Early and long-term results of pectoralis muscle flap reconstruction vs sternal rewiring following failed sternal closure.

OBJECTIVES: The aim of the study was to compare early and long-term results of pectoralis muscle flap reconstruction with those of sternal rewiring following failed sternal closure. Primary outcomes of the study were survival and failure rate. Respiratory function, chronic pain and quality of life were also evaluated. METHODS: In a propensity-score matching analysis, of 94 patients who underwent sternal reconstruction, 40 were selected; 20 underwent sternal reconstruction with bilateral pectoralis muscle flaps (Group 1) and 20 underwent sternal rewiring (Group 2). Survival and failure rates were evaluated by in-hospital records and at follow-up. Respiratory function measures, including vital capacity (VC), were evaluated both by spirometry and computed tomography (CT) volumetry. Chronic pain was evaluated by the visual analogue pain scale. RESULTS: At 85 ± 24 months of follow-up, survival and procedure failure were 95 and 90% in Group 1 and 60 and 55% in Group 2, respectively (P < 0.01, for both comparisons). Based on CT-scan volumetry, in Group 1, severe non-union and hemisternal paradoxical movement occurred less frequently (2 vs 7, P = 0.01). At spirometry assessment, postoperative VC was greater in Group 1 (3220 ± 290 vs 3070 ± 290 ml, P = 0.04). The same trend was detected by CT-scan in-expiratory measures (4034 ± 1800 vs 3182 ± 862 mm3, P < 0.05). Correspondingly, in Group 1, less patients presented in NYHA Class III (P < 0.05), and both chronic persistent pain score and physical health quality-of-life score were significantly better in the same group. CONCLUSIONS: In our study, muscle flap reconstruction guaranteed better early and late-term results as shown by lower rates of mortality, procedure failure and hemisternum stability. Moreover, Group 1 patients had greater postoperative VC, lower NYHA class and better quality of life. These results suggest that, in patients with multiple bone fracture, the rewiring approach does not promote physiological bone consolidation, whereas the muscle flap reconstruction can assure more physiological ventilatory dynamics

Mini-extracorporeal circulation minimizes coagulation abnormalities and ameliorates pulmonary outcome in coronary artery bypass grafting surgery

Hemostasis is impaired during CABG and coagulation abnormalities often result in clinically relevant organ dysfunctions, eventually increasing morbidity and mortality rates. Fifteen consecutive patients with coronary artery disease submitted to conventional extracorporeal circulation (cECC) have been compared with 15 matched patients, using mini-ECC (MECC). Postoperative lung function was evaluated according to gas exchange, intubation time and lung injury score. In the MECC group, thrombin-antithrombin complex levels (TaTc), prothrombin fragments (PF1+2) formation and thromboelastography (TEG) clotting times were lower compared to the cECC group (p=0.002 and p&lt;0.001, respectively) whereas postoperative blood loss was higher in the cECC group (p=0.030) and more patients required blood transfusion (p=0.020). In the MECC group, postoperative gas exchange values were better, intubation time shorter and lung injury score lower (p&lt;0.001 for all comparisons). Our study suggests that MECC induces less coagulation disorders, leading to lower postoperative blood loss and better postoperative lung function. This approach may be advantageous in high-risk patients. © The Author(s) 2013

Sex-dependent differences in left ventricular function and structure in chronic pressure overload

To evaluate gender-related differences in left ventricular (LV) structure and function in aortic stenosis, LV biplane cineangiography, micromanometry and endomyocardial biopsies were carried out in 56 patients with aortic stenosis and normal coronary arteries. Patients were divided into males (M: n= θ35), and females (F: n= θ21). Sixteen normal subjects 8 M, 8 F) served as haemodynamic controls. Control biopsy data were obtained from six pre-transplantation donor hearts (3 M and 3 F). LV systolic function was evaluated by ejection fraction and its relationship to mean systolic circumferential wall stress, diastolic function by the time constant of LV pressure decay, peak filling rates and passive myocardial stiffness constant. Biopsy samples were evaluated for interstitial fibrosis, muscle fibre diameter and volume fraction of myofibrils. In a subset of 27 consecutive patients, biopsy samples were evaluated with a morphometric-morphological method, for total collagen volume fraction, endocardial fibrosis and the extension and thickness of orthogonal collagen fibres (cross-hatching). In patients with aortic stenosis, aortic valve area, aortic valve resistance and mean aortic pressure gradient were comparable in males and females, whereas end-systolic and end-diastolic volumes were larger in males than females. Ejection fraction was lower (56%) in males than females (64%) (P 1.5 grade) was present in 11 males and four females with aortic stenosis (P<0.0I). An abnormal collagen architecture was present in 13114 males and 5113 females (V<0.002). In aortic stenosis, males have a depressed systolic function and abnormal passive elastic properties when compared to females with valve lesions of similar severity. Changes in collagen architecture may account, at least in part, for these difference

Superhydrophobic coatings as anti-icing systems for small aircraft

Traditional anti-icing/de-icing systems, i.e., thermal and pneumatic, in most cases require a power consumption not always allowable in small aircraft. Therefore, the use of passive systems, able to delay the ice formation, or reduce the ice adhesion strength once formed, with no additional energy consumption, can be considered as the most promising solution to solve the problem of the ice formation, most of all, for small aircraft. In some cases, the combination of a traditional icing protection system (electrical, pneumatic, and thermal) and the passive coatings can be considered as a strategic instrument to reduce the energy consumption. The effort of the present work was to develop a superhydrophobic coating, able to reduce the surface free energy (SFE) and the work of adhesion (WA) of substrates, by a simplified and non-expensive method. The developed coating, applied as a common paint with an aerograph, is able to reduce the SFE of substrates by 99% and the WA by 94%. The effects of both chemistry and surface morphology on the wettability of surfaces were also studied. In the reference samples, the higher the roughness, the lower the SFE and the WA. In coated samples with roughness ranging from 0.4 and 3 μm no relevant variations in water contact angle, nor in SFE andWA were observed

Early and long-term results of pectoralis muscle flap reconstruction versus sternal rewiring following failed sternal closure

Objectives: The aim of the study was to compare early and long-term results of pectoralis muscle flap reconstruction with those of sternal rewiring following failed sternal closure. Primary outcomes of the study were survival and failure rate. Respiratory function, chronic pain and quality of life were also evaluated. Methods: In a propensity-score matching analysis, of 94 patients who underwent sternal reconstruction, 40 were selected; 20 underwent sternal reconstruction with bilateral pectoralis muscle flaps (Group 1) and 20 underwent sternal rewiring (Group 2). Survival and failure rates were evaluated by in-hospital records and at follow-up. Respiratory function measures, including vital capacity (VC), were evaluated both by spirometry and computed tomography (CT) volumetry. Chronic pain was evaluated by the visual analogue pain scale. Results: At 85 ± 24 months of follow-up, survival and procedure failure were 95 and 90% in Group 1 and 60 and 55% in Group 2, respectively (P < 0.01, for both comparisons). Based on CT-scan volumetry, in Group 1, severe non-union and hemisternal paradoxical movement occurred less frequently (2 vs 7, P = 0.01). At spirometry assessment, postoperative VC was greater in Group 1 (3220 ± 290 vs 3070 ± 290 ml, P = 0.04). The same trend was detected by CT-scan in-expiratory measures (4034 ± 1800 vs 3182 ± 862 mm3, P < 0.05). Correspondingly, in Group 1, less patients presented in NYHA Class III (P < 0.05), and both chronic persistent pain score and physical health quality-of-life score were significantly better in the same group. Conclusions: In our study, muscle flap reconstruction guaranteed better early and late-term results as shown by lower rates of mortality, procedure failure and hemisternum stability. Moreover, Group 1 patients had greater postoperative VC, lower NYHA class and better quality of life. These results suggest that, in patients with multiple bone fracture, the rewiring approach does not promote physiological bone consolidation, whereas the muscle flap reconstruction can assure more physiological ventilatory dynamics.© The Author 2013. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved

Drop test simulation and validation of a full composite fuselage section of a regional aircraft

Abstract In the aircraft industry, the use of fiber reinforced materials for primary structural components over metallic parts has increased up to more than 50% in the recent years, because of their high strength and high modulus to weight ratios, high fatigue and corrosion resistance. Currently, the need of lowering weight and fuel consumption is pushing the world's largest aircraft manufacturers in the design and building of structures entirely made of composites. Fuselage structure plays an important role in absorbing the kinetic energy during a crash. Through the deformation, crushing and damage of fuselage sub-floor structure, a survivable space inside the cabin area should be preserved during and after a crash impact in order to minimize the risk of passengers' injuries. In this work, a Finite Element (FE) model of a full-scale 95% composites made fuselage section of a regional aircraft under vertical drop test is presented. The experiment, conducted by the Italian Aerospace Research Centre (CIRA) with an actual impact velocity of 9.14 m/s in according to the FAR/CS 25, has been numerically simulated. Two ATDs (Anthropomorphic Test Dummies), both 50th percentile, seats and belts have been modelled to reproduce the experimental setup. The results of the simulation, performed by using LS-DYNA® explicit FE code, have been validated by correlation with the experimental ones. Such comparisons highlight that a good agreement has been achieved. The presented FE model allows verifying the structural behavior under a dynamic load condition and also estimating the passive safety capabilities of the designed structure. Since the experiment is expensive and non-repeatable, a FE model can be used for Certification by Analysis purposes since, if established, it is able to virtually demonstrate the compliance to the airworthiness rules

Fostering Functional Occupation and Mobility in People with Intellectual Disability and Visual Impairment Through Technology-Aided Support

Objectives: The study assessed a smartphone-based technology system, which was designed to support functional occupation and mobility in people with severe to profound intellectual disability and visual impairment. Methods: The technology system provided (a) verbal orientation cues to guide the participants to a desk with two containers (and two groups of 10 objects that were to be transported to two different destinations), (b) verbal instructions to take the objects (one at a time), (c) verbal orientation cues to reach the destinations where the objects taken had to be transported, (d) instructions to put away the objects at the destinations, and (e) praise and brief periods of preferred stimulation. Seven participants were involved in the study, which was carried out according to a nonconcurrent multiple baseline across participants design. Results: During the baseline (when the technology system was not available), the participants produced few or no correct responses (i.e., failed to collect, transport, and deposit objects at the right destinations). During the intervention phase (i.e., with the support of the technology system), their mean frequency of correct responses per session was between close to 19 and close to 20 (out of a maximum possible of 20) and their mean session duration varied between about 16 and 29&nbsp;min. Conclusions: The data suggest that the technology system used in this study may be a viable resource to support activity and mobility in people with intellectual and visual disabilities

MAPK15 protects from oxidative stress-dependent cellular senescence by inducing the mitophagic process

Mitochondria are the major source of reactive oxygen species (ROS), whose aberrant production by dysfunctional mitochondria leads to oxidative stress, thus contributing to aging as well as neurodegenerative disorders and cancer. Cells efficiently eliminate damaged mitochondria through a selective type of autophagy, named mitophagy. Here, we demonstrate the involvement of the atypical MAP kinase family member MAPK15 in cellular senescence, by preserving mitochondrial quality, thanks to its ability to control mitophagy and, therefore, prevent oxidative stress. We indeed demonstrate that reduced MAPK15 expression strongly decreases mitochondrial respiration and ATP production, while increasing mitochondrial ROS levels. We show that MAPK15 controls the mitophagic process by stimulating ULK1-dependent PRKN Ser108 phosphorylation and inducing the recruitment of damaged mitochondria to autophagosomal and lysosomal compartments, thus leading to a reduction of their mass, but also by participating in the reorganization of the mitochondrial network that usually anticipates their disposal. Consequently, MAPK15-dependent mitophagy protects cells from accumulating nuclear DNA damage due to mitochondrial ROS and, consequently, from senescence deriving from this chronic DNA insult. Indeed, we ultimately demonstrate that MAPK15 protects primary human airway epithelial cells from senescence, establishing a new specific role for MAPK15 in controlling mitochondrial fitness by efficient disposal of old and damaged organelles and suggesting this kinase as a new potential therapeutic target in diverse age-associated human diseases