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During COVID-19, restrictions to elective endoscopy were introduced worldwide. A reduction in procedures may impact trainees' endoscopy learning. This study aims to assess Australian advanced gastroenterology and general surgery trainees' self-perceived efficacy and knowledge in endoscopy during the pandemic.All Australian gastroenterology and general surgery trainees in their last 2 years of accredited training were invited to participate through email (2020-2021 and 2021-2022 training cycles). The primary outcome was to assess trainees' self-efficacy and knowledge regarding gastrointestinal endoscopy. Secondary outcomes included subgroup analysis between gastroenterology and general surgery trainees. Self-perceived efficacy was assessed with Likert-scale questions on 20 endoscopy procedures and knowledge was assessed through 21 endoscopy-related multiple choice questions.Eighty-one trainees responded to a self-efficacy questionnaire and 77 responded to the knowledge questionnaire. Over 90% of the trainees were confident or extremely confident in diagnostic endoscopy, but only half demonstrated similar efficacy for therapeutic endoscopy. The efficacy for basic endoscopy procedures was higher for gastroenterology trainees (64.0%During COVID-19, endoscopy trainees' self-efficacy in endoscopic diagnostic procedures was achieved for most trainees. The differences in self-perceived efficacy and knowledge between gastroenterology and surgical trainees may be reflective of the different opportunities for learning between the two groups.

BACKGROUND AND AIM Cholecystectomy and endoscopic retrograde cholangiopancreatography are the gold standard for managing acute cholecystitis and malignant biliary obstruction, respectively. Recent advances in therapeutic endoscopic ultrasound (EUS) have provided alternatives for managing patients in whom these approaches fail, namely, EUS-guided gallbladder drainage (EUS-GB) and EUS-guided bile duct drainage (EUS-BD). We aimed to assess the technical and clinical success of these techniques in the largest multicenter cohort published to date. METHODS A retrospective, multicenter, observational study involving 17 centers across Australia and New Zealand was conducted. All patients who had EUS-GB or EUS-BD performed in a participating center using a lumen apposing metal stent between 2016 and 2020 were included. Primary outcome was technical success, defined as intra-procedural successful drainage. Secondary outcomes included clinical success and 30-day mortality. RESULTS One hundred and fifteen patients underwent EUS-GB (n = 49) or EUS-BD (n = 66). EUS-GB was technically successful in 47 (95.9%) while EUS-BD was successful in 60 (90.9%). All failed cases were due to maldeployment of the distal flange outside of the targeted lumen. Clinical success of EUS-GB was achieved in 39 (79.6%). No patients required subsequent cholecystectomy. Clinical success of EUS-BD was achieved in 52 (78.8 %). Thirty-day mortality was 14.3% for EUS-GB and 12.1% for EUS-BD. CONCLUSIONS EUS-guided gallbladder drainage and EUS-BD are promising alternatives for managing nonsurgical candidates with cholecystitis and malignant biliary obstruction following failed endoscopic retrograde pancreatography. Both techniques delivered high technical success with acceptable clinical success. Further research is needed to investigate the gap between technical and clinical success.

Background and Aim Telehealth has become the standard of care during the COVID‐19 outbreak. This study aimed to assess doctor and patient satisfaction of endoscopy‐related telehealth clinics with video consultations. Methods A prospective observational study of patients consecutively booked to attend two endoscopy‐related telehealth clinics at an ambulatory tertiary care setting was conducted from July to October 2020. Data collected from our previously published study using phone consultations (data collected in April–May 2020) were used as a control arm. The primary outcome (satisfaction) was assessed through the six‐question score (6Q_score) as per previous research. Secondary outcomes included failure‐to‐attend (FTA) rate and perceived necessity of physical examination/in‐person follow‐up appointment. Results There were 962 endoscopy clinic appointments between July and October, of which 157 were conducted through video. Data on 127 doctor questionnaires and 94 patient questionnaires were analyzed. The median age (years) of patients reviewed via video [57, interquartile range (IQR) 48–66] was lower than those reviewed via phone (65, IQR 55–74, P, The COVID‐19 pandemic has drastically changed the manner we deliver outpatient consultations with most hospitals shifting to telehealth as the preferred method. However, little is known about patient and doctor satisfaction with telehealth, especially when comparing its different modalities. Our study has demonstrated superior satisfaction with video consults compared to phone consults for telehealth endoscopy‐related clinics during the COVID‐19 pandemic.

