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1.
PURPOSE: To determine whether preoperative aortoiliac arteriography can be replaced with noninvasive evaluation in the management of some patients with chronic lower extremity ischemia. METHODS: Preoperative evaluation was performed on 184 ischemic limbs (119 patients) over 19 months by means of aortoiliac arteriography with runoff and noninvasive studies, which included common femoral artery duplex scanning, waveform and acceleration time (normal <140 msec), and aortoiliac duplex scanning. An algorithm was proposed for combining indirect (common femoral artery evaluation) and direct (aortoiliac evaluation) noninvasive studies to decrease the need for aortoiliac arteriography when possible. RESULTS: Aortoiliac occlusive disease (> or =50% stenosis to occlusion) was present at arteriography in 48 limbs (30%), and there was no inflow disease in 114 (70%). Aortoiliac lesions were identified by means of noninvasive studies. The accuracies of femoral waveform, acceleration time, and aortoiliac duplex studies were 85%, 89% and 87%. The negative predictive values were 92%, 94% and 100%. The acceleration time results were not affected by runoff status but were significantly different for various categories of stenosis (p < 0.05). The algorithm was applied to the data obtained. When acceleration time and waveform were normal, 84 of 86 patients (98%) had no stenosis at arteriography. When aortoiliac duplex findings were normal, the arteriographic findings were normal in all examinations. CONCLUSION: A combination of indirect and direct noninvasive studies can be used reliably to rule out clinically significant inflow occlusive disease and allows selective use of aortoiliac arteriography in patients with lower extremity ischemia.  相似文献   

2.
The Marlex mesh PerFix plug groin hernioplasty   总被引:1,自引:0,他引:1  
Ultrasonic duplex scanning was used to examine 77 internal thoracic arteries (ITA). The investigated vessels were classified as normal, stenosed (peak systolic velocity was faster than 150 cm/sec and doppler signals showed turbulent pattern), small (diameter measurements were smaller than 1.4 mm and mean flow velocities were slower than 20 cm/sec in distal part of the vessels), and occluded (no flow characteristics could be detected) by the doppler spectrum analysis and the two-dimensional B-mode images. The results of the duplex examination were compared with operative findings and angiograpic findings. Diameter measurements by duplex scanning compared with operative findings showed virtually no differences. One stenosed ITA, a 75% stenosis in the proximal part of the vessel, and two small ITAs were detected by duplex scanning. We performed coronary artery bypass grafting using distal part of the stenosed ITA as a free graft, and used small ITAs as individual bypass grafts. Two normal ITAs were misjudged as small, and one small ITA was misjudged as occluded. All normal ITAs of duplex examination showed normal findings of angiography. Duplex scanning is a reliable, sensitive, and noninvasive technique for the preoperative assessment of the ITA, and is a suitable screening for coronary artery surgery.  相似文献   

3.
Measurement of cardiac output by Doppler echocardiography were compared to simultaneous measurements by thermodilution in 9 conscious horses. In the Doppler technique, mean blood flow velocities for estimation of cardiac output were recorded from the aorta and pulmonary artery. The flow area of each vessel was calculated from the vessel diameter, measured from a 2-dimensional ultrasound image. Differences in the site and method of measuring the vessel diameter altered the estimation of cardiac output by the Doppler method. Cardiac output was modified by the i.v. infusion of 4 micrograms/kg bwt/min dopamine and 4 micrograms/kg bwt/min dobutamine and by the i.v. administration of 10 micrograms/kg bwt detomidine and 20 micrograms/kg bwt butorphanol. Doppler measurements of cardiac output correlated closely with measurement by thermodilution. Measurements from the aortic outflow correlated more closely with thermodilution, than those from the pulmonary artery (r = 0.89 and r = 0.77, respectively). Doppler measurements when the mean flow velocity was recorded from the aorta and the flow area was measured from the ascending aorta using the leading edge method. There was no significant bias between the 2 techniques when Doppler flow velocities were recorded by this method and the limits of agreement were narrow (+/- 12.26 l/min). The differences between the 2 methods increased with increasing cardiac output. Doppler echocardiography is a safe noninvasive method of measuring cardiac output in horses. The agreement between Doppler echocardiography and thermodilution in this study is similar to that reported in man and is similar to that reported between thermodilution and other techniques in man.  相似文献   

