Markers of coagulation activation for evaluation of the antithrombotic efficacy of heparin: a prospective study in acute deep venous thrombosis

The potential value of measurements of prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin complexes (TAT) and D-dimer for the assessment of antithrombotic efficacy of heparin in acute deep venous thrombosis (DVT) was prospectively investigated. These variables were determined at presentation and subsequently once daily during a course of seven days heparin therapy. Heparin doses were adjusted according to the activated partial thromboplastin time (APTT). Compression ultrasonography was performed at presentation and on day 7 to determine the extent of thrombosis according to a predefined score. Out of a total of 50 patients accrued to the study 44 patients had reduced or unchanged extent of thrombosis, whereas in six patients an extension was documented. Although thrombin generation was significantly inhibited after initiation of heparin therapy as reflected by a decrease in F1 + 2 and TAT levels, these markers were not useful for the detection of patients with DVT extension. In contrast, anti-factor-Xa activities but not APTT measurements were significantly lower in the group of patients with propagation of DVT (median: 0.22 U/ml versus 0.38 U/ml, interquartile range: 0.1-0.33 U/ml versus 0.19-0.55 U/ml; P = 0.001). D-dimer decreased within the first days of heparin therapy but failed to indicate DVT progression. These data suggest that plasma anti-factor-Xa activity correlates better with the antithrombotic efficacy of heparin than APTT measurements and markers of coagulation or fibrinolysis activation.

In vitro correlation of intravascular ultrasound and direct magnification radiography for calcified arterial lesions

RATIONALE AND OBJECTIVES

Intravascular ultrasound (IVUS) is an adjunct to contrast angiography that gives additional information concerning the morphology of the vascular wall. The authors examined the accuracy of intravascular ultrasound (IVUS) in the evaluation of calcified lesions within the abdominal aorta and the iliac artery.

METHODS

Forty-nine human specimens (iliac artery, 26; abdominal aorta, 23) were examined using a 20-MHz 6.0-F ultrasound catheter, followed by magnification radiography of the same specimens using a newly developed microfocus x-ray tube. Magnification radiographs and ultrasound images were divided into identical sectors to analyze the morphology of calcified arteriosclerotic lesions.

RESULTS

A total of 644 sectors was analyzed. Sensitivity of intravascular sonography was 70%, specificity 53%. Sensitivity strongly depended on the morphology of the calcified lesions.

CONCLUSION

The detection of calcified arteriosclerotic lesions by means of IVUS revealed a sensitivity of 70% in an in vitro study using human specimens. However, the specificity of IVUS was only 53%, which is basically a random chance occurrence.

[Intravascular ultrasound in peripheral calcified vascular lesions: comparison with direct magnification radiography]

Intravascular ultrasound can detect calcified peripheral arteriosclerotic lesions by hyperdense echo patterns and shadowing of subintimal layers. Nevertheless, 20 MHz ultrasound systems have not been validated for the detection of peripheral calcifications; besides, it is unknown whether the depiction of calcified lesions by intravascular ultrasound depends on the morphology of the calcification. Histological evaluation of severely calcified arteries is difficult because the preparation of those specimens often causes artefacts, e.g., fracture of calcified structures. Direct magnification radiography, currently used in forensic medicine or skeleton examination, is based on a minimized focus and enables the edge-enhanced views of calcifications with high discrimination. In this in-vitro-study direct radiological magnification was used to validate intravascular ultrasound. Forty-nine segments of human peripheral arteries were fixed in formalin, examined with intravascular ultrasound and, as a reference, radiographically magnified using a newly developed microfocus x-ray tube. Sensitivity, specificity, positive and negative predictive value, and accuracy of intravascular ultrasound for the detection of calcified wall areas were determined and compared to the appearance (configuration, circumferential and areal expansion, density, number of fragments) of these calcifications. Thicknesses of 110 single calcified structures were estimated on sonograms and radiograms. The overall sensitivity of the 20 MHz intravascular ultrasound system for the detection of calcification in 913 sectors was 70%, specificity 53%, positive predictive value 66%, negative value 58% and accuracy 62%. The depiction of calcified regions by direct magnification radiography showed that the sensitivity strongly depended on the density of the calcification. Sensitivity was 81% with calcified lesions of high density, but only 51% with lesions of low density.(ABSTRACT TRUNCATED AT 250 WORDS)

Characteristic EEG findings in childhood moyamoya syndrome

Moyamoya syndrome-specific alterations of EEG recordings are only observed in children. These consist of a gradual frequency decrease and amplitude activation after hyperventilation. This is referred to as re-build-up phenomenon. Thus, a tentative diagnosis of Moyamoya syndrome in children can be based on the EEG finding. This should be radiologically confirmed by angiography.