Background and Aims Endoscopy guidelines recommend adhering to policies such as resect and discard only if the optical biopsy is accurate. However, accuracy in predicting histology can vary greatly. Computer-aided diagnosis (CAD) for characterization of colorectal lesions may help with this issue. In this study, CAD software developed at the University of Adelaide (Australia) that includes serrated polyp differentiation was validated with Japanese images on narrow-band imaging (NBI) and blue-laser imaging (BLI). Methods CAD software developed using machine learning and densely connected convolutional neural networks was modeled with NBI colorectal lesion images (Olympus 190 series - Australia) and validated for NBI (Olympus 290 series) and BLI (Fujifilm 700 series) with Japanese datasets. All images were correlated with histology according to the modified Sano classification. The CAD software was trained with Australian NBI images and tested with separate sets of images from Australia (NBI) and Japan (NBI and BLI). Results An Australian dataset of 1235 polyp images was used as training, testing, and internal validation sets. A Japanese dataset of 20 polyp images on NBI and 49 polyp images on BLI was used as external validation sets. The CAD software had a mean area under the curve (AUC) of 94.3% for the internal set and 84.5% and 90.3% for the external sets (NBI and BLI, respectively). Conclusions The CAD achieved AUCs comparable with experts and similar results with NBI and BLI. Accurate CAD prediction was achievable, even when the predicted endoscopy imaging technology was not part of the training set.

Background and Aim Electric burns can induce fibrinolytic activity. Endoscopic mucosal resection (EMR) is a minimally invasive technique utilizing electrocautery for resection of dysplastic lesions from the gastrointestinal tract. EMR's main complication is clinically significant postendoscopic bleeding. Currently, no studies have investigated the impact of electrocautery during EMR on the coagulation cascade by viscoelastic hemostatic assay. Methods Thrombelastometry was performed and plasminogen levels were measured on blood samples taken prior to EMR, within an hour following the procedure and 2 days post‐EMR. Data were natural log‐transformed and analyzed using repeated‐measure analysis of covariance (ANCOVA) accounting for age, sex, body mass index (BMI) and site of EMR. Results Plasminogen levels decreased post‐EMR (P = 0.001) and then increased 2 days post‐EMR (P, Decreased post‐EMR plasminogen corresponded with decreased clot firmness and enhanced lysis. We suspect plasminogen activation may lead to fibrinogen utilization and our results highlight the possible utility of incorporating point of care testing in assessing fibrinolytic activity in EMR.

Background and Aim Endoscopic submucosal dissection (ESD) is a challenging procedure. A dissection speed of ≥9 cm2/h has been acknowledged as a mark for expertise, alongside a complication rate of ≤5% and en bloc resection rate of ≥90%. However, there is lack of objective information on whether the three measures correlate with each other. This study aims to evaluate the dissection speed, safety, and efficacy of colorectal ESDs performed by experts and trainees. Methods Consecutive patients undergoing colorectal ESD at a Japanese hospital (2006–2017) were included in a prospectively collected database. Information on patient demographics, proceduralist, and intra‐/postprocedure data was retrieved. The primary outcome was the comparison in dissection speed. The secondary outcomes included differences in safety and efficacy. Log‐linear regression models adjusted for confounders (e.g. R0 resection) were used to assess the differences in dissection speed. Results Five hundred ninety procedures (514 patients) performed by 26 endoscopists were analyzed. Experts performed a higher number of difficult lesions (e.g. F2 fibrosis) but achieved higher dissection speed (10.3 vs 6.7 cm2/h). The difference was statistically significant for both unadjusted and adjusted models (P, Endoscopic submucosal dissection (ESD) expertise is commonly measured through dissection speed, en bloc resection, and complication rates. However, it is unclear whether the slower pace during ESD training is necessarily accompanied by worst outcomes regarding efficacy and safety. This study found that colorectal ESD can be safely and efficaciously performed by ESD trainees.

BACKGROUND Image-guided radiotherapy (IGRT) has significantly improved the precision in which radiotherapy is delivered in cancer treatment. Typically, IGRT uses bony landmarks and key anatomical structures to locate the tumor. Recent studies have demonstrated the feasibility of peri-tumor fiducials in enabling even more accurate delineation of target and normal tissue. The use of gold coils as fiducials in gastrointestinal tumors has been extensively studied. However, placement requires expertise and specialized endoscopic ultrasound equipment. This article reports the long-term outcomes of using a standard gastroscopy to inject liquid fiducials for the treatment of oesophageal and gastric tumors with IGRT. AIM To assess the long-term outcomes of liquid fiducial-guided IGRT in a cohort of oesophageal and gastric cancer patients. METHODS A retrospective cohort study of consecutive adults with Oesophagogastric cancers referred for liquid fiducial placement before definitive/neo-adjuvant or palliative IGRT between 2013 and 2021 at a tertiary hospital in Melbourne, Australia was conducted. Up to four liquid fiducials were inserted per patient, each injection consisting of 0.2-0.5mL of a 1:1 mixture of iodized oil (Lipiodol; Aspen Pharmacare) and n-butyl 2-cyanoacrylate (Histoacryl®; B. Braun). A 23-gauge injector (Cook Medical) was used for the injection. All procedures were performed by or under the supervision of a gastroenterologist. Liquid fiducial-based IGRT (LF-IGRT) consisted of computer-assisted direct matching of the fiducial region on cone-beam computerised tomography at the time of radiotherapy. Patients received standard-IGRT (S-IGRT) if fiducial visibility was insufficient, consisting of bone match as a surrogate for tumor position. Radiotherapy was delivered to 54Gy in 30 fractions for curative patients and up to 45Gy in 15 fractions for palliative treatments. RESULTS 52 patients were referred for liquid fiducial placement within the study period. A total of 51 patients underwent liquid fiducial implantation. Of these a total of 31 patients received radiotherapy. Among these, the median age was 77.4 years with a range between 57.5 and 88.8, and 64.5% were male. Twenty-seven out of the 31 patients were able to have LF-IGRT while four had S-IGRT. There were no complications after endoscopic implantation of liquid fiducials in our cohort. The cohort overall survival (OS) post-radiotherapy was 19 mo (range 0 to 87 mo). Whilst the progression-free survival (PFS) post-radiotherapy was 13 mo (range 0 to 74 mo). For those treated with curative intent, the median OS was 22.0 mo (range 0 to 87 mo) with a PFS median of 14.0 mo (range 0 to 74 mo). Grade 3 complication rate post-radiotherapy was 29%. CONCLUSION LF-IGRT is feasible in 87.1% of patients undergoing liquid fiducial placement through standard gastroscopy injection technique. Our cohort has an overall survival of 19 mo and PFS of 13 mo. Further studies are warranted to determine the long-term outcomes of liquid-fiducial based IGRT.

