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Background The conduction delay and block that compose the critical isthmus of macroreentrant ventricular tachycardia (VT) is partly “functional” in that they only occur at faster cycle lengths. Close-coupled pacing stresses the myocardium's conduction capacity and may reveal late potentials (LPs) and fractionation. Interest has emerged in targeting this functional substrate. Objective The purpose of this study was to assess the feasibility and efficacy of a functional substrate VT ablation strategy. Methods Patients with scar-related VT undergoing their first ablation were recruited. A closely coupled extrastimulus (ventricular effective refractory period + 30 ms) was delivered at the right ventricular apex while mapping with a high-density catheter. Sites of functional impaired conduction exhibited increased electrogram duration due to LPs/fractionation. The time to last deflection was annotated on an electroanatomic map, readily identifying ablation targets. Results A total of 40 patients were recruited (34 [85%] ischemic). Median procedure duration was 330 minutes (interquartile range [IQR] 300–369), and ablation time was 49.4 minutes (IQR 33.8–48.3). Median functional substrate area was 41.9 cm2 (IQR 22.1–73.9). It was similarly distributed across bipolar voltage zones. Noninducibility was achieved in 34 of 40 patients (85%). Median follow-up was 711 days (IQR 255.5–972.8), during which 35 of 39 patients (89.7%) did not have VT recurrence, and 3 of 39 (7.5%) died. Antiarrhythmic drugs were continued in 53.8% (21/39). Conclusion Functional substrate ablation resulted in high rates of noninducibility and freedom from VT. Mapping times were increased considerably. Our findings add to the encouraging trend reported by related techniques. Randomized multicenter trials are warranted to assess this next phase of VT ablation.

This Canadian Cardiovascular Society position statement is focused on the management of sustained ventricular tachycardia (VT) and ventricular fibrillation (VF) that occurs in patients with structural heart disease (SHD), including previous myocardial infarction, dilated cardiomyopathy, and other forms of nonischemic cardiomyopathy. This patient population is rapidly increasing because of advances in care and improved overall survival of patients with all forms of SHD. In this position statement, the acute and long-term management of VT/VF are outlined, and the many unique aspects of care in this population are emphasized. The initial evaluation, acute therapy, indications for chronic suppressive therapy, choices of chronic suppressive therapy, implantable cardioverter-defibrillator programming, alternative therapies, and psychosocial care are reviewed and recommendations for optimal care are provided. The target audience for this statement includes all health professionals involved in the continuum of care of patients with SHD and VT/VF.

Objective: The aim of this study was to examine the clinical efficacy and safety of the duodenal-jejunal bypass liner (DJBL) while in situ for 12 months and for 12 months after explantation.Summary of background data: This is the largest randomized controlled trial (RCT) of the DJBL, a medical device used for the treatment of people with type 2 diabetes mellitus (T2DM) and obesity. Endoscopic interventions have been developed as potential alternatives to those not eligible or fearful of the risks of metabolic surgery.Methods: In this multicenter open-label RCT, 170 adults with inadequately controlled T2DM and obesity were randomized to intensive medical care with or without the DJBL. Primary outcome was the percentage of participants achieving a glycated hemoglobin reduction of ≥20% at 12 months. Secondary outcomes included weight loss and cardiometabolic risk factors at 12 and 24 months.Results: There were no significant differences in the percentage of patients achieving the primary outcome between both groups at 12 months [DJBL 54.6% (n = 30) vs control 55.2% (n = 32); odds ratio (OR) 0.93, 95% confidence interval (CI): 0.44-2.0; P = 0.85]. Twenty-four percent (n = 16) patients achieved ≥15% weight loss in the DJBL group compared to 4% (n = 2) in the controls at 12 months (OR 8.3, 95% CI: 1.8-39; P = .007). The DJBL group experienced superior reductions in systolic blood pressure, serum cholesterol, and alanine transaminase at 12 months. There were more adverse events in the DJBL group.Conclusions: The addition of the DJBL to intensive medical care was associated with superior weight loss, improvements in cardiometabolic risk factors, and fatty liver disease markers, but not glycemia, only while the device was in situ. The benefits of the devices need to be balanced against the higher rate of adverse events when making clinical decisions.Trial registration: ISRCTN30845205. isrctn.org; Efficacy and Mechanism Evaluation Programme, a Medical Research Council and National Institute for Health Research (NIHR) partnership reference 12/10/04.

