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Biomedical subjects

E Minar

Publications and source records attributed to E Minar.

At least 127 records · Page 7Linked to original sources
PubMed1988

Influence of postoperative anticoagulant treatment on patient survival after femoropopliteal vein bypass surgery.

To examine whether anticoagulants given after autologous saphenous bypass surgery influenced patient survival 119 patients who received such a graft for obliterative arterial disease were recruited for a controlled clinical trial. Patients were randomly assigned to start, in the second postoperative week, phenprocoumon (60 patients) or no treatment (59 patients). The median duration of survival for all patients was greater than 60 months, and the 75%-quartile was 39.0 (SE of the median 3.9) months. 10 patients died in the treated group and 20 in the control group. The treated group had a greater probability of survival (p less than 0.023, Breslow; p less than 0.043, Mantel). Graft occlusions occurred in 11 patients in the treatment group and in 17 controls. When these patients were excluded from the analysis, the difference in probability of survival between the two groups remained significant (p less than 0.009, Breslow; p less than 0.013, Mantel).

Aged↗
PubMed1988

Vein bypass surgery for femoro-popliteal arteriosclerosis: influence of different risk factors on patient survival and the importance of anticoagulant treatment.

For femoro-popliteal arteriosclerosis the autologous saphenous vein graft implanted in reverse has evolved as the standard procedure, but the impact of postoperative anticoagulant treatment upon patient survival in particular remains uncertain. Patients undergoing elective surgery during the years 1970-86 (n = 668) were analysed using Kaplan-Meier estimates. This demonstrated that the preoperative status of the patient exerted a significant influence on the probability of survival (P less than 0.0001 Mantel). Anticoagulants started postoperatively significantly prolonged the life of the patients (P less than 0.0001). Of the various risk factors the patient's age had the most important influence (P less than 0.0001), whereas the presence or absence of diabetes mellitus (P less than 0.064) and the duration of the operation (P less than 0.407), were not significant. Using the proportional hazards regression model to test the validity of a prognostic factor, while other variables were checked, we found preoperative clinical status (P less than 0.0001), the patient's age (P less than 0.0001) and anticoagulant treatment (P less than 0.0001) to be of statistical importance.

Age Factors↗
PubMed1988

[Percutaneous transluminal angioplasty in peripheral arterial occlusive disease].

Non-surgical recanalization of arterial obstructions has gained world wide acceptance since the development of the balloon dilatation catheter by Gruentzig. The indication for this treatment depends on the clinical stage of the disease, on the location and extension of the occlusion and on the general clinical situation of the patient. Ideal situations with excellent short- and long-term results are stenoses of the iliac arteries and stenoses and short occlusions of the femoropopliteal arteries, whereas treatment of long occlusions of this region is less successful. Definite recommendations concerning additional medical therapy to improve the early and longterm patency rate cannot be given because of lacking studies. The most important advantage of PTA--compared to surgical recanalization--is the lower complication rate. A further improvement of early and late results can be expected by the combined use of different non-surgical recanalization procedures.

Angioplasty, Balloon↗
PubMed1988

[Instrumental diagnosis of peripheral arterial occlusive disease].

The increasing frequency of peripheral occlusive arterial disease in the general population emphasizes the need of suitable methods for early detection of this disease. This overview summarizes the methods of current use of angiologic investigation. Their sensitivity and practicability are critically discussed. Mechanical and electronic oscillography are simple screening methods and allow a slight localization of arterial occlusive disease. Exercise tests increase the sensitivity of oscillographic methods. Continuous wave Doppler-ultrasound can be used for measuring peripheral arterial pressure, directional or pulsed Doppler-ultrasound are needed for the determination of flow direction and for registration of flow-pressure curves. Multichannel pulsed Doppler-ultrasound is needed for quantitative flow registration in determined arteries. Detailed high quality pictures of the arterial structures can be obtained by high resolution B-mode scanners-while information on flow properties is given by frequency-analysis of Doppler signals achieved in duplex scans or color-coded scans. Plethysmography is still the standard method for quantitative flow determination in upper and lower extremities, suitable for the evaluation of the vascular capacity of the examined member. Capillaroscopy gives a direct view in the situation of microcirculation, which is very valuable for the management of diabetic microangiopathy and collagen diseases. Thermography offers the opportunity of registration of impressive imaging of functional vascular reactions.

Arterial Occlusive Diseases↗
PubMed1987

Reproducibility of platelet survival time measurements in patients with peripheral arterial occlusive disease.

In this study we investigated the reproducibility of 111-In-platelet survival time (PST) measurements and of plasma levels of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF 4) in 30 patients (median age: 60.5 years) with arteriographically proven peripheral arterial occlusive disease (PAOD) in a chronic stable phase. PST calculated by both the weighted mean - WM - (1. investigation: 187.1 [median] hours - repeat investigation: 188.3 hours) and multiple hit - MH - model (181.4----177.4 hours) demonstrated only a small spontaneous variation. The median coefficient of variation (CV) was 3.0 (WM) and 3.2 (MH), respectively. The reproducibility of beta-TG (CV: 6.1) was also satisfactory. We conclude that the good reproducibility of PST and plasma levels of beta-TG make them well suited to judge the influence of platelet-suppressant drugs on these parameters in patients with PAOD.

