162 resultados para Ischemia-reperfusion
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OBJECTIVE Recent small single-center data indicate that the current hemodynamic parameters used to diagnose critical limb ischemia are insensitive. We investigated the validity of the societal guidelines-recommended hemodynamic parameters against core laboratory-adjudicated angiographic data from the multicenter IN.PACT DEEP (RandomIzed AmPhirion DEEP DEB vs StAndard PTA for the treatment of below the knee Critical limb ischemia) Trial. METHODS Of the 358 patients in the IN.PACT DEEP Trial to assess drug-eluting balloon vs standard balloon angioplasty for infrapopliteal disease, 237 had isolated infrapopliteal disease with an available ankle-brachial index (ABI), and only 40 of the latter had available toe pressure measurements. The associations between ABI, ankle pressure, and toe pressure with tibial runoff, Rutherford category, and plantar arch were examined according to the cutoff points recommended by the societal guidelines. Abnormal tibial runoff was defined as severely stenotic (≥70%) or occluded and scored as one-, two-, or three-vessel disease. A stenotic or occluded plantar arch was considered abnormal. RESULTS Only 14 of 237 patients (6%) had an ABI <0.4. Abnormal ankle pressure, defined as <50 mm Hg if Rutherford category 4 and <70 mm Hg if Rutherford category 5 or 6, was found only in 37 patients (16%). Abnormal toe pressure, defined as <30 mm Hg if Rutherford category 4 and <50 mm Hg if Rutherford category 5 or 6, was found in 24 of 40 patients (60%) with available measurements. Importantly, 29% of these 24 patients had an ABI within normal reference ranges. A univariate multinomial logistic regression found no association between the above hemodynamic parameters and the number of diseased infrapopliteal vessels. However, there was a significant paradoxic association where patients with Rutherford category 6 had higher ABI and ankle pressure than those with Rutherford category 5. Similarly, there was no association between ABI and pedal arch patency. CONCLUSIONS The current recommended hemodynamic parameters fail to identify a significant portion of patients with lower extremity ulcers and angiographically proven severe disease. Toe pressure has better sensitivity and should be considered in all patients with critical limb ischemia.
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BACKGROUND Current guidelines limit the use of high oxygen tension after return of spontaneous circulation after cardiac arrest, focusing on neurological outcome and mortality. Little is known about the impact of hyperoxia on the ischemic heart. Oxygen is frequently administered and is generally expected to be beneficial. This study seeks to assess the effects of hyperoxia on myocardia oxygenation in the presence of severe coronary artery stenosis in swine. METHODS AND RESULTS In 22 healthy pigs, we surgically attached a magnetic resonance compatible flow probe to the left anterior descending coronary artery (LAD). In 11 pigs, a hydraulic occluder was inflated distal to the flow probe. After increasing PaO2 to >300 mm Hg, LAD flow decreased in all animals. In 8 stenosed animals with a mean fractional flow reserve of 0.64±0.02, hyperoxia resulted in a significant decrease of myocardial signal intensity in oxygenation-sensitive cardiovascular magnetic resonance images of the midapical segments of the LAD territory. This was not seen in remote myocardium or in the other 8 healthy animals. The decreased signal intensity was accompanied by a decrease in circumferential strain in the same segments. Furthermore, ejection fraction, cardiac output, and oxygen extraction ratio declined in these animals. Changing PaCO2 levels did not have a significant effect on any of the parameters; however, hypercapnia seemed to nonsignificantly attenuate the hyperoxia-induced changes. CONCLUSIONS Ventilation-induced hyperoxia may decrease myocardial oxygenation and lead to ischemia in myocardium subject to severe coronary artery stenosis.
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BACKGROUND The study set out to identify clinical, laboratory and radiological predictors of early mortality after an acute ischaemic stroke (AIS) and to analyse medical and neurological complications that caused death. METHODS A total of 479 consecutive patients (mean age 63+/-14 years) with AIS underwent stroke examination and treatment. Examination included clinical evaluation, laboratory tests, and brain CT and/or MRI. Follow-up data at 30 days were available for 467 patients (93%) who were included in the present analysis. RESULTS The median National Institute of Health Stroke Study (NIHSS) score on admission was 6. A total of 62 patients (13%) died within 30 days. The cause of death was the initial event in 43 (69%), pneumonia in 12 (19%), intracerebral haemorrhage in 9 (15%), recurrent stroke in 6 (10%), myocardial infarction in 2 (3%), and cancer in 1 (2%) of the patients. In univariate comparisons, advanced age (p<0.001), hypertension (p=0.013), coronary disease (p=0.001), NIHSS score (p<0.001), undetermined stroke etiology (p=0.031), relevant co-morbidities (p=0.008), hyperglycemia (p<0.001), atrial fibrillation (p<0.001), early CT signs of ischemia (p<0.001), dense artery sign (p<0.001), proximal vessel occlusion (p<0.001), and thrombolysis (p=0.008) were associated with early mortality. In multivariate analysis, advanced age (HR=1.12; 95% CI 1.05-1.19; p<0.001) and high NIHSS score on admission (HR=1.15, 95% CI 1.05-1.25; p=0.002) were independent predictors of early mortality. CONCLUSIONS We report 13% mortality at 30 days after AIS. More than two thirds of the deaths are related to the initial stroke. Advanced age and high NIHSS score are the only independent predictors of early mortality in this series.