4.
RATIONALE AND OBJECTIVES: The authors compared the postocclusion hyperemic responses of the brachial artery after occluding blood flow proximal to and distal to the studied area. MATERIALS AND METHODS: Response of the brachial artery to hypoxia was evaluated with duplex Doppler ultrasound in 13 healthy subjects. A pneumatic tourniquet was first positioned 2-5 cm superior to the left elbow, proximal to the area of artery studied. Two hours later the response was remeasured with the tourniquet positioned 2-5 cm inferior to the elbow, distal to the artery studied. Arterial diameter, mean and peak flow velocities, and heart rate were assessed. RESULTS: No significant differences were observed between measurements of baseline and postischemic arterial diameter, percentage diameter change, baseline mean arterial blood flow velocity, baseline peak arterial blood flow velocity, or postischemic heart rate obtained with proximal occlusion of the artery and those obtained with distal occlusion. In contrast, mean and peak postischemic arterial blood flow velocity and preocclusion heart rate were higher in measurements made during proximal artery occlusion. Significant correlation was found between measurements of percentage change in artery diameter obtained with proximal artery occlusion and those obtained with distal occlusion (r = 0.611, P < .05). CONCLUSION: There are no major differences in postischemic changes in brachial artery diameter related to reactive hyperemia between blood flow occlusion applied proximal and distal to the studied area. However, there are significant differences in the mean and peak systolic velocities. Either occlusion site can be used for clinical studies if arterial diameter change is monitored, but if velocity measurements are being compared, a single occlusion site should be chosen.  相似文献   

5.
Velocity measurements in major blood vessels were obtained in studies of volunteers using magnetic resonance imaging (MRI) and compared with Doppler ultrasound (US). The vessels studied were the abdominal aorta, superior mesenteric artery, common carotid artery, superficial femoral artery and middle cerebral artery. Using a paired t-test, no significant difference was found between velocity values estimated by MRI and US (p > 0.08). The relative advantages of each technique in radiological practice are discussed.  相似文献   

6.
Central retinal artery and orbital artery were examined by ultrasonograph in 348 patients with atherosclerosis of the carotid arteries. Doppler shift of frequency spectrum was detected in the central retinal artery, which is typical of the ischemic syndrome of the eye. Its characteristics include decreased diastolic component of velocity and increased resistance index. The possibility of using duplex scanning with color Doppler flow mapping for assessing the treatment efficacy is demonstrated. A direct relationship between the degree of stenosis in the internal carotid artery and blood flow in the orbital artery is revealed. The detected changes do not notably affect the Doppler spectrum characteristics in the central retinal artery.  相似文献   

7.
BACKGROUND: Because of the wide range of recommended threshold values for carotid stenosis graduation we performed a prospective study to determine interobserver and interequipment variability of quantitative blood flow velocity measurements. PATIENTS AND METHODS: We recorded absolute blood flow velocities and velocity ratios in 21 patients with carotid artery stenosis using two colour coded duplex ultrasound systems an ATL Ultramark 9 HDI, and a Hewlett Packard SONOS 2500 system. The ATL system was used for the interobserver variation study, where each patient was examined twice on the same day. The Doppler angle was recorded together with blood flow velocities (peak systolic velocity and mean maximum velocity from the velocity-time-integral both in the stenosis jet and 4-5 cm distally in the cranial portion of the internal carotid artery off poststenotic turbulences). RESULTS: The ATL system generated significantly higher blood flow velocity values as compared with the HP system (218 +/- 156 cm/s vs. 169 +/- 114 cm/s; p < 0.001). The Mean Velocity Ratio (the ratio of intrastenotic Vmean and poststenotic Vmean) was constant with both duplex systems. The HP system yielded 10% (Cl, 7-13%) lower predicted stenosis estimates than the ATL system with Vmax as the stenosis criterion. The stenosis estimates calculated from Mean Velocity Ratio values did not differ significantly. The 95% Cl for predicted diameter reduction between two observer was 13.6% (Vmax) and 15.4% (Mean Velocity Ratio). CONCLUSION: Because of significant interequipment differences of colour coded duplex ultrasound systems we recommend calculation of the Mean Velocity Ratio to avoid interpatient and interequipment variation of absolute flow velocities. According to our interobserver variability study, a change of more than 15% diameter reduction on follow-up examinations indicates disease progression or regression.  相似文献   

