New endoscopes and add-on devices to improve colonoscopy performance

Colonoscopy is the gold standard for colorectal cancer prevention; however, it is still an imperfect modality. Precancerous lesions can be lost during screening examinations, thus increasing the risk of interval cancer. A variety of factors either patient-, or endoscopist dependent or even the procedure itself may contribute to loss of lesions. Sophisticated modalities including advanced technology endoscopes and add-on devices have been developed in an effort to eliminate colonoscopy's drawbacks and maximize its ability to detect potentially culprit polyps. Novel colonoscopes aim to widen the field of view. They incorporate more than one cameras enabling simultaneous image transmission. In that way the field of view can expand up to 330°. On the other hand a plethora of add-on devices attachable on the standard colonoscope promise to detect lesions in the proximal aspect of colonic folds either by offering a retrograde view of the lumen or by straightening the haustral folds during withdrawal. In this minireview we discuss how these recent advances affect colonoscopy performance by improving its quality indicators(cecal intubation rate, adenoma detection rate) and other metrics(polyp detection rate, adenomas per colonoscopy, polyp/adenoma miss rate) associated with examination's outcomes.

Gut microbiota and non-alcoholic fatty liver disease

BACKGROUND： Non-alcoholic fatty liver disease （NAFLD） is a common disorder with poorly understood pathogenesis. Beyond environmental and genetic factors, cumulative data support the causative role of gut microbiota in disease development and progression.

Colonoscopy attachments for the detection of precancerous lesions during colonoscopy:A review of the literature

Although colonoscopy has been proven effective in reducing the incidence of colorectal cancer through the detection and removal of precancerous lesions, it remains an imperfect examination, as it can fail in detecting up to almost one fourth of existing adenomas. Among reasons accounting for such failures, is the inability to meticulously visualize the colonic mucosa located either proximal to haustral folds or anatomic curves, including the hepatic and splenic flexures. In order to overcome these limitations, various colonoscope attachments aiming to improve mucosal visualization have been developed. All of them-transparent cap, Endocuff, Endocuff Vision and Endorings-are simply mounted onto the distal tip of the scope. In this review article, we introduce the rationale of their development, present their mode of action and discuss in detail the effect of their implementation in the detection of lesions during colonoscopy.

Effect of Endocuff use on colonoscopy outcomes: A systematic review and meta-analysis

BACKGROUND Endocuff-a plastic device with flexible projections-mounted on the distal tip of the colonoscope, promises improved colonic mucosa inspection.AIM To elucidate the effect of Endocuff on adenoma detection rate(ADR), advanced ADR(AADR) and mean number of adenomas per colonoscopy(MAC).METHODS Literature searches identified randomized-controlled trials evaluating Endocuffassisted colonoscopy(EAC) vs conventional colonoscopy(CC) in terms of ADR,AADR and MAC. The effect size on study outcomes was calculated using fixed or random effect model, as appropriate, and it is shown as relative risk(RR) [95%confidence interval(CI)] and mean difference(MD)(95%CI). The rate of device removal in EAC arms was also calculated.RESULTS We identified nine studies enrolling 6038 patients. All studies included mixed population(screening, surveillance and diagnostic examinations). Seven and two studies evaluated the first and the second-generation device, respectively. EAC was associated with increased ADR compared to CC [RR(95%CI): 1.18(1.05-1.32); Ι~2 = 71%]; EAC benefits more endoscopists with ADR ≤ 35% compared to those with ADR > 35% [RR(95%CI): 1.37(1.08-1.74); Ι~2 = 49% vs 1.10(0.99-1.24); Ι~2= 71%]. In terms of AADR and MAC, no difference was detected between EAC and CC [RR(95%CI): 1.03(0.85-1.25); Ι~2 = 15% and MD(95%CI): 0.30(-0.17-0.78);Ι~2 = 99%]. Subgroup analysis did not show any difference between the two device generations regarding all three endpoints. In EAC arms, the device had to be removed in 3%(95%CI: 2%-5%) of the cases mainly due to tortuous sigmoid or presence of diverticula along it.CONCLUSION EAC increases ADR compared to CC, especially for endoscopists with lower ADR. On the other hand, no significant effect on AADR and MAC was detected.