BACKGROUND AND AIM Microbiota have been associated with several diseases including colorectal cancer (CRC). This study aimed to evaluate the microbiota in early/invasive CRC utilizing stool and cytological brushes to determine differences in relative abundance (RA). METHODS Colonoscopy patients referred for endoscopic submucosal dissection or previous to CRC surgery were prospectively enrolled. Stool was collected pre-bowel preparation; and brush samples were taken during colonoscopy (three regions). DNA extraction, 16S rRNA next generation sequencing, and biostatistics (qiime and stamp software packages) followed. Primary outcome was the difference in RA of the Fusobacterium genus between the groups. Secondary outcomes included analyses of other microbiota. RESULTS Twenty-five patients were included, of which 14 had invasive cancer (≥ 1000 mm into the submucosa). The three major genera for invasive cancer were Bacterioides, Oribacterium, and Fusobacterium, whereas for early cancer were Oribacterium, Bacterioides, and Prevotella (decreasing order of RA). There was a significantly higher RA of Fusobacterium in the invasive cancer group (9.65% vs 0.95%, respectively, P

Introduction Narrow-band imaging with magnification endoscopy (NBI-ME) allows real-time visual assessment of the mucosal surface and vasculature of the gastrointestinal tract. This study aimed to determine the performance of NBI-ME combined with the water immersion technique (NBI-ME-WIT) in detecting villous atrophy. Methods All patients who underwent gastroscopy were included. The duodenum was further examined with NBI-ME-WIT only after examination with white light endoscopy did not reveal a cause of anaemia or dyspepsia. Targeted biopsies were taken of visualised areas. NBI-ME-WIT findings were compared with the final histopathological analysis. We calculated the sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of NBI-ME-WIT in detecting villous atrophy and the hypothetical cost saved by using a biopsy-avoiding approach. Results 124 patients (83 female) with a mean age of 46 (range 18-82) years were included. The most common indication for gastroscopy was abdominal pain (39%), followed by anaemia (35%), chronic diarrhoea/altered bowel habits (19%) and dyspepsia (6%). NBI-ME-WIT was able to detect all nine patients with villous atrophy - eight patchy and one total villous atrophy. The Sn, Sp, PPV and NPV of NBI-ME-WIT in detecting villous atrophy were 100.0%, 99.1%, 90.0% and 100.0%, respectively. Taking into account the cost of biopsy forceps (AUD 17) and pathology (AUD 140), this biopsy-avoidance strategy could have saved AUD 18,055 in these patients. Conclusion NBI-ME-WIT is a specific and sensitive tool to recognise and accurately diagnose villous atrophy. Biopsies can be avoided in patients with normal-sized villi, which may decrease the overall cost of the procedure.

BACKGROUND AND AIM Adenoma detection rate (ADR) is an important quality metric in colonoscopy. However, there is conflicting evidence around factors that influence ADR. This study aims to investigate the effect of time of day and endoscopist background on ADR and sessile serrated adenoma/polyp detection rate (SSA/P-DR) for screening colonoscopies. METHODS Consecutive patients undergoing colonoscopy in 2016 were retrospectively evaluated. Primary outcome was the effect of time of day and endoscopist specialty on screening ADR. Secondary outcomes included evaluation of the same factors on SSA/P-DR and other metrics and collinearity of ADR and SSA/P-DR. Linear regression models were used for association between ADR, time of day, and endoscopist background. Bowel preparation, endoscopist, session, patient age, and gender were adjusted for. Linear regression model was also used for comparing ADR and SSA/P-DR. Chi-square was used for difference of proportions. RESULTS Two thousand six hundred fifty-seven colonoscopies, of which 558 were screening colonoscopies, were performed. The adjusted mean ADR (screening) was 36.8% in the morning compared with 30.5% in the afternoon (P

Upper gastrointestinal bleeding from oesophageal or gastric varices is an important medical condition in patients with portal hypertension. Despite the emergence of a number of novel endoscopic and radiologic therapies for oesophagogastric varices, controversy exists regarding the indication, timing and modality of therapy. The aim of this review is to provide a concise and practical evidence-based overview of these issues.

