Volumetric laser endomicroscopy and its application to Barrett's esophagus: results from a 1,000 patient registry.

Volumetric laser endomicroscopy (VLE) uses optical coherence tomography (OCT) for real-time, microscopic cross-sectional imaging. A US-based multi-center registry was constructed to prospectively collect data on patients undergoing upper endoscopy during which a VLE scan was performed. The objective of this registry was to determine usage patterns of VLE in clinical practice and to estimate quantitative and qualitative performance metrics as they are applied to Barrett's esophagus (BE) management. All procedures utilized the NvisionVLE Imaging System (NinePoint Medical, Bedford, MA) which was used by investigators to identify the tissue types present, along with focal areas of concern. Following the VLE procedure, investigators were asked to answer six key questions regarding how VLE impacted each case. Statistical analyses including neoplasia diagnostic yield improvement using VLE was performed. One thousand patients were enrolled across 18 US trial sites from August 2014 through April 2016. In patients with previously diagnosed or suspected BE (894/1000), investigators used VLE and identified areas of concern not seen on white light endoscopy (WLE) in 59% of the procedures. VLE imaging also guided tissue acquisition and treatment in 71% and 54% of procedures, respectively. VLE as an adjunct modality improved the neoplasia diagnostic yield by 55% beyond the standard of care practice. In patients with no prior history of therapy, and without visual findings from other technologies, VLE-guided tissue acquisition increased neoplasia detection over random biopsies by 700%. Registry investigators reported that VLE improved the BE management process when used as an adjunct tissue acquisition and treatment guidance tool. The ability of VLE to image large segments of the esophagus with microscopic cross-sectional detail may provide additional benefits including higher yield biopsies and more efficient tissue acquisition. Clinicaltrials.gov NCT02215291

Endoscopic bariatric and metabolic therapies for non-alcoholic fatty liver disease: Evidence and perspectives

Non-alcoholic fatty liver disease (NAFLD) has become the most common liver disease in industrialized countries because of the worldwide epidemic of obesity. Beyond metabolic complications, a subset of patients with NAFLD develop non-alcoholic steatohepatitis (NASH) with fibrosis, which is emerging as a leading cause of liver transplantation due to progression to cirrhosis and cancer. For these reasons, NAFLD is considered a public health burden. In recent years endoscopic bariatric and metabolic therapies (EBMT) have emerged as safe and effective for the treatment of obesity and type 2 diabetes mellitus. EBMT include gastric and duodenal devices and techniques such as intragastric balloons, endoscopic sleeve gastroplasty, endoscopic small bowel by-pass and duodenal mucosal resurfacing. Observational studies and pilot trials have revealed beneficial effects of EBMT on NAFLD as assessed by non-invasive parameters or histology. In this review we summarise current evidence for the efficacy and safety of EBMT in obese patients with NAFLD and examine future clinical applications

Efficacy and safety of self-expandable metal stents for management of bariatric surgery leaks. A systematic review and meta-analysis

