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Biomedical subjects

E Minar

Publications and source records attributed to E Minar.

At least 91 records · Page 5Linked to original sources
PubMed1996

Tissue concentration of clindamycin and gentamicin near ischaemic ulcers with transvenous injection in Bier's arterial arrest.

BACKGROUND: In the treatment of patients with inflamed ischaemic ulcers in peripheral arterial occlusive disease, high tissue concentrations of antibiotics (TCA) are important. With local transvenous pressure injection in Biers' arterial arrest (TVA-Bier) higher TCAs are assumed to be obtained but they have not been measured. METHODS: Two groups of 16 patients each with ischaemic foot ulcers were studied. In one group, patients received a mean of 284 (SD 116) mg gentamicin and in the other, 1200 mg clindamycin. The antibiotics were given intravenously, intra-arterially, and by TVA-Bier in a randomised order at intervals of 48 hours. Biopsy samples were taken from the edge of the ulcers 20 minutes and 3 hours after TVA-Bier, and 1 hour and 3 hours after intravenous and intra-arterial injection. At the same times blood samples were taken. FINDINGS: TCAs of gentamicin and clindamycin with TVA-Bier were significantly higher compared with intravenous or intra-arterial injection. Median TCA-enhancing factor of clindamycin achieved by TVA-Bier at 20 min 1 hour was 18.3 and 14.1 versus intravenous and intra-arterial infusion, respectively, and at 3 hours 7.3 and 5.6, respectively. The median TCA-enhancing factor for gentamicin by TVA-Bier versus intravenous and intra-arterial application was, at 1 hour 20 min, 9.4 and 9.7, respectively, and at 3 hours 1.2 and 1.7, respectively. INTERPRETATION: Higher TCAs could be achieved with TVA-Bier than with intravenous or intra-arterial infusion. TCAs were lower when using gentamicin and higher with clindamycin.

Aged↗
PubMed1996

Spontaneous laser doppler flux distribution in ischemic ulcers and the effect of prostanoids: a crossover study comparing the acute action of prostaglandin E1 and iloprost vs saline.

The flux distribution within ischemic ulcers and adjacent skin and its change by prostanoids was investigated using laser Doppler flux scanning. A prostanoid-induced increase in ulcer flux could be a rationale for the improved wound healing. In a single-blind prospective study 18 patients received prostaglandin E1 (PGE1) (333.3 ng/min.), iloprost (41.7 ng/min final dose), and 0.9% saline in a randomized order. The average laser Doppler flux within the ulcer (LFU, x +/- SEM, arbitrary units) or in the adjacent skin (LFS) was evaluated before and 30, 60, 90, and 120 min after prostanoid/saline infusion. LFU increased with PGE1 from 2.30 +/- 0.27 to 3.08 +/- 0.31 (+33.9%; P < 0.001) and with iloprost from 2.37 +/- 0.26 to 3.03 +/- 0.27 (+27.8%; P < 0.001) after 120 min, respectively. Saline did not change LFU significantly: 2.19 +/- 0.18 vs 2.55 +/- 0.26 (+16.4%; P > 0.05). Simultaneously, LFS was not significantly changed when pretreatment values were compared with mean flux at 120 min: PGE1 2.13 +/- 0.27 vs 2.54 +/- 0.34, iloprost 2.03 +/- 0.26 vs 1.94 +/- 0.21, and saline 1.74 +/- 0.27 vs 1.92 +/- 0.30 (P > 0.05, each), respectively. The laser Doppler flux scanning technique might be a tool to study the distribution of laser Doppler flux within ischemic ulcers. This might be useful to study the physiological or pathophysiological control of flux within ischemic ulcers as well as possible therapeutic approaches.

Adult↗
PubMed1996

Femoropopliteal artery: initial and 6-month results of color duplex US-guided percutaneous transluminal angioplasty.