Adult↗
PubMed1987

[Role of postoperative anticoagulant treatment following femoro-popliteal venous bypass. Interim evaluation of a controlled clinical study].

Eighty-eight patients underwent a classical reversed saphenous vein graft for femoro-popliteal occlusive disease and were enrolled in a controlled clinical trial. During the second postoperative week the patients were allocated randomly into one of two groups: group I consisted of 42 patients who received dicumarol and group II (46 patients) served as a control group without any anticoagulant treatment. The mean follow-up time was 24 months. After 12 months the cumulative patency rate was 82%, after 18 months 76% and after 24 months 76%; for patients receiving dicumarol treatment the respective figures were 92%, 86% and 86% and for those with no treatment 70%, 67% and 67%, the difference being significant. When the bypass operation was performed for limb salvage (clinical stages III and IV) the overall results were worse (12 months: 72%, 18 months: 68%, 24 months: 68%) than in stages II, II-III (12 months: 90%, 18 months: 85%, 24 months: 85%). In limb salvage surgery the positive effects of anticoagulant treatment were significant (with treatment: 12 months 87%, 18 months 86%, 24 months 86%; without treatment: 12 months 58%, 18 months 54%, 24 months 54%).

Aged↗
PubMed1987

Platelet deposition at angioplasty sites and platelet survival time after PTA in iliac and femoral arteries: investigations with indium-111-oxine labelled platelets in patients with ASA (1.0 g/day)-therapy.

In this study we have assessed the deposition of 111-In-oxine-labelled platelets--using a dual radiotracer method--at angioplasty sites of the lower extremities in 20 patients (14 male, 6 female; median age: 60 years) with ASA (1.0 g/day)-therapy. The platelet survival time (PST)--using the multiple hit model--was evaluated before and after percutaneous transluminal angioplasty, and we also measured the plasma levels of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF 4) before and after PTA. Before PTA, scintigraphy was positive in only one patient, while 24 hours after PTA a positive scintigraphic result was observed in 16/20 patients. The median target/non target-ratio was 1.0 (0.66-1.3) before PTA, and this ratio increased significantly (p less than 0.0005) to 1.53 (1.0-3.3) after PTA. The median PST decreased significantly (185.0 hours before PTA----145.2 hours after PTA; p less than 0.001), while the median platelet turnover increased from 34,000/microliter/day to 47,900/microliter/day (p less than 0.01). The median plasma levels of the platelet specific proteins increased significantly immediately after PTA (p less than 0.001), but one day later they were not significantly different from the pretreatment values. The quantitative methods used in this study seem a valuable tool to evaluate the effects of different therapeutical--especially antiplatelet--interventions after PTA in humans, thus helping to find the best antithrombotic regimen for this widely used therapeutical procedure.

Adult↗
PubMed1987

Lack of elevation of beta-thromboglobulin and platelet factor 4 in plasma during exercise in patients with chronic peripheral arterial occlusive disease.

We investigated the behavior of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF 4) during exercise--upright bicycle ergometry--in 30 patients (median age, 62.4 years) with arteriographically proven peripheral arterial occlusive disease (PAOD) in a chronic stable phase. In 15 patients the exercise study was done twice; the second time was concurrent with administration of acetylsalicylic acid (ASA) in a dosage of 1.0 g/day, while the first time was without ASA therapy. There were no significant differences in either the group of patients with or that without ASA with regard to the platelet-specific proteins at rest, immediately after, and 30 min after exercise. Blood collected simultaneously (n = 6) from an arm vein and from a femoral artery and femoral vein also revealed no significant differences. Our findings support the conclusion that exercise-induced peripheral ischemia with severe symptoms of claudication does not produce platelet alpha-granule release.

Adult↗
PubMed1987

Influence of acetylsalicylic acid (1.0 g/day) on platelet survival time, beta-thromboglobulin and platelet factor 4 in patients with peripheral arterial occlusive disease.

In this study we investigated the influence of acetylsalicylic acid (ASA) 1.0 g/day on 111-In-platelet survival time (PST) and on plasma levels of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF 4) in 37 patients (median age: 63.4 years) with arteriographically proven peripheral arterial occlusive disease (PAOD) in a chronic stable phase. We found a slight but significant increase of PST during therapy with ASA (weighted mean (WM): 184.3----193.2 [median] hours, p less than 0.05; multiple hit (MH): 182.4----192.8 hours, p less than 0.005) for the total group of patients. Concerning the influence of risk factors of PAOD on PST during ASA-therapy, there was a significant increase of PST only in the nondiabetics (WM: 180.3----204.6 hours, p less than 0.01; MH: 176.8----195.3 hours, p less than 0.01). There was a negative correlation between the baseline values of PST and their increase following ASA therapy (WM: r = -0.63; p less than 0.0001; MH: r = -0.61, p less than 0.0001). The pretreatment levels of beta-TG--but not PF 4--were significantly (p less than 0.001) elevated compared to healthy controls. Therapy with ASA caused a significant decrease in the plasma levels of beta-TG (median: 30.4----26.6 ng/ml, p less than 0.001) and PF 4 (2.95----2.2 ng/ml, p less than 0.01).

