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D Neuerburg-Heusler

Publications and source records attributed to D Neuerburg-Heusler.

At least 19 recordsLinked to original sources
PubMed1996

[Determining the degree of stenosis of peripheral arteries. Hemodynamic and ultrasound principles].

With colour duplex sonography, the identification and quantification of arterial stenoses in peripheral arteries had become feasible in reasonable time. However, the haemodynamic considerations are more complicated in peripheral arteries than in carotid arteries. This is attributable to the much longer vessel length, the influences of peripheral resistance, the frequency of multiple stenoses and combinations of occlusion and stenosis with multiple collateral vessels. Different qualitative and quantitative approaches are used: b-mode sonography, spectral analysis, velocity measurements, continuity equation and estimation of systolic pressure gradients (Bernoulli equation). Although standardized criteria in the grading of stenoses are not commonly used, the peak velocity ratio (PVR as a ratio of intra-and prestenotic velocity) seems to be mathematically founded, usefully versatile and reliable.

Arterial Occlusive Diseases↗
PubMed1993

[Color-coded duplex ultrasonography in the diagnosis of renal artery stenosis].

To diagnose possible renal artery stenosis in 120 patients (36 women, 84 men; mean age 57.3 [21-84] years) colour duplex sonography (CDS) of the renal arterial tree was performed before 53 intraarterial angiographies and 67 central venous digital subtraction angiographies. The criterion of stenosis was a maximal flow velocity of > 180 cm/s in the colour duplex sonogram and a diameter reduction of > 50% in the angiogram. CDS demonstrated the renal artery bed in 209 of 247 renal arteries (85%). 84 of the 209 had regional maximal velocities of > 180 cm/s. The sensitivity and specificity of CDS when comparing it with both angiographic methods (in 185 cases that could be evaluated, in 74 of them with abnormal results) were 91 and 88.2%, respectively. Comparing CDS results with those by intraarterial angiography alone (88 cases, with 51 abnormal findings), sensitivity and specificity were 92.1 and 91.8%, respectively. These results demonstrate that CDS can reliably demonstrate flow obstructions in the renal arterial tree and can thus be recommended for the diagnosis of renovascular hypertension.

Aged↗
PubMed1993

[Determination of the length of the occlusion in extremity arteries--color duplex ultrasound versus angiography].

In the management of patients with peripheral arterial occlusive disease the length and location of an arterial occlusion has an impact on the choice of the method of arterial reconstruction, i.e. percutaneous transluminal angioplasty or vascular surgery. The aim of this study was to determine the accuracy of colour-coded Doppler sonography (CDS) compared to conventional contrast arteriography in detecting the length and localisation of an occlusion in peripheral arteries. 100 legs of 94 patients (27 women, 44 to 82 years of age [mean 60.9 years] and 67 men, 21 to 78 years of age [mean 61.3 years]) with clinically suspected artery occlusion were examined prospectively with CDS before angiography and angioplasty. The exact localisation was correctly diagnosed by CDS in 95% with a high correlation (r = 0.95) of occlusion length between both methods. The sensitivity in detecting occlusions was 98% (positive predictive value 98%). It is concluded that colour-coded Doppler sonography can diagnose the length and location of an occlusion in peripheral arteries accurately and therefore can be used as a noninvasive method to select patients for further therapy management.

Adult↗
PubMed1993

[Effect of transient therapeutic occlusion on some hemodynamic parameters and walking distance].

The effect of a one hour lasting occlusion was studied by recording the ankle/arm pressure ratios at rest and during post-occlusive reactive hyperemia 30 min, 1 day, 3 days and 7 days after the procedure. Both parameters improved, reaching a maximum on the 7th day at which time the changes became statistically significant. Finally, a standardized walking distance test yielded a highly significant improvement when determined on the 7th day (mean increase in walking distance: 69%). Although the underlying mechanism is yet unclear, the positive therapeutic results and absence of side effects warrant further investigations to be focused on the mechanism as well as on practical implications related to the procedure itself to optimize the results.