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Spontaneous vertebral artery dissection (sVADs) mainly cause cerebral ischemia, with or without associated local symptoms and signs (headache, neck pain, or cervical radiculopathy), or with local symptoms and signs only.
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In ischemic stroke, the site of arterial obstruction has been shown to influence recanalization and clinical outcomes. However, this has not been studied in randomized controlled trials, nor has the impact of arterial obstruction site on reperfusion and infarct growth been assessed. We studied the influence of site and degree of arterial obstruction patients enrolled in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET).
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PURPOSE: To evaluate the use of covered stent-grafts in the endovascular treatment (ET) of popliteal artery aneurysms (PAAs). MATERIALS AND METHODS: A retrospective analysis was conducted over a period of 52 months in 18 consecutive patients (17 men; mean age +/- SD, 70 years +/- 11) undergoing ET of PAAs with the Viabahn endograft in a single center. Patient symptoms, aneurysm characteristics, technical outcomes, complications, and follow-up were assessed. RESULTS: Aneurysm diameters ranged from 12 to 51 mm with a mean of 30 mm (+/-11). Thirteen aneurysms (72.2%) were partially thrombosed and 12 patients (66.6%) had symptoms of lower limb ischemia at presentation (11 chronic and one acute). The technical success rate was 94%. Intraprocedural emboli and endoleak occurred in one and two patients, respectively. Fourteen patients were available for follow-up after successful treatment, with a mean follow-up time of 15 months (range, 7-37 months). All stent-grafts were patent after 1 month, with no mortality or limb loss. The primary patency rate with complete exclusion of the aneurysm at 6 months was 86%. Pre- and postprocedural noninvasive arterial studies were available in 10 patients, demonstrating improvement of the ankle-brachial index from 0.96 +/- 0.41 to 1.17 +/- 0.18, respectively (P = .06). CONCLUSIONS: Endovascular stent-graft repair of PAAs is a feasible treatment option. However, further follow-up studies regarding the durability of results are required.
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Pituitary apoplexy in pregnancy is rare. Its clinical features may range from unspecific complaints to panhypopituitarism resulting even in coma and death. Therefore, alertness to signs and symptoms of acute loss of pituitary function in pregnancy is mandatory. We report a woman in her 7th week of her first gestation presenting with sudden coma due to severe hyponatremia. Secondary adrenal insufficiency could be identified as the underlying cause. Panhypopituitarism including central diabetes insipidus and spontaneous abortion developed during the follow-up. Magnetic resonance imaging showed pituitary apoplexy without a pre-existing pituitary mass. The clinical course was notable for severe complications, including neurological deficits through cerebral ischemia, but eventual recovery could be achieved. We discuss the diagnostic difficulties in the evaluation of pituitary disease in pregnancy.
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Background The goal when resuscitating trauma patients is to achieve adequate tissue perfusion. One parameter of tissue perfusion is tissue oxygen saturation (StO2), as measured by near infrared spectroscopy. Using a commercially available device, we investigated whether clinically relevant blood loss of 500 ml in healthy volunteers can be detected by changes in StO2 after a standardized ischemic event. Methods We performed occlusion of the brachial artery for 3 minutes in 20 healthy female blood donors before and after blood donation. StO2 and total oxygenated tissue hemoglobin (O2Hb) were measured continuously at the thenar eminence. 10 healthy volunteers were assessed in the same way, to examine whether repeated vascular occlusion without blood donation exhibits time dependent effects. Results Blood donation caused a substantial decrease in systolic blood pressure, but did not affect resting StO2 and O2Hb values. No changes were measured in the blood donor group in the reaction to the vascular occlusion test, but in the control group there was an increase in the O2Hb rate of recovery during the reperfusion phase. Conclusion StO2 measured at the thenar eminence seems to be insensitive to blood loss of 500 ml in this setting. Probably blood loss greater than this might lead to detectable changes guiding the treating physician. The exact cut off for detectable changes and the time effect on repeated vascular occlusion tests should be explored further. Until now no such data exist.