8.
OBJECTIVES: To assess the accuracy of Duplex ultrasound in the assessment of aortoiliac disease. DESIGN: Prospective, semi-blind study. SETTING: Vascular laboratory and radiology departments, University Hospital. MATERIALS AND METHODS: Ninety-two patients underwent assessment of the aortoiliac segment by femoral pulse palpation, Duplex ultrasound and biplanar arteriography. Of these 184 aortoiliac segments, 68 were also assessed by intraarterial pressure measurements and 80 by magnetic resonance angiography (MRA). MAIN RESULTS: Femoral pulses were abnormal in all 32 occluded aortoiliac segments. Of 152 patent segments, femoral pulse palpation was misleading in 50 (33%). MRA detected all occlusions and had a sensitivity of 71% and specificity of 68% for stenoses, compared to arteriography. Colour flow Duplex misdiagnosed four occlusions as stenoses. Duplex had a sensitivity of 91% and specificity of 93% for stenoses when compared to arteriography. Two stenoses, detected by Duplex and confirmed by pressure gradients, were missed by arteriography. CONCLUSIONS: Pressure measurements remain the gold standard for aortoiliac examination, arteriography providing only morphological information. The limitations of femoral pulse palpation should be appreciated. Although MRA was faster, Duplex examination proved slightly more sensitive to stenoses. At present, colour Duplex provides the best non-invasive assessment of aortoiliac disease and could prevent unnecessary arteriograms.  相似文献   

9.
OBJECTIVES: This study evaluated two methods for the quantitative measurement of collaterals using intracoronary (IC) blood flow velocity or pressure measurements. BACKGROUND: The extent of myocardial necrosis after coronary artery occlusion is substantially influenced by the collateral circulation. So far, qualitative methods have been available to assess the human coronary collateral circulation, thus restraining the conclusive investigation of, for example, therapies to promote collateral development. METHODS: Fifty-one patients with a coronary artery stenosis to be treated by percutaneous transluminal coronary angioplasty (PTCA) were investigated using IC PTCA guidewire-based Doppler and pressure sensors positioned distal to the stenosis. Simultaneous measurements of aortic pressure, IC velocity and pressure distal to the stenosis during and after PTCA provided the variables for calculating collateral flow indices (CFIv and CFIp) that express collateral flow as a fraction of flow via the patent vessel. Both CFIv and CFIp were compared with conventional methods for collateral assessment, among them ST-segment changes >1 mm on IC and surface electrocardiogram (ECG) at PTCA. Also, CFIv and CFIp were compared with each other. RESULTS: In 11 patients without ECG signs of ischemia during PTCA (sufficient collaterals), relative collateral flow amounted to 46% as determined by Doppler and pressure wire. Patients with insufficient collaterals (n=40) had relative collateral flow values of 18%. Using a threshold of CFI=30%, sufficient and insufficient collaterals could be diagnosed with 100% sensitivity and 93% specificity by IC Doppler, and 75% sensitivity and 92% specificity by IC pressure measurements. The agreement between Doppler and pressure measurements was good: CFIv=0.08 + 0.8 CFIp, r=0.80, p=0.0001. CONCLUSIONS: Intracoronary flow velocity or pressure measurements during routine PTCA represent an accurate and, at last, quantitative method for assessing the coronary collateral circulation in humans.  相似文献   

10.
PURPOSE: To compare the orbital blood flow velocities of patients with long-standing ocular hypertension and patients with primary open-angle glaucoma. METHODS: Twenty patients with ocular hypertension were recruited from our clinic and underwent color Doppler imaging evaluation of their retrobulbar vessels. The blood flow velocities and resistance index of their central retinal artery, temporal short posterior ciliary artery, and ophthalmic artery were compared with those of 20 glaucoma patients individually matched for age and level of the highest untreated intraocular pressure ever recorded. RESULTS: Glaucoma patients had significantly lower peak systolic velocity and end-diastolic velocity than did patients with ocular hypertension in their central retinal artery (p < 0.001). No significant difference between the groups was observed in the other vessels studied. CONCLUSIONS: Glaucoma patients had lower blood flow velocity in the central retinal artery compared with that of ocular hypertension patients of similar age and level of untreated intraocular pressure. This might be important in the development of glaucomatous damage in those patients.  相似文献   

