Aspects on endoscopic characterization and clinical management of Barrett's esophagus

Barrett's esophagus (BE) is considered to result from prolonged gastroesophageal reflux and is the only known precursor of esophageal adenocarcinoma. The clinical management of BE patients aims to control esophageal reflux to reduce mucosal injury and neoplastic progression, and to detect early neoplastic lesions in Barrett’s mucosa, suitable for curative endoscopic treatment. The first part of this thesis evaluates the effect of a stepwise increase in the dose of proton pump inhibitors (PPI), on esophageal acidic reflux, symptoms and histology in long segment BE patients (group 1, n=24). We also compare these outcomes in BE patients under PPI with the results of BE patients after clinically successful fundoplication (group 2, n=30). In all but one patient in group 1, it was possible to normalize acid reflux with PPI, resulting in improvements in symptom scores. However, symptomatic amelioration was only significant in the first step of PPI treatment. Patients with PPI or fundoplication had the same levels of symptom scores. Normalization of the acid reflux in both groups was associated with reductions of papillary length, thickness of the basal cell layers, dilation of intercellular spaces, and acute and chronic inflammation of the squamous epithelium. We did not find a significant change in markers of proliferation and differentiation in Barrett’s mucosa associated with normalization of acid reflux in either group. The second part of this thesis assesses 3 different endoscopic classification systems, Amsterdam, Kansas and Nottingham, developed for the characterization of Barrett’s mucosa. These classifications use magnification endoscopy with narrow band imaging (ME-NBI) for the identification of intestinal metaplasia and dysplasia in Barrett’s mucosa. We used 84 video segments from Barrett’s mucosa, that were randomly selected and blindly evaluated by 9 observers with different expertise in the field. All classifications were feasibly but showed suboptimal accuracy and low inter-observer agreement, with slightly better results for the Amsterdam classification. The last part of this thesis evaluates the role of a structured learning program for the application of the Amsterdam classification system. We used the first 70 videos from the 84 randomly selected videos from the previous study. While, during the learning process, there was a decrease in the time spent for evaluation and an increase in declared certainty of prediction, the accuracy in histological prediction did not improve. This classification system was found to be suboptimal in terms of accuracy and inter- and intra-observer agreements. This thesis shows that, in long segment BE patients, acid reflux and symptom scores correlated through several steps of the PPI treatment process, achieving the same level as after a successful fundoplication. If a single dose of PPI is associated with marked improvement of symptoms, higher doses still may be needed for complete acid suppression. Minor changes were found among morphological markers of reflux disease, both in the glandular and in the squamous epithelium, irrespective of medical or surgical treatment. Our results underscore the questionable utility of ME-NBI classification systems for clinical routine practice in BE

Clip and snare lifting technique to assist cannulation of a papilla hidden behind a mucosal fold

No abstract availabl

Mecanismos de modulação da inflamação e angiogénese por polifenois naturais

Metabolismo - Clínica e ExperimentaçãoDoctoral Programme in Metabolism - Clinical and Experimenta

Reconstructing discards profiles of unreported catches

In Portugal it has been estimated that unreported catches represent one third of total catches. Herein, information on landings and total unreported catches (discards) by commercial métier were disaggregated into high taxonomic detail using published scientific studies. Fish accounted for 93.5% (115493 t) of overall unreported catches per year, followed by cephalopods (2345 t, 1.9%) and crustaceans (1754 t, 1.4%). Sharks accounted for 1.3% of total unreported catches in weight (1638 t/y). Unreported taxa consisted mostly of the commercial landed fish species: Scomber colias, Boops boops, Trachurus picturatus, T. trachurus, Merluccius merluccius, Sardina pilchardus, Liza aurata and Micromesistius poutassou, which together accounted for 70% of the unreported discarded catches. The number of unreported/discarded species was highest in artisanal fisheries, followed by trawl and purse seine. In artisanal fisheries, L. aurata, S. colias, S. pilchardus, Trachinus draco and B. boops accounted for 76.4% of the unreported discards. B. boops, S. colias and S. pilchardus were also among the most discarded purse seine species, together with Belone belone accounting for 79% of the unreported catches. In trawl fisheries, T. picturatus (16%), M. merluccius (13%), S. colias (13%) and M. poutassou (13%) accounted for 55% of the trawl discarded unreported catches. The discarded species that most contribute to overall unreported catches are those that are most frequently landed and that most contribute to overall landings in weight.SFRH/BD/104209/2014 and SFRH/ BPD/108949/2015). This work received national funds through the Foundation for Science and Technology (FCT) through project UID/Multi/04326/2013. Karim Erzini was supported by funding from the European Commission’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 634495 for the project Science, Technology, and Society Initiative to minimize Unwanted Catches in European Fisheries (MINOUW)info:eu-repo/semantics/publishedVersio

Predicting procedure duration of colorectal endoscopic submucosal dissection at Western endoscopy centers

