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Biomedical subjects

H Ehringer

Publications and source records attributed to H Ehringer.

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

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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

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)

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PubMed1986

Sensitivity of 125J-fibrinogen uptake test for diagnosis of established venous thrombosis in heparinized patients.

The sensitivity of the radiofibrinogen test was investigated to determine the accuracy of the test in diagnosis of venographically proven venous thrombosis in 70 heparinized patients. 125J-fibrinogen was administered between 2 h and 4 days (mean: 1.5 days) after initiating heparin therapy. There were two criteria for a positive test: if the difference between the counts for adjacent points on the same leg or equivalent sites on opposite legs was at least 15%; and/or if there were three adjacent points each with counts greater than 5% that of the same three points on the other leg. The fibrinogen uptake test was positive at the first examination in 67 of 70 patients, giving a sensitivity of 96%. The respective frequencies of truly abnormal results for the 3 X 5% and the 1 X 15% criteria were 94% and 71%. As far as localization and extension of thrombosis were concerned, the fibrinogen uptake test agreed with phlebography in 73% of the cases, when the counts in the groin and the upper third of the thigh were ignored. The 125J-fibrinogen uptake test is an accurate method for detecting established deep leg vein thrombosis even in anticoagulated patients.

Adult↗
PubMed1986

[Percutaneous transluminal angioplasty (PTA) in peripheral arterial occlusive disease of the lower extremities].

The results of 185 percutaneous transluminal angioplasties (PTA) of the iliac (n = 62) and femoropopliteal segment (n = 123) with a double-lumen balloon catheter (Olbert) are presented. The mean age of the 150 patients was 64 years (range 39 to 91). While there were 87% stenoses and only 13% occlusions of the iliac segment, in the femoropopliteal segment the respective ratios were 46% and 54%. 71% of the patients suffered from intermittent claudication and 29% were severely ischaemic cases (Fontaine stages III and IV). Platelet inhibition was induced by means of acetylsalicylic acid 1 g/day prior to and during the procedure, and afterwards heparin was also administered for 4 days. The primary success rate in the iliac segment of 88.7% (of which 12.9% were classified as a partial success) was identical with that in the femoropopliteal region. Stenoses were successfully treated in 94.6% cases (9.9% being partial successes), occlusions in 79.7% (partial success in 16.2% of these cases). Complications occurred in 8.6% of cases, whereby surgical correction was required in half of these. When the procedure was complicated by major embolization into the distal popliteal artery, this was handled successfully by means of local thrombolytic therapy. Over the follow-up period of up to 21 months reocclusion--or high-grade restenosis--occurred in 26 patients. The cumulative patency rate 1 year after PTA was 92% for the iliac and 70% for the femoropopliteal segment.

Adult↗
PubMed1986

Influence of anticoagulant treatment in preventing graft occlusion following saphenous vein bypass for femoropopliteal occlusive disease.

Seventy-one patients underwent a classical reversed saphenous vein graft for femoropopliteal 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 1 consisted of 34 patients who received coumarin, group 2 (37 patients) served as a control group without any anticoagulant treatment. The mean follow-up was 18 months. After 12 months the cumulative patency rate was 81 per cent and after 18 months 75 per cent; for patients receiving coumarin treatment, the respective figures were 90 and 82 per cent and for those with no anticoagulant treatment 72 and 67 per cent, the decrease being significant. When the bypass operation was performed for limb salvage (clinical stages III and IV) the overall results were worse (12 months, 72 per cent; 18 months, 68 per cent) than in stage II and stage II-III (12 months, 90 per cent; 18 months, 85 per cent). In limb salvage surgery the positive effects of anticoagulant treatment were significant (with treatment: 12 months, 87 per cent; 18 months, 87 per cent; without treatment: 12 months, 60 per cent; 18 months, 53 per cent). The site of the distal anastomosis (above knee: 12 months, 81 per cent; 18 months, 73 per cent versus below knee: 12 months, 80 per cent; 18 months, 75 per cent) did not have any demonstrable influence on the patency rate.

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PubMed1986

Early postoperative changes after desobliteration of the carotid artery. Subsequent diagnostic control using a high resolution ultrasonic-real-time-duplex-scanner.