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There is a demand for technologies able to assess the perfusion of surgical flaps quantitatively and reliably to avoid ischemic complications. The aim of this study is to test a new high-speed high-definition laser Doppler imaging (LDI) system (FluxEXPLORER, Microvascular Imaging, Lausanne, Switzerland) in terms of preoperative mapping of the vascular supply (perforator vessels) and postoperative flow monitoring. The FluxEXPLORER performs perfusion mapping of an area 9 x 9 cm with a resolution of 256 x 256 pixels within 6 s in high-definition imaging mode. The sensitivity and predictability to localize perforators is expressed by the coincidence of preoperatively assessed LDI high flow spots with intraoperatively verified perforators in nine patients. 18 free flaps are monitored before, during, and after total ischemia. 63% of all verified perforators correspond to a high flow spot, and 38% of all high flow spots correspond to a verified perforator (positive predictive value). All perfused flaps reveal a value of above 221 perfusion units (PUs), and all values obtained in the ischemic flaps are beneath 187 PU. In summary, we conclude that the present LDI system can serve as a reliable, fast, and easy-to-handle tool to detect ischemia in free flaps, whereas perforator vessels cannot be detected appropriately.
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Early reperfusion with prompt re-establishment of coronary blood flow improves survival in patients suffering from acute ST-elevation myocardial infarction (STEMI). Leaving systemic thrombolysis for primary percutaneous coronary intervention (PCI) is justified by clinical results in favor of PCI. Nevertheless, primary PCI necessitates additional transfer time and requires an efficient territorial networking. The present article summarizes the up-to-dated management of patients with acute STEMI and/or overt cardiogenic shock.
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Peripheral artery disease is a progressive disease. Primary ischemic leg symptoms are muscle fatigue, discomfort or pain during ambulation, known as intermittent claudication. The most severe manifestation of peripheral artery disease is critical limb ischemia (CLI). The long-term safety of gene therapy in peripheral artery disease remains unclear. This four center peripheral artery disease registry was designed to evaluate the long-term safety of the intramuscular non-viral fibroblast growth factor-1 (NV1FGF), a plasmid-based angiogenic gene for local expression of fibroblast growth factor-1 versus placebo in patients with peripheral artery disease who had been included in five different phase I and II trials. Here we report a 3-year follow-up in patients suffering from CLI or intermittent claudication. There were 93 evaluable patients, 72 of them in Fontaine stage IV (47 NV1FGF versus 25 placebo) and 21 patients in Fontaine stage IIb peripheral artery disease (15 NV1FGF versus 6 placebo). Safety parameters included rates of non-fatal myocardial infarction (MI), stroke, death, cancer, retinopathy and renal dysfunction. At 3 years, in 93 patients included this registry, there was no increase in retinopathy or renal dysfunction associated with delivery of this angiogenic factor. There was also no difference in the number of strokes, MI or deaths, respectively, for NV1FGF versus placebo. In the CLI group, new cancer occurred in two patients in the NV1FGF group. Conclusions that can be drawn from this relatively small patient group are limited because of the number of patients followed and can only be restricted to safety. Yet, data presented may be valuable concerning rates in cancer, retinopathy, MI or strokes following angiogenesis gene therapy in the absence of any long-term data in angiogenesis gene therapy. It may take several years until data from larger patient populations will become available.
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PURPOSE: To evaluate arterial lesion characteristics and their impact on angiographic and clinical outcomes after endovascular below-the-knee (BTK) revascularization. MATERIALS AND METHODS: Between April 2008 and June 2009, 33 patients (mean age 74.9 years) with 34 limbs and 50 arterial segments (mean lesion length 59.3 mm) undergoing endovascular BTK revascularization agreed to undergo prospective clinical and intraarterial angiographic 6-month follow-up evaluation. Clinical indication for BTK revascularization was critical limb ischemia (CLI) in 18 patients and delayed wound healing without hemodynamic evidence of CLI and intermittent claudication (IC) in 15 patients. RESULTS: Binary restenosis was observed in 40% of treated segments at 6 months. Primary sustained clinical improvement was 82.4% and 55.9% at 3 months and 6 months. Lesion length was independently associated with binary restenosis (hazard ratio [HR] 1.013, 95% confidence interval [CI] 1.000-1.016, P = .05) and lower rates of primary sustained clinical improvement (HR 1.024, 95% CI 1.006-1.042, P = .008). CONCLUSIONS: Endovascular BTK revascularization yields clinical and angiographic benefits both for patients with IC and for patients with CLI. Although arterial lesion length adversely affects angiographic and clinical outcomes after endovascular revascularization, limb salvage rates were substantially higher compared with the comparatively low patency rates after BTK angioplasty.
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Critical limb ischemia (CLI) is the most severe manifestation of peripheral artery disease (PAD), is associated with high rates of myocardial infarction, stroke, and amputation, and has a high health economic cost. The objective of this study was to estimate the incidence of lower limb amputation, the most serious consequence of CLI, and to create a surveillance methodology for the incidence of ischemic amputation in Minnesota.