ObjectivesHelicobacter pylori infection is a common cause of chronic gastritis worldwide and an established risk factor for developing gastric malignancy. The endoscopic appearances predicting H. pylori status are an ongoing area of research, as are their diagnostic accuracies. This study aimed to establish the diagnostic accuracy of several mucosal features predictive of H. pylori negative status and formulate a simple prediction model for use at the time of endoscopy.DesignPatients undergoing high-definition upper gastrointestinal (GI) endoscopy without magnification were recruited prospectively. During the endoscopy, the presence or absence of specific endoscopic findings was noted. Sydney protocol biopsies were used as the diagnostic reference standard, and urease test if taken. The results informed a logistic regression model used to produce a simple diagnostic approach. This model was subsequently validated using a further cohort of 30 patients.Results153 patients were recruited and completed the study protocol. The prevalence of active H. pylori infection was 18.3% (28/153). The overall diagnostic accuracy of the simple prediction model was 80.0%, and 100% of patients with active H. pylori infection were correctly classified. The presence of regular arrangement of collecting venules (RAC) showed a positive predictive value for H. pylori naïve status of 90.7%, rising to 93.6% for patients under the age of 60.ConclusionA simple endoscopic model may be accurate for predicting H. pylori status of a patient, and the need for biopsy-based tests. The presence of RAC in the stomach is an accurate predictor of H. pylori negative status, particularly in patients under the age of 60.Trial registration numberThe study was registered with ClinicalTrials.gov, No. NCT02385045.

Background Interventional endoluminal therapy is rapidly advancing as a minimally invasive surgical technique. The expanding remit of endoscopic therapy necessitates precision control. Eye tracking is an emerging technology which allows intuitive control of devices. This was a feasibility study to establish if a novel eye gaze-controlled endoscopic system could be used to intuitively control an endoscope. Methods An eye gaze-control system consisting of eye tracking glasses, specialist cameras and a joystick was used to control a robotically driven endoscope allowing steering, advancement, withdrawal and retroflexion. Eight experienced and eight non-endoscopists used both the eye gaze system and a conventional endoscope to identify ten targets in two simulated environments: a sphere and an upper gastrointestinal (UGI) model. Completion of tasks was timed. Subjective feedback was collected from each participant on task load (NASA Task Load Index) and acceptance of technology (Van der Laan scale). Results When using gaze-control endoscopy, non-endoscopists were significantly quicker when using gaze-control rather than conventional endoscopy (sphere task 3:54 ± 1:17 vs. 9:05 ± 5:40 min, p = 0.012, and UGI model task 1:59 ± 0:24 vs 3:45 ± 0:53 min, p Non-endoscopists reported significantly higher NASA-TLX workload total scores using conventional endoscopy versus gaze-control (80.6 ± 11.3 vs 22.5 ± 13.8, p p = 0.012). All subjects reported that the gaze-control had positive ‘usefulness’ and ‘satisfaction’ score of 0.56 ± 0.83 and 1.43 ± 0.51 respectively. Conclusions The novel eye gaze-control system was significantly quicker to use and subjectively lower in workload when used by non-endoscopists. Further work is needed to see if this would translate into a shallower learning curve to proficiency versus conventional endoscopy. The eye gaze-control system appears feasible as an intuitive endoscope control system. Hybrid gaze and hand control may prove a beneficial technology to evolving endoscopic platforms.

Background Colonoscopy reduces the incidence of colorectal cancer (CRC) by allowing detection and resection of neoplastic polyps. Evidence shows that many small polyps are missed on a single colonoscopy. There has been a successful adoption of artificial intelligence (AI) technologies to tackle the issues around missed polyps and as tools to increase the adenoma detection rate (ADR). Objective The aim of this review was to examine the diagnostic accuracy of AI-based technologies in assessing colorectal polyps. Methods A comprehensive literature search was undertaken using the databases of Embase, MEDLINE, and the Cochrane Library. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. Studies reporting the use of computer-aided diagnosis for polyp detection or characterization during colonoscopy were included. Independent proportions and their differences were calculated and pooled through DerSimonian and Laird random-effects modeling. Results A total of 48 studies were included. The meta-analysis showed a significant increase in pooled polyp detection rate in patients with the use of AI for polyp detection during colonoscopy compared with patients who had standard colonoscopy (odds ratio [OR] 1.75, 95% CI 1.56-1.96; P Conclusions With the aid of machine learning, there is potential to improve ADR and, consequently, reduce the incidence of CRC. The current generation of AI-based systems demonstrate impressive accuracy for the detection and characterization of colorectal polyps. However, this is an evolving field and before its adoption into a clinical setting, AI systems must prove worthy to patients and clinicians. Trial Registration PROSPERO International Prospective Register of Systematic Reviews CRD42020169786; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020169786

