The Experts below are selected from a list of 204 Experts worldwide ranked by ideXlab platform

Roberto F Casal - One of the best experts on this subject based on the ideXlab platform.

Peter E. Mchugh - One of the best experts on this subject based on the ideXlab platform.

  • Evaluating the interaction of a Tracheobronchial Stent in an ovine in-vivo model
    Biomechanics and Modeling in Mechanobiology, 2018
    Co-Authors: Donnacha J. Mcgrath, Anja Lena Thiebes, Christian G. Cornelissen, Barry O’brien, Stefan Jockenhoevel, Mark Bruzzi, Peter E. Mchugh
    Abstract:

    Tracheobronchial Stents are used to restore patency to stenosed airways. However, these devices are associated with many complications such as Stent migration, granulation tissue formation, mucous plugging and Stent strut fracture. Of these, granulation tissue formation is the complication that most frequently requires costly secondary interventions. In this study a biomechanical lung modelling framework recently developed by the authors to capture the lung in-vivo stress state under physiological loading is employed in conjunction with ovine pre-clinical Stenting results and device experimental data to evaluate the effect of Stent interaction on granulation tissue formation. Stenting is simulated using a validated model of a prototype covered laser-cut Tracheobronchial Stent in a semi-specific biomechanical lung model, and physiological loading is performed. Two computational methods are then used to predict possible granulation tissue formation: the standard method which utilises the increase in maximum principal stress change, and a newly proposed method which compares the change in contact pressure over a respiratory cycle. These computational predictions of granulation tissue formation are then compared to pre-clinical Stenting observations after a 6-week implantation period. Experimental results of the pre-clinical Stent implantation showed signs of granulation tissue formation both proximally and distally, with a greater proximal reaction. The standard method failed to show a correlation with the experimental results. However, the contact change method showed an apparent correlation with granulation tissue formation. These results suggest that this new method could be used as a tool to improve future device designs.

  • An ovine in vivo framework for Tracheobronchial Stent analysis
    Biomechanics and Modeling in Mechanobiology, 2017
    Co-Authors: Donnacha J. Mcgrath, Anja Lena Thiebes, Christian G. Cornelissen, Mary B. O’shea, Barry O’brien, Stefan Jockenhoevel, Mark Bruzzi, Peter E. Mchugh
    Abstract:

    Tracheobronchial Stents are most commonly used to restore patency to airways stenosed by tumour growth. Currently all Tracheobronchial Stents are associated with complications such as Stent migration, granulation tissue formation, mucous plugging and Stent strut fracture. The present work develops a computational framework to evaluate Tracheobronchial Stent designs in vivo. Pressurised computed tomography is used to create a biomechanical lung model which takes into account the in vivo stress state, global lung deformation and local loading from pressure variation. Stent interaction with the airway is then evaluated for a number of loading conditions including normal breathing, coughing and ventilation. Results of the analysis indicate that three of the major complications associated with Tracheobronchial Stents can potentially be analysed with this framework, which can be readily applied to the human case. Airway deformation caused by lung motion is shown to have a significant effect on Stent mechanical performance, including implications for Stent migration, granulation formation and Stent fracture.

  • Evaluation of cover effects on bare Stent mechanical response
    Journal of The Mechanical Behavior of Biomedical Materials, 2016
    Co-Authors: Donnacha J. Mcgrath, Mark Bruzzi, Barry O'brien, Nicola Kelly, Johanna Clauser, Ulrich Steinseifer, Peter E. Mchugh
    Abstract:

    Covered Tracheobronchial Stents are used to prevent tumour growth from reoccluding the airways. In the present work a combination of experimental and computational methods are used to present the mechanical effects that adhered covers can have on Stent performance. A prototype Tracheobronchial Stent is characterised in bare and covered configurations using radial force, flat plate and a novel non-uniform radial force test, while computational modelling is performed in parallel to extensively inform the physical testing. Results of the study show that cover configuration can have a significant structural effect on Stent performance, and that Stent response (bare or covered) is especially loading specific, highlighting that the loading configuration that a Stent is about to be subjected to should be considered before Stent implantation.

Jose Melendez - One of the best experts on this subject based on the ideXlab platform.

Paul Anderson - One of the best experts on this subject based on the ideXlab platform.