BACKGROUND AND AIM Endoscopic surveillance for dysplasia in Barrett's esophagus (BE) with random biopsies is the primary diagnostic tool for monitoring clinical progression into esophageal adenocarcinoma. As an alternative, narrow-band imaging (NBI) endoscopy offers targeted biopsies that can improve dysplasia detection. This study aimed to evaluate NBI-guided targeted biopsies' diagnostic accuracy for detecting dysplasia in patients undergoing endoscopic BE surveillance compared with the widely used Seattle protocol. METHODS Cochrane DTA Register, MEDLINE/PubMed, EMBASE, OpenGrey, and bibliographies of identified papers were searched until 2018. Two independent investigators resolved discrepancies by consensus, study selection, data extraction, and quality assessment. Data on sensitivity, specificity, and predictive values were pooled and analyzed using a random-effects model. RESULTS Of 9528 identified articles, six studies comprising 493 participants were eligible for quantitative synthesis. NBI-targeted biopsy showed high diagnostic accuracy in detection of dysplasia in BE with a sensitivity of 76% (95% confidence interval [CI]: 0.61-0.91), specificity of 99% (95% CI: 0.99-1.00), positive predictive value of 97% (95% CI: 0.96-0.99), and negative predictive value of 84% (95% CI: 0.69-0.99) for detection of all grades of dysplasia. The receiver-operating characteristic curve for NBI model performance was 0.8550 for detecting all dysplasia. CONCLUSION Narrow-band imaging-guided biopsy demonstrated high diagnostic accuracy and might constitute a valid substitute for random biopsies during endoscopic surveillance for dysplasia in BE.

Esophageal cancer consistently ranks amongst the top ten cancer killers in the world and appears to be increasing in incidence. There are mainly two histology subtypes of esophageal cancer, derived either from squamous or glandular epithelium of the esophagus. Although they have different biological behaviors and contributing factors, both of these can be diagnosed by endoscopy imaging at an early stage. In order to maximize the chances for cure, a thorough and precise diagnosis of superficial neoplasia is of utmost importance. Several methods have been studied in advanced endoscopy imaging in order to obtain more accurate real-time diagnosis of premalignant and malignant changes in the esophagus. These include the use of vital stains and virtual chromoendoscopy. Improvement in endoscopic technologies over the past 2 decades has led to a massive deluge and development of various endoscopic classifications. In this chapter, we will summarize the application of advanced imaging modalities in the diagnosis of superficial esophageal neoplasia specifically concentrating on squamous cell carcinoma.

As in the rest of the gastrointestinal (GI) tract, Endoscopic Mucosal Resection (EMR) and Endoscopic Submucosal Dissection (ESD) techniques are used to address premalignant lesions and early cancers in the esophagus. The latter has been described as one of the most complex interventional procedures in endoscopy to date. Even though the technique of ESD shares common ground throughout the GI tract, there are some nuances to esophageal ESD based mainly on anatomical differences between different luminal organs (e.g., thickness of the esophageal wall, lumen size, and access issues). In this chapter, we will describe these and highlight some of the peculiarities of ESD in the esophagus.

BACKGROUND AND AIM: During COVID-19 outbreak, restrictions to in-person consultations were introduced with a rise in telehealth. An indirect benefit of telehealth could be better attendance. This study aimed to assess "failure-to-attend" (FTA) rate and satisfaction for two endoscopy-related compulsory telehealth clinics during the COVID-19 outbreak. METHODS: Consecutive patients booked for endoscopy-related telehealth clinics at a tertiary hospital were prospectively assessed. In-person clinic control data were assessed retrospectively. Sample size was calculated to detect an anticipated increase in attendance of 8%. Secondary outcomes included FTA differences between clinics and evaluation of patients and doctors satisfaction. Satisfaction was assessed based on six Likert scale questions used in previous telehealth research and asked to both patients and doctors (6Q_score). This study was exempt from IRB review after institutional IRB review. RESULTS: There were 691 patients booked for appointments in our endoscopy clinics during the study periods (373 in 2020). FTA rates were lowered by half during the compulsory telehealth clinics (12.6% to 6.4%, P

