Objectives: To develop and test a new concept of the degradation kinetics of newly developed coronary stents consisting of magnesium alloys. Methods: Design of a coronary stent prototype consisting of the non-commercial magnesium based alloy AE21 (containing 2% aluminium and 1% rare earths) with an expected 50% loss of mass within six months. Eleven domestic pigs underwent coronary implantation of 20 stents (overstretch injury). Results: No stent caused major problems during implantation or showed signs of initial breakage in the histological evaluation. There were no thromboembolic events. Quantitative angiography at follow up showed a significant (p < 0.01) 40% loss of perfused lumen diameter between days 10 and 35, corresponding to neointima formation seen on histological analysis, and a 25% re-enlargement (p < 0.05) between days 35 and 56 caused by vascular remodelling (based on intravascular ultrasound) resulting from the loss of mechanical integrity of the stent. Inflammation (p < 0.001) and neointimal plaque area (p < 0.05) depended significantly on injury score. Planimetric degradation correlated with time (r = 0.67, p < 0.01). Conclusion: Vascular implants consisting of magnesium alloy degradable by biocorrosion seem to be a realistic alternative to permanent implants. P ermanent metallic implants are key treatment options in cardiovascular interventions. However, specific drawbacks limit their more widespread use. These limitations include thrombogenicity, permanent physical irritation, mismatches in mechanical behaviour between stented and non-stented vessel areas, long term endothelial dysfunction, inability to adapt to growth, non-permissive or disadvantageous characteristics for later surgical revascularisation, and chronic inflammatory local reactions. Degradable implants offer more physiological repair, reconstitution of local vascular compliance, and a temporary, limited, longitudinal, and radial straightening effect, including the possibility for growth. These implants are "fulfilling the mission and stepping away" 1 and may act as a new biomedical tool satisfying the requirements of compatibility and integration.2 However, most biodegradable synthetic polymer stents must have greater bulk to approximate the mechanical performance required in arteries. Many also induce exaggerated acute and chronic inflammatory responses during degradation. 3To address this issue, we developed and tested a new concept of degradation after endovascular implantation of tailored magnesium alloys. We anticipated a more useful combination of mechanical stability over a limited time and complete degradation of the implants. METHODS AlloysMagnesium alloys containing small amounts of aluminium, manganese, zinc, lithium, and rare earth elements were preselected for their mechanical aspects and tested in vitro for degradation kinetics (synthetic seawater, Ringer lactate, and porcine and human serum; calculated stent half lives for different magnesium alloys were between minutes and about half a year) and the potential in...
Objective. To introduce a new standardized ultrasound score based on 7 joints of the clinically dominant hand and foot (German US7 score) implemented in daily rheumatologic practice. Methods. The ultrasound score included the following joints of the clinically dominant hand and foot: wrist, second and third metacarpophalangeal and proximal interphalangeal, and second and fifth metatarsophalangeal joints. Synovitis and synovial/tenosynovial vascularity were scored semiquantitatively (grade 0 -3) by gray-scale (GS) and power Doppler (PD) ultrasound. Tenosynovitis and erosions were scored for presence. The scoring range was 0 -27 for GS synovitis, 0 -39 for PD synovitis, 0 -7 for GS tenosynovitis, 0 -21 for PD tenosynovitis, and 0 -14 for erosions. Patients with arthritis were examined at baseline and after the start or change of disease-modifying antirheumatic drug (DMARD) and/or tumor necrosis factor ␣ (TNF␣) inhibitor therapy 3 and 6 months later. C-reactive protein level, erythrocyte sedimentation rate, rheumatoid factor, anti-cyclic citrullinated peptide, Disease Activity Score in 28 joints (DAS28), and radiographs of the hands and feet were performed. Results. One hundred twenty patients (76% women) with rheumatoid arthritis (91%) and psoriatic arthritis (9%) were enrolled. In 52 cases (43%), erosions were seen in radiography at baseline. Patients received DMARDs (41%), DMARDs plus TNF␣ inhibitors (41%), or TNF␣ inhibitor monotherapy (18%). At baseline, the mean DAS28 was 5.0 and the synovitis scores were 8.1 in GS ultrasound and 3.3 in PD ultrasound. After 6 months of therapy, the DAS28 significantly decreased to 3.6 (⌬ ؍ 1.4), and the GS and PD ultrasound scores significantly decreased to 5.5 (؊32%) and 2.0 (؊39%), respectively. Conclusion. The German US7 score is a viable tool for examining patients with arthritis in daily rheumatologic practice because it significantly reflects therapeutic response.
ObjectivesTo define the elementary ultrasound (US) lesions in giant cell arteritis (GCA) and to evaluate the reliability of the assessment of US lesions according to these definitions in a web-based reliability exercise.MethodsPotential definitions of normal and abnormal US findings of temporal and extracranial large arteries were retrieved by a systematic literature review. As a subsequent step, a structured Delphi exercise was conducted involving an expert panel of the Outcome Measures in Rheumatology (OMERACT) US Large Vessel Vasculitis Group to agree definitions of normal US appearance and key elementary US lesions of vasculitis of temporal and extracranial large arteries. The reliability of these definitions on normal and abnormal blood vessels was tested on 150 still images and videos in a web-based reliability exercise.ResultsTwenty-four experts participated in both Delphi rounds. From originally 25 statements, nine definitions were obtained for normal appearance, vasculitis and arteriosclerosis of cranial and extracranial vessels. The ‘halo’ and ‘compression’ signs were the key US lesions in GCA. The reliability of the definitions for normal temporal and axillary arteries, the ‘halo’ sign and the ‘compression’ sign was excellent with inter-rater agreements of 91–99% and mean kappa values of 0.83–0.98 for both inter-rater and intra-rater reliabilities of all 25 experts.ConclusionsThe ‘halo’ and the ‘compression’ signs are regarded as the most important US abnormalities for GCA. The inter-rater and intra-rater agreement of the new OMERACT definitions for US lesions in GCA was excellent.
These results demonstrate that IA SIJ injections remain technically challenging despite ultrasound guidance. However, peri-articular deposition of triamcinolone appears sufficient for pain and symptom control in patients suffering from active sacroiliitis.
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