[Measurement of portal vein blood flow by Doppler ultrasonography: pharmacological applications].
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Blood Flow Velocity↗
Biomedical subjects
M Dauzat
Publications and source records attributed to M Dauzat.
[Pulsatile vaginal expansion: Case report of an internal iliac aneurysm detected after an injury].
After a pelvic trauma, in a 78 years old women, systematic radiograms showed a polycyclic mass in the left side of the pelvis. This finding was confirmed by B-mode ultrasound echography. The vaginal touch found a pulsatile and expanding mass. At surgery, the diagnosis of a fissuring aneurysm of the internal iliac artery was confirmed, and a curative treatment was undertaken. Reviewing the literature, the authors emphasize the diagnostic usefulness of rectal and vaginal touch, and the importance of an early diagnosis using noninvasive imaging techniques. Surgery is the only treatment for isolated internal iliac aneurysms.
Aged↗
Portal hypertension in lymphoproliferative and myeloproliferative disorders: hemodynamic and histological correlations.
The pathogenesis of portal hypertension in patients with lymphoproliferative and myeloproliferative disorders is not fully understood. We investigated 20 patients with myeloproliferative disease and 47 patients with lymphoproliferative disease. Transvenous liver biopsies and hepatic vein pressure gradient measurements were performed in all patients, and portal vein blood flow was measured by pulsed Doppler sonography in 31 of these patients and in 22 normal volunteers. The hepatic vein pressure gradient was significantly higher in patients with hepatic infiltrates, fibrosis or both than in patients without hepatic lesions (8.3 +/- 5.0 mmHg vs. 4.1 +/- 2.3 mmHg; p < 0.01). Portal vein blood flow was significantly higher in patients with hematological disease than in normal volunteers (31.2 +/- 15.5 ml/min.kg vs. 14.2 +/- 4.6 ml/min.kg;p < 0.01). In 81.8% of patients with hepatic infiltrates, fibrosis or both and increased portal vein blood flow, the hepatic vein pressure gradient was greater than 6 mm Hg. Although we saw a significant correlation between splenic vein blood flow and portal vein blood flow (n = 20; p < 0.01), we found no significant correlation between splenic vein blood flow and hepatic vein pressure gradient or spleen size. Hepatic infiltration and fibrosis appear to be major determinants of increased hepatic vein pressure gradient, probably because they increase intrahepatic vascular resistance. The role of increased splenic blood flow is probably not determinant. However, because portal pressure was not measured directly in this study, the incidence of portal hypertension may have been underestimated.
Adult↗
Sonographic approach to diagnosing pulmonary consolidation.
Thirty-nine consecutive patients with consolidated lung confirmed radiologically underwent sonography, and their sonograms were compared with results for 100 healthy subjects. The hyperechoic line of normal aerated lung and its air artifacts showed respiratory motions ("gliding sign," n = 100). Patients with pneumonia demonstrated distinct sonographic patterns. Strong linear echoes with characteristic air artifacts (air bronchogram) and anechoic tubular structures (fluid bronchogram) were visualized in 36 of 39 patients (92.30%). The superficial lung showed a homogeneous hypoechoic band termed "superficial fluid alveolograms" (n = 39) with respiratory motions in 35 of 39 patients. We conclude that sonography can evaluate pulmonary consolidation and may provide additional roentgenographic information, especially when fluid bronchograms are visualized.
Adolescent↗
[Arteriovenous fistula caused by spontaneous rupture of an aortic or iliac aneurysm in the iliocaval venous system. Apropos of 2 cases].
The authors report two cases of arteriovenous fistula due to spontaneous rupture of an aortic or iliac aneurysm into the iliocaval venous axis. This is a rare complication of atheromatous aneurysm (less than 4% of ruptured aneurysms), often difficult to diagnose as the clinical presentation may be obscure. Although aortography is the reference diagnostic investigation, color Doppler ultrasonography enabled visualisation of the arteriovenous communication and provided an accurate diagnosis in one recent case. Treatment of these aortocaval fistulae is always surgical. The prognosis and immediate operative mortality depend mainly on the presence of an associated retroperitoneal rupture.
Aged↗
[Diagnosis by Doppler color echography of dural carotid-cavernous fistula of ophthalmological manifestation].
