125 resultados para Limb dimension
Resumo:
The rare occurrence of angiosarcoma in postmastectomy upper-limb lymphedema with magnetic resonance (MR) imaging is discussed. Unfamiliarity with this aggressive vascular tumor and its harmless appearance often leads to delayed diagnosis. Angiosarcoma complicating chronic lymphedema may be low in signal intensity on T2-weighting and short tau inversion recovery (STIR) imaging reflecting the densely cellular, fibrous stroma, and sparsely vascularized tumor histology. Additional administration of intravenous contrast medium revealed significant enhancement of the tumorous lesions. Awareness of angiosarcoma and its MR imaging appearance in patients with chronic lymphedema may be a key to early diagnosis or allow at least inclusion in the differential diagnosis.
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BACKGROUND/AIM: Because the pericapillary basement membrane in skeletal muscles of patients with chronic critical limb ischemia (CLI) is thickened, we determined the expression patterns of genes involved in collagen metabolism, using samples from 9 CLI patients, 4 patients with acute limb ischemia and 4 healthy controls. METHODS: Gene array analysis, quantitative RT-PCR and semiquantitative grading of immunohistochemical reactivity were performed to determine mRNA/cDNA and protein concentrations. RESULTS: In CLI patients compared to controls, cDNA levels of matrix metalloproteinase (MMP)-9 and MMP-19 were higher, collagen type IV chains A1 and A2, tissue inhibitor of matrix metalloproteinase (TIMP)-1 and TIMP-2 were similar and MMP-2 were lower. On the protein level, MMP-2, MMP-9, MMP-19 and TIMP-1 were more abundantly expressed. In skeletal muscles from patients with acute limb ischemia, cDNA and protein levels of MMP-9, MMP-19, collagen type IV chains, TIMP-1 and TIMP-2 were high. MMP-2 was elevated at the protein but decreased on the cDNA level. CONCLUSION: Expression of basement membrane components in skeletal muscles of CLI and acute limb ischemia patients is altered, possibly contributing to the pathogenesis of peripheral arterial disease.
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Endovascular therapy is a rapidly evolving field for the treatment of patients with peripheral arterial disease, and a magnitude of studies reporting on various modern revascularization concepts have been recently published. Thus, studies assessing the efficacy of endovascular therapy of peripheral arteries do not operate with uniformly defined endpoints, rendering a direct comparison of studies difficult. The purpose of this consensus statement is to highlight differences in the terminology used in the current literature and to propose some standardized criteria that must be considered when reporting results of endovascular revascularization for chronic ischaemia of lower limb arteries.
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Alterations in nitric oxide synthase (NOS) are implicated in ischemia and ischemia-reperfusion injury. Changes in the 3 NOS isoforms in human skeletal muscle subjected to acute ischemia and reperfusion were studied. Muscle biopsies were taken from patients undergoing total knee replacement. Distribution of the specific NOS isoforms within muscle sections was studied using immunohistochemistry. NOS mRNA levels were measured using real-time reverse transcription-polymerase chain reaction and protein levels studied using Western blotting. NOS activity was also assessed using the citrulline assay. All 3 NOS isoforms were found in muscle sections associated with muscle fibers and microvessels. In muscle subjected to acute ischemia and reperfusion, NOS I/neuronal NOS mRNA and protein were elevated during reperfusion. NOS III/endothelial NOS was also upregulated at the protein level during reperfusion. No changes in NOS II/inducible NOS expression or NOS activity occurred. In conclusion, alterations in NOS I and III (neuronal NOS and endothelial NOS) at different levels occurred after acute ischemia and reperfusion in human skeletal muscle; however, this did not result in increased NOS activity. In the development of therapeutic agents based on manipulation of the NO pathway, targeting the appropriate NOS isoenzymes may be important.
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BACKGROUND: Calcitonin was effective in a study of acute phantom limb pain, but it was not studied in the chronic phase. The overall literature on N-methyl-D-aspartate antagonists is equivocal. We tested the hypothesis that calcitonin, ketamine, and their combination are effective in treating chronic phantom limb pain. Our secondary aim was to improve our understanding of the mechanisms of action of the investigated drugs using quantitative sensory testing. METHODS: Twenty patients received, in a randomized, double-blind, crossover manner, 4 i.v. infusions of: 200 IE calcitonin; ketamine 0.4 mg/kg (only 10 patients); 200 IE of calcitonin combined with ketamine 0.4 mg/kg; placebo, 0.9% saline. Intensity of phantom pain (visual analog scale) was recorded before, during, at the end, and the 48 h after each infusion. Pain thresholds after electrical, thermal, and pressure stimulation were recorded before and during each infusion. RESULTS: Ketamine, but not calcitonin, reduced phantom limb pain. The combination was not superior to ketamine alone. There was no difference in basal pain thresholds between the amputated and contralateral side except for pressure pain. Pain thresholds were unaffected by calcitonin. The analgesic effect of the combination of calcitonin and ketamine was associated with a significant increase in electrical thresholds, but with no change in pressure and heat thresholds. CONCLUSIONS: Our results question the usefulness of calcitonin in chronic phantom limb pain and stress the potential interest of N-methyl-D-aspartate antagonists. Sensory assessments indicated that peripheral mechanisms are unlikely important determinants of phantom limb pain. Ketamine, but not calcitonin, affects central sensitization processes that are probably involved in the pathophysiology of phantom limb pain.
