1,721,107 research outputs found

    Acute hyperfibrinogenemia impairs cochlear blood flow and hearing function in guinea pigs in vivo

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    Objective: Impairment of microcirculation is a possible cause of sudden sensorineural hearing loss (SSNHL). Fibrinogen is known as a risk factor for both microvascular dysfunction and SSNHL. Therefore, the aim of this study was to investigate the effect of elevated serum levels of fibrinogen on cochlear blood flow and hearing function in vivo. Design: One group of guinea pigs received two consecutive injections of 100 mg fibrinogen while a control group received equimolar doses of albumin. Measurements of cochlear microcirculation by intravital microscopy and of hearing thresholds by auditory brainstem response (ABR) recordings were carried out before, after first and after second injection. Study sample: Ten healthy guinea pigs were randomly assigned to a treatment group or a control group of five animals each. Results: Serum fibrinogen levels were elevated after the first and second injections of fibrinogen compared to basal values and control group respectively. Increasing levels of fibrinogen were paralleled by decreasing cochlear blood flow as well as increasing hearing thresholds. Hearing threshold correlated negatively with cochlear blood flow. Conclusions: The effect of microcirculatory impairment on hearing function could be explained by a malfunction of the cochlear amplifier. Further investigation is needed to quantify cochlear potentials under elevated serum fibrinogen levels

    CT-assisted navigation for retrosigmoidal implantation of the Bonebridge

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    The Bonebridge is an active bone conduction implant (BCI) that is primarily indicated in patients with conductive and combined hearing loss. However, many of these patients present with a radical cavity as a result of previous surgery. In these cases, the implant should not be introduced into the mastoid region, but rather via a retrosigmoid approach to maintain separation from the pathological alteration. To ensure the best possible acoustic transduction, the Bone Conduction-Floating Mass Transducer (BC-FMT) should be positioned near to the cochlea. This requires precise identification of the sigmoid sinus, which cannot be achieved accurately enough using external anatomical landmarks. We thus report on two patients in whom the Bonebridge was implanted via a retrosigmoid approach using CT-guided navigation

    Long-term functional outcome and satisfaction of patients with an active middle ear implant for sensorineural hearing loss compared to a matched population with conventional hearing aids

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    The objectives of the study were to review the results of an active middle ear implant for sensorineural hearing loss in patients who were unable to wear or did not benefit from conventional hearing aids in comparison to patients with a matched degree of hearing loss successfully fitted with a conventional hearing aid. A retrospective chart review of 10 patients (10 ears) after implantation of an active middle ear implant and 12 patients (13 ears) with conventional hearing aids in one tertiary referral center was performed. Intervention for sensorineural hearing loss was the implantation of an active middle ear implant in one group or fitting of conventional hearing aids in the other group. Outcome measures were pure-tone audiometry (auditory thresholds, functional gain), speech audiometry (Freiburg Monosyllabic Test in quiet and in noise) and a quality-of-life questionnaire (Glasgow Benefit Inventory). Average functional gain was 25.2 +/- A 8.6 and 14.6 +/- A 10.8 dB, speech recognition score in noise was 36.6 +/- A 18.4 and 31.2 +/- A 19.2 % and in quiet was 66.0 +/- A 23.2 and 61.5 +/- A 23.8 %, Glasgow Benefit Inventory total score was 38.3 +/- A 32.3 and 24.8 +/- A 22.2 in patients with active middle ear implants and conventional hearing aids, respectively. In two patient groups matched for degree of sensorineural hearing loss, active middle ear implants provided comparable speech recognition and superior functional gain and quality of life compared to conventional hearing aids. Level of evidence: 4

    TNF-alpha inhibition using etanercept prevents noise-induced hearing loss by improvement of cochlear blood flow in vivo

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    Objective: Exposure to loud noise can impair cochlear microcirculation and cause noise-induced hearing loss (NIHL). TNF-alpha signaling has been shown to be activated in NIHL and to control spiral modiolar artery vasoconstriction that regulates cochlear microcirculation. It was the aim of this experimental study to analyse the effects of the TNF-alpha inhibitor etanercept on cochlear microcirculation and hearing threshold shift in NIHL in vivo. Design: After assessment of normacusis using ABR, loud noise (106 dB SPL, 30 minutes) was applied on both ears in guinea pigs. Etanercept was administered systemically after loud noise exposure while control animals received a saline solution. In vivo fluorescence microscopy of strial capillaries was performed after surgical exposure of the cochlea for microcirculatory analysis. ABR measurements were derived from the contralateral ear. Study sample: Guinea pigs (n=6, per group). Results: Compared to controls, cochlear blood flow in strial capillary segments was significantly increased in etanercept-treated animals. Additionally, hearing threshold was preserved in animals receiving the TNF-alpha inhibitor in contrast to a significant threshold raising in controls. Conclusions: TNF-alpha inhibition using etanercept improves cochlear microcirculation and protects hearing levels after loud noise exposure and appears as a promising treatment strategy for human NIHL