The case reported here, concerns a spontaneous low-flow fistula between the external carotid arterial network and the cavernous sinus, with ophthalmological symptoms (exophthalmos, red eye) in an old woman with cardiac failure. The shunt was diagnosed by color-Doppler-imaging, which showed a flow reversal with a systolic component in the superior and inferior enlarged ophthalmic veins. This finding led the authors to extend the arterial filling sequence since the shunt was not detectable on standard arterial views. Embolization was performed during angiography which remains necessary to localize the shunt and to treat the fistula. The clinical symptoms progressively returned to normal and the correction of the hemodynamic disturbances could be followed by color-Doppler imaging, a non-invasive technique which can be easily repeated.
Aged↗
Influence of ventilation of the face on thermoregulation in man during hyper- and hypothermia.
It has been suggested that a thermal countercurrent exchange may occur in the cerebral vascular bed of humans, thereby creating for the brain a state of relative thermal independence with regard to the rest of the body. However, worrying questions have arisen concerning this suggestion. Experiments were carried out on seven young male volunteers. Hyper- and hypothermic conditions were produced by immersion in water at 38.5 degrees C and 25 degrees C, respectively. During the last few minutes of immersion, the face was cooled or warmed by ventilation with a 200 l.min-1 air flow at 5 degrees C or 40 degrees C, respectively. Internal and peripheral temperatures were recorded. Blood flow in the anastomotic vessels between face and brain was measured by Doppler techniques associated with computerized frequency analysis. The general responses were as classically described, i.e. an increase in peripheral and central temperatures during immersion in the warm bath and a decrease in these variables in the cold bath. The reactions produced by cooling or warming the face were small and easily explained by the direct changes of the heat load they induced. Whatever the thermal conditions, the blood flow in the anastomotic vessels between the vascular bed of the face and that of the brain was never reversed. It was concluded that there was no experimental evidence for an efficient thermal counter-current exchange in the vascular bed of the human head.
Adult↗
Post-operative Doppler evaluation of 48 arterial reconstructions at the wrist.
C. W. Doppler ultrasound was used for the assessment and follow-up of 35 ulnar or radial arteries, repaired in emergency, and 13 secondarily repaired arteries, after traumatic section. Doppler examination appeared to be more sensitive than Allen test, because it can distinguish, among non functional arteries, those with or without Doppler signal. Moreover, when a Doppler signal is present, the compression test of the other artery can increase or not this signal. Thus, Doppler examination gives an help for surgical decision.
Adolescent↗
Portal vein blood flow measurements using pulsed Doppler and electromagnetic flowmetry in dogs: a comparative study.
Comparative measurements of portal vein blood flow were performed at laparatomy in anesthetized dogs using either a pulsed Doppler echo system or electromagnetic flowmeters. Three hundred four simultaneous determinations were obtained under baseline conditions and during vasopressin and glucagon infusions. In each dog, serial triplicate measurements were taken within 10 min of each other. In all the cases, flow changes induced by vasoactive drugs followed the same direction regardless of the method used. Portal vein blood flow as measured by electromagnetic flowmetry ranged from 85 to 1570 ml/min. Portal vein blood flow values obtained with Doppler and electromagnetic flowmeters were not significantly different (609 +/- 335 vs. 600 +/- 370 ml/min; p = NS) and were highly correlated (r = 0.918, p less than 0.001). The difference between values obtained by the two techniques was -3 +/- 159 ml/min or -1.0% +/- 21.2% (mean +/- SD). This difference was not influenced by the portal vein diameter but increased slightly as a function of the angle of insonation. When considering the mean of triplicate measurements, we also found a highly significant correlation between data obtained by the two techniques (r = 0.934, p less than 0.001; n = 63). The mean difference was 11 ml/min, but limits of agreement between these methods were -267 and +239 ml/min. This relative discrepancy was explained by a coefficient of variation higher in Doppler measurements than in electromagnetic measurements (10.9% vs. 5.9%). These data demonstrate that under our experimental conditions, Doppler flowmetry is probably not an ideal method to measure absolute portal vein blood flow values, and that more sophisticated equipment is needed to improve its reproducibility and accuracy. In humans, however, this method might be a useful tool to assess the direction of portal flow changes in the same individual.
Animals↗
[Medical, social, economic value of the rational use of non-invasive studies for diagnosing phlebitis. Experience of the Regional Hospital Center of Nimes from 1984 to 1988].
