed for ECU colonoscopy when compared to HD colonoscopy. These results were also consistent on network meta-analysis. Lower overall complication rates (RR: 0.14, 95 % CI 0.02-0.84) and particularly lacerations/erosions (RR: 0.11, 95 % CI 0.02-0.70) were noted with ECV compared to ECU colonoscopy. Conclusions  Although safe, the newer ECV did not significantly improve ADR compared to ECU and HD colonoscopy. Further device modification is needed to increase the overall ADR and PDR.

Comparing endoscopic interventions to improve serrated adenoma detection rates during colonoscopy: a systematic review and network meta-analysis of randomized controlled trials

OBJECTIVE

Serrated lesions (sessile serrated adenomas/polyps and traditional serrated adenomas) owing to their subtle appearance and proximal location have a high miss rate. The objective of this study is to compare all the available endoscopic interventions for improving serrated adenoma detection rate (SADR) through a network meta-analysis.

METHODS

We conducted a systematic review of the available literature (PubMed, Embase, Cochrane and WoS) from inception to 29 November 2019 to identify all the relevant randomized controlled trials. A total of 28 trials with 22 830 patients were included. The studies compared the efficacy of add-on devices (endocap, endocuff, endocuff vision, G-EYE, endorings, AmplifEYE), electronic chromoendoscopy (linked-color imaging, blue laser imaging, narrow band imaging), dye-based chromoendoscopy, full-spectrum endoscopy (FUSE) and water-based techniques (WBT) with each other or high-definition colonoscopy. Both pairwise and network meta-analysis was conducted using the random-effects model. Risk ratios (RR) with 95% confidence intervals (CI) and P-values were calculated.

RESULTS

Direct meta-analysis demonstrated superiority for WBT (RR: 1.41, CI: 1.01-1.98), add-on devices (RR: 1.53, CI: 1.13-2.08), narrow band imaging (RR: 1.93, CI: 1.12-3.32) and endocuff vision (RR: 1.87, CI: 1.13-3.11) compared to high-definition colonoscopy. The results were consistent on network meta-analysis with chromoendoscopy as an additional modality for improving SADR (RR: 1.74, CI: 1.03-2.93).

CONCLUSION

In a network meta-analysis, add-on devices (particularly endocuff vision), narrow band imaging, WBT and chromoendoscopy were comparable to each other and improved SADR compared to high-definition colonoscopy.

Polyphenol Profile and Antimicrobial and Cytotoxic Activities of Natural Mentha × piperita and Mentha longifolia Populations in Northern Saudi Arabia

New sources of polyphenols with anticancer, antioxidant, and antimicrobial properties in arid environments are critical for the development of alternative medicines and natural remedies. This study explored the polyphenol profiles and biological activities of methanolic leaf extracts from natural Mentha × piperita and Mentha longifolia populations in northern Saudi Arabia. Chromatographic analyses identified several polyphenols in M. × piperita including phenolic acids: rosmarinic acid (1547.6 mg/100 g DW (dry weight)), cryptochlorogenic acid (91.7 mg/100 g DW), and chlorogenic acid (69.4 mg/100 g DW), as well as flavonoids: naringin (328.8 mg/100 g DW) and cynaroside (162.8 mg/100 g DW). The major polyphenols in M. longifolia were: rosmarinic acid (781.6 mg/100 g DW), cryptochlorogenic acid (191.1 mg/100 g DW), p-coumaric acid (113.0 mg/100 g DW), m-coumaric acid (112.2 mg/100 g DW), and chlorogenic acid (63.8 mg/100 g DW). M. × piperita and M. longifolia leaf extracts had high antioxidant activities due to the major polyphenols (cynaroside, rosmarinic and cryptochlorogenic acids). M. × piperita had higher activities against different cancer cells than M. longifolia. Naringin, cryptochlorogenic acid, and rosmarinic acid had the highest activities against cancer cells. The leaf extracts had antibacterial effects against most bacteria species (Pseudomonas aeruginosa was most sensitive), which was attributed to the polyphenols. Antifungal activities were similarly broad (Aspergillus flavus was most sensitive) and attributed to naringin, cryptochlorogenic acid, and caffeic acid. Populations of M. × piperita and M. longifolia in Northern Riyadh may be a valuable source of natural biologically active compounds.