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BACKGROUND: Abciximab, a glycoprotein IIb/IIIa antagonist has been shown to improve patency and clinical outcome in patients undergoing endovascular recanalization of femoro-popliteal occlusions. However, data on abciximab therapy in complex peripheral catheter interventions of lower limbs are quite limited. The objective of this retrospective study was to evaluate the clinical and hemodynamic outcomes of patients treated with provisional abciximab during complex peripheral catheter interventions. PATIENTS AND METHODS: Analysis of a consecutive series of 44 patients with provisional abciximab therapy in complex peripheral catheter interventions with imminent risk of early rethrombosis defined as revascularization of arterial occlusions associated with one or more of the following additional circumstances named as time-consuming intervention > 3 hours, compromised contrast flow not solved by stenting, distal embolization not solved by mechanical thromboembolectomy, and peri-interventional notice of thrombus evolution despite adequate heparin adjustment of lower limbs. Adjunctive abciximab therapy was started in accordance to percutaneous coronary bailout situations. The decision to add abciximab was based on the decision of the operator and went along with the judgement that there is a rising risk of reocclusion due to the progressive complexity of an individual intervention. A bolus of 0.25 mg per kilogram of body weight, followed by a maintenance infusion of 0.125 microg/kg/min (up to a maximum dosage of 10 microg/min) for 12 hours was administered. Clinical and hemodynamic outcome was prospectively assessed at discharge, three and six months after the index procedure. RESULTS: The occluded artery of 44 limbs was in the iliac (2%), in the femoro-popliteal (73%) or below the knee segment (25%). Overall, occlusion length was 11.5 +/- 6.5 cm. Technical success rate was 95%. Mean ABI increased from 0.5 +/- 0.16 to 0.88 +/- 0.19 (p < 0.001) with immediate hemodynamic improvement of 91%. Overall, sustained clinical improvement was 84% and 66% at three and six months follow-up, with best results in iliac (100%), followed by below the knee (73%) and by femoro-popliteal segment (63%) at six months, respectively. Overall, secondary clinical improvement was 86% at six months. Minor and major bleeding complications were 16% and 9%, respectively. CONCLUSION: Abciximab should be noticed as medical adjunct in the interventional armamentarium to prevent imminent rethrombosis in complex peripheral catheter interventions.
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This study evaluated the efficacy and safety of intramuscular administration of NV1FGF, a plasmid-based angiogenic gene delivery system for local expression of fibroblast growth factor 1 (FGF-1), versus placebo, in patients with critical limb ischemia (CLI). In a double-blind, randomized, placebo-controlled, European, multinational study, 125 patients in whom revascularization was not considered to be a suitable option, presenting with nonhealing ulcer(s), were randomized to receive eight intramuscular injections of placebo or 2.5 ml of NV1FGF at 0.2 mg/ml on days 1, 15, 30, and 45 (total 16 mg: 4 x 4 mg). The primary end point was occurrence of complete healing of at least one ulcer in the treated limb at week 25. Secondary end points included ankle brachial index (ABI), amputation, and death. There were 107 patients eligible for evaluation. Improvements in ulcer healing were similar for use of NV1FGF (19.6%) and placebo (14.3%; P = 0.514). However, the use of NV1FGF significantly reduced (by twofold) the risk of all amputations [hazard ratio (HR) 0.498; P = 0.015] and major amputations (HR 0.371; P = 0.015). Furthermore, there was a trend for reduced risk of death with the use of NV1FGF (HR 0.460; P = 0.105). The adverse event incidence was high, and similar between the groups. In patients with CLI, plasmid-based NV1FGF gene transfer was well tolerated, and resulted in a significantly reduced risk of major amputation when compared with placebo.
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BACKGROUND: Reperfusion injury is insufficiently addressed in current clinical management of acute limb ischemia. Controlled reperfusion carries an enormous clinical potential and was tested in a new reality-driven rodent model. METHODS AND RESULTS: Acute hind-limb ischemia was induced in Wistar rats and maintained for 4 hours. Unlike previous tourniquets models, femoral vessels were surgically prepared to facilitate controlled reperfusion and to prevent venous stasis. Rats were randomized into an experimental group (n=7), in which limbs were selectively perfused with a cooled isotone heparin solution at a limited flow rate before blood flow was restored, and a conventional group (n=7; uncontrolled blood reperfusion). Rats were killed 4 hours after blood reperfusion. Nonischemic limbs served as controls. Ischemia/reperfusion injury was significant in both groups; total wet-to-dry ratio was 159+/-44% of normal (P=0.016), whereas muscle viability and contraction force were reduced to 65+/-13% (P=0.016) and 45+/-34% (P=0.045), respectively. Controlled reperfusion, however, attenuated reperfusion injury significantly. Tissue edema was less pronounced (132+/-16% versus 185+/-42%; P=0.011) and muscle viability (74+/-11% versus 57+/-9%; P=0.004) and contraction force (68+/-40% versus 26+/-7%; P=0.045) were better preserved than after uncontrolled reperfusion. Moreover, subsequent blood circulation as assessed by laser Doppler recovered completely after controlled reperfusion but stayed durably impaired after uncontrolled reperfusion (P=0.027). CONCLUSIONS: Reperfusion injury was significantly alleviated by basic modifications of the initial reperfusion period in a new in vivo model of acute limb ischemia. With this model, systematic optimizations of according protocols may eventually translate into improved clinical management of acute limb ischemia.