The impact of carotid stenting on the hemodynamic parameters and cerebrovascular reactivity of the ipsilateral middle cerebral artery.

OBJECTIVE: The study was conducted to determine the effect of carotid angioplasty and stenting (CAS) on the hemodynamic parameters and cerebrovascular reactivity (CVR) of the ipsilateral middle cerebral artery (MCA) and examine the relation between preprocedural exhausted CVR and perioperative neurologic events.

METHODS: The study included 29 patients with severe extracranial carotid stenosis undergoing CAS. Transcranial Doppler imaging was performed before the procedure, 2 days, and 2 to 4 months postoperatively. Peak systolic velocity, end-diastolic velocity, mean flow velocity, and pulsatility index of the ipsilateral MCA were recorded at rest. CVR was assessed with the breath holding test: the increase of mean flow velocity and the breath holding index were calculated.

RESULTS: Peak systolic and mean flow velocities increased significantly in both postoperative studies compared to the preoperative values, end-diastolic velocity was significantly elevated only in the first study, and pulsatility index did not change significantly. When stimulated by breath holding, preoperative mean flow velocity did not increase significantly compared with the resting values; however, it did increase significantly during breath holding in both studies after CAS. The breath holding index improved significantly from -0.35 (-0.71 to 0.55) to 0.38 (0.12 to 0.61) at 2 days (P = .049) and 0.44 (0.31 to 0.92) at 2 to 4 months (P = .020). Exhausted CVR of the MCA preoperatively was associated with increased risk of neurological complications during or after the procedure (P = .006).

CONCLUSIONS: CAS may improve the hemodynamic parameters and the vasomotor reactivity in the ipsilateral MCA. Exhausted CVR is associated with an increased risk of periprocedural neurologic complications.