PURPOSE: To evaluate color duplex ultrasonographic (US) guidance of percutaneous transluminal angioplasty (PTA) of femoropopliteal artery stenoses and occlusions. MATERIALS AND METHODS: Twenty-four patients (11 women, 13 men; mean age, 65.0 years) with severe claudication, abnormal ankle-arm pressure indexes, and lesions in the superficial femoral or popliteal artery depicted at US underwent balloon PTA with US guidance. US findings were confirmed before and after PTA by means of intravenous digital subtraction angiography. RESULTS: All of 22 segmental stenoses and three of four superficial femoral artery occlusions were successfully treated (in 23 patients). In three cases, a residual stenosis was detected after initial PTA, and PTA was repeated with a larger balloon catheter. Of the 21 patients followed up for 6 months, one had reocclusion and three had hemodynamically significant restenosis. CONCLUSION: Results of PTA with US guidance in short stenoses or occlusions of the femoral or popliteal artery are similar to those of PTA with fluoroscopic control.

Aged↗
PubMed1996

Deep venous thrombosis of the lower extremity: efficacy of spiral CT venography compared with conventional venography in diagnosis.

PURPOSE: To compare the efficacy of spiral computed tomographic (CT) venography with conventional venography in the diagnosis of suspected deep venous thrombosis (DVT). MATERIALS AND METHODS: In a prospective study, 52 consecutive patients with clinically suspected unilateral or bilateral DVT were studied with CT venography and conventional venography. In cases in which conventional venographic findings were inconclusive, color-coded duplex sonography and follow-up examinations were performed to make a final diagnosis. CT venography of both extremities covered a 100-cm section from the ankle to the inferior vena cava (IVC). Contrast material diluted with saline was injected in a dorsal vein of each foot. CT and conventional venography (including color-coded duplex sonography and follow-up findings) were correlated for three venous regions for each patient. RESULTS: Correlation was excellent between CT and conventional venographic findings in the detection of DVT. The sensitivity of CT venography was 100% (confidence interval: 0.92, 1.00), specificity was 96% (confidence interval: 0.84, 0.98), positive predictive value was 91%, and negative predictive value was 100%. CT venography more clearly demonstrated thrombus extension of DVT into the pelvic veins and IVC than conventional venography alone. CONCLUSION: CT venography is a valuable tool in the diagnosis of DVT. Compared with conventional venography, CT requires use of 80% less contrast material.

Contrast Media↗
PubMed1996

[Leriche syndrome: treatment with local lysis and subsequent percutaneous transluminal angioplasty].

Two cases of Leriche's syndrome treated by local thrombolysis and subsequent percutaneous transluminal angioplasty with or without additional stent implantation are described. The fibrinolytic drugs were applied locally into the occlusions through a Mewissen Infusion Catheter and a Katzen Infusion Wire (initial 2.5 mg rt-PA as bolus followed by Urokinase (50000 IU/h) during 24 and 48 hours respectively. Residual stenotic lesions and occlusions were successfully treated with PTA alone in case 1 and with PTA in combination with a stent implantation in case 2. In accordance with Bean et al. (1985) and Goffette et al. (1989) we recommend local lysis in combination with PTA with or without additional stent implantation as an alternative treatment to surgery or systemic lysis for the treatment of Leriche's syndrome.

Adult↗
PubMed1995

Comparison of effects of high-dose and low-dose aspirin on restenosis after femoropopliteal percutaneous transluminal angioplasty.

BACKGROUND: Long-term treatment with aspirin is recommended in patients with large-vessel peripheral arterial disease since these patients have a high risk of death from cardiovascular causes. Recent studies have demonstrated the prophylactic effect of low-dose aspirin in reducing the risk of cardiovascular events. Since aspirin is also recommended for prevention of late recurrence after peripheral angioplasty, the present study was undertaken to compare the effects of high-dose (1000 mg/d) and low-dose (100 mg/d) aspirin on long-term patency after femoropopliteal angioplasty. METHODS AND RESULTS: Two hundred sixteen patients treated successfully by percutaneous transluminal angioplasty for femoropopliteal lesions were randomly allocated to therapy with either 1000 or 100 mg aspirin daily. The follow-up was 24 months. The long-term results were analyzed using the Kaplan-Meier method, and differences between curves of cumulative patency were determined with the Wilcoxon and log-rank statistics. Complete follow-up information (patency after 24 months, restenosis, and death) was obtained in 207 patients. During the 2-year follow-up period, 72 patients--36 in the high-dose and 36 in the low-dose aspirin group, respectively--developed angiographically verified reobstruction within the recanalized segment. By intention-to-treat analysis, the cumulative patency rates at 24 months were 62.5% in the high-dose and 62.6% in the low-dose aspirin group (Wilcoxon, P = .97; log-rank, P = .97). The cumulative survival at 24 months of follow-up was 86.6% in the high-dose and 87.7% in the low-dose aspirin group. The number of patients discontinuing therapy was 30 in the high-dose and 11 in the low-dose aspirin group (P < .01). Fewer patients receiving 100 mg of aspirin discontinued therapy because of gastrointestinal symptoms (4 versus 20). CONCLUSIONS: The data indicate that 100 mg aspirin is no less effective in the prevention of restenosis after femoropopliteal PTA than a 1000-mg dose and has fewer side effects.