Continuous wave Doppler, and B-Mode ultrasound allow the diagnosis of deep venous thrombosis with a 96% sensitivity, and a 98% specificity versus venography (1). Therefore, these methods can be extensively used for the detection of deep venous thrombosis, following a new diagnostic algorithm: X ray venography is used only for the assessment of topographic extent of iliac and caval thrombosis, and when non invasive methods give equivocal results. As a result, the number of X ray venographies significantly decreased since 1984 (7) in Nîmes University Hospital. About 75% of patients with a deep venous thrombosis (diagnosed by non invasive methods) were treated without necessity of X ray venography.
Algorithms↗
[Doppler ultrasound and portal hypertension: quantitative analysis].
Usually, the clinical evaluation of diffuse hepatic changes only needs the answers to three important questions: is there a flow, in which direction and are the porto-caval shunts efficient? When an answer is found to these questions, the quantitative measurement of the portal flow can give complementary precisions to achieve a better physiopathological understanding of portal hypertension or blood malignancies and for the follow-up evaluation.
Adult↗
[Doppler ultrasound in portal hypertension: qualitative analysis].
Duplex Doppler US is a procedure that enables confirmation--and in many instances--detection of portal hypertension by visualizing the presence of collateral blood vessels and determining the direction of the portal flow. In addition, absence of Doppler signal into the veins allows assessment of venous thrombosis both in the portal and hepatic veins.
Budd-Chiari Syndrome↗
Transcranial Doppler evaluation of middle cerebral artery stenosis.
Symptomatic stenoses of the middle cerebral artery (MCA) are not uncommon, although Corston observed the occurrence of stroke in 24% of patients with MCA stenoses during a 6-year follow-up study. We tried to use transcranial Doppler (TCD) sonography for the detection and evaluation of MCA stenoses. Intra-arterial angiography demonstrated 16 MCA stenoses of more than 30% diameter reduction in 15 patients (14 atheromatous stenoses, 2 dysplasias). Severe associated lesions were present in 2 cases (more than 75% internal carotid artery stenosis). These 15 patients with MCA stenosis were examined with TCD in a blind study. A Doppler signal from the MCA was obtained through the temporal bone and was recognized on the result of common carotid artery compression test. We ascertained MCA stenosis when TCD demonstrated 1) segmental flow acceleration with peak systolic frequency of more than 3 KHz with or without high energy low frequency direct or reverse components; or 2) segmental increase in systolic peak frequency of more than 20%. Using these criteria, we confirmed through TCD the presence of MCA stenosis in nine out of 12 cases with diameter reduction of at least 50%, and one among four cases with less than 50% diameter reduction. Although our results are consistent with Aaslid and von Reutern's figures, methodological problems and diagnostic criteria have to be improved. Nevertheless, TCD seems to be a useful tool for the detection of stenosis with at least 50% diameter reduction, where it proved to offer a 75% sensitivity. Further studies are necessary to improve sensitivity and specificity.
Adult↗
[Non-invasive methods for vascular studies in the diagnosis of deep venous thrombosis].
The sonographic diagnosis of deep venous thrombosis must be made up of a functional continuous wave Doppler study of the whole deep venous system of the limbs, including leg veins, as well as saphenous veins. Then, high resolution B-mode real time sonography is used for the detection of direct (echogenic thrombus) or indirect (incompressible vein) signs of thrombosis. This noninvasive approach offers a good sensitivity (about 96%) and a high level of specificity (about 98%). Moreover, B-mode sonography can ensure the differential diagnosis (hematoma, extrinsic compression...) in most cases. So, X-Ray venography is required only when an interventional therapy is planned (thrombectomy, fibrinolysis, inferior vena cava interruption...), or when the noninvasive techniques are not able to show the upper limit of the thrombosis (especially for iliac veins or inferior vena cava), or when there is still a doubt about deep venous thrombosis. Therefore, the number of X Ray venographies can be consistently reduced, thus decreasing both cost and risks.
Angiography↗
Ultrastructural study of arterial wall repair after argon laser micro-anastomosis.