Background and study aims Overcoming logistical obstacles for the implementation of colorectal endoscopic submucosal dissection (ESD) requires accurate prediction of procedure times. We aimed to evaluate existing and new prediction models for ESD duration.Patients and methods Records of all consecutive patients who underwent single, non-hybrid colorectal ESDs before 2020 at three Dutch centers were reviewed. The performance of an Eastern prediction model [GIE 2021;94(1):133–144] was assessed in the Dutch cohort. A prediction model for procedure duration was built using multivariable linear regression. The model’s performance was validated using internal validation by bootstrap resampling, internal-external cross-validation and external validation in an independent Swedish ESD cohort.Results A total of 435 colorectal ESDs were analyzed (92% en bloc resections, mean duration 139 minutes, mean tumor size 39 mm). The performance of current unstandardized time scheduling practice was suboptimal (explained variance: R2=27%). We successfully validated the Eastern prediction model for colorectal ESD duration <60 minutes (c-statistic 0.70, 95% CI 0.62–0.77), but this model was limited due to dichotomization of the outcome and a relatively low frequency (14%) of ESDs completed <60 minutes in the Dutch centers. The model was more useful with a dichotomization cut-off of 120 minutes (c-statistic: 0.75; 88% and 17% of “easy” and “very difficult” ESDs completed <120 minutes, respectively). To predict ESD duration as continuous outcome, we developed and validated the six-variable cESD-TIME formula (https://cesdtimeformula.shinyapps.io/calculator/; optimism-corrected R2=61%; R2=66% after recalibration of the slope).Conclusions We provided two useful tools for predicting colorectal ESD duration at Western centers. Further improvements and validations are encouraged with potential local adaptation to optimize time planning

A deep learning system for detection of early Barrett's neoplasia:a model development and validation study

BACKGROUND: Computer-aided detection (CADe) systems could assist endoscopists in detecting early neoplasia in Barrett's oesophagus, which could be difficult to detect in endoscopic images. The aim of this study was to develop, test, and benchmark a CADe system for early neoplasia in Barrett's oesophagus.METHODS: The CADe system was first pretrained with ImageNet followed by domain-specific pretraining with GastroNet. We trained the CADe system on a dataset of 14 046 images (2506 patients) of confirmed Barrett's oesophagus neoplasia and non-dysplastic Barrett's oesophagus from 15 centres. Neoplasia was delineated by 14 Barrett's oesophagus experts for all datasets. We tested the performance of the CADe system on two independent test sets. The all-comers test set comprised 327 (73 patients) non-dysplastic Barrett's oesophagus images, 82 (46 patients) neoplastic images, 180 (66 of the same patients) non-dysplastic Barrett's oesophagus videos, and 71 (45 of the same patients) neoplastic videos. The benchmarking test set comprised 100 (50 patients) neoplastic images, 300 (125 patients) non-dysplastic images, 47 (47 of the same patients) neoplastic videos, and 141 (82 of the same patients) non-dysplastic videos, and was enriched with subtle neoplasia cases. The benchmarking test set was evaluated by 112 endoscopists from six countries (first without CADe and, after 6 weeks, with CADe) and by 28 external international Barrett's oesophagus experts. The primary outcome was the sensitivity of Barrett's neoplasia detection by general endoscopists without CADe assistance versus with CADe assistance on the benchmarking test set. We compared sensitivity using a mixed-effects logistic regression model with conditional odds ratios (ORs; likelihood profile 95% CIs).FINDINGS: Sensitivity for neoplasia detection among endoscopists increased from 74% to 88% with CADe assistance (OR 2·04; 95% CI 1·73-2·42; p&lt;0·0001 for images and from 67% to 79% [2·35; 1·90-2·94; p&lt;0·0001] for video) without compromising specificity (from 89% to 90% [1·07; 0·96-1·19; p=0·20] for images and from 96% to 94% [0·94; 0·79-1·11; ] for video; p=0·46). In the all-comers test set, CADe detected neoplastic lesions in 95% (88-98) of images and 97% (90-99) of videos. In the benchmarking test set, the CADe system was superior to endoscopists in detecting neoplasia (90% vs 74% [OR 3·75; 95% CI 1·93-8·05; p=0·0002] for images and 91% vs 67% [11·68; 3·85-47·53; p&lt;0·0001] for video) and non-inferior to Barrett's oesophagus experts (90% vs 87% [OR 1·74; 95% CI 0·83-3·65] for images and 91% vs 86% [2·94; 0·99-11·40] for video).INTERPRETATION: CADe outperformed endoscopists in detecting Barrett's oesophagus neoplasia and, when used as an assistive tool, it improved their detection rate. CADe detected virtually all neoplasia in a test set of consecutive cases.FUNDING: Olympus.</p

Peroral Endoscopic Myotomy: Establishing a New Program

Achalasia is an esophageal motility disorder characterized by incomplete relaxation of the lower esophageal sphincter (LES) and aperistalsis of the esophageal body. Treatment of achalasia is aimed at decreasing the resting pressure in the LES. Peroral endoscopic myotomy (POEM), derived from natural orifice transluminal endoscopic surgery (NOTES) and advances in endoscopic submucosal dissection (ESD), presents a novel, minimally invasive, and curative endoscopic treatment for achalasia. POEM involves an esophageal mucosal incision followed by creation of a submucosal tunnel crossing the esophagogastric junction and myotomy before closure of the mucosal incision. Although the procedure is technically demanding and requires a certain degree of skill and competency, treatment success is high (90%) with low complication rates. Since the first described POEM in humans in 2010, it has been used increasingly at centers worldwide. This article reviews available published clinical studies demonstrating POEM efficacy and safety in order to present a proposal on how to establish a dedicated POEM program and reach base proficiency for the procedure