Background and Aim Pancreatic cancer (PC) carries a poor prognosis and is often detected at later stages. Screening programs for moderate‐ and high‐risk people are still under debate. We present the results from a prospective study on endoscopic ultrasound (EUS) as a one‐off screening tool for pancreatic cancer screening. Methods Asymptomatic patients with moderate‐ or high‐risk of PC were invited to participate. Moderate risk consisted of one first‐degree and at least one second‐degree relative with PC and no PC‐associated genetic mutations. High risk consisted of >1 first‐degree relatives with PC or PC‐associated mutations (i.e. BRCA2, Lynch Syndrome, Familial Atypical Multiple Mole Melanoma Syndrome, STK11, or PALB2). All included patients had genetic counseling and a screening EUS done. Primary outcome was the detection of PC on EUS. Secondary outcomes assessed the evolution of psychological symptoms based on the Impact of Events Scale (IES) and Personal Consequences Questionnaire (PCQ) before and after the screening took place. Results A total of 122 patients had a screening EUS performed between 2013 and 2019; 60 were male, 55.8 years was the mean age, 78 were at high risk for PC, and 25 had PC‐associated mutations. No pancreatic cancers were identified at the one‐off EUS screening. Overall, patients' IES/PCQ scores did not change after screening and feedback of no malignancy, with the exception of females (less concerned about PC after screening EUS). Conclusions EUS did not detect any PCs in either a moderate‐ or high‐risk population as a one‐off screening method. The EUS procedure and genetic counseling improved psychological symptoms for the female subset of this population., There is still paucity of data on screening for pancreatic cancer. Although medical consensus seems to advocate for screening through endoscopic ultrasound or computer tomography/magnetic resonance cholangiopancreatography for “high‐risk” individuals, more data are needed to determine what the benefits are of such screening. Our study presents data on a cohort of individuals at moderate and high risk for pancreatic cancer.

Detection of early gastrointestinal tract malignancy can be challenging on white light endoscopy especially as lesions can be subtle and inconspicuous. With the advent of electronic chromoendoscopy technologies, lesions which have already been detected can be quickly and "conveniently" characterised. This review will discuss some of the indications and modern applications of chromoendoscopy in various conditions including Barrett's oesophagus, oesophageal squamous cell carcinoma, early gastric cancer, inflammatory bowel disease and neoplastic colonic lesions. In carefully selected situations, chromoendoscopy could still be a useful adjunct to white light endoscopy in day-to-day clinical practice.

The automatic detection of frames containing polyps from a colonoscopy video sequence is an important first step for a fully automated colonoscopy analysis tool. Typically, such detection system is built using a large annotated data set of frames with and without polyps, which is expensive to be obtained. In this paper, we introduce a new system that detects frames containing polyps as anomalies from a distribution of frames from exams that do not contain any polyps. The system is trained using a one-class training set consisting of colonoscopy frames without polyps - such training set is considerably less expensive to obtain, compared to the 2-class data set mentioned above. During inference, the system is only able to reconstruct frames without polyps, and when it tries to reconstruct a frame with polyp, it automatically removes (i.e., photoshop) it from the frame - the difference between the input and reconstructed frames is used to detect frames with polyps. We name our proposed model as anomaly detection generative adversarial network (ADGAN), comprising a dual GAN with two generators and two discriminators. To test our framework, we use a new colonoscopy data set with 14317 images, split as a training set with 13350 images without polyps, and a testing set with 290 abnormal images containing polyps and 677 normal images without polyps. We show that our proposed approach achieves the state-of-the-art result on this data set, compared with recently proposed anomaly detection systems.

Introduction: Quality measures for colonoscopy such as adenoma detection rate (ADR) have been proposed to be surveilled for ensuring minimum standards. However, its direct measurement is time consuming and often neglected. Extrapolating ADR and other quality measures from polyp detection rate (PDR) can be a pragmatic alternative. Objective: To determine quotients for estimating ADR and sessile serrated adenoma/polyp detection rate (SSA/P-DR) from PDR in an Australian cohort. Methods: Consecutive adult patient colonoscopies during a 1-year period were retrospectively assessed in a single Australian tertiary endoscopy center. Adenoma detection quotient (ADQ) and SSA/P detection quotient (SSA/P-DQ) were defined as the division of ADR and SSA/P-DR by PDR, respectively. The primary outcome was the number of procedures to achieve a stable cumulative ADQ and SSA/P-DQ. Secondary outcomes included evaluation of ADQ and SSA/P-DQ in different subsets. Results: In total, 2,657 colonoscopies were performed by 15 endoscopists in 2016. The ADR, SSA/P-DR, and PDR found were 32.2, 6.7, and 47.3%, respectively. The ADQ and SSA/P-DQ values found were 0.68 and 0.14, respectively. After approximately 500 procedures, both ADQ and SSA/P-DQ became stable. Interclass correlation coefficient (ICC) for the prediction of ADR from ADQ was excellent for all endoscopists that performed >177 procedures in that year (ICC 0.84). Conclusions: ADQ and SSA/P-DQ values were consistent when over 500 procedures were analyzed. ADQ had an excellent correlation with ADR when >177 procedures per endoscopist were evaluated.