Aged↗
PubMed1995

Incidence of pseudoaneurysm after diagnostic and therapeutic angiography.

PURPOSE: To investigate prospectively with color flow duplex (CFD) sonography the incidence of pseudoaneurysm or arteriovenous fistula (AVF) after transfemoral arterial catheterization with angiography, percutaneous transluminal angioplasty (PTA), or local lysis (LL). MATERIALS AND METHODS: CFD sonography was used to examine the puncture site in 565 consecutive patients who had undergone PTA, LL, or angiography (581 procedures). RESULTS: The incidence of pseudoaneurysm in the first 300 procedures in which standard compression was used was 14.0% overall, 27.0% after LL with antegrade-puncture PTA, 18.5% after antegrade-puncture PTA, 9.3% after retrograde-puncture PTA, and 1.2% after angiography. To decrease the high incidence, in the next 281 procedures manual compression was continued for at least 5 minutes after local bleeding had stopped. This significantly reduced the incidence to 1.1% overall, 8.0% after LL in combination with PTA, 0.9% after antegrade PTA alone, 0.9% after retrograde PTA, and 0% after angiography (P < .01). CONCLUSION: The incidence of pseudoaneurysm after transfemoral arterial catheterization depends on the type of intervention. The main risk factor is too brief a period of manual compression.

Adult↗
PubMed1994

Clinical in vitro endothelialization of femoropopliteal bypass grafts: an actuarial follow-up over three years.

PURPOSE: The creation of an endothelial coverage on prosthetic vascular surfaces may improve the performance of synthetic small diameter vascular grafts. In vitro lining with cultured autologous endothelial cells offers a confluent endothelium at the time of implantation. METHODS: Between June 1989 and December 1991, 49 patients who had no saphenous vein available entered the study. Indication for operation was disabling claudication in 37 patients and critical ischemia in 12 patients. With a random 1:2 assignment, 33 patients were admitted to the endothelialized group and 16 control patients received an untreated polytetrafluoroethylene prosthesis. Cultured autologous endothelial cells from the external jugular vein were confluently lined onto polytetrafluoroethylene grafts precoated with fibrinolytically inhibited fibrin glue. The follow-up was based on angiography, platelet labeling studies with indium 111-labeled oxine, assessment of the ankle-brachial index, and duplex sonography. RESULTS: First-passage mass cultures of 16 million endothelial cells-required for the confluent lining of a 70 cm long 6 mm graft-were reached 25.1 +/- 11.2 days after vein excision. Growth failure occurred in 27.3%. After 32 months, the actuarial patency was 84.7% for endothelialized grafts and 55.4% for control grafts (p < 0.041 by Breslow test; p < 0.068 by Mantel-Cox test). The ankle-brachial index was continually diverging, reaching significantly lower values in the control group at 24 months (0.98 +/- 0.14 in the endothelialized group versus 0.70 +/- 0.12 in the control; p < 0.0023). The uptake of indium 111-labeled platelets--measured at 9 days, 3 months, 6 months, and 12 months--was significantly lower in the endothelialized group during the entire observation period.

Actuarial Analysis↗
PubMed1993

[The radiologic diagnosis of venous diseases. A challenge].

