Current Issue : October - December Volume : 2015 Issue Number : 4 Articles : 4 Articles
Background. Specific clinical conditions could compromise cochlear implantation outcomes and drastically reduce the chance of\nan acceptable development of perceptual and linguistic capabilities. These conditions should certainly include the presence of inner\near malformations or brain abnormalities. The aims of this work were to study the diagnostic value of high resolution computed\ntomography (HRCT) and magnetic resonance imaging (MRI) in children with sensorineural hearing loss who were candidates for\ncochlear implants and to analyse the anatomic abnormalities of the ear and brain in patients who underwent cochlear implantation.\nWe also analysed the effects of ear malformations and brain anomalies on the CI outcomes, speculating on their potential role in the\nmanagement of language developmental disorders. Methods.The present study is a retrospective observational review of cochlear\nimplant outcomes among hearing-impaired children who presented ear and/or brain anomalies at neuroimaging investigations\nwith MRI and HRCT. Furthermore, genetic results frommolecular genetic investigations (GJB2/GJB6 and, additionally, in selected\ncases, SLC26A4 or mitochondrial-DNA mutations) on this study group were herein described. Longitudinal and cross-sectional\nanalysis was conducted using statistical tests. Results. Between January 1, 1996 and April 1, 2012, at the ENT-Audiology Department\nof the University Hospital of Ferrara, 620 cochlear implantations were performed.There were 426 implanted children at the time\nof the present study (who were <18 years). Among these, 143 patients (64 females and 79 males) presented ear and/or brain\nanomalies/lesions/malformations at neuroimaging investigations with MRI and HRCT. The age of the main study group (143\nimplanted children) ranged from 9 months and 16 years (average = 4.4; median = 3.0). Conclusions. Good outcomes with cochlear\nimplants are possible in patients who present with inner ear or brain abnormalities, even if central nervous system anomalies\nrepresent a negative prognostic factor that is made worse by the concomitant presence of cochlear malformations. Common cavity\nand stenosis of the internal auditory canal (less than 2 mm) are negative prognostic factors even if brain lesions are absent....
To further understand the response of the human\nbrainstem to electrical stimulation, a series of experiments\ncompared the effect of pulse rate and polarity\non detection thresholds between auditory brainstem\nimplant (ABI) and cochlear implant (CI) patients.\nExperiment 1 showed that for 400-ms pulse trains, ABI\nusers� thresholds dropped by about 2 dB as pulse rate\nwas increased from 71 to 500 pps, but only by an\naverage of 0.6 dB as rate was increased further to 3500\npps. This latter decrease was much smaller than the\n7.7-dB observed for CI users. A similar result was\nobtained for pulse trains with a 40-ms duration.\nFurthermore, experiment 2 showed that the threshold\ndifference between 500- and 3500-pps pulse trains\nremained much smaller for ABI than for CI users,\neven for durations as short as 2 ms, indicating the\neffect of a fast-acting mechanism. Experiment 3\nshowed that ABI users� thresholds were lower for\nalternating-polarity than for fixed-polarity pulse trains,\nand that this difference was greater at 3500 pps than\nat 500 pps, consistent with the effect of pulse rate on\nABI users� thresholds being influenced by charge\ninteractions between successive biphasic pulses. Experiment\n4 compared thresholds and loudness between\ntrains of asymmetric pulses of opposite polarity,\nin monopolar mode, and showed that in both cases\nless current was needed when the anodic, rather than\nthe cathodic, current was concentrated into a short\ntime interval. This finding is similar to that previously\nobserved for CI users and is consistent with ABI users\nbeing more sensitive to anodic than cathodic current.\nWe argue that our results constrain potential explanations\nfor the differences in the perception of\nelectrical stimulation by CI and ABI users, and have\npotential implications for future ABI stimulation\nstrategies....