A carotid end-to-end anastomosis was performed in 50 Wistar rats by means of a Coherent 900 argon laser. The vessel sealing was obtained with laser shots (average 19) of 300 mW power and 5-second duration, the beam being focused in a spot of 150 micron diameter (1,700 W/cm2). From day 0 to day 120, 25 specimens underwent semithin and electron microscopic examinations. The results showed the immediate sealing effect of the argon laser owing to protein denaturation and collagen fusion of the media and adventitia 100 micron in width. Re-endothelialization of the anastomotic line began by day 3, while myofibroblast proliferation was observed in the media by day 10. By day 20 media scar was still occupied by numerous myofibroblasts and surrounded by abundant collagen and elastic fibres. At long term the endothelial repair was complete and the anastomotic strength was assured by medial collagenous network.
Animals↗
Duplex Doppler examination in portal hypertension: technique and anatomy.
Three hundred fifty duplex Doppler examinations were performed in 195 patients (150 adults and 45 children) with radiologically and/or clinically proved portal hypertension. In this paper we describe this duplex Doppler technique for the qualitative assessment of splanchnic venous hemodynamics in these patients. The caliber of and the presence and direction of flow in the following veins are assessed: splenic, superior mesenteric, portal and intrahepatic portal, and portasystemic collateral. This examination can be performed on patients of any age without sedation and can establish the diagnosis of clinically significant portal hypertension. Technical success rate was 95%, although 10% of examinations were incomplete because of intestinal meteorism. We conclude that the combined use of Doppler and routine sonography permits precise evaluation of the vascular anatomy in portal venous hypertension.
Adolescent↗
[Pre- and postoperative Doppler ultrasound findings in coarctation of the aorta].
A retrospective study was done about 73 patients who had undergone a surgical operation for correction of coarctation of the aorta, between 1975 and 1985. Among these patients, 45 had both pre- and post-operative continuous wave Doppler ultrasound examination of cervical, upper, and lower limbs arteries, with pressure measurement. The age was under 14 years for 18 patients, between 14 and 25 for 10 patients, and more than 25 for the remaining 17 patients. The surgical procedure was resection with end-to-end anastomosis for 27 patients, tube graft insertion for 8 patients, dacron patch for 7 patients, subclavian arterioplasty or shunt for the others. Systolic Pressure Index and femoral Pulsatility Index showed a highly significant increase after operation (P less than 0.001) (tables I, II) regardless of the age or the surgical technique, thus demonstrating a satisfying hemodynamic efficiency of the correction (fig. 1-6) (2-6, 9). Nevertheless, 17 patients had, after operation, a greater than 15 Hg mm pressure gradient between left and right arm: the retrospective study showed that most of them had congenital abnormalities involving the left subclavian artery and/or had undergone a surgical procedure using the left subclavian artery for arterioplasty (10).
Adolescent↗
[Diagnostic contribution of ultrasonic diagnosis coupled with pulsed Doppler combined with continuous Doppler to the exploration of the vertebral arteries of atherosclerotic patients. Preliminary report].
Velocimetric exploration by continuous emission Doppler is still essential for non-invasive evaluation of vertebral circulation but it does not provide morphologic data. Results were compared of exploration with combined continuous emission Doppler and a Duplex examination (sectorial scanning ultrasound imaging coupled with pulsed emission Doppler) and data from arteriography of 186 vertebral arteries in patients, mean age 57 years, admitted for exploration of a cerebral ischemic accident or a cervical murmur. The Duplex examination allowed identification of proximal segment (VI) in 98% of permeable vertebral arteries. The ostium of the vertebral artery was more difficult to visualize because of possible tortuosities, of sometimes a too posterior or intrathoracic localization or of a short neck. Nevertheless the vertebral ostium was identified in 78% of cases on the right and 48% on the left. The Duplex examination demonstrated sensitivity of 72% and specificity of 98% for detection of proximal stenosis of vertebral artery, and its sensitivity was therefore twice as sensitive as continuous emission Doppler for detection of stenoses of less than 50%. The Duplex examination should complete data from continuous emission Doppler by providing an evaluation of vertebral artery diameter and information on presence and characters of an elongation or stenosis. In this way, 9 atheromatous plaques not identified on arteriography were detected by ultrasound imaging. Similarly, the Duplex examination is particularly useful for identification of a hypoplastic vertebral artery, to distinguish the specific lesions of the subclavian artery from those extending onto vertebral ostium, and to characterize ostial lesions when these are accessible to examination.(ABSTRACT TRUNCATED AT 250 WORDS)
Basilar Artery↗