Limited accuracy in the clinical diagnosis of deep vein thrombosis (VT) makes such diagnostic tests such as duplex sonography or venography necessary. Exact information on the age and extent of the thrombus are necessary for the clinician to optimize the therapeutic management. The correct diagnosis of calf vein thrombosis and of recurrent VT in patients with postphlebitis changes also has implications for treatment. After exclusion of thrombosis, the radiologist should evaluate the leg for other possible causes of symptoms besides VT. Investigation of the venous system also has a role in the diagnosis in patients with suspected pulmonary embolism. In patients with chronic venous insufficiency the deep venous system should be assessed for patency and venous valve function. The superficial veins should be differentiated in segments with sufficient or insufficient venous valves, and it is also necessary to look for insufficiency of the perforating veins. In patients with superficial phlebitis there is risk of propagation into the deep venous system.

Adult↗
PubMed1993

[Macroembolism as a complication of ultra-high dose urokinase lysis of occlusion of a bifurcation prosthesis].

The case of a 70-year-old woman suffering from a long occlusion of the right branch of an aortobifemoral dacron-graft implanted six years ago is reported. Patency could be achieved by a systemic application of an ultrahigh dose of urokinase (UHUK = 9,000,000 I.U/6 h, intermittent daily application, two cycles). As a major complication macro-embolism to the popliteal artery and to the superficial femoral artery occurred, however. A further cycle of UHUK, local thrombolytic therapy (12 mg rtPA) and surgical thrombectomy failed to achieve persistent recanalization. So the patient finally had to be provided with a femoro-crural composite bypass. In conclusion, in a systemic thrombolytic therapy of occlusions of dacron grafts in the aorto-iliacal area a standard dose of urokinase (initial dose 600,000 I.U., maintenance dose 150,000 I.U./h, infusion pump) is recommended.

Aged↗
PubMed1992

[Prevention of pulmonary embolism].

Pulmonary embolism (PE) is one of the most common causes of death in hospitalized patients. Several groups of patients at high risk of developing venous thromboembolic complications have been identified. The effect of primary prophylaxis on the incidence of fatal PE has been demonstrated only in a few studies, while evidence for a benefit of pharmacologic and physical modalities of prophylaxis in preventing venous thrombosis has been documented in many prospective randomized clinical trials. The preventive measures differ according to the type of patient at risk, and in some groups of patients at risk several prophylactic regimen can be used. Application of low-dose heparin is the best documented prophylactic modality. General primary prophylaxis in 100 patients at risk could save one life. However, low-dose heparin is of limited efficacy in patients at high risk for thromboembolism. The following anithrombotic regimens are recommended in these patients: adjusted - dose heparin; oral anticoagulants with low intensity of anticoagulation; dextran; heparin in combination with dihydroergotamine; low-molecular-weight heparin fractions (LMWH). It is likely that prevention with LMWH will become the most important prophylactic modality in the near future. Mechanical methods of prophylaxis should be used primarily in combination with pharmacologic prevention. In low-risk patients mechanical methods alone offer sufficient prophylaxis. Low-dose heparin which is effective for primary prevention is not effective in secondary prophylaxis to prevent extension or embolization of established thrombosis. Inadequate anticoagulant therapy results in increased risk of recurrent thromboembolism. The general application of primary prophylaxis in patients at risk is superior to secondary prophylaxis with treatment of established thromboembolism.

Anticoagulants↗
PubMed1992

Implantation of in vitro endothelialized polytetrafluoroethylene grafts in human beings. A preliminary report.

