RESUMO
The authors emphasize the need for the investigation of the central venous system prior to the insertion of an avfistula, this they consider to be of utmost importance in patients with anamnesis of central vessel access. After the av-fistula is inserted, an unrecognized obstacle (stenosis or thrombosis) may result in the occurrence of venous hypertension and hypofunction, this may lead to av-fistula malfunction.
Assuntos
Derivação Arteriovenosa Cirúrgica/efeitos adversos , Diálise Renal , Pressão Venosa , Oclusão de Enxerto Vascular/complicações , Oclusão de Enxerto Vascular/diagnóstico , HumanosRESUMO
PURPOSE: Subintimal angioplasty is becoming more frequently used treatment option for patients with long arterial occlusions or diffuse atherosclerotic changes as an alternative to surgical treatment in claudicants especially in patients with critical limb ischemia. The aim of our article is to retrospectively assess mid-term outcomes of subintimal angioplasty of chronic arterial occlusions in femoropopliteal region followed clinically and by Doppler ultrasonography. MATERIALS AND METHODS: From May 2002 to December 2007, 133 femoropopliteal artery occlusions in 123 patients were indicated for subintimal recanalisation. The indications for treatment were intermittent claudications in 84 patients (63.15%) and critical limb ischemia in 49 patients (36.85%). The median length of lesions was 11.4 cm, range 2-30 cm. Except doppler ultrasonographic examination done 24h after the procedure and clinical examination before discharge, both clinical and ultrasonographic examinations were performed 6 and 12 months after the procedure and yearly thereafter. Statistical analysis of our cohort was performed by Kaplan-Meier analysis, log-rank test and Cox regression. RESULTS: Technical success was achieved in 86.46%. Primary patency rate was 83.1% (SE: 3.9%), 67.5% (SE: 5%), 58% (SE: 5.9%) a 48.4% (SE: 7.1%) at 6, 12, 24 and 36 months respectively. No statistically significant difference of primary patency was found between the group of claudicants and the group of patient with critical limb ischemia. Statistically significant prediction factors for primary patency were only the quality of the run off and the length of the occlusion. Limb salvage rate in our group of patients with critical limb ischemia was 80.8% at 12 months. CONCLUSION: : Subintimal recanalisation is a simple and safe procedure for treatment of chronic peripheral arterial occlusions with high primary technical success rate, acceptable primary patency rate, low percentage of complications and mortality is as low as nil. Subintimal angioplasty is definitely advantageous and fast method in patients with critical limb ischemia with high possibility of limb salvage. Surgical treatment can be replaced by subintimal angioplasty in claudicants with high risk of operative treatment, without suitable autologous vein graft or where distal femoropopliteal or femorocrural bypass is needed.
Assuntos
Arteriopatias Oclusivas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Arteriopatias Oclusivas/diagnóstico por imagem , Doença Crônica , Feminino , Artéria Femoral , Humanos , Claudicação Intermitente/diagnóstico por imagem , Claudicação Intermitente/cirurgia , Isquemia/diagnóstico por imagem , Isquemia/cirurgia , Masculino , Pessoa de Meia-Idade , Artéria Poplítea , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Ultrassonografia DopplerRESUMO
We interpret the nucleus properties and jet activity from the Stardust spacecraft imaging and the onboard dust monitoring system data. Triangulation of 20 jets shows that 2 emanate from the nucleus dark side and 16 emanate from sources that are on slopes where the Sun's elevation is greater than predicted from the fitted triaxial ellipsoid. Seven sources, including five in the Mayo depression, coincide with relatively bright surface spots. Fitting the imaged jets, the spikelike temporal distribution of dust impacts indicates that the spacecraft crossed thin, densely populated sheets of particulate ejecta extending from small sources on the rotating nucleus, consistent with an emission cone model.
Assuntos
Meteoroides , Algoritmos , Poeira Cósmica , Modelos Teóricos , Software , AstronaveRESUMO
Images taken by the Stardust mission during its flyby of 81P/Wild 2 show the comet to be a 5-kilometer oblate body covered with remarkable topographic features, including unusual circular features that appear to be impact craters. The presence of high-angle slopes shows that the surface is cohesive and self-supporting. The comet does not appear to be a rubble pile, and its rounded shape is not directly consistent with the comet being a fragment of a larger body. The surface is active and yet it retains ancient terrain. Wild 2 appears to be in the early stages of its degradation phase as a small volatile-rich body in the inner solar system.