11.
A recently developed ultrasound phase-locked echo-tracking system makes it possible to measure non-invasive pulsatile vessel diameter changes, and, in combination with blood-pressure measurement, to calculate pressure strain elastic modulus (Ep) and stiffness (beta). The reproducibility in measurements of pulsatile diameter changes with this system was evaluated. Also the precision of indirect blood-pressure measurements, as compared to the simultaneously measured intra-arterial blood pressure was tested. The resulting reproducibility in pressure strain elastic modulus (Ep) and stiffness (beta) was evaluated. Intra-observer variabilities in measuring pulsatile diameter changes were 16% for the abdominal aorta, 10% for the common carotid artery, and 15% for the common femoral artery, respectively. Intra-observer variabilities for Ep and beta were 21% for both in the abdominal aorta, 17% for both in the common carotid artery, and 18% for both in the common femoral artery, respectively. There were only small differences in indirect and direct measurement of systolic blood pressure, whereas indirect blood pressure measurement systematically overestimated the diastolic blood pressure, on average by 20%. The variabilities in indirect blood pressure measurements were 2% for the systolic and 3% for the diastolic blood pressure, respectively. Inter-observer variability in the investigation of the common carotid artery was 10% for the pulsatile diameter changes, and 21% and 23% for Ep and beta, respectively. Thus, the echo-tracking system represents a reliable system for estimation of pressure strain elastic modulus and stiffness. However, Ep and beta are systematically underestimated by 25-30%, when used in combination with indirect blood pressure measurements.  相似文献   

12.
The effect of repeated doses of indomethacin on mean peak velocity (MPV) and time-averaged mean velocity in the middle cerebral artery was assessed in 10 ventilated neonates with a patent ductus arteriosus using colour/duplex Doppler technique prior to, and 10, 30, and 120 min after the first and the third dose. Velocities were significantly reduced up to 120 min after the first dose. The third dose resulted in a significant reduction in MPV at 10 and 30 min following treatment. This reduction was half of that observed after the first dose. Systemic blood pressure (BP) and heart rate did not change significantly after each separate dose. However, by the third dose, mean and diastolic BP were significantly increased from pretreatment levels. The attenuated response of cerebral blood flow (CBF) velocities to the third dose of indomethacin compared with the first dose is probably related to altered haemodynamics. Indomethacin should be used cautiously in infants with other conditions which are known to decrease CBF such as hypotension, hypocarbia and polycythaemia.  相似文献   

13.
The paper summarizes the principles, techniques and efficiency of ultrasound methods as indicator systems in the assessment of the peripheral and cerebral arteries; our studies predominantly refer to the use of these simple, non-invasive procedures in combination with sphygmo-oscillography and dynamographic circulation analysis, respectively. Ultrasound Doppler flowmetry (Pulse Doppler method), which permits relative measurements of the flow velocity in the peripheral haemodynamic regions, is of great importance in the rapid ascertainment of the patency of the major arterial trunks and the non-palpable vessels and also in the diagnosis, localization and follow-up control of stenoses and occlusions. Changes in the flow velocity due to organic or functional factors can be recorded by this method acoustically, oscilloscopically and graphically; measurements of the systolic blood pressure in the limb arteries by the Doppler technique provide semi-quantitative information in regard to the condition of the circulation. The registration of Doppler signals over the supra-orbital artery before and after compression of the superficial temporal artery and the common carotid artery has become established as a screening procedure for stenoses of the internal carotid artery. Ultrasound echography, which enables pulse registration and determination of vessel diameters, especially of the carotid siphon, can also be used for the detection of obstructions in the region of the internal carotid artery, as well as the vertebral artery.  相似文献   

