PERIPHERAL VASCULAR S69

PVO 3001 THE ROLE OF INTERNAL CAROTID ARTERY STENOSIS IN RETROBULBAR CIRCULATION

Lkzlo Molniir, Jose G. M. P. Caldas, Vital P. Costa, Giovanni Cerri Heart Institute of the University of Ssio Paul0 Medical School, Brazil.

Objectives: To analyze the peak systolic velocity (PSV) and end-diastolic velocity (EDV) in the ophthalmic and central retinal arteries as markers of internal carotid artery (ICA) stenosis. Methods: The study was carried out by color flow duplex mapping (CFDM) in 130 segments of the arterial carotid-ophthalmic-central retinal axis of 65 individuals submitted to an angiographic study. Results: The statistically significant reduction in PSV in the ophthalmic and central retinal arteries was confirmed in the patients with ipsilateral ICA stenosis greater than 95% . A clear tendency to better preservation of the PSV and EDV was seen in the central retinal arteries associated with ICA stenosis greater than 50%. Conclusions: CFDM may provide a more complete understanding of the hemodynamic characteristics of the retrobulbar circulation.

PVO 3002 ULTRASONIC EVALUATION OF EARLY CAROTID ATHEROSCLEROSIS IN ASYMPTOMATIC CEREBRAL INFARCTION.

Hiroharu Narikawa Miyagi National Hospital,Miyagi-ken,Japan.

We used ultrasonography to evaluate atherosclerotic lesions in the common carotid arteries of 50 asymptomatic cerebral infarction patients. In all sublects,measurements were made of

the intima-media thickness of the common carotid arteries, in addition, the sonographer classified the findings during the scanning into four categories; 1) no atherosclerotic lesion, 2)

intimal-media thickening, 3) nonstenotic plaque, and 4) large stenotic plaque.lntimal-medial thickening (category 2) of the

arterial wall was defined as a distance of more than 1 .Omm. (Salonen’classification.)

Of the 50 cases examined, 14(280/o) had no structural changes, 1 O(ZO%) had intimal-medial thickening, 22(45%) had small plaques, and 4(8%) had large stenotic plaques. A case above (category 2) were complicated 5 cases of diabetis mellitus, 4 cases of hypertention and 4 smoking cases. Ultrasonographically measured wall thickness was clinically

useful for detecting the presence of such atherosclerotic disease as asymptomatic cerebral infarction.

PVO 3003

WHAT ARE THE ADVANTAGES OF POWER DOPP- LER IMAGING IN THE SONOGRAPAIC EXAMI- NATION OF CEREBROVASCULAR DISEASES? Eva Bartels, K.A.Fhigel, Department of Neurology and Clin. Neurophysiology, Hospital Bogenhausen, Munich, Germany

Power Doppler Imaging (PDI) is a new sonographic techni- que which detects and color codes the energy (amplitude) of the Doppler signal. This method is less angle-dependent, it is not affected by aliasing and seems to be favorable for the vi- sualization of low flow velocities. On the other hand, PDI does not provide information on the flow direction. The aim of this study is to present the advantages of PDI in comparison with frequency-coded color Doppler imaging (CDI) in the sonographic evaluation of extra- and intracra- nial cerebral vessels based on three years clinical experien- ce with this method. The examinations were performed with Acuson 128 XP 10 ART by using a 2 MHz sector transdu- cer (transcranial imaging) and a 7 MHz linear transducer. 1) In the examination of carotid arteries, PDI facilitates the visualization of the low blood flow velocities in a subtotal stenosis.It improves the characterization of a plaque surface. 2) In vertebral sonography, PDI enables better imaging of hypoplastic vertebral arteries with low blood flow velocities. 3) Using transcranial PDI, the blood flow in a partially thrombosed aneurysm can be detected more easily. The imaging of intracranial veins with PDT is possible. Conclusions: PDI is a useful sonographic technique for non- invasive examination in patients with cerebrovascular disea- ses. However, because the visualization of hemodynamics is not possible with PDI, it should be combined with CDL

PVO 3004 PLAQUE MORPHOLOGY & INTERNAL CAROTID ARTERY RESTENOSIS AFTER ENDARTERIECTOMY M.Elwertowski,S.Leszczyriski,M.Szostek,A.Ma~ek,S.Toutounchi J.Leszczynski Infectious Diseases HospWarsaw POLAND

In the group of 156 patients which underwent carotid endarte- riectomy repeated colour Doppler follow up ultrasound exami-

nations were performed every 3 months for next 3 years in order to reveal recurrent stenosis. Out of 177 operated vessels (21 bilateral operation) minimal

alterations - uneveness of ICA walls, without Doppler changes were observed in 64 (36,2%) patients. Their appearance in most cases did not change during observation period. On the other hand moderate restenosis (50-70%) were observed in 3 , 6 and 5 cases in examinations 3, 6 & I2 months after operation, while major restenosis (>70%) were found in I, 5 & IO cases during the same period. Control studies performed 18, 24 & 36 after operation found moderate restenosis in 4,3 & 4 cases, and major restenosis in 6, 7& 9 patients. Internal carotid artery occlusion was found in 4 cases during first year after operation and 4 cases during next 2 years. Progressing stenosis of contralateral (not operated) ICA were observed in 25 patients (in I5 cases major changes required operation).

Recurrent plaque in most 42/63 cases was present as sot?, ho- mogenous hypoechoic, mass most readily visible during colour (power Dopper), heterogenous changes were observed in I3 patients while major calcifications developed in 8 arteries.

Colour/power Doppler is mandatory for postopoerative evalu- ation of internal carotid arteries.