Anomaly detection methods generally target the learning of a normal image distribution (i.e., inliers showing healthy cases) and during testing, samples relatively far from the learned distribution are classified as anomalies (i.e., outliers showing disease cases). These approaches tend to be sensitive to outliers that lie relatively close to inliers (e.g., a colonoscopy image with a small polyp). In this paper, we address the inappropriate sensitivity to outliers by also learning from inliers. We propose a new few-shot anomaly detection method based on an encoder trained to maximise the mutual information between feature embeddings and normal images, followed by a few-shot score inference network, trained with a large set of inliers and a substantially smaller set of outliers. We evaluate our proposed method on the clinical problem of detecting frames containing polyps from colonoscopy video sequences, where the training set has 13350 normal images (i.e., without polyps) and less than 100 abnormal images (i.e., with polyps). The results of our proposed model on this data set reveal a state-of-the-art detection result, while the performance based on different number of anomaly samples is relatively stable after approximately 40 abnormal training images. Code is available at https://github.com/tianyu0207/FSAD-Net .

AIM To assess the utility of modified Sano′s (MS) vs the narrow band imaging international colorectal endoscopic (NICE) classification in differentiating colorectal polyps. METHODS Patients undergoing colonoscopy between 2013 and 2015 were enrolled in this trial. Based on the MS or the NICE classifications, patients were randomised for real-time endoscopic diagnosis. This was followed by biopsies, endoscopic or surgical resection. The endoscopic diagnosis was then compared to the final (blinded) histopathology. The primary endpoint was the sensitivity (Sn), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of differentiating neoplastic and non-neoplastic polyps (MS II/IIo / IIIa / IIIb vs I or NICE 1 vs 2/3). The secondary endpoints were “endoscopic resectability” (MS II/IIo/IIIa vs I/IIIb or NICE 2 vs 1/3), NPV for diminutive distal adenomas and prediction of post-polypectomy surveillance intervals. RESULTS A total of 348 patients were evaluated. The Sn, Sp, PPV and NPV in differentiating neoplastic polyps from non-neoplastic polyps were, 98.9%, 85.7%, 98.2% and 90.9% for MS; and 99.1%, 57.7%, 95.4% and 88.2% for NICE, respectively. The area under the receiver operating characteristic curve (AUC) for MS was 0.92 (95%CI: 0.86-0.98); and AUC for NICE was 0.78 (95%CI: 0.69, 0.88). The Sn, Sp, PPV and NPV in predicting “endoscopic resectability” were 98.9%, 86.1%, 97.8% and 92.5% for MS; and 98.6%, 66.7%, 94.7% and 88.9% for NICE, respectively. The AUC for MS was 0.92 (95%CI: 0.87-0.98); and the AUC for NICE was 0.83 (95%CI: 0.75-0.90). The AUC values were statistically different for both comparisons (P = 0.0165 and P = 0.0420, respectively). The accuracy for diagnosis of sessile serrated adenoma/polyp (SSA/P) with high confidence utilizing MS classification was 93.2%. The differentiation of SSA/P from other lesions achieved Sp, Sn, PPV and NPV of 87.2%, 91.5%, 89.6% and 98.6%, respectively. The NPV for predicting adenomas in diminutive rectosigmoid polyps (n = 150) was 96.6% and 95% with MS and NICE respectively. The calculated accuracy of post-polypectomy surveillance for MS group was 98.2% (167 out of 170) and for NICE group was 92.1% (139 out of 151). CONCLUSION The MS classification outperformed the NICE classification in differentiating neoplastic polyps and predicting endoscopic resectability. Both classifications met ASGE PIVI thresholds.

AIM To compare high definition white light endoscopy and bright narrow band imaging for colon polyps’ detection rates. METHODS Patients were randomised to high definition white light endoscopy (HD-WLE) or the bright narrow band imaging (bNBI) during withdrawal of the colonoscope. Polyps identified in either mode were characterised using bNBI with dual focus (bNBI-DF) according to the Sano’s classification. The primary outcome was to compare adenoma detection rates (ADRs) between the two arms. The secondary outcome was to assess the negative predictive value (NPV) in differentiating adenomas from hyperplastic polyps for diminutive rectosigmoid lesions. RESULTS A total of 1006 patients were randomised to HD-WLE (n = 511) or bNBI (n = 495). The mean of adenoma per patient was 1.62 and 1.84, respectively. The ADRs in bNBI and HD-WLE group were 37.4% and 39.3%, respectively. When adjusted for withdrawal time (OR = 1.19, 95%CI: 1.15-1.24, P < 0.001), the use of bNBI was associated with a reduced ADR (OR = 0.69, 95%CI: 0.52-0.92). Nine hundred and thirty three polyps (86%) in both arms were predicted with high confidence. The sensitivity (Sn), specificity (Sp), positive predictive value and NPV in differentiating adenomatous from non-adenomatous polyps of all sizes were 95.9%, 87.2%, 94.0% and 91.1% respectively. The NPV in differentiating an adenoma from hyperplastic polyp using bNBI-DF for diminutive rectal polyps was 91.0%. CONCLUSION ADRs did not differ between bNBI and HD-WLE, however HD-WLE had higher ADR after adjustment of withdrawal time. bNBI surpassed the PIVI threshold for diminutive polyps.