14.
Transcranial Doppler ultrasonography is a useful method for the estimation and monitoring of cerebral circulation in dialyzed patients. The aim of this study was to evaluate the effect of disease and treatment on cerebral circulation in children on maintenance hemodialysis (HD) and children prior to renal replacement therapy. We demonstrated that in uremic children blood flow velocities of the internal carotid artery (ICA), anterior cerebral artery (ACA), middle cerebral artery (MCA), and posterior cerebral artery (PCA) 120 min and 240 min from the beginning of an HD session were significantly lower than values immediately before HD. Changes in blood flow velocities of MCA and ACA during HD correlated significantly with changes in mean arterial pressure during HD. There was no correlation between changes in blood flow velocities and intradialytic changes in hematocrit values, ultrafiltration, hemoglobin concentration, and blood urea nitrogen values. Mean blood flow velocities of ICA, MCA, and PCA in euvolemic children on conservative treatment were significantly higher than after a HD session in children on maintenance HD. The factors responsible for intradialytic velocity changes of cerebral arteries in uremic children require further examination.  相似文献   

15.
Directional flow in the frontal artery, a terminal branch of the ophthalmic artery, was assessed nonivasively by Doppler ultrasound druing brief digital compression of the ipsilateral common carotid artery in 62 patients. Directional frontal artery flow during carotid compression was compared with mean distal internal carotid back pressure measured at subsequent carotid endarterectomy. Mean carotid back pressure in 28 patients with normal frontal artery flow direction during carotid compression, 68 +/- 14 millimeters of mercury, was significantly higher than that observed in 24 patients in whom frontal artery flow was completely obliterated and ten in whom frontal artery flow was reversed. Distal internal carotid back pressure exceeded 48 millimeters of mercury in all patients with normal frontal artery flow direction during carotid compression. Conversely, carotid back pressure was below 41 millimeters of mercury in all but one patient in whom frontal artery flow was obliterated or bliterated or reversed during carotid compression. The results of this study indicate that Doppler ultrasound assessment of frontal artery flow direction during simultaneous carotid compression provides a rapid, sale noninvasive estimate of the adequacy of collateral hemispheric circulation.  相似文献   

16.
Using transthoracic B-mode imaging and Doppler spectrum analysis it was found that the luminal diameter of the internal mammary artery and its hemodynamics were not significantly different among 15 preoperative patients (64 +/- 10 years) who underwent myocardial revascularization using the left internal mammary artery and young and older control groups (25 +/- 3 years and 61 +/- 9 years, respectively). These data indicate that older age does not significantly adversely influence the degree of intimal thickening and compliance in the internal mammary artery. Doppler spectrum analysis of the internal mammary artery in the patients who were operated on revealed conversion from a triphasic systolic waveform preoperatively to a unidirectional combined systolic/diastolic waveform at 1 week and 2 and 6 months postoperatively, characterized by a significant increase in the diastolic blood flow velocity and a significant decrease in the systolic blood flow velocity and the pulsatility and resistance indices. This study indicates that transthoracic B-mode imaging and Doppler spectrum analysis are promising noninvasive techniques in the preoperative assessment of internal mammary artery morphology and physiology. In addition, Doppler spectrum analysis can also be used in the long-term serial assessment of the internal mammary artery conduit after myocardial revascularization.  相似文献   

17.
Computed duplex sonography was used to examine the renal arteries in 36 hypertensive children and adolescents (ages 4-17 years) with arterial hypertension of either renal or non-renal origin. Time-averaged flow velocities, maximum blood flow velocities as well as absolute renal blood flow and renal blood flow per gram kidney weight were measured. Normal flow velocities and normal to elevated renal blood flow volume was found in patients with acute glomerulonephritis and those with signs of chronic glomerulonephritis onset. Patients having advanced stages of chronic glomerulonephritis, on the other hand, were characterized by lower levels of all parameters. Unilateral renal artery stenosis was diagnosed correctly in four patients, although one intra-renal artery stenosis escaped imaging. Scarred kidneys exhibited low-normal or reduced flow velocities and renal blood flow volumes corresponded roughly to kidney size and preservation of normal kidney structure. Hypertension in some patients with normal kidneys showed a tendency to cause higher renal blood flow without consistent acceleration of blood flow velocities. We conclude that duplex sonography is a suitable primary diagnostic tool in measuring blood flow velocities and absolute renal blood flow volume in hypertensive children, thus facilitating the choice of the next diagnostic step.  相似文献   