Artificial intelligence-aided colonoscopy:Recent developments and future perspectives

Artificial intelligence(AI)systems,especially after the successful application of Convolutional Neural Networks,are revolutionizing modern medicine.Gastrointestinal Endoscopy has shown to be a fertile terrain for the development of AI systems aiming to aid endoscopists in various aspects of their daily activity.Lesion detection can be one of the two main aspects in which AI can increase diagnostic yield and abilities of endoscopists.In colonoscopy,it is well known that a substantial rate of missed neoplasia is still present,representing the major cause of interval cancer.In addition,an extremely high variability in adenoma detection rate,the main key quality indicator in colonoscopy,has been extensively reported.The other domain in which AI is believed to have a considerable impact on everyday clinical practice is lesion characterization and aid in“optical diagnosis”.By predicting in vivo histology,such pathology costs may be averted by the implementation of two separate but synergistic strategies,namely the“leave-in-situ”strategy for<5 mm hyperplastic lesions in the rectosigmoid tract,and“resect and discard”for the other diminutive lesions.In this opinion review we present current available evidence regarding the role of AI in improving lesions’detection and characterization during colonoscopy.

An unusual case of prolonged post-endoscopic retrograde cholangiopancreatography jaundice

Despite the effectiveness of endoscopic retrograde cholangiopancreatography（ERCP） for the treatment of choledocholithiasis, various complications have been described. We herein report the first case of prolonged postERCP jaundice due to toxicity of the contrast agent Iobitridol（~174;XENETIX, Guerbet, Roissy Cd G Cedex, France） in a patient who underwent ERCP with sphincterectomy and common bile duct stone removal. While clinical improvement and normalization of aminotransferases and cholestatic enzymes after the procedure, an unexplained increase of direct bilirubin was noticed. A second ERCP was performed one week later, excluding possible remaining choledocholithiasis. Nevertheless, serum direct bilirubin increased further up to 15 mg/d L. Other potential causes of direct hyperbilirubinemia were ruled out and patient＇s liver biopsy was compatible with drug-induced liver toxicity. Additionally, the cause-result time connection between the use of Iobitridol and bilirubin increase indicated the possibility of a toxic effect related to the repeated use of the particular contrast agent. Iobitridol, a contrast agent, can induce prolonged direct hyperbilirubinemia.

Academic hospital staff compliance with a fecal immunochemical test-based colorectal cancer screening program

AIM: To measure the compliance of an Academic Hospital staff with a colorectal cancer(CRC) screening program using fecal immunochemical test(FIT).METHODS: All employees of 'Attikon' University General Hospital aged over 50 years were thoroughly informed by a team of physicians and medical students about the study aims and they were invited to undergo CRC screening using two rounds of FIT(DyoniFOB~ Combo H, DyonMed SA, Athens, Greece). The tests were provided for free and subjects tested positive were subsequently referred for colonoscopy. One year after completing the two rounds, participants were asked to be re-screened by means of the same test.RESULTS: Among our target population consisted of 211 employees, 59(27.9%) consented to participate, but only 41(19.4%) and 24(11.4%) completed the first and the second FIT round, respectively. Female gender was significantly associated with higher initial participation(P = 0.005) and test completion- first and second round-(P = 0.004 and P = 0.05) rates, respectively. Phy sician’s(13.5% vs 70.2%, P < 0.0001) participation and test completion rates(7.5% vs 57.6%, P < 0.0001 for the first and 2.3% vs 34%, P < 0.0001 for the second round) were significantly lower compared to those of the administrative/technical staff. Similarly, nurses participated(25.8% vs 70.2%, P = 0.0002) and completed the first test round(19.3% vs 57.6%, P = 0.004) in a significant lower rate than the administrative/technical staff. One test proved false positive. No participant repeated the test one year later.CONCLUSION: Despite the well-organized, guided and supervised provision of the service, the compliance of the Academic Hospital personnel with a FIT-based CRC screening program was suboptimal, especially among physicians.

