Purpose: To evaluate intracranial hemodynamic stabilization patterns after carotid artery stenting (CAS) in patients having variable collateral developments before CAS.
Methods: The hemodynamic and angiographic data of 62 patients (58 men; mean age 68.0±8.4 years) who underwent CAS for unilateral proximal internal carotid artery stenosis were analyzed. The patients had transcranial Doppler examinations before and at 1 and 90 days after CAS. Patients were classified according to pre-CAS mean blood flow velocity (MBFV) of the ipsilateral middle cerebral artery (MCA): low (<30 cm/s; n=17), normal (30 to 48 cm/s; n=26), or high (>48 cm/s; n=19). The collaterals from contralateral anterior and/or posterior circulations prior to CAS, the stabilization pattern of MBFV, and the pulsatility index (PI) after CAS were compared across the 3 groups.
Results: The presence of collaterals was lowest in the low MBFV group (17.6% of patients) than in the normal (38.5%) or high (68.4%) MBFV groups (p=0.008). The low MBFV group exhibited an increase in MBFV and PI in the ipsilateral MCA at 1 and 90 days after CAS (p<0.05). By contrast, the high MBFV group exhibited a decrease in MBFV and no change in PI in the ipsilateral MCA up to 90 days after CAS (p<0.05). The normal MBFV group showed an increase in MBFV at post-CAS day 1 but a subsequent decrease at 90 days and an increase in PI in the ipsilateral MCA at 1 and 90 days post-CAS (p<0.05).
Conclusion: The pattern of post-CAS intracranial hemodynamic stabilization differs according to the pre-CAS MBFV in the ipsilateral MCA.