Objectives Helicobacter pylori infection is a common cause of chronic gastritis worldwide and an established risk factor for developing gastric malignancy. The endoscopic appearances predicting H. pylori status are an ongoing area of research, as are their diagnostic accuracies. This study aimed to establish the diagnostic accuracy of several mucosal features predictive of H. pylori negative status and formulate a simple prediction model for use at the time of endoscopy. Design Patients undergoing high-definition upper gastrointestinal (GI) endoscopy without magnification were recruited prospectively. During the endoscopy, the presence or absence of specific endoscopic findings was noted. Sydney protocol biopsies were used as the diagnostic reference standard, and urease test if taken. The results informed a logistic regression model used to produce a simple diagnostic approach. This model was subsequently validated using a further cohort of 30 patients. Results 153 patients were recruited and completed the study protocol. The prevalence of active H. pylori infection was 18.3% (28/153). The overall diagnostic accuracy of the simple prediction model was 80.0%, and 100% of patients with active H. pylori infection were correctly classified. The presence of regular arrangement of collecting venules (RAC) showed a positive predictive value for H. pylori naïve status of 90.7%, rising to 93.6% for patients under the age of 60. Conclusion A simple endoscopic model may be accurate for predicting H. pylori status of a patient, and the need for biopsy-based tests. The presence of RAC in the stomach is an accurate predictor of H. pylori negative status, particularly in patients under the age of 60. Trial registration number The study was registered with ClinicalTrials.gov, No. NCT02385045.

BACKGROUND Colonoscopy reduces the incidence of colorectal cancer (CRC) by allowing detection and resection of neoplastic polyps. Evidence shows that many small polyps are missed on a single colonoscopy. There has been a successful adoption of artificial intelligence (AI) technologies to tackle the issues around missed polyps and as tools to increase the adenoma detection rate (ADR). OBJECTIVE The aim of this review was to examine the diagnostic accuracy of AI-based technologies in assessing colorectal polyps. METHODS A comprehensive literature search was undertaken using the databases of Embase, MEDLINE, and the Cochrane Library. PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed. Studies reporting the use of computer-aided diagnosis for polyp detection or characterization during colonoscopy were included. Independent proportions and their differences were calculated and pooled through DerSimonian and Laird random-effects modeling. RESULTS A total of 48 studies were included. The meta-analysis showed a significant increase in pooled polyp detection rate in patients with the use of AI for polyp detection during colonoscopy compared with patients who had standard colonoscopy (odds ratio [OR] 1.75, 95% CI 1.56-1.96; PP CONCLUSIONS With the aid of machine learning, there is potential to improve ADR and, consequently, reduce the incidence of CRC. The current generation of AI-based systems demonstrate impressive accuracy for the detection and characterization of colorectal polyps. However, this is an evolving field and before its adoption into a clinical setting, AI systems must prove worthy to patients and clinicians. CLINICALTRIAL PROSPERO International Prospective Register of Systematic Reviews CRD42020169786; https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020169786

Lower gastrointestinal endoscopy has evolved over time, fulfilling a widening diagnostic and therapeutic remit. As our understanding of colorectal cancer and its prevention has improved, endoscopy has progressed with improved diagnostic technologies and advancing endoscopic therapies. Despite this, the fundamental design of the endoscope has remained similar since its inception. This review presents the important role lower gastrointestinal endoscopy serves in the prevention of colorectal cancer and the desirable characteristics of the endoscope that would enhance this. A brief history of the endoscope is presented. Current and future robotic endoscopic platforms, which may fulfil these desirable characteristics, are discussed. The incorporation of new technologies from allied scientific disciplines will help the endoscope fulfil its maximum potential in preventing the increasing global burden of colorectal cancer. There are a number of endoscopic platforms under development, which show significant promise.

