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Ophthalmosonometry

An Ultrasonic Method for Assessing Carotid Blood Flow

J. C. Maroon, D. W. Pieroni and R. L. Campbell

I n 1966, Stegall, et al. , described an ultrasonic flowmeter, based on the Doppler effect, which could continuously record arterial or venous blood flow velocity through the intact human skin. 12 Vascular surgeons found application for this instrument in the localization of arterial and venous occlusions of the extremities. 11, 14, 15 Attempts to detect sites of obstruction in the extracerebral carotid arteries, however, have thus far been disappointing. 13 While using this blood velocity detector, we found that an arterial pulsation could be routinely

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Joseph C. Maroon, John Edmonds-Seal and Robert L. Campbell

stethescope, 12, 13 frequent or continuous recording of the electrocardiogram, 18 and continuous monitoring of the carbon dioxide and nitrogen concentrations in the expired air. 2 Recently the use of a Doppler ultrasonic flow detector has proved to be an extremely sensitive method for detecting intracardiac air emboli. 10 The instrument was initially designed for determining instantaneous arterial or venous blood flow velocity through the intact skin 14 and is dependent on the frequency shift of ultrasonic waves reflected from moving red blood cells. Since an air

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Glenn W. Kindt, Julian R. Youmans and Louis W. Conway

arteriography revealed total occlusion of the right internal carotid artery at its origin from the common carotid artery, the external carotid remaining patent. The left external and internal carotid were not compromised. Blood flow velocity was studied in each common carotid artery. When the inspiratory gas was changed from 100% O 2 to 5% CO 2 in 95% O 2 , there was a decrease in right common carotid flow of 30% ( Fig. 3 ). Similar recordings from the left common carotid artery showed essentially no changes in blood flow ( Fig. 4 ). Fig. 3. Case 2. Right common

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Gary G. Ferguson

of flow is shown by the arrow . Evans blue dye has been injected to demonstrate the flow patterns. Right: Turbulence in both loculi of the large bilocular glass model aneurysm. Flow in the stem and both branches is streamlined. Discussion Hardesty, et al. , 12 found an average mean flow of 370 ml/min in the human internal carotid artery. If one assumes an internal diameter of 4 mm, the calculated mean blood flow velocity within the vessel is 50 cm/sec. This corresponds to a calculated Re number of 750 (see above). Similar calculations from the data

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Carotid endarterectomy

Temporal profile of the healing process and effects of anticoagulation therapy

Richard A. Dirrenberger and Thoralf M. Sundt Jr.

, as a function of mean blood flow velocity. Nature 227 : 926 – 930 , 1970 Begent N, Born GVR: Growth rate in vivo of platelet thrombi, produced by iontophoresis of ADP, as a function of mean blood flow velocity. Nature 227: 926–930, 1970 4. Blaisdell FW , Lim R Jr , Hall AD : Technical result of carotid endarterectomy. Arteriographic assessment. Am J Surg 114 : 239 – 246 , 1967 Blaisdell FW, Lim R Jr, Hall AD: Technical result of carotid endarterectomy. Arteriographic assessment. Am J Surg 114

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Helge Nornes, Arne Grip and Per Wikeby

) to a non-visible parietal AVM in Case 1. Flow in Artery 1 was detected at a depth of 2 cm below the brain surface. The skull films show the arterial and venous filling ( Fig. 3 ). The cortical incision could then be planned and the dissection performed with minimal destruction of viable tissue. Fig. 2. Case 1. Records showing identification of two inflow arteries. V max = maximum blood flow velocity, V mean = mean of velocities across vessel lumen. See Fig. 3 for an angiogram of these two vessels. Fig. 3. Case 1. Angiograms showing

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Helge Nornes, Arne Grip and Per Wikeby

, other means must be used to determine flow in a particular microvascular system. In contrast to the electromagnetic flowmeter, which requires exposure of the vessel for application of a cuff probe, 5, 17, 22 ultrasonic Doppler techniques determine blood-flow velocity noninvasively through the intact skin, 4 through intact, exposed cerebrum, or through saline when the vessel is exposed. 19 We have previously reported the use of both methods during intracranial procedures. 15–20 This paper presents our experience with a pulsed echo Doppler technique in aneurysm

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Subclavian steal syndrome

Part 2: Intraoperative vertebral artery blood flow measurement

George L. Bohmfalk, Jim L. Story, Willis E. Brown Jr. and Arthur E. Marlin

✓ Intraoperative vertebral artery blood flow was measured in two patients with symptomatic subclavian steal syndrome, before and after proximal end-to-side vertebral to common carotid artery transposition. This confirmed retrograde flow in the vertebral artery before transposition, and antegrade flow after transposition. The measured flow rates were compared to values in other series involving different operative procedures for correction of symptomatic subclavian steal. The greatest mean antegrade flow rates in the vertebral artery were restored by proximal end-to-side vertebral to common carotid artery transposition.

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Helge Nornes and Arne Grip

previously. 24 This AVM shunt flow ranged from about 150 to more than 900 ml/min (average, 490 ml/min). One patient exhibited, for reasons unknown, marked variations in the systemic blood pressure that caused parallel changes in AVM feeder flow, thus demonstrating the complete absence of vasomotor control of this shunt system. The same phenomenon was seen in patients in whom hypotension was induced before AVM exclusion. Fig. 2. Inner diameter of the feeding arteries plotted against time-average blood flow velocity in the 16 patients. Lines connect Figures obtained

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Rune Aaslid, Thomas-Marc Markwalder and Helge Nornes

D oppler ultrasound recording of the blood flow velocity in the extracranial arteries supplying the brain was reported by Miyazaki and Kato 6 in 1965 and is now used routinely in neurological and neurosurgical practice. 1, 4 The velocity in the intracranial vessels has been observed by Doppler technique during surgery, 2, 8, 9 and in children with open fontanels. 7 In adults, however, the skull is a severe obstacle to the penetration of ultrasound. Bone strongly attenuates the ultrasonic wave, making it impossible to record noninvasively the blood flow