To assess the impact of in vitro endothelialization on prosthetic graft patency, we performed femorotibial reconstruction in four patients. Polytetrafluoroethylene grafts (6 mm), lined with cultivated autologous endothelial cells, harvested from the veins of the forearm, were used. Autologous endothelial cells were harvested enzymatically and characterized by morphology and factor VII staining. After a cultivation period of 17 to 23 days, the cell count increased from 27 +/- 3 x 10(4) endothelial cells to 5.4 +/- 1.1 x 10(6). Endothelial cell seeding on polytetrafluoroethylene prostheses was then performed. To improve endothelial cell attachment to the graft surface, polytetrafluoroethylene grafts (60 to 70 cm; 6 mm diameter) were precoated with fibrin glue containing fibrin and fibronectin and the fibrinolysis inhibitor aprotinin. Seeding density of 49 +/- 10 x 10(3) endothelial cells per square centimeter yielded a preconfluent monolayer immediately after seeding, as demonstrated by scanning electron microscopy. A second cultivation period of 6 days, after seeding and before implantation, was necessary for establishment of a confluent monolayer and to allow for maturation of the endothelial cell cytoskeleton as well as production and excretion of extracellular matrix. Grafts endothelialized in vitro were implanted in four patients requiring femorotibial reconstruction. Scintigraphic studies with indium 111-labeled platelets demonstrated little or no platelet deposition, indicating persistent endothelialization. All grafts remained patent at 3 months after implantation.

Aged↗
PubMed1992

Prospective clinical study with in vitro endothelial cell lining of expanded polytetrafluoroethylene grafts in crural repeat reconstruction.

A nonrandomized prospective clinical study was undertaken to evaluate the technique and efficacy of in vitro endothelial cell lining of synthetic grafts. Twenty-six patients (10 men and 16 women with a mean age of 68.4 years; range, 49 to 80 years) with end stage chronic peripheral vascular disease requiring reoperation were entered into the study. In 13 patients venous endothelial cells were harvested 4 to 7 weeks before operation, grown to confluency in culture flasks, and seeded onto the inner surface of expanded polytetrafluoroethylene grafts. Thirteen patients received untreated expanded polytetrafluoroethylene grafts and served as a control. A scoring system with use of intraarterial angiography was used to assess disease severity. No statistically significant differences in angiographic score were seen between the two groups, indicating comparable severity of disease. Early secondary graft patency (0 to 30 days) was 92% for the in vitro endothelial cell lining group and 53% for control patients. The amputation rate after 18 months for the in vitro endothelial cell lining group was 15%, with a 31% rate in the control group. The functional performance of the in vitro endothelial cell lining bypasses was superior to that of untreated bypass grafts during the observed follow-up period. These early results suggest that in vitro endothelial cell lining is a method that can reduce the early occlusion rate now seen after repeat reconstruction of crural vessels.

Aged↗
PubMed1991

[Prevention of cerebrovascular disorders].

The decision for the optimal preventive and therapeutic interventions in cerebrovascular disease depends on the underlying disease process. Therefore it is important to identify the different pathomechanisms by modern techniques. The significantly increased cardiovascular risk of patients with atherosclerotic extracranial arterial disease--even when neurologically asymptomatic--makes identification and elimination of all vascular risk factors of crucial importance for primary and secondary prevention. The low risk of stroke without prior transient ischemic attacks makes prophylactic carotid surgery not advisable in asymptomatic patients. Regular controls by sonography are necessary to identify patients with progression of carotid stenosis, and the patients should be informed about warning symptoms of threatening stroke. Secondary prevention with antiplatelet agents (aspirin, ticlopidine) proved effective in patients with cerebrovascular diseases by significant reduction in mortality and in the incidence of stroke and myocardial infarction. The optimum dose of aspirin is not known. Patients with atherosclerotic lesions of the major cerebral arteries have not been shown convincingly to benefit from long-term anticoagulation, while the risk of bleeding complications is increased significantly. Major clinical trials have been initiated to evaluate the benefit of carotid endarterectomy. Anticoagulation therapy can reduce the risk of cardiogenic emboli. Recently it was demonstrated that also aspirin seems effective in reducing incidence of thromboembolic complications in patients with chronic atrial fibrillation. The start of anticoagulant therapy after cerebral embolism depends mainly on CT scan findings.

Carotid Artery Thrombosis↗
PubMed1990

D-dimer in local thrombolytic therapy with low doses of recombinant human tissue-type plasminogen activator (rt-PA) in patients with peripheral arterial occlusive disease.