Background This study investigated the relationships\nbetween histomorphological aspects of breast capsules,\nincluding capsule thickness, collagen fiber alignment, the\npresence of a-smooth muscle actin (a-SMA)ââ?¬â??positive\nmyofibroblasts, and clinical observations of capsular\ncontracture.\nMethods Breast capsule samples were collected at the\ntime of implant removal in patients undergoing breast\nimplant replacement or revision surgery. Capsular contracture\nwas scored preoperatively using the Baker scale.\nHistological analysis included hematoxylin and eosin\nstaining, quantitative analysis of capsule thickness, collagen\nfiber alignment, and immunohistochemical evaluation\nfor a-SMA and CD68.\nResults Forty-nine samples were harvested from 41 patients.\nA large variation in histomorphology was observed\nbetween samples, including differences in cellularity, fiber\ndensity and organization, and overall structure. Baker I\ncapsules were significantly thinner than Baker II, III, and\nIV capsules. Capsule thickness positively correlated with\nimplantation time for all capsules and for contracted capsules\n(Baker III and IV). Contracted capsules had significantly\ngreater collagen fiber alignment and a-SMAââ?¬â??\npositive immunoreactivity than uncontracted capsules\n(Baker I and II). Capsules from textured implants had\nsignificantly less a-SMAââ?¬â??positive immunoreactivity than\ncapsules from smooth implants.\nConclusion The histomorphological diversity observed\nbetween the breast capsules highlights the challenges of\nidentifying mechanistic trends in capsular contracture. Our\nfindings support the role of increasing capsule thickness\nand collagen fiber alignment, and the presence of contractile\nmyofibroblasts in the development of contracture.\nThese changes in capsule structure may be directly related\nto palpation stiffness considered in the Baker score. Approaches\nto disrupt these processes may aid in decreasing\ncapsular contracture rates.\nLevel of Evidence III This journal requires that authors\nassign a level of evidence to each article. For a full description\nof these Evidence-Based Medicine ratings, please\nrefer to the Table of Contents or the online Instructions to\nAuthors www.springer.com/00266....
Background\nDue to an ageing population and demographic changes worldwide, a higher prevalence of\nheart disease is forecasted, which causes an even higher demand for cardiac implants in future.\nThe increasing high incidence of clinical adverse events attributed especially to highrisk\nmedical devices has led an advocated change from many stakeholders. This holds especially\ntrue for devices like cardiac implants, with their high-risk nature and high complication\nrates associated with considerable mortality, due to their frequent use in older\npopulations with frequent co-morbidities. To ensure patients� safety, the objective of this\nstudy is to analyze different cardiac implants recall reasons and different recall systems,\nbased on an overview of the recalls of cardiac implant medical devices in the last decade.\nOn the basis of the results from this structured analysis, this study provides recommendations\non how to avoid such recalls from a manufacturer perspective, as well as how to timely\nreact to an adverse event from a post-surveillance system perspective.\nMethods and Findings\nA systematic search of cardiac implant recalls information has been performed in the\nPubMed, ScienceDirect and Scopus databases, as well as data sources in regulatory authorities\nfrom 193 UN Member States. Data has been extracted for the years 2004-2014\nwith the following criteria applied: cardiac implant medical device recalls and reasons for recall,\nassociated harm or risk to patients. From the data sources described above, eleven\nregulatory authorities and 103 recall reports have been included in this study. The largest\ncardiac implant categories include ICDs 40.8%, pacemakers 14.5%and stents 14.5%. Regarding\nthe recall reasons, the majority of reports were related to device battery problems\n(33.0%) and incorrect therapy delivery (31.1%). From a total of 103 recall reports, five reported\ndeath and serious injuries. Our review highlights weaknesses in the current cardiac\nimplant recall system, including data reporting and management issues and provides recommendations\nfor the improvement of safety information and management.\nConclusion\nDue to the mortality associated with the nature of cardiac implants, the traceability and\ntransparency of safety hazards information is crucial. By a structured analysis of recall reasons\nand their efficient management, important knowledge is gained to inform an effective\nsafety-reporting system for monitoring the safety of cardiac implanted patients, ideally by\nbuilding up cardiac implant registries worldwide in the future....
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