Arterial Occlusive Diseases↗
PubMed1993

[Behavior of post-occlusion systolic blood pressure after long duration blockade. Effect of induced hypertension].

A suprasystolic blockade (300 mm Hg) was applied for 50 to 60 min to the thigh of the affected leg with a blood pressure cuff in 13 patients with occlusions of the femoral artery. Afterwards, the pre-postocclusive systolic pressure difference was clearly less in most patients than before the compression manoeuvre. This reduction of the systolic pressure gradient, which was greatest in the first hour and slowly decreased in subsequent days, is likely to be based on a dilatation of the collateral arteries. The reaction was especially pronounced in patients with isolated occlusion of the femoral artery. Since the entire collateral circulation is largely in the region of the cuff compression in these cases, the collateral dilatation might arise from the powerful and long lasting pressure. In 9 patients it was investigated whether an increase of systemic blood pressure induced by hypertension can be transduced more effectively to the postocclusive arterial system when the collateral arteries are "paralyzed". The heterogeneous results show that such an effect can evidently only be expected when the collateral circulation is restricted to the thigh. However, such conditions are probably not usual in poorly compensated stage IV following Fontaine, in which a temporary peripheral increase of blood pressure is likely to be reasonable for therapy.

Adult↗
PubMed1992

[Value of duplex sonography in diagnosis of renal artery stenosis and its value in follow-up after angioplasty (PTA)].

The assessment of the renal arteries is particularly important in the detection of a renovascular cause of the arterial hypertension. The purpose of the present study was twofold: to evaluate the accuracy of duplex scanning in non-invasively diagnosing renal artery stenoses in hypertensive patients, and to determine the results of transluminal angioplasty of renal artery stenoses as assessed by duplex scanning. In 76 patients with arterial hyertension, 170 renal arteries (18 kidneys supplied by two renal arteries) were examined by both duplex scanning and angiography (DSA in intraarterial and intravenous technique, and conventional arteriography). Peak systolic and end-diastolic flow velocity parameters as well as the Pourcelot-index were determined in the proximal renal artery and compared with the indendently performed angiography. In 102 angiographically proven normal renal arteries, mean +/- SD peak systolic and end-diastolic velocity values were 84.7 +/- 13.9 cm/s and 31.2 +/- 7.8 cm/s, respectively, with a Pourcelot-index of 0.66 +/- 0.07. For detecting renal artery stenoses greater than 50%, duplex scanning had a sensitivity of 86%, and a specificity of 83% for a systolic peak velocity of 140 cm/s and more in the renal artery. In 13 patients with 14 stenosed renal arteries, duplex scanning and intraarterial DSA densitometry were performed before and after transluminal angioplasty of the renal artery stenoses. There was fairly good agreement between transstenotic peak systolic velocities and densitometrically determined degrees of stenosis in the renal artery (r = 0.84). These results show that duplex scanning is an accurate noninvasive diagnostic tool in detecting proximal renal artery stenoses.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Varicosis of the great saphenous vein as a main symptom of iatrogenic arteriovenous fistula].

A 22-year-old man with movement-dependent knee-joint pain was operated on for patellar chondroplasia and meniscal dysplasia after two previous arthroscopic removal of free joint bodies had failed to bring relief. A few months after the operation the same leg had become swollen with signs of venous congestion, long saphenous vein varicosity and traumatic pretibial crural ulcer. The long saphenous vein was partially excised. 18 months after the arthrotomy there was clinical and colour-Doppler evidence of an arteriovenous fistula with false aneurysm in the region of the popliteal artery as cause of the venous congestion. The ulcer healed completely after ligation of the fistula and excision of the false aneurysm. --Arterio-venous fistula should be included in the differential diagnosis as a possible cause of postoperative swelling of a limb.

Adult↗
PubMed1991

[Determination of the length and site of the occlusion of extremity arteries--color duplex sonography versus angiography].

The aim of the study was to determine the accuracy of colour--coded Doppler sonography (CDS) compared to angiography in detecting the localisation and length of an occlusion in peripheral arteries. 118 legs of 107 patients with clinical suspected occlusion were examined prospectively with CDS before angiography. In 110 cases both methods identify identical localisations. The sensitivity in detecting occlusions was 97%, the exact localisation was diagnosed by CDS in 95% with a high correlation (r = 0, 96) of length measurements.

