Blood flow changes caused by distal filter protection and catheter aspiration in the internal carotid artery during carotid stenting: evaluation using carotid Doppler sonography.
OBJECTIVE
If blood flow in the ICA is reduced by the use of a distal filter during CAS, flow stagnation proximal to the filter occurs and this increases the probability of floating debris. The floating debris that remains after filter retrieval may cause cerebral embolism. However, if blood flow is increased by aspiration of blood from the ICA through an aspiration catheter, debris could be removed while the filter is still in place. The purpose of this study was to investigate blood flow changes in the ICA induced by filter use and aspiration.


METHODS
A filter-protection device (AngioGuard XP) was used during CAS in 13 consecutive patients with carotid stenosis. Blood flow velocity in the ICA was measured by carotid Doppler sonography during filter deployment, filter retrieval, and catheter aspiration.


RESULTS
Blood flow velocity significantly decreased with filter placement and significantly increased with filter retrieval in patients with normal angiographic flow (P < .05). Aspiration of a 20-mL blood sample from the proximal ICA column significantly increased the blood flow velocity (P < .05).


CONCLUSIONS
The blood flow changes in the ICA induced by the use of a distal filter may cause cerebral embolism in filter-protected CAS. A routine aspiration method can potentially reduce the amount of migrating debris during CAS, even in cases with angiographic normal flow.
Department of Neurosurgery, Brain Research Institute, University of Niigata, Japan. sorimachi@bri.niigata-u.ac.jp
T
T
Sorimachi
K
K
Nishino
K
K
Morita
S
S
Takeuchi
Y
Y
Ito
Y
Y
Fujii
D000368:Aged; D000369:Aged, 80 and over; D017130:Angioplasty / Q000009:adverse effects; D001783:Blood Flow Velocity / Q000502:physiology; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy; D002560:Cerebrovascular Circulation / Q000502:physiology*; D057505:Embolic Protection Devices; D005260:Female; D006801:Humans; D020766:Intracranial Embolism / Q000209:etiology / Q000517:prevention & control*; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D015607:Stents; D013396:Suction; D018608:Ultrasonography, Doppler / Q000379:methods*