  • Is There a Beneficial Role for a Flexible Bronchoscopic Approach to Oesophageal Tumour-related Tracheobronchial Stenosis?
    Lung, 2011
    Co-Authors: Emmet E. Mcgrath, David Warriner, Paul Anderson
    Abstract:

    Background Interventional pulmonology, in particular, Tracheobronchial Stent insertion, has been well described in the treatment of Tracheobronchial malignant disease. Its benefits are particularly obvious in patients with inoperable malignancy or in those unfit for surgery and have been extensively described. Fewer data exist on the benefits of using self-expanding metal Stents (SEMS) inserted via flexible bronchoscopy in the treatment of Tracheobronchial stenosis due to extrinsic compression or infiltration from primary oesophageal malignancy. Methods We retrospectively reviewed all patients who had Stent insertion via flexible bronchoscopy from 2002 to 2010 at our institution. Results We found 14 patients who had Ultraflex™ self-expanding metal Stent insertion for this condition. We analysed this group of patients with respect to their presentation; indications for Stent insertion over surgery; size, location, and number of Stents inserted; sedative dose; complications of therapy; and survival time. Conclusion We conclude that insertion of SEMS via flexible bronchoscopy is a safe and effective therapy for those individuals who require palliation or are too unfit for the general anaesthesia required for surgery. Moreover, this form of Stent insertion may be performed by respiratory physicians in the bronchoscopy suite, rather than by their cardiothoracic counterparts in theatre.

Jeffrey A Golden - One of the best experts on this subject based on the ideXlab platform.

  • outcomes of Tracheobronchial Stent placement for benign disease
    Radiology, 2006
    Co-Authors: Raymond H Thornton, Roy L Gordon, Robert K Kerlan, Jeanne M Laberge, Mark W Wilson, Kristen A Wolanske, Michael B Gotway, Geoffrey S Hastings, Jeffrey A Golden
    Abstract:

    Purpose: To retrospectively determine long-term outcomes in patients who have undergone Tracheobronchial Stent placement for benign diseases. Materials and Methods: Institutional Review Board approval was obtained for this retrospective HIPAA-compliant study, with waiver of informed consent. Forty patients (22 female, 18 male; mean age, 52.0 years) who were treated with metallic airway Stents for benign stenosis were identified from an interventional radiology database. Causes of airway stenosis included transplant stricture (n = 13), tracheal tube injury (n = 10), inflammation (n = 6), tracheobronchomalacia (n = 4), infection (n = 3), and extrinsic compression (n = 4). Follow-up, which ranged from 6 to 2473 days, was performed by means of chart review for deceased patients and by means of clinical visit or telephone interview for surviving patients. Survival, primary patency, and assisted patency were estimated by using the Kaplan-Meier product limits method. Results: Initial technical success was achiev...

  • benign Tracheobronchial stenoses changes in short term and long term pulmonary function testing after expandable metallic Stent placement
    Journal of Computer Assisted Tomography, 2002
    Co-Authors: Michael B Gotway, Robert K Kerlan, Jeanne M Laberge, Mark W Wilson, Jeffrey A Golden, Richard W Webb, Gautham P Reddy, Roy L Gordon
    Abstract:

    Purpose: To determine the short- and long-term improvement in airflow dynamics in patients undergoing Tracheobronchial Stent placement for benign airway stenoses. Methods: Twenty-two patients underwent 34 tracheal and/or bronchial Stent placement procedures for benign airway stenoses and had the results of pulmonary function tests available. Stent placement indications included bronchomalacia after lung transplantation (n = 11), postintubation stenoses (n = 6), relapsing polychondritis (n = 2), and 1 each of tracheomalacia, tracheal compression, and histoplasmosis. Six patients underwent more than one Stent placement procedure (range: 2-7 procedures). The mean forced expiratory volume in one second (FEV 1 ), forced expiratory flow rate in the midportion of the forced vital capacity curve (FEF 25-75 ), forced vital capacity, and peak flow (PF) rate obtained before Stent placement were compared with those immediately after Stent placement and with those measurements most remote from Stent placement using the paired two-tailed t test. Results: All patients reported improved respiratory function immediately after Stent placement. The mean FEV 1 , FEF 25-75 , and PF rate improved significantly (p < 0.001, p = 0.002, and p = 0.009, respectively) after Stent placement. On long-term follow-up averaging 15 months after Stent placement, these parameters declined despite patients' subjective sense of improvement. Segregating the population into transplant and non-transplant airway stenosis etiologies, however, FEF 25-75 and PF rate remained significantly improved (p = 0.045, p = 0.027, respectively), over the long term for the latter. FEV 1 increased after subsequent Stent placements for patients receiving multiple Stents. Conclusion: Stent placement for benign Tracheobronchial stenoses provides significant immediate improvement in airflow dynamics. Long-term improvement in airflow obstruction may be expected, and additional Stent placements may further improve pulmonary function.