There are two challenges associated with the interpretability of deep learning models in medical image analysis applications that need to be addressed: confidence calibration and classification uncertainty. Confidence calibration associates the classification probability with the likelihood that it is actually correct - hence, a sample that is classified with confidence X% has a chance of X% of being correctly classified. Classification uncertainty estimates the noise present in the classification process, where such noise estimate can be used to assess the reliability of a particular classification result. Both confidence calibration and classification uncertainty are considered to be helpful in the interpretation of a classification result produced by a deep learning model, but it is unclear how much they affect classification accuracy and calibration, and how they interact. In this paper, we study the roles of confidence calibration (via post-process temperature scaling) and classification uncertainty (computed either from classification entropy or the predicted variance produced by Bayesian methods) in deep learning models. Results suggest that calibration and uncertainty improve classification interpretation and accuracy. This motivates us to propose a new Bayesian deep learning method that relies both on calibration and uncertainty to improve classification accuracy and model interpretability. Experiments are conducted on a recently proposed five-class polyp classification problem, using a data set containing 940 high-quality images of colorectal polyps, and results indicate that our proposed method holds the state-of-the-art results in terms of confidence calibration and classification accuracy.

The detection and classification of anatomies from medical images has traditionally been developed in a two-stage process, where the first stage detects the regions of interest (ROIs), while the second stage classifies the detected ROIs. Recent developments from the computer vision community allowed the unification of these two stages into a single detection and classification model that is trained in an end to end fashion. This allows for a simpler and faster training and inference procedures because only one model (instead of the two models needed for the two-stage approach) is required. In this paper, we adapt a recently proposed onestage detection and classification approach for the new 5class polyp classification problem. We show that this onestage approach is not only competitive in terms of detection and classification accuracy with respect to the two-stage approach, but it is also substantially faster for training and testing. We also show that the one-stage approach produces competitive detection results compared to the state of the art results on the MICCAI 2015 polyp detection challenge.

Achalasia is an esophageal motility disorder associated with abnormalities in peristalsis and lower esophageal sphincter (LES) relaxation. The etiology of the disease remains elusive. It is often misdiagnosed initially as gastroesophageal reflux disease. Patients with achalasia often complain of dysphagia to solids and liquids but may focus on regurgitation as the primary symptom, leading to the early misdiagnosis. Chest pain, weight loss, and occasional vomiting may be additional symptoms encountered in those with achalasia. The disease may be suspected on the basis of clinical presentation, but diagnosis depends on classic findings using high-resolution manometry, showing either failed or simultaneous contractions with associated normal or high LES pressures with no or incomplete relaxation with swallows. There are no cures for achalasia, and, in most patients, treatments have to be repeated over time. Definitive treatment options in achalasia include pneumatic dilation, surgical myotomy, and the new technique of per-oral endoscopic myotomy. Botulinum toxin (Botox) or other medical therapies are often reserved for those who cannot have definitive therapies owing to comorbid conditions.

The aim of this study is to address the outcomes of endoscopic resection compared with surgery in the treatment of ampullary adenomas. A systematic review and meta-analysis were performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. For this purpose, the Medline, Embase, Cochrane, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Scopus and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases were scanned. Studies included patients with ampullary adenomas and data considering endoscopic treatment compared with surgery. The entire analysis was based on a fixed-effects model. Five retrospective cohort studies were selected (466 patients). All five studies (466 patients) had complete primary resection data available and showed a difference that favored surgical treatment (risk difference [RD] = -0.24, 95% confidence interval [CI] = -0.44 to -0.04). Primary success data were identified in all five studies as well. Analysis showed that the surgical approach outperformed endoscopic treatment for this outcome (RD = -0.37, 95% CI = -0.50 to -0.24). Recurrence data were found in all studies (466 patients), with a benefit indicated for surgical treatment (RD = 0.10, 95% CI = -0.01 to 0.19). Three studies (252 patients) presented complication data, but analysis showed no difference between the approaches for this parameter (RD = -0.15, 95% CI = -0.53 to 0.23). Considering complete primary resection, primary success and recurrence outcomes, the surgical approach achieves significantly better results. Regarding complication data, this systematic review concludes that rates are not significantly different.