The generation of D-dimer was studied in the course of local thrombolytic therapy of peripheral arterial occlusions with low doses of recombinant human tissue-type plasminogen activator (rt-PA) in 7 patients. Intermittent local application of rt-PA resulted in a marked increase in D-dimer exceeding values usually seen after intravenous application of manifold higher doses used in myocardial infarction. The increase in D-dimer was related to the estimated thrombus size (length of the occlusion) and the total dose of rt-PA applied. During local rt-PA infusion of 6 of 7 patients maintained plasminogen activator inhibitor capacity (PAI-cap) between 34% and 79% of their corresponding pre-treatment levels; detectable levels of PAI-cap in circulating blood during the procedure did not interfere with the success of therapy.

Adult↗
PubMed1990

D-dimer and TAT measurement in patients with deep venous thrombosis: utility in diagnosis and judgement of anticoagulant treatment effectiveness.

The plasma levels of thrombin-antithrombin III-complexes (TAT) and the fibrin split product D-Dimer were measured in 39 patients with phlebographically proven acute DVT: 34 patients had proximal DVT, 5 had calf DVT. The sensitivity of D-Dimer and TAT measurements in the diagnosis of proximal DVT was found to be dependent on the duration of symptoms: 0 to 7 days (n = 27): elevated D-Dimer levels (greater than 120 ng/ml) = 1, D-Dimer Latex test positive (greater than 500 ng/ml) = 1, elevated TAT levels (greater than 6 ng/ml) = 0.88. Eight to 14 days (n = 7): elevated D-Dimer levels = 1, D-Dimer Latex test positive = 0.33, elevated TAT levels = 0.66; specificity: elevated D-Dimer: 0.48, D-Dimer Latex test: 1, elevated TAT: 0.76. Calf DVT patients (n = 5) had elevated D-Dimer levels, negative Latex tests and 3 of them had normal TAT values. Hemostatic and fibrinolytic parameters were also determined in 13 patients during heparin treatment of proximal DVT. Elevated D-Dimer and TAT levels rapidly decreased after initiation of anticoagulant therapy. In 2 of 13 patients a marked increase in D-Dimer and TAT levels was observed in periods of ineffective heparinization, documented by normal or only slightly prolonged thrombin clotting times. We conclude from our results that 1) D-Dimer EIA measurement, in contrast to TAT measurement, shows a very high sensitivity in the diagnosis of DVT, 2) due to low specificity this test can only be used to exclude thrombosis in patients with suspected DVT, and 3) the determination of the plasma levels of D-Dimer and TAT may be useful for judging the effect of anticoagulant treatment on thrombotic processes.

Adult↗
PubMed1990

Activation of coagulation and fibrinolysis in patients with arteriosclerosis: relation to localization of vessel disease and risk factors.

Activation markers of blood coagulation and fibrinolysis and several fibrinolytic parameters were determined in arteriosclerotic patients to investigate the relation between extension and main localization of vessel disease, risk factors and disturbances within the blood coagulation and the fibrinolytic system. Indications of an increased intravascular fibrin formation and subsequent fibrinolysis were found in peripheral artery disease (PAD) patients but not in coronary artery disease (CAD) patients. Compared with healthy controls PAD patients had elevated TAT (median: 3.2 ng/ml, 1.5-70 vs. 2.1, 1.2-4.7, p less than 0.005) and D-Dimer (median: 365 ng/ml, range 85-2000 vs. 185, 79-360; p less than 0.0001) plasma levels, whereas TAT (2.4, 1.2-13) and D-Dimer (190, 58-1000) levels of CAD patients were in the normal range. No associations were detected between risk factors of arteriosclerosis (hyperlipidemia, diabetes mellitus, cigarette smoking, hypertension) and the plasma levels of the activation markers TAT and D-Dimer. Independent from risk factors PAD and CAD patients had elevated plasma plasminogen activator inhibitor capacity (PAI cap). Our results provide evidence that 1) increased plasma levels of blood coagulation and fibrinolysis activation markers are not related to risk factors of arteriosclerosis but seem to be unspecifically caused by activation processes on arteriosclerotic vessel wall defects, 2) increased plasma PAI cap found in arteriosclerotic patients is a relatively unspecific phenomenon associated with arterial vessel disease.

Antithrombin III↗