[Asymptomatic Moyamoya syndrome. Diagnosis by EEG and magnetic resonance angiography]

Alternating hemiplegias in children suggest the possibility of a Moyamoya syndrome. In the absence of clinical symptoms it is the EEG which will offer the decisive clue in childhood Moyamoya syndrome. The pertinent finding, which consists in progressive frequency decrease and amplitude activation after hyperventilation, has only been described in pediatric patients. It has been termed re-build-up phenomenon. Magnet resonance imaging and magnet resonance angiography (MR angiography) are able to confirm the tentative diagnosis of a Moyamoya syndrome based on the EEG.

[Injury of the pelvic ring and abdominal trauma]

Fractures and disruptions of the pelvic ring are usually found in multiply injured patients and exacerbate the life-threatening character of the concomitant injuries. The main prognostic factors are haemorrhagic complications, abdominal trauma and associated injuries of the urogenital tract. All patients admitted to the Department of Surgery of the University of Münster between July 1985 to December 1989 were analysed with particular reference to pelvic ring instability and the accompanying pelvic and abdominal lesions. Of 27 patients with unstable displaced lesions of the pelvic ring, 9 were female (33.3%) and 18 male (66.7%); the average age was 35.1 years. Multiple trauma was present in 25 patients (92.6%). Associated pelvic or abdominal injuries were found in 15 cases (55.6%) [multiple entries]. In 9 patients (33.3%) there were lesions of the urogenital tract. Injuries to pelvic blood vessels were diagnosed in 3 patients (11.1%). In 2 patients (7.4%) there were lesions of the perineum. A ruptured spleen was found in 4 patients (14.8%), lesions of the liver in 3 patients (11.1%), lacerations of the mesentery in 2 patients (7.4%). Bleeding into the mesentery, lacerations of serosa of the sigmoid colon and contusion of the pancreas were each seen in 1 case (3.7%). In 12 patients (44.4%) laparotomy was performed: The mortality in this series was 22.2% (6 patients). The authors propose a procedure for immediate diagnosis of these associated pelvic and abdominal injuries. The key factor for a favourable outcome is the differentiation between intraabdominal and retroperitoneal bleeding. A treatment algorithm is described. The value of laparotomy, interventional radiology and primary anterior stabilization of the pelvic ring with an external frame is discussed.

[The place of magnetic resonance tomography in the diagnosis of diseases of the shoulder joint]

In a prospective study 43 patients with shoulder pain were examined by sonography and MRI. The findings were controlled by plain radiography, arthrography, and CT arthrography. Joint effusions and humeral head defects were equally identified by MR and sonography. In the diagnosis of labrum lesions, rotator cuff lesions, subacromial spurs, and synovial inflammatory disease sonography was not as accurate as MR. A special MR scoring system improved the diagnosis of an impingement syndrome.

[Changes in the lungs in mucoviscidosis. Feasibility and advantages of different imaging techniques]

Pulmonary abnormalities in cystic fibrosis result from the obstruction of small bronchi by highly viscous mucus. Chronic obstructive lung disease and recurrent pulmonary infections result in a typical radiographic pattern later in the disease. Most patients can now be expected to survive into adulthood. The radiologist must make a careful comparison of serial films in order to detect complications early. By far the most important imaging modality is the conventional chest radiograph. CT is more sensitive for detection of structural abnormalities of the lung. Bronchography is a dangerous procedure and can lead to rapid deterioration of lung function. Lung scanning is a very sensitive method for demonstrating regional disturbances of ventilation and may reveal abnormalities earlier than conventional radiographs. In severe hemoptysis, selective bronchial arteriography with embolization of the bleeding vessel can be a life-saving procedure.

[The diagnosis of deep venous thrombosis of the lower extremities using high-resolution real-time and CW-Doppler sonography. Accuracy and limitations]

The combination of high-resolution real time and continuous wave (CW) Doppler sonography is particularly valuable for the detection of venous thrombosis in the lower limbs. A total of 235 venous sonograms were prospectively compared with phlebography (gold standard) and indicated a sensitivity and specificity of 93%-100% and 96%-99%, respectively, depending on the thrombosis site. The positive and negative predictive values ranged between 90% and 97% and 97% and 100%, respectively. The value of real-time venous sonography, which basically entails assessing venous compressibility for the exclusion of thrombosis, is limited in the presence of small non-occlusive thrombi by the elasticity of the surrounding anatomic structures and the sonographic visibility of the veins. It is also evident that partial thrombosis in readily visualized veins (e.g., the inguinal region) is more obvious with sonography than phlebography. In addition, the proximal end of acute, extensive thrombus with poor collateral circulation is better visualized by sonography.