ObjectivesThe association between obesity and atrial fibrillation (AF) is well-established. We aimed to evaluate the impact of index body mass index (BMI) on AF recurrence at 12 months following catheter ablation using propensity-weighted analysis. In addition, periprocedural complications and fluoroscopy details were examined to assess overall safety in relationship to increasing BMI ranges.MethodsBaseline, periprocedural and follow-up data were collected on consecutive patients scheduled for AF ablation. There were no specific exclusion criteria. Patients were categorised according to baseline BMI in order to assess the outcomes for each category.ResultsAmong 3333 patients, 728 (21.8%) were classified as normal (BMI 2), 1537 (46.1%) as overweight (BMI 25.5–29.0 kg/m2) and 1068 (32.0%) as obese (BMI ≥30.0 kg/m2). Procedural duration and radiation dose were higher for overweight and obese patients compared with those with a normal BMI (p=0.002 and p2led to a 1.2-fold increased likelihood of experiencing recurrent AF at 12-months follow-up as compared with overweight patients (HR 1.223; 95% CI 1.047 to 1.429; p=0.011), while no significant correlation was found between overweight and normal BMI groups (HR 0.954; 95% CI 0.798 to 1.140; p=0.605) and obese versus normal BMI (HR 1.16; 95% CI 0.965 to 1.412; p=0.112).ConclusionsPatients with a baseline BMI ≥30 kg/m2have a higher recurrence rate of AF following catheter ablation and therefore lifestyle modification to target obesity preprocedure should be considered in these patients.

BackgroundThe EndoBarrier®(GI Dynamics Inc., Boston, MA, USA) is an endoluminal duodenal–jejunal bypass liner developed for the treatment of patients with obesity and type 2 diabetes mellitus. Meta-analyses of its effects on glycaemia and weight have called for larger randomised controlled trials with longer follow-up.ObjectivesThe primary objective was to compare intensive medical therapy with a duodenal–jejunal bypass liner with intensive medical therapy without a duodenal–jejunal bypass liner, comparing effectiveness on the metabolic state as defined by the International Diabetes Federation as a glycated haemoglobin level reduction of ≥ 20%. The secondary objectives were to compare intensive medical therapy with a duodenal–jejunal bypass liner with intensive medical therapy without a duodenal–jejunal bypass liner, comparing effectiveness on the metabolic state as defined by the International Diabetes Federation as a glycated haemoglobin level of DesignA multicentre, open-label, randomised controlled trial.SettingImperial College Healthcare NHS Trust and University Hospital Southampton NHS Foundation Trust.ParticipantsPatients aged 18–65 years with a body mass index of 30–50 kg/m2and with inadequately controlled type 2 diabetes mellitus who were on oral glucose-lowering medications.InterventionsParticipants were randomised equally to receive intensive medical therapy alongside a duodenal–jejunal bypass liner device (n = 85) or intensive medical therapy alone for 12 months (n = 85), and were followed up for a further 12 months.ResultsThere was no significant difference between groups in the percentage of patients achieving the glycaemic primary or secondary outcomes [primary outcome at 12 months: duodenal–jejunal bypass liner group 54.5% vs. control group 55.2% (odds ratio 0.93, 95% confidence interval 0.44 to 1.98;p = 0.85); primary outcome at 24 months: duodenal–jejunal bypass liner group 39.7% vs. control group 36.5% (odds ratio 1.13, 95% confidence interval 0.52 to 2.47;p = 0.75)]. Significantly more patients in the duodenal–jejunal bypass liner group than in the control group lost > 15% of their total body weight (duodenal–jejunal bypass liner group 24.2% vs. control group 3.7%; odds ratio 8.33, 95% confidence interval 1.78 to 39.0;p = 0.007) and achieved blood pressure targets (duodenal–jejunal bypass liner group 68.2% vs. control group 44.4%; odds ratio 2.57, 95% confidence interval 1.21 to 5.48;p = 0.014). These differences were observed at 12 months but not at 24 months. There were more adverse events in the duodenal–jejunal bypass liner group, including one liver abscess. The increase in peripheral insulin sensitivity was superior in the duodenal–jejunal bypass liner group. Spectroscopic analyses of plasma, urine and faeces revealed several distinct metabolic perturbations in the duodenal–jejunal bypass liner group but not in the control group. Brain reward responses to food cues were not different between groups. The number of mean quality-adjusted life-years gained was similar in both groups and the additional costs of the duodenal–jejunal bypass liner may outweigh the value of the health benefits by £2560 per patient treated.ConclusionsThe results show that the endoluminal duodenal–jejunal bypass liner was not superior to intensive medical therapy for glycaemic control and was associated with more adverse events. The duodenal–jejunal bypass liner was associated with significant weight loss and improvement in cardiometabolic parameters at 12 months but not at 24 months. Economic evaluation showed that the bypass liner was not cost-effective for glycaemic control or for weight loss.Trial registrationCurrent Controlled Trials ISRCTN30845205.FundingThis project was funded by the Efficacy and Mechanism Evaluation (EME) Programme, a Medical Research Council (MRC) and National Institute for Health Research (NIHR) partnership. This will be published in full inEfficacy and Mechanism Evaluation; Vol. 7, No. 6. See the NIHR Journals Library website for further project information. This study was executed with the support of GI Dynamics Inc. and with the kind support of Nutricia Advanced Medical Nutrition for providing oral nutritional supplements.