Adult↗
PubMed1987

Excessive myocardial calcinosis in a chronic hemodialyzed patient.

Secondary oxalosis in chronic hemodialyzed patients is caused by impaired renal excretion and inadequate removal of oxalic acid during hemodialysis. Ascorbic acid is a precursor of oxalic acid. We report a parathyroidectomized patient with chronic renal failure, on hemodialysis, who received over a period of several months a total dose of 91.0 g ascorbic acid i.v. The plasma oxalic acid level in this patient was 14-fold higher than in healthy persons. Increased oxalic acid synthesis from its precursor ascorbic acid may be responsible for hyperoxalemia, high content of oxalic acid in myocardium, aorta and lung, and calcium oxalate deposition in soft tissues. Application of high doses of ascorbic acid should be avoided in hemodialysed patients with chronic renal failure.

Adult↗
PubMed1987

Endothelial cell seeding of polytetrafluoroethylene vascular grafts in humans: a preliminary report.

The importance of initial human trials with autologous endothelial seeding lies not only in the implementation of a promising idea but also in the fact that canine data are only partially applicable to humans. The surface area of jugular veins in humans is much smaller than in dogs and considerably longer grafts are needed. Moreover, the reproductive capacity of adult human endothelial cells under in vivo conditions, which probably determines the success of seeding more than the seeding density, is also uncertain. Therefore the efficiency of autologous endothelial seeding in humans was investigated in 18 patients undergoing distal femoropopliteal bypass surgery. The average surface area of the jugular veins was 4.9 +/- 1.7 cm2 with an average cell yield of 32.6 +/- 18.0 x 10(4). The mean number of seeded cells per square centimeter of graft surface was 3.1 x 10(3). In a follow-up extending for 14 weeks, plasma levels of platelet factor 4 and beta-thromboglobulin as well as the platelet function in the whole blood aggregometer showed significantly better results in the seeded group. Plasma thromboxane B2, uptake and survival of indium 111-labeled platelets, and Doppler ultrasound investigations also favored the seeded group, but the results were statistically insignificant. No difference at all was found for the platelet dense granule compounds, releasable adenosine triphosphate and platelet serotonin. Thus our findings did not indicate the development of a closed endothelialized surface after 14 weeks, which is a period three times as long as the one required for confluent endothelial cell coverage in dogs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

The influence of anticoagulant treatment on the probability of function in femoropopliteal vein bypass surgery: analysis of a clinical series (1970 to 1985) and interim evaluation of a controlled clinical trial.

During the years 1970 to 1985, 463 patients with obliterative atherosclerosis at the femoropopliteal level underwent elective surgery. The operation performed was an autologous saphenous vein bypass using the reversed technique. The vascular surgical treatment was documented in reasonable detail (both baseline and follow-up) in accordance with the documentation system of the Austrian Society of Vascular Surgery. On-line data entry with use of SAS data-base management software was used. The patency curves were estimated in accordance with the Kaplan-Meier method; possible differences were checked by means Breslow's and Mantel's tests. The preoperative clinical status (claudicants, n = 200; limb salvage, n = 263) influenced the postoperative results in a statistically significant manner (Breslow p less than 0.01; Mantel p less than 0.03). All the other risk factors analyzed (site of distal anastomosis above versus below the knee, n = 231, and n = 232, respectively; Breslow p less than 0.58, Mantel p less than 0.58. Presence [n = 122] or nonpresence [n = 341], of diabetes mellitus [Breslow p less than 0.77, Mantel p less than 0.68]; smoking habits [nonsmokers, n = 93, smokers n = 370, Breslow p less than 0.68, Mantel p less than 0.69;]) did not reach statistical significance. Anticoagulant treatment (n = 101) had no effect (Breslow p less than 0.93, Mantel p less than 0.72), even when the therapy was restricted to cases with disease at advanced clinical stages (stages III, IV; n = 50; Breslow p less than 0.55, Mantel p less than 0.95). On the basis of these analyses, a prospective trial was initiated in 1979. Eighty-eight patients were studied; those in group I (n = 42) received dicumarol, and those in group II (n = 46) were controls who did not receive anticoagulant treatment. At present, the median follow-up time is at 30 months. Treatment with dicumarol favorably influenced graft patency (Breslow, p less than 0.03, Mantel p less than 0.07; one-tailed tests). The patients' preoperative clinical status affected the results of surgery (Breslow p less than 0.03, Mantel p less than 0.02; one-tailed tests). In relation to the preoperative clinical status, a therapeutic effect was observed in stages III and IV (n = 45; Breslow p less than 0.03, Mantel p less than 0.07; one-tailed tests), while no effect of therapy was demonstrable in claudicants (n = 43; Breslow p less than 0.3, Mantel p less than 0.4; one-tailed tests).(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