18.
PURPOSE: To compare the reproducibility of laser interferometric measurements of fundus pulsation, pneumatonometric measurement of pulse amplitude (PA) and pulsatile ocular blood flow (POBF), and Doppler ultrasonic measurements of blood flow velocity in the ophthalmic artery (OA) and the posterior ciliary arteries (PCAs) and to investigate the association of the results obtained with these methods and to characterize ocular hemodynamics during Valsalva maneuver and isometric handgrip. METHODS: All studies were performed in healthy subjects. Fundus pulsation (n = 48), POBF (n = 24), and blood flow velocities (n = 24) were measured at baseline and during the Valsalva maneuver and isometric handgrip. Intraclass correlation coefficients were calculated for test/retest variability, for short-term variability, and for interobserver variability. RESULTS: Intraclass correlation coefficients were between 0.95 and 0.98 for fundus pulsation measurements, between 0.54 and 0.76 for pneumatonometric measurements, between 0.44 and 0.88 for Doppler sonographic measurements in the OA and between 0.32 and 0.60 in the PCAs. There was a high degree of association between pneumatonometric parameters and fundus pulsation amplitude. Valsalva maneuver significantly reduced fundus pulsations, PA, and POBF, whereas isometric handgripping did not change these parameters. CONCLUSIONS: The reproducibility of fundus pulsation measurements was excellent. Reproducibility of pneumatonometric parameters and ultrasonographic measurements in the OA was satisfactory. Reproducibility of ultrasonographic measurements in the PCAs was low. Data obtained during the autonomic stimuli experiments argue against the sole use of systems to measure pulsatile blood flow, if no additional data on flow pulsatility are available. At least in cases when changes in blood pressure are likely to occur the ratio of pulsatile to nonpulsatile blood flow might not be constant and POBF might not be an adequate measure of total ocular blood flow.  相似文献   

19.
OBJECTIVE: To investigate the effect of normal pregnancy and hypertensive disorders of pregnancy on the maternal renal artery Doppler blood flow velocity indices. METHODS: The patient material consisted of 30 normal pregnant women, 29 women with pregnancy induced hypertension, 43 women with preeclampsia and 22 pregnant women with chronic hypertension. Blood flow velocities in the segmental renal arteries from the right kidney were analysed by pulsed and color Doppler. The systolic/diastolic (s.d.) ratio, resistance index (RI) and pulsatility index (PI) were used for Doppler waveform analysis. RESULTS: In all of the groups of hypertensive pregnant women renal artery Doppler indices were significantly lower compared to the normal pregnant women group. There was a significant negative relationship between renal artery PI and mean arterial pressure in the preeclampsia group and in the chronic hypertension group. CONCLUSION: The present results demonstrate that the mechanism of renal autoregulation in preeclampsia might be altered, leaving glomerulus unprotected from increased blood pressure. It seems that the concept of renal vasoconstriction in preeclampsia might be disputed and needs further investigation.  相似文献   

20.
Profundaplasty has been performed on 112 limbs (88 primary and 24 secondary) in eighty-five men. Seventy-six limbs had incapacitating claudication, twenty-three rest pain, and thirteen either gangrene or ischemic ulceration. In thirty-six limbs treated by profundaplasty alone there were no deaths but five subsequently had amputation for ischemic pain. In the seventy-six limbs treated by profundaplasty plus other operative augmentation there were three operative deaths and one late death; three required further operative surgery and in four amputation was necessary. Oblique arteriographic films of the femoral area are essential for evaluation of the profunda femoris artery. Both radionuclide and Doppler pressure studies confirmed physical and arteriographic findings. The latter would appear superior because of ease of availability and cost. After profundaplasty alone and aortofemoral bypass there was a moderate increase in calf blood flow, but in only those with a patent superficial femoral artery did blood flow and pressure studies return to within normal limits. Profundaplasty is an important addition to the armamentarium of the vascular surgeon in dealing with arteriosclerotic insufficiency of the lower extremities.  相似文献   

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