Background: Post bariatric surgery leaks can be difficult to manage, and surgical re-exploration is associated with significant morbidity and mortality. Endoscopic deployment of self-expandable metal stents (SEMS) is a less invasive modality and has been utilized for management of such leaks avoiding the need for re-exploration surgery in selected patients. Aim: Conduct a systematic review and meta-analysis to evaluate the efficacy and safety of endoscopically placed SEMS for management of post bariatric surgery leaks. Methods: We searched Medline, Embase and Cochrane library from inception through November 26, 2019 to identify studies evaluating the efficacy of SEMS for treatment of post bariatric surgery leaks. The primary outcome of interest was rate of successful closure of leaks determined radiologically after removal of SEMS. Secondary outcomes included rates of successful stent removal and adverse events including rate of stent migration. These outcomes were presented as weighted pooled rates WPR and analyzed using random effects model of meta-analysis. Publication bias was calculated with funnel plots and Beg Mazumdar test. Duval and Tweedie’s trim and fill test was used to adjust for publication bias. To avoid inherent bias associated with case reports and small case series only studies with at least 10 patients were included. NIH tool was used for single arm before-after studies for quality assessment of individual studies. Results: A total of 19 observational studies with 539 patients with post-surgery leaks were included in this systematic review and meta-analysis. Among the patients, 58% were females. 22% of patients had undergone Roux-en-Y bypass surgery, 73% % had laparoscopic sleeve gastrectomy 2% had duodenal switch surgery while the remaining 3% had laparoscopic gastric banding. Fourteen studies were rated as good quality, while 5 studies were rated as fair quality as per NIH tool for quality assessment. Pooled WPR with 95% confidence interval (CI) was 83.2% (79.6%, 86.3%), I2=0%. Funnel plot appeared asymmetric and publication bias was detected by Beg Mazumdar test (P=0.05). After adjusting for publication bias pooled WPR was 82.6% (78%, 86.4%). Pooled WPR for successful removal of stents was 94.9% (90.7%, 97.3%), I2=0%. Pooled WPR with 95% CI for rate of stent migration was 18.8% (13.3%, 25.9%) with significant heterogeneity. Conclusions: SEMS appear to be a favorable option for management of majority of patients with post bariatric surgery leaks. However, they have a significant risk of stent migration thus necessitating multiple endoscopies. Prospective studies evaluating the timing of stent placement and comparison with re-exploration surgery are needed

An Evolutionary Approach to the Multi-Level Capacitated Minimum Spanning Tree Problem

Capacitated network design is a crucial problem to telecommunications network planners. In this paper we consider the Multi-Level Capacitated Minimum Spanning Tree Problem (MLCMST), a generalization of the well-known Capacitated Minimum Spanning Tree Problem. We present a genetic algorithm, based on the notion of grouping, that is quite effective in solving large-scale problems to within 10% of optimality

Development and external validation of a prediction risk model for short-term mortality among hospitalized U.S. COVID-19 patients: A proposal for the COVID-AID risk tool

BACKGROUND: The 2019 novel coronavirus disease (COVID-19) has created unprecedented medical challenges. There remains a need for validated risk prediction models to assess short-term mortality risk among hospitalized patients with COVID-19. The objective of this study was to develop and validate a 7-day and 14-day mortality risk prediction model for patients hospitalized with COVID-19. METHODS: We performed a multicenter retrospective cohort study with a separate multicenter cohort for external validation using two hospitals in New York, NY, and 9 hospitals in Massachusetts, respectively. A total of 664 patients in NY and 265 patients with COVID-19 in Massachusetts, hospitalized from March to April 2020. RESULTS: We developed a risk model consisting of patient age, hypoxia severity, mean arterial pressure and presence of kidney dysfunction at hospital presentation. Multivariable regression model was based on risk factors selected from univariable and Chi-squared automatic interaction detection analyses. Validation was by receiver operating characteristic curve (discrimination) and Hosmer-Lemeshow goodness of fit (GOF) test (calibration). In internal cross-validation, prediction of 7-day mortality had an AUC of 0.86 (95%CI 0.74–0.98; GOF p = 0.744); while 14-day had an AUC of 0.83 (95%CI 0.69–0.97; GOF p = 0.588). External validation was achieved using 265 patients from an outside cohort and confirmed 7- and 14-day mortality prediction performance with an AUC of 0.85 (95%CI 0.78–0.92; GOF p = 0.340) and 0.83 (95%CI 0.76–0.89; GOF p = 0.471) respectively, along with excellent calibration. Retrospective data collection, short follow-up time, and development in COVID-19 epicenter may limit model generalizability. CONCLUSIONS: The COVID-AID risk tool is a well-calibrated model that demonstrates accuracy in the prediction of both 7-day and 14-day mortality risk among patients hospitalized with COVID-19. This prediction score could assist with resource utilization, patient and caregiver education, and provide a risk stratification instrument for future research trials