Background Ablation of scar related ventricular tachycardia (VT) has been shown to be superior to escalation of drug therapy. However, the incremental benefit remains modest, with 42% experiencing recurrent shocks and 64% appropriate anti-tachycardia pacing (ATP) in the VANISH study. Improved ablation strategies are needed. Paced electrogram feature analysis (PEFA) is a novel substrate based ablation technique. Purpose To investigate the effectiveness of the PEFA based VT ablation technique. Methods A single centre, prospective study. Consecutive cases of scar related VT that had an implantable cardiac defibrillator (ICD) and no prior ablations were recruited. Close coupled pacing was performed at the right ventricular apex and the VT isthmus(es) identified on high density mapping catheters by increased electrogram (EGM) duration and latency. A algorithm was developed to identify the latest EGM component after the S2 pacing artefact,. This millisecond value was displayed on the geometry as a colour (PEFA map) (St Jude Ensite Precision Electroanatomic Mapping). PEFA identified VT isthmus sites were targeted for ablation (Figure 1). Follow up ICD interrogation data was utilized to assess for VT recurrence. Results A total of 20 patients were recruited. These comprised ischaemic cardiomyopathy (CM) (17/20), dilated CM (2/20), and arrhythmogenic CM (1/20), male (18/20), and endocardial only approach (19/20). Mean age was 64.3±11.3 years, ejection fraction 24.4% ± 14.4, and ablation time was 1989.9±1078.1 seconds. Non-inducibility was demonstrated at the end of the case in 18/20. A class I or III anti-arrhythmic drug was continued in 50%. VT recurred in three cases (Day 28,30,55). One death occurred following a stroke on day 181. Mean follow up was 437.5±231.7 days. Figure 1 Conclusion This is the largest study to date on PEFA based VT ablation, the first to include non-ischaemic aetiologies, and reports a longer mean follow up. A high proportion of cases were non-inducible, and low VT recurrence rates were observed. PEFA appears to be a promising tool to guide VT ablation targets. Acknowledgement/Funding This research was funded in part by the Canadian Institute for Health Research (139080) and a grant from St. Jude Medical.