Angiography↗
PubMed1991

[Terminology of ultrasound vascular diagnosis].

There is at present no accepted nomenclature regarding diagnostic vascular ultrasound. At two scientific meetings, the Study Group for Vascular Diagnosis of the German Society of Ultrasound in Medicine (DEGUM) developed a terminology for Doppler and duplex sonography of the arteries and veins supplying the brain and of peripheral vessels. The most important of these sonographic terms and their synonyms are presented. Recommendations as to which of the presently employed terms should be avoided, are given.

Blood Flow Velocity↗
PubMed1990

[Terminology of ultrasonic vascular diagnosis].

There is at present no accepted nomenclature regarding diagnostic vascular ultrasound. At two scientific meetings, the Study Group for Vascular Diagnosis of the German Society of Ultrasound in Medicine (DEGUM) developed a terminology for Doppler and duplex sonography of the arteries and veins supplying the brain and of peripheral vessels. The most important of these sonographic terms and their synonyms are presented. Recommendations as to which of the presently employed terms should be avoided, are given.

Brain↗
PubMed1989

[Duplex ultrasound studies of the deep femoral artery].

In case of occlusion of the superficial femoral artery (SFA), the deep femoral artery (DFA) supplies the entire lower extremity. Not infrequently, the SFA occlusion is associated with stenosis of the origin of the DFA. The angiographic study of the origin of DFA is often unsatisfactory. The purpose of the present study was to develop objective criteria for the diagnosis of the DFA origin stenosis by duplex scanning. In 60 patients, we examined 75 femoral bifurcations by duplex scanning and compared them with the independently performed angiography. Group 1 (n = 20 DFA origins) consisted of 10 normal individuals. Group 2 (n = 30 DFA origins) consisted of 25 patients with angiographically proven SFA occlusion and normal DFA. Group 3 (n = 25 DFA origins) consisted of 25 patients with angiographically proven SFA occlusion and DFA orifice stenosis. We measured the maximal systolic and mean flow velocity in the orifice of the DFA at rest and during the maximal hyperemia following 3 min of ischemia of the lower leg. At rest, the maximal flow velocity in groups 1-3 was 60 +/- 15, 142 +/- 44, and 255 +/- 60 cm/s (p less than 0.01) and the mean flow velocity was 8 +/- 6, 32 +/- 9, and 96 +/- 42 cm/s (p less than 0.01). During hyperemia, the maximal and mean flow velocity for groups 1-3 was 59 +/- 15, 155 +/- 42, and 286 +/- 82 cm/s (p less than 0.01) and 8 +/- 5, 55 +/- 19, and 144 +/- 51 cm/s (p less than 0.01), respectively. An origin stenosis of the DFA is highly probable when at rest the mean and maximal velocity in the proximal DFA exceed 50 cm/s and 180 cm/s, respectively. These results show that duplex scanning is able to detect safely DFA origin stenosis. The increase in postischemic DFA flow velocity when SFA occlusion is present, helps to evaluate total flow resistance of the deep-outflow channels (run-off) thereby being useful in planning appropriate therapy.

Adult↗
PubMed1986

[Statistical principles for the validation of diagnostic procedures. A contribution to quality assurance exemplified by Doppler sonography].

This article presents an introduction to some basic considerations for the evaluation of diagnostic tests and procedures. In order to determine the characteristics of a diagnostic procedure sensitivity and specificity are estimated from results of an evaluation study. The statement of confidence limits gives an idea of the safety of the estimates. Different scales of measurement and their respective distributions must be taken into consideration. Quite often sensitivity and specificity are dependent on various threshold values. ROC-curves can be used to study this dependence. In practice the interpretation of test results relies on the predictive value. The Bayes formula permits calculation of the predictive value depending on sensitivity, specificity and prevalence. This paper illustrates the application of statistical methods by analysing data of Doppler ultrasound studies.

Diagnosis, Differential↗