    IgE reactivity patterns in patients with allergic rhinoconjunctivitis to ragweed and mugwort pollens

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    Background: Differential diagnosis between ragweed and mugwort pollen allergy represents a large clinical problem in areas where both plants are present. The aim of this study was to investigate ragweed-and mugwort-sensitized patients to identify specific IgE reactivity profiles. Results were correlated to clinical findings such as medical history and health-related quality of life (HRQL). Methods: Seventy-four patients with allergic rhinoconjunctivitis between July and October were examined and underwent in vivo tests (skin-prick test [SPT] and nasal provocation). Sera were evaluated for IgE reactivity to mugwort and ragweed pollen extracts, major (Art v 1; Amb a 1) and minor (profilin and calcium-binding protein) allergens. HRQL was evaluated using a standardized questionnaire. Results: Seventy-one patients revealed positive SPT reactivity against mugwort and 60 patients against ragweed extracts. Of these patients, 74 revealed IgE antibodies against mugwort extracts, whereas anti-Art v 1 antibodies were detectable in 50 individuals. Fifty-five patients showed IgE antibodies against natural ragweed extracts; anti-Amb v 1 antibodies were detected in six cases only. Using standardized clinical history and HRQL questionnaires we were not able to detect any differences within different reactivity patterns. Conclusion: Within the investigated population of 74 weed-allergic patients the prevalence of true mugwort and ragweed sensitization can be calculated as 68 and 8%. High prevalence of ragweed sensitization when testing with full extracts can be explained by cross-reactivity between other weeds, e. g., mugwort rather than cosensitization. Differences in medical history and HRQL between different reactivity patterns were not detectable. (Am J Rhinol Allergy 26, 31-35, 2012; doi: 10.2500/ajra.2012.26.3698

    Preliminary Functional Results and Quality of Life After Implantation of a New Bone Conduction Hearing Device in Patients With Conductive and Mixed Hearing Loss

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    Objective: To review functional results and quality of life of the first patients implanted with a newly introduced bone conduction implant system. Study Design: Retrospective chart analysis of 6 patients (6 ears) implanted for conductive hearing loss (CHL) and mixed hearing loss (MHL) in 1 tertiary referral center between July 2012 and February 2013. Methods: Implantation of a new bone conduction hearing device. Pure tone audiometry (air conduction and bone conduction thresholds, pure tone average, air-bone gap, and functional gain), speech audiometry (Freiburg Monosyllabic Test), intraoperative and postoperative complication rate, and patient satisfaction (Glasgow benefit inventory [GBI]) were assessed. Results: Air-conduction pure tone average (PTA) was 58.8 +/- 8.2 dB HL. Unaided average air-bone gap (ABG) was 33.3 +/- 6.2 dB. Aided air-conduction PTA in sound field was 25.2 +/- 5.1 dB HL. Aided average ABG was -0.3 +/- 7.3 dB. Average functional gain was 33.6 +/- 7.2 dB. Mean improvement of GBI was +36.1. No intraoperative complications occurred. During a follow-up period of 8.5 +/- 2.2 months, no device failure and no need for revision surgery occurred. Conclusion: Audiometric results of the new bone conduction hearing system are satisfying and comparable to the results of devices that have been applied previously for CHL and MHL. Intraoperatively and postoperatively, no complications were noted. Level of Evidence: 4 (Individual retrospective cohort study) Level of Evidence: 4 (Individual retrospective cohort study

    Coated collagen patches for closure of pharyngo-cutaneous fistulas

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    After laryngectomy or lateral pharyngotomy for treatment of laryngeal or hypopharyngeal cancer the occurrence of a pharyngo-cutaneous fistula is a challenging complication. Especially after previous radiotherapy and expanded surgical resections of mucosa the management is demanding. Besides the prolonged hospital stay, increased treatment costs and reduced quality of life, a delayed adjuvant treatment follows the development of a fistula. Treatment strategies range from conservative procedures comprising parenteral nutrition, antibiotics and local wound care to primary surgical closure or reconstructive tissue transfer. We report three cases of using the fibrin/thrombin-coated collagen patch TachoSil (R) as a solitary or adjuvant strategy in surgical treatment. In one patient primary closure of the fistula was achieved by transoral application of the collagen patch. In the other cases a not tension free primary suture was strengthened by the adjuvant use of TachoSil (R). The healing process was rapid and straightforward in all patients. The use of TachoSil (R) may be indicated in between conservative treatment strategies and reconstructive surgery. After occurrence of a fistula the healing process is intended to be accelerated by primary closure with TachoSil (R) or by sealing of a primary suture. (C) 2014 Elsevier Inc. All rights reserved
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