Development Of A Prototype Of Video Synchronisation For Relocalization Of Biopsy Sites During Endoscopic Evaluation Of Barrett's Oesophagus: Preliminary Experimental And Clinical Study

International audienceINTRODUCTION: The prevalence of Barrett's oesophagus (BE) is 5 to 6% in the general population, with a progression from dysplasia to adenocarcinoma 0.6 to 0.7 patient-years. Hence, endoscopic surveillance is justified to detect early lesions accessible to endoscopic treatment. However, the relocalisation of lesions detected by biopsies may be difficult during follow-up endoscopies. The purpose of this study was to evaluate the prototype of a magnetic probe for accurate location of the position of the endoscope, allowing the relocalisation of this position in a subsequent endoscopy. We report the results of a feasibility study in pigs and the use of this device in two patients with BE. AIMS & METHODS: The system consists of an electromagnetic (EM) field transmitter and an EM probe constituting the electromagnetic tracking system (EMS) (NDI, Aurora). The EM probe is inserted through the operating channel of a double channel gastroscope. The EM field generator is positionned on the patient chest wall. The system also includes a new software developed at IHU/IRCAD, which performs simultaneous recording of the video from the endoscope alongwith its corresponding position, as measured by the EMS. During a second endoscopy, this software allows automatic synchronization of the recorded video to provide relocalisation of the endoscope in front of previous biopsy sites in the oesophagus. The system was tested in 5 anesthetized pigs. During the first endoscopy, ten markings were performed by argon plasma electrocoagulation (ERBE Tübingen, Germany) in the distal esophagus. The position of each marking was recorded by the system. A second operator to then performed a blind endoscopy on the same pigs and was asked to follow the system implicitly as a guide to relocate the markings. In 2 patients with BE, the system was then tested to facilitate relocalization of the biopsy sites. RESULTS: Ten markings were made in the distal oeosphagus of 5. After withdrawal of the endoscope the second operator found 48 of the 50 markings (96%) using the guidance provided by the system. The positioning of the endoscope provided by the EMS system was within a 2mm range from the initial positionning. In the evaluation of BE patients, the system relocalized the biospy sites within a range of 3mm. CONCLUSION: This preliminary study shows the feasibility of the EMS prototype to relocalize the endoscope in the oesophagus within an acceptable range. The clinical usefulness of this system should be evaluated further during the follow-up of patients with BE

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Second-generation colon capsule endoscopy compared with colonoscopy

Colon capsule endoscopy (CCE) represents a noninvasive technology that allows visualization of the colon without requiring sedation and air insufflation. A second-generation colon capsule endoscopy system (PillCam Colon 2) (CCE-2) was developed to increase sensitivity for colorectal polyp detection compared with the first-generation system. OBJECTIVE: To assess the feasibility, accuracy, and safety of CCE-2 in a head-to-head comparison with colonoscopy. DESIGN AND SETTING: Prospective, multicenter trial including 8 European sites. PATIENTS: This study involved 117 patients (mean age 60 years). Data from 109 patients were analyzed. INTERVENTION: CCE-2 was prospectively compared with conventional colonoscopy as the criterion standard for the detection of colorectal polyps that are >/=6 mm or masses in a cohort of patients at average or increased risk of colorectal neoplasia. Colonoscopy was independently performed within 10 hours after capsule ingestion or on the next day. MAIN OUTCOME MEASUREMENTS: CCE-2 sensitivity and specificity for detecting patients with polyps >/=6 mm and >/=10 mm were assessed. Capsule-positive but colonoscopy-negative cases were counted as false positive. Capsule excretion rate, level of bowel preparation, and rate of adverse events also were assessed. RESULTS: Per-patient CCE-2 sensitivity for polyps >/=6 mm and >/=10 mm was 84% and 88%, with specificities of 64% and 95%, respectively. All 3 invasive carcinomas were detected by CCE-2. The capsule excretion rate was 88% within 10 hours. Overall colon cleanliness for CCE-2 was adequate in 81% of patients. LIMITATIONS: Not unblinding the CCE-2 results at colonoscopy; heterogenous patient population; nonconsecutive patients. CONCLUSION: In this European, multicenter study, CCE-2 appeared to have a high sensitivity for the detection of clinically relevant polypoid lesions, and it might be considered an adequate tool for colorectal imaging

Natalizumab treatment shows low cumulative probabilities of confirmed disability worsening to EDSS milestones in the long-term setting.

Abstract Background Though the Expanded Disability Status Scale (EDSS) is commonly used to assess disability level in relapsing-remitting multiple sclerosis (RRMS), the criteria defining disability progression are used for patients with a wide range of baseline levels of disability in relatively short-term trials. As a result, not all EDSS changes carry the same weight in terms of future disability, and treatment benefits such as decreased risk of reaching particular disability milestones may not be reliably captured. The objectives of this analysis are to assess the probability of confirmed disability worsening to specific EDSS milestones (i.e., EDSS scores ≥3.0, ≥4.0, or ≥6.0) at 288 weeks in the Tysabri Observational Program (TOP) and to examine the impact of relapses occurring during natalizumab therapy in TOP patients who had received natalizumab for ≥24 months. Methods TOP is an ongoing, open-label, observational, prospective study of patients with RRMS in clinical practice. Enrolled patients were naive to natalizumab at treatment initiation or had received ≤3 doses at the time of enrollment. Intravenous natalizumab (300 mg) infusions were given every 4 weeks, and the EDSS was assessed at baseline and every 24 weeks during treatment. Results Of the 4161 patients enrolled in TOP with follow-up of at least 24 months, 3253 patients with available baseline EDSS scores had continued natalizumab treatment and 908 had discontinued (5.4% due to a reported lack of efficacy and 16.4% for other reasons) at the 24-month time point. Those who discontinued due to lack of efficacy had higher baseline EDSS scores (median 4.5 vs. 3.5), higher on-treatment relapse rates (0.82 vs. 0.23), and higher cumulative probabilities of EDSS worsening (16% vs. 9%) at 24 months than those completing therapy. Among 24-month completers, after approximately 5.5 years of natalizumab treatment, the cumulative probabilities of confirmed EDSS worsening by 1.0 and 2.0 points were 18.5% and 7.9%, respectively (24-week confirmation), and 13.5% and 5.3%, respectively (48-week confirmation). The risks of 24- and 48-week confirmed EDSS worsening were significantly higher in patients with on-treatment relapses than in those without relapses. An analysis of time to specific EDSS milestones showed that the probabilities of 48-week confirmed transition from EDSS scores of 0.0–2.0 to ≥3.0, 2.0–3.0 to ≥4.0, and 4.0–5.0 to ≥6.0 at week 288 in TOP were 11.1%, 11.8%, and 9.5%, respectively, with lower probabilities observed among patients without on-treatment relapses (8.1%, 8.4%, and 5.7%, respectively). Conclusions In TOP patients with a median (range) baseline EDSS score of 3.5 (0.0–9.5) who completed 24 months of natalizumab treatment, the rate of 48-week confirmed disability worsening events was below 15%; after approximately 5.5 years of natalizumab treatment, 86.5% and 94.7% of patients did not have EDSS score increases of ≥1.0 or ≥2.0 points, respectively. The presence of relapses was associated with higher rates of overall disability worsening. These results were confirmed by assessing transition to EDSS milestones. Lower rates of overall 48-week confirmed EDSS worsening and of transitioning from EDSS score 4.0–5.0 to ≥6.0 in the absence of relapses suggest that relapses remain a significant driver of disability worsening and that on-treatment relapses in natalizumab-treated patients are of prognostic importance

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation