3,687 research outputs found

    Osteolytic vs. Osteoblastic Metastatic Lesion: Computational Modeling of the Mechanical Behavior in the Human Vertebra after Screws Fixation Procedure

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    Metastatic lesions compromise the mechanical integrity of vertebrae, increasing the fracture risk. Screw fixation is usually performed to guarantee spinal stability and prevent dramatic fracture events. Accordingly, predicting the overall mechanical response in such conditions is critical to planning and optimizing surgical treatment. This work proposes an image-based finite element computational approach describing the mechanical behavior of a patient-specific instrumented metastatic vertebra by assessing the effect of lesion size, location, type, and shape on the fracture load and fracture patterns under physiological loading conditions. A specific constitutive model for metastasis is integrated to account for the effect of the diseased tissue on the bone material properties. Computational results demonstrate that size, location, and type of metastasis significantly affect the overall vertebral mechanical response and suggest a better way to account for these parameters in estimating the fracture risk. Combining multiple osteolytic lesions to account for the irregular shape of the overall metastatic tissue does not significantly affect the vertebra fracture load. In addition, the combination of loading mode and metastasis type is shown for the first time as a critical modeling parameter in determining fracture risk. The proposed computational approach moves toward defining a clinically integrated tool to improve the management of metastatic vertebrae and quantitatively evaluate fracture risk

    Qualitative and Quantitative Assessment of Vascular Changes in Diabetic Macular Edema after Dexamethasone Implant Using Optical Coherence Tomography Angiography

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    The aim of this study was to investigate retinal and choriocapillaris vessel changes in diabetic macular edema (DME) after the intravitreal dexamethasone implant (IDI) using optical coherence tomography angiography (OCTA). Moreover, a comparison between morphological and functional parameters of DME and healthy patients was performed. Twenty-five eyes of 25 type 2 diabetic retinopathy patients complicated by macular edema (DME group) and 25 healthy subjects (control group) were enrolled. Superficial capillary plexus density (SCPD) and deep capillary plexus density (DCPD) in the foveal and parafoveal areas, choricapillary density (CCD) and optic disc vessel density (ODVD) were detected using OCTA at baseline and after 7, 30, 60, 90 and 120 days post injection. Best corrected visual acuity (BCVA), retinal sensitivity, and central retinal thickness (CMT) were also evaluated in both groups of patients. A statistically significant difference between the two groups (DME and controls) was found in terms of functional (MP, p < 0.001 and BCVA, p < 0.001) and morphological (CMT, p < 0.001; SCPD in the parafoveal area, p < 0.001; DCPD in the foveal area, p < 0.05 and parafoveal area, p < 0.001; CCD, p < 0.001) parameters. After the treatment, SCPD and DCPD in the foveal and parafoveal areas did not modify significantly during the follow up

    HCC in Elderly Patients. Curative Intraoperative Strategies and Management in Recurrences

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    Hepatocellular carcinoma (HCC) incidence is growing among general population and especially in elderly patients. Recent development in surgical technique, surgical equipment, interventional radiology, and radiotherapy (hadrontherapy) allows us to use different techniques and approaches in order to treat this cancer. Patients are conventionally considered disease-free after a 10-year recurrence-free period. Commonly, patients remain into a lifelong follow-up and recurrences are treated as they show. In this chapter, we will give description and indications of different curative techniques, especially hepatic resections and Radio-frequency thermal ablation (RFTA). We will also describe and give indications to palliative care techniques such as transarterial chemoembolization (TACE), Selective Internal Radio-Therapy (SIRT), hadrontherapy, and supportive care. The aim of this chapter is to give information to clinicians and specialists dealing with the disease about the most effective approach to treat HCC, taking into account not only biological age, but also “physiological age,” performance status, comorbidities, and number of liver operative treatments. This chapter highlights that patients advanced in age are in particular need of a tailored medicine, where benefits are well weighted against invasivity of treatment and its side effects, in spite of assuring the best QoL and survival

    Small bowel cancer diagnosis: role of nuclear magnetic resonance

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    The diagnosis of small intestine tumors is challenging. Even in the era of modern medicine, standard approaches including echography, computed tomography-scan and conventional endoscopy are unable to reveal small bowel lesions. Video-capsule has substantially improved the evaluation of small bowel; however this procedure cannot be proposed to all patients and in particular to those experiencing intestine sub-occlusion. Nuclear magnetic resonance (NMR) of the abdomen is an additional diagnostic approach that offers high sensitivity in the identification of small bowel lesions. Here, we describe a case of small bowel neoplasia identified with NMR of the abdomen

    HCC in Cirrhotic and Non-cirrhotic Liver: Timing to Surgery and Outcome - State of the Art

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    In this chapter we aim at presenting the state of the art in liver surgery. After a brief introduction about natural evolution of hepatocellular carcinoma (HCC) either in cirrhotic or non-cirrhotic patients, this manuscript will focus on planning and timing surgery: CT evaluation of the remnant liver; biopsy and ultrasonography (US) evaluation of liver disease; intraoperative US; surgical techniques, such as major and limited hepatectomies and two-stage hepatectomies, each of them in open or mini-invasive approach; and their possible complications. Follow-up and further interventions during expected recurrences will be highlighted. Our chapter will also treat topics such as patient’s quality of life, importance of multidisciplinary evaluation and the role of surgeon in it

    Femoral Head Autograft to Manage Acetabular Bone Loss Defects in THA for Crowe III Hips by DAA: Retrospective Study and Surgical Technique

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    Introduction: The pathologic anatomy of Crowe III is characterized by the erosion of the superior rim of acetabulum, with a typical bone defect in its supero–lateral portion. The performance of a total hip arthroplasty requires the management of the acetabular bone defect, and femoral head autograft can be a valid option to optimize implant coverage. Material and Methods: In all, eight Crowe III patients (nine hips), seven of which having unilateral hip affected, and one with bilateral involvement by secondary osteoarthritis in DDH; maximum limb length discrepancy (LLD) of 3.5 cm in unilateral patients. All were operated on by direct anterior approach. Patients were evaluated in terms of clinical, surgical, and radiological (center-edge, horizontal coverage, cup inclination) parameters. Results: Cup placement was implanted with a mean of 39.5 ± 7.5°. Stem alignment showed average 1.5 ± 2.3° in valgus. LLD showed an overall average preoperative of −29.5 ± 10.5 mm at the affected side, with a significant improvement to −2.5 ± 6.4 mm (p = 0.023). The mean initial coverage evaluated like a percentage of the horizontal bone host was 52.1 ± 7.1%, while the mean final coverage at the last post-operative X-ray from femoral autograft bone was 97.0 ± 4.5% with an average improvement of 44.5%. Average CE improved from −9.5 ± 5.2° (CE I) to the immediate post-operative (CE II) of 40.6 ± 8.2°. At the final follow up, CE III showed a mean of 38.6 ± 6.2°, with an average decrease of 2.0°. Discussion: Acetabular bone defect in Crowe III DDH patients undergoing THA by DAA, can be efficiently managed by massive autograft femoral head, which allowed an adequate and long-lasting coverage of the implant, with cup positioning at the native acetabulum

    Geosystemics View of Earthquakes

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    Earthquakes are the most energetic phenomena in the lithosphere: their study and comprehension are greatly worth doing because of the obvious importance for society. Geosystemics intends to study the Earth system as a whole, looking at the possible couplings among the different geo-layers, i.e., from the earth’s interior to the above atmosphere. It uses specific universal tools to integrate different methods that can be applied to multi-parameter data, often taken on different platforms (e.g., ground,marine or satellite observations). Itsmain objective is to understand the particular phenomenon of interest from a holistic point of view. Central is the use of entropy, together with other physical quantities that will be introduced case by case. In this paper, we will deal with earthquakes, as final part of a long-term chain of processes involving, not only the interaction between different components of the Earth’s interior but also the coupling of the solid earth with the above neutral or ionized atmosphere, and finally culminating with the main rupture along the fault of concern. Particular emphasis will be given to some Italian seismic sequences.Publishedid 4121A. Geomagnetismo e PaleomagnetismoJCR Journa

    The future of Cybersecurity in Italy: Strategic focus area

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