Introduction A gaze-controlled robotic endoscope is innovative technology with myriad potential applications in the rapidly advancing field of flexible endoscopy. Improvements to the current flexible device to allow examination of the gastrointestinal tract whilst minimising procedural discomfort and complications are desirable. Methods Users are able to control endoscope movements without handling the device. A flexible gastroscope (Karl Storz 13801 PKS) was attached to a UR5 6 axis robotic arm (Universal Robots), mounted onto a rail and placed on top of a surgical table. Two cogwheel shaped dials were 3D printed and placed onto the up/down and left/right wheels on the head of the gastroscope (Figure 1a). Robotization of these controls was achieved by using two motors (DYNAMIXEL RX-24F) to steer the distal tip. This system allows users to operate a robotised flexible endoscope using eye gaze control. Gaze interaction with the screen was based on a 3D gaze framework we developed with the synergy of conventional wearable eye-tracking glasses, a motion capture system and fixed in space RGB-D cameras for 3D reconstruction of the environment. The eye gaze technology was calibrated for each user prior to the task. The distal tip of the gastroscope was controlled using eye gaze technology. The UR5 robot was used to enable shaft rotation. This was initiated by fixed head movements left and right rotating the shaft clockwise/anticlockwise. Linear movements of the gastroscope were triggered using a joystick handle (up for forward movement, down for endoscope withdrawal). Pause and automatic retroflexion of the endoscope are achieved by moving the joystick left and right respectively. Users were asked to navigate an endoscope through an UGIT model (Chamberlain group) simulating a diagnostic gastroscopy using gaze control and targeting ten points scattered through the stomach (Figure 1b). Results Four expert endoscopists and one novice used gaze control to successfully navigate a gastroscope through the simulated UGIT. All were able to independently intubate the oesophagus and accurately locate ten targets placed in the fundus, body, antrum and pylorus of the stomach without touching the endoscope. Conclusions Gaze control endoscopy is a feasible concept. It allows ergonomic, user-friendly and intuitive control whilst maintaining the benefits of a flexible endoscope.

Although deep learning pathology diagnostic algorithms are proving comparable results with human experts in a wide variety of tasks, they still require a huge amount of well annotated data for training. Generating such extensive and well labelled datasets is time consuming and is not feasible for certain tasks and so, most of the medical datasets available are scarce in images and therefore, not enough for training. In this work we validate that the use of few shot learning techniques can transfer knowledge from a well defined source domain from Colon tissue into a more generic domain composed by Colon, Lung and Breast tissue by using very few training images. Our results show that our few-shot approach is able to obtain a balanced accuracy (BAC) of 90% with just 60 training images, even for the Lung and Breast tissues that were not present on the training set. This outperforms the finetune transfer learning approach that obtains 73% BAC with 60 images and requires 600 images to get up to 81% BAC. This study has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 732111 (PICCOLO project).

Introduction: The progressive miniaturisation of photonics components presents the opportunity to obtain unprecedented microscopic images of colonic polyps in real-time, during endoscopy. This information has the potential to act as an ‘optical biopsy’ to aid clinical decision making, including the possibility of adopting new paradigms such as a ‘resect and discard’ approach for low-risk lesions. The technologies discussed in this review include Confocal Laser Endomicroscopy, Optical Coherence Tomography, Multiphoton Microscopy, Raman Spectroscopy and Hyperspectral Imaging. These are in different stages of development and clinical readiness, but all show the potential to produce reliable in-vivo discrimination of different tissue types. Methods: A structured literature search of the imaging techniques for colorectal polyps has been conducted. The significant developments in endoscopic imaging was identified for each modality, and the status of current development was discussed. Conclusions: Of the advanced imaging techniques discussed, Confocal Laser Endomicroscopy is in clinical use, and under optimal conditions with an experienced operator, can provide accurate histological assessment of tissue. The remaining techniques show potential for incorporation into endoscopic equipment and practice, although further component development is needed, followed by robust prospective validation of accuracy. Optical Coherence Tomography illustrates tissue ‘texture’ well and gives good assessment of mucosal thickness and layers. Multiphoton Microscopy produces high resolution images at a subcellular resolution. Raman Spectroscopy and Hyperspectral Imaging are less developed endoscopically but provide a tissue ‘fingerprint’ which can distinguish between tissue types. Molecular Imaging may become a powerful adjunct to other techniques, with its ability to precisely label specific molecules within tissue and thereby enhance imaging.

Objective: i-Scan is a digital image enhancement technology, reported to improve diagnostic performance during endoscopy. Previous studies have investigated the accuracy of i-scan for distinguishing between neoplastic and non-neoplastic colonic polyps and suggested diagnostic accuracy close to that required for use in routine clinical practice. The aim of this study was to perform a meta-analysis of the available literature investigating diagnostic accuracy for i-scan optical diagnosis when made in real time for colorectal polyps Data sources: The databases of Medline, Embase and the Cochrane Library were searched for relevant studies. Methods: A bivariate random effects model was used to produce pooled sensitivity and specificity values, and univariable meta-regression was applied for subgroup analysis. Results: The meta-analysis included 15 studies, and diagnosis of 2817 polyps. The area under the hierarchical summary receiver-operating characteristic curve was 0.96. The pooled sensitivity of i-scan optical diagnosis was 0.92 (95% confidence interval 0.85–0.95). The specificity was 0.90 (95% confidence interval 0.83–0.94). Conclusions: This meta-analysis updates and summarizes the available evidence concerning the diagnostic performance of i-scan for small colorectal polyps. An acceptable degree of accuracy was found, showing potential to support a ‘resect and discard’ strategy for colonic polyps. There was not found to be a significant difference in diagnostic performance between different clinical settings (i.e. teaching hospitals or general hospitals).