[Duplex sonography in the diagnosis of renal artery stenoses following allogenic kidney transplantation]

Posttransplant renal artery stenosis (TRAS) as a cause of secondary hypertension is reported with an incidence of 1 to 10%. Early diagnosis of TRAS should be made by non-nephrotoxic and non-invasive means to lower the risk of hypertension. One to 66 months after kidney transplantation 335 patients underwent Duplex-scanning, 38 of cases for clinical tentative diagnosis of TRAS. Parameters for clinical diagnosis of TRAS were diastolic hypertension greater than 100 mm Hg with resistance to therapy (A), an abdominal bruit over the transplant (B), disturbance of renal function (serum-creatinine greater than 2 mg/dl) (C). Admission to study followed the parameter-combination A + B. A + C, B + C. Rejection crisis was excluded in 18/38 cases by fine needle biopsy, cyclosporine over-dosage was negative in 38/38 cases, 20/38 cases had normal renal function. Duplex-/Doppler-ultrasound criteria for TRAS were systolic peak velocity greater than 100 cm/s-1 and broadening of the diastolic frequency spectra with a smooth decline in diastole to an elevated diastolic level. In 32/38 cases (84.2%, n = 38) diagnosis of TRAS was made by duplex-scanning, angiography confirmed the result in 30/32 cases (93.75%, n = 32); sensitivity was 88.2% with a specificity of 66.6%. Duplex-scanning as a primary diagnostic means for TRAS seems a promising method compared to e.g. radionuclide imaging or angiography. Duplex-scanning is a non-nephrotoxic and non-invasive procedure repeatable at any time with only few preliminary conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

[Digital subtraction angiography (i.v. DSA) in the planning of infradiaphragmatic irradiation of malignant lymphoma]

Intravenous digital subtraction angiography (i.v. DSA) - an almost non-invasive imaging procedure - makes it possible to visualize the vascular topography of the upper abdominal region, with the parenchyma of spleen and kidney, simultaneously with bony structures (spine) in a frontal view. With the aid of a subtrascope, spleen and kidney and the vascular topography can be directly superimposed on a simulation film. By this procedure an individual target volume can be delineated. From December 1985 to December 1987, planning procedures for 44 treatment regimens were evaluated using i.v. DSA. With reference to the determination of a precise and individual target volume, DSA-assisted treatment planning was found to be superior to non-individualized standard definitions.

Catheter-lysis: indications and primary results

Catheter-lysis--local low-dose fibrinolytic therapy--extends the indication to catheter-treatment. Occlusions longer than 10 cm younger than 3 months may be treated by this method. This treatment is primarily indicated for Fontaine stage III/IV occlusions. The complication of acute embolism or acute reocclusion during routine angioplasty can be treated satisfactorily by catheter-lysis. The primary result of low-dose fibrinolysis depends on the clinical stage, peripheral outflow, age and length of the occlusion.

Seldom indications for angioplasty

Rare applications and localisations of angioplasty are presented. The technique, the primary results and the complications of angioplasty of the visceral arteries, the branches of the aortic arch, the aorta and the venous bypass graft are discussed. The angioplasty is also a good therapeutic principle in the treatment of obstructive arterial vascular disease in these arterial areas.

[Cinedensitometric flow measurements before and after angioplasty in the femoropopliteal region]

In 31 patients with obstructions of the superficial femoral artery in occlusive vascular disease the flow in the popliteal artery was cinedensitometrically measured before and after angioplasty with the balloon catheter. Under resting conditions the flow was improved to the 2.63 fold value by recanalization of the 18 occlusions. By dilatation of the 13 stenoses the flow nearly could be doubled (f = 1.82). The idea is that a high flow is able to counteract to a reocclusion immediately after angioplasty. Therefore a vasodilatator should be applied in order to diminish the peripheral resistance and increase the flow in the treated region.

Release Reaction from Human Platelets Submitted to Viscometric and Tube Flow

A reliable sign of stimulation of human platelets is the release reaction (RR) as measured by the amount of cellular H-C-serotonin set free in the medium. Until now only chemical mediators were known as being able to trigger the RR. According to our experiments flow forces can also induce the RR in the absence of any aggregating substance. In vis-cometric flow we find a strong correlation (r=0.982) between the amount of H-C-serotonin set free in the plasma and the extent of occuring pla telet aggregation. A similiar result we obtained in platelet rich plasma submitted to a stationary laminar tube flow. A positive correlation can be established between constant wall shear stresses and the 14-C-seroto nin release. In counter-distinction to this, the lactate-dehydrogenase of the platelet cytogel is not released by shearing. These data suggest that the RR of human platelets can be induced mechanically and that the extent Of this reaction is proportionalto the intensity and time of shearing.