Surveillance post-endoscopic resection (ER) currently warrants biopsy samples from the resection site scar in most cases, although clinical practice is variable. A classification with standard criteria for scars has not yet been established. We aimed to create and validate a novel classification for post-ER scars by using specific criteria based on advanced imaging.Key endoscopic features for scars with and without recurrence were (1) dark brown color, elongated/branched pit pattern, and dense capillary pattern and (2) whitish, pale appearance, round/slightly large pits, and irregular sparse vessels. Scars were first assessed with high-definition white-light endoscopy (HD-WLE) followed by interrogation with narrow-band imaging (NBI). Scars with at least 2 concordant characteristics were diagnosed with "high confidence" for NBI for scar (NBI-SCAR) classification. The final endoscopic predictions were correlated with histopathology. The primary outcome was the difference in sensitivity between NBI-SCAR and HD-WLE predictions. Secondary outcomes included the validation of our findings in 6 different endoscopy settings (Australia, United States, Japan, Brazil, Singapore, and Malaysia). The validation took place in 2 sessions separated by 2 to 3 weeks, each with 10 one-minute videos of post-ER scars on underwater NBI with dual focus. Inter-rater and intrarater reliability were calculated with Fleiss' free-marginal kappa and Bennett et al. S score, respectively.One hundred scars from 82 patients were included. Ninety-five scars were accurately predicted with high confidence by NBI-SCAR in the exploratory phase. NBI-SCAR sensitivity was significantly higher compared with HD-WLE (100% vs 73.7%, P .05). In the validation phase, similar results were found for endoscopists who routinely perform colonoscopies and use NBI (sensitivity of 96.4%). The inter-rater and intrarater reliability throughout all centers were, respectively, substantial (κ = .61) and moderate (average S = .52) for this subset.NBI-SCAR has a high sensitivity and negative predictive value for excluding recurrence for endoscopists experienced in colonoscopy and NBI. In this setting, this approach may help to accurately evaluate or resect scars and potentially mitigate the burden of unnecessary biopsy samples.

by intestinal lipomatosis: double-balloon endoscopic and laparoscopic views A 52-year-oldwhitemanwithout co-morbidities presented with a 6-year history of recurrent abdominal pain and episodes of melena twice a week for the past year. He was started on oral iron sulfate supplements and had already received a blood transfusion. Findings from physical examination were normal. The hemoglobin level was 10.8g/dL. Gastroduodenoscopy and colonoscopy revealed several smooth sessile and pedunculated lesions covered by normal mucosa, which are characteristics of lipomas, and with no signs of bleeding. Double-balloon endoscopy (DBE) revealed innumerable similar subepithelial lesions, measuring 1–4cm in diameter, throughout the entire small bowel (●" Video 1). In the distal jejunum, multiple pedunculated lesions were seen, with twisted pedicles, superficial erosion, and covered by fibrin, suggestive of vascular damage (●" Fig.1, ●" Fig.2). Abdominal computed tomography scan showed multiple hypodense lesions compatible with lipomas, and areas of intussusception with mild proximal smallbowel dilation (●" Fig.3). The patient underwent laparoscopy, which confirmed irreducible intussusception, and led to minilaparotomy with four enterotomies and resection of multiple lipomas (●" Fig.4, ●" Fig.5). A total of 26 lesions were resected, including some with signs of bleeding. Histopathology confirmed the diagnosis of lipomatosis (●" Fig.6). The patient was discharged 3 days after surgery, and at the 5-month follow-up visit he remained asymptomatic with a hemoglobin level of 12.9g/dL. Lipomas of the gastrointestinal (GI) tract arebenign tumors and are usually solitary; however, they can rarely present as GI lipomatosis [1]. Althoughmostlyasymptomatic, GI lipomas may cause symptoms, including obstruction as a result of intussusceptions, and GI bleeding [2,3]. Treatment consists of surgical or endoscopic resection. Endoscopic options includemucosal or submucosal resection, unroofing technique, and application of an endoloop or endoclip [4,5]. This case demonstrated the endoscopic and laparoscopic characteristics of diffuse GI lipomatosis. DBE was essential to the diagnosis, and surgical resection resolved the intussusception and obscure GI bleeding.

What should be done next? Is the stricture benign? Is it resectable? Should I place a stent? Which one? These are some of the questions one ponders when dealing with biliary strictures. In resectable cases, ongoing questions remain as to whether the biliary tree should be drained prior to surgery. In palliative cases, the relief of obstruction remains the main goal. Options for palliative therapy include surgical bypass, percutaneous drainage, and stenting or endoscopic stenting (transpapillary or via an endoscopic ultrasound approach). This review gathers scientific foundations behind these interventions. For operable cases, preoperative biliary drainage should not be performed unless there is evidence of cholangitis, there is delay in surgical intervention, or intense jaundice is present. For inoperable cases, transpapillary stenting after sphincterotomy is preferable over percutaneous drainage. The use of plastic stents (PS) has no benefit over Self-Expandable Metallic Stents (SEMS). In case transpapillary drainage is not possible, Endoscopic Ultrasonography- (EUS-) guided drainage is still an option over percutaneous means. There is no significant difference between the types of SEMS and its indication should be individualized.