In August 2016, Muddy Waters LLC released a short-sell report outlining potential cybersecurity vulnerabilities in several St. Jude Medical (now Abbott) pacemaker models following a demonstration of a "crash attack" and a "battery drain attack" by vulnerability research firm MedSec. 1 The motivation behind the release of this report does not appear to have been focused on patient safety; rather than inform Abbott or the US Food and Drug Administration (FDA) directly, the information was released to the public sector. 2 This event was followed by a safety communication issued by the FDA in January of 2017 describing the vulnerabilities and informing the public of a software patch. 3 Shortly after, the FDA issued a warning letter to Abbott in April of 2017. In response to these events, Abbott released a firmware upgrade with enhanced cybersecurity. Installation of this firmware upgrade is non-invasive and takes a few minutes to complete. During the installation procedure the pacemaker may temporarily change its pacing mode, leaving open the possibility that patients may become symptomatic during the upgrade. 4

Despite the fact that a significant number of patients with an established diagnosis of atrial fibrillation (AF) attend the Emergency Department (ED) with symptoms perceived to be related to underlying arrhythmia, many of these attendances may not be appropriate. We sought to understand the main

Implantable cardioverter-defibrillator (ICD) remains the main therapeutic option in reducing sudden cardiac death . Several randomized trials and registries have shown that ICDs extend survival in patients with severely impaired left ventricular function and mild to moderate heart failure . The delivery of ICD shocks remain an important source of mortality and morbidity. They are potentially proarrhythmic if delivered inappropriately and can worsen heart failure. Shocks are also painful, cause significant anxiety and can also lead to a post-traumatic stress disorder . Inappropriate ICD shocks remain also contribute a significant burden to ICD therapies. We provide an overview of important ICD trials and evolution of anti-tachycardia therapy and identify the principles on which the programming recommendations can be based to safely minimise anti-tachycardia therapies.

Coronary artery perforation as a result of percutaneous coronary intervention is a rare complication which may result in cardiac tamponade, myocardial infarction and death. Perforation of a saphenous vein graft is unusual and generally requires surgical intervention. We describe a novel percutaneous approach that facilitated the successful management of a potentially catastrophic saphenous vein graft (SVG) perforation.

Within the last few years, several resource books on conditions peculiar to the aged have been published. Handbook of Geriatric Psychiatry , edited by Ewald Busse and Dan Blazer, is limited to a subdivision of geriatric knowledge where psychological, biological, and social information is necessary for reference and text purposes in the education of new students and practitioners. The combination of an older and a younger geriatrician as editors has produced an assertive, clear, and concise volume. Of the 26 contributors, almost half are from the Duke University Center for the Study of Aging and Human Development. The rest represent a variety of institutions, such as the Texas Research Institute of Mental Health Services, University of Washington, and universities in New York State, Chicago, and Tampa. All are among the outstanding researchers and teachers in their medical subspecialties and include in their contributions intelligent basic science material, to give a comprehensive

To the Editor.— In light of our own past experience with "Tissue Committee Questions Justification of Surgical Procedure—I" (217:347,1971), we are presently reviewing our own most recent series of surgically removed solitary metastatic tumors of the brain. Craniotomy for solitary metastatic lesions of the brain is recorded in standard texts as a reasonable means of palliating very distressing symptoms as well as prolonging life. Careful preoperative evaluation is most important, both as to the general condition of the patient and the surgical accessibility of the tumor mass. Most favorable are those lesions in a polar position, that is, occupying the frontal, temporal, or occipital pole. Less favorable are the centrally located lesions, and completely unfavorable for excision are those adjacent to and involving the thalamus. Lesions in the posterior fossa are generally unfavorable. Accurate localization of the tumor by contrast studies, preoperative preparation with steroids and osmolar diuretics, accurate