The ultrasonic morphology of the carotid artery following 55 endarterectomies in 50 patients (36 males, 14 females, mean age 68 (53-83) years) was studied using a high resolution ultrasound duplex system (HUDS). The examinations were done 1-3 days before as well as 2-4 days and 1, 2, 4 and 8 weeks after surgery, respectively. The following typical appearance after carotid endarterectomy was found: At the site of endarterectomy the new vessel wall showed the following details: lack of the "sonographic tunica intima" the thickness of the vessel wall was reduced with less pronounced ultrasonic structure compared with healthy subjects the surface toward the lumen was less smooth "ultrasonic soft" thrombotic layers with irregular surface, individual distribution (sometimes only spots) and thickness (0.5 to 4.0 mm) were seen in the majority of patients. The edge of the tunica intima was always visible in the common carotid (edge of endarterectomy) whereas in the internal carotid artery there was often an interference of the jaw. The change of caliber at the site of the edge of the tunica intima was dependent on the thickness of the "sonographic intima" as well as on the layer of the vessel wall in which endarterectomy was done. At the site of arterial clamping, intramural hematomas, lesions of the tunica intima with thrombotic layers causing some stenosis were observed after 9 of 55 procedures. Vascular sutures were always visible as bright spots. A "normalization" of local flow patterns could be seen in dependence on the morphological "normalization".(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1984

[The extracranial carotid artery in a high-resolution real-time ultrasonic imaging system: the morphological findings in healthy young adults].

Using a high-resolution ultrasound real time scanner the average normal appearance of the carotid bifurcation, variations and especially norms for the average diameters of the common, internal and external carotid arteries were established in 53 healthy young adults. Highly significant correlations were found between a variety of anthropometric parameters (body weight, height, body surface area) and the diameters of the common and internal carotids (p less than 0.001) and less pronounced of the external carotid (p less than 0.05). No statistically significant differences between the two sides of the neck were found. The average carotid diameters were larger in men compared with women in accordance with the anthropometric data (p less than 0.001). The carotid bulb was more pronounced in men than in women (p less than 0.05). The average thickness of the "sonographic tunica intima" was 0.3 mm. This does not exactly correspond to the anatomical tunica intima, which is actually thinner. It is, however, valuable as normal reference in diagnosing early pathological changes (arteriosclerosis) of the vessel wall. Based on these measurements, pathological changes in these vessels--dilating as well as occlusive arterial disease--or variations and changes with age can definitely be better evaluated.

Adult↗
PubMed1984

[Early postoperative morphology of the carotid artery following endarterectomy: systematic prospective studies with a high resolution ultrasound real-time imaging system].

The ultrasonic morphology of the carotid artery following 55 endarterectomies in 50 patients was systematically studied using a high resolution ultrasound duplex system. The typical findings were: At the site of endarterectomy the new vessel wall showed: lack of the "sonographic tunica intima"; the thickness of the vessel wall was reduced with less pronounced ultrasonic structure compared with healthy subjects; the surface toward the lumen was less smooth; "ultrasonically soft" thrombotic layers with irregular surface, individual distribution (sometimes only spots) and thickness (0.5 to 4.0 mm) were seen in the majority of patients. The edge of the tunica intima was always visible in the common carotid (edge of endarterectomy), whereas in the internal carotid artery there was often an interference of the jaw. The change of caliber at the site of the edge of the tunica intima was dependant on the thickness of the "sonographic intima" as well as on the layer of the vessel wall in which endarterectomy was done. At the site of arterial clamping intramural haematomas, lesions of the tunica intima with thrombotic layers causing some stenosis were observed after 9 of 55 procedures. Vascular sutures were always visible as bright spots. A "normalisation" of the pulsatory motion of the vessel wall as well as "normalisation" of local flow patterns could be seen in dependence on the morphological "normalisation". The soft thrombotic layers of the new vessel wall were especially pronounced at sites of incomplete endarterectomy, in one case with change of the vessel geometry and in another case were the opposite carotid was operated on 3 days later. Obviously, a short phase of high instability of the endarterectomy site (3 days, development of the platelet-fibrin layer) is followed by a period of relative instability of the new vessel wall, which lasted for 4 to 8 weeks. In 5 patients with central neurological deficits following surgery, especially pronounced soft thrombotic layers of the new vessel wall including 2 complete occlusions and 1 near-occlusion were observed.

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