COVID-19 in the endoscopy unit:How likely is transmission of infection?Results from an international,multicenter study

BACKGROUND Coronavirus disease 2019(COVID-19)significantly affected endoscopy practice,as gastrointestinal endoscopy is considered a risky procedure for transmission of infection to patients and personnel of endoscopy units(PEU).AIM To assess the impact of COVID-19 on endoscopy during the first European lockdown(March-May 2020).METHODS Patients undergoing endoscopy in nine endoscopy units across six European countries during the period of the first European lockdown for COVID-19(March-May 2020)were included.Prior to the endoscopy procedure,participants were stratified as low-or high-risk for potential COVID-19 infection according to the European Society of Gastrointestinal Endoscopy(ESGE)and the European Society of Gastroenterology and Endoscopy Nurses and Associates(ESGENA)joint statement,and contacted 7-14 d later to assess COVID-19 infection status.PEU were questioned regarding COVID-19 symptoms and/or infection via questionnaire,while information regarding hospitalizations,intensive care unitadmissions and COVID-19-related deaths were collected.The number of weekly endoscopies at each center during the lockdown period was also recorded.RESULTS A total of 1267 endoscopies were performed in 1222 individuals across nine European endoscopy departments in six countries.Eighty-seven(7%)were excluded because of initial positive testing.Of the 1135 pre-endoscopy low risk or polymerase chain reaction negative for COVID-19,254(22.4%)were tested post endoscopy and 8 were eventually found positive,resulting in an infection rate of 0.7%[95%CI:0.2-0.12].The majority(6 of the 8 patients,75%)had undergone esophagogastroduodenoscopy.Of the 163 PEU,5[3%;(95%CI:0.4-5.7)]tested positive during the study period.A decrease of 68.7%(95%CI:64.8-72.7)in the number of weekly endoscopies was recorded in all centers after March 2020.All centers implemented appropriate personal protective measures(PPM)from the initial phases of the lockdown.CONCLUSION COVID-19 transmission in endoscopy units is highly unlikely in a lockdown setting,provided endoscopies are restricted to emergency cases and PPM are implemented.

Endoscopic ultrasound fine-needle biopsy vs fine-needle aspiration for lymph nodes tissue acquisition:a systematic review and meta-analysis

Background:Endoscopic ultrasound(EUS)-guided tissue acquisition represents the choice of methods for suspected lymph nodes(LNs)located next to the gastrointestinal tract.This study aimed to compare the pooled diagnostic performance of EUS-guided fine-needle biopsy(EUS-FNB)and fine-needle aspiration(EUS-FNA)for LNs sampling.Methods:We searched PubMed/MedLine and Embase databases through August 2021.Primary outcome was diagnostic accuracy;secondary outcomes were sensitivity,specificity,sample adequacy,optimal histological core procurement,number of passes,and adverse events.We performed a pairwise meta-analysis using a random-effects model.The results are presented as odds ratio(OR)or mean difference along with 95%confidence interval(CI).Results:We identified nine studies(1,276 patients)in this meta-analysis.Among these patients,66.4%were male;the median age was 67 years.Diagnostic accuracy was not significantly different between the two approaches(OR,1.31;95%CI,0.81–2.10;P=0.270).The accuracy of EUS-FNB was significantly higher when being performed with newer end-cutting needles(OR,1.87;95%CI,1.17–3.00;P=0.009)and in abdominal LNs(OR,2.48;95%CI,1.52–4.05;P<0.001)than that of EUSFNA.No difference in terms of sample adequacy was observed between the two approaches(OR,1.40;95%CI,0.46–4.26;P=0.550);however,histological core procurement and diagnostic sensitivity with EUS-FNB were significantly higher than those with EUS-FNA(OR,6.15;95%CI,1.51–25.07;P=0.010 and OR,1.87;95%CI,1.27–2.74,P=0.001).The number of needle passes needed was significantly lower in the EUS-FNB group than in the EUS-FNA group(mean difference,-0.54;95%CI,-0.97 to -0.12;P=0.010).Conclusions EUS-FNA and EUS-FNB perform similarly in LN sampling;however,FNB performed with end-cutting needles outperformed FNA in terms of diagnostic accuracy.