What influenced the lesion patterns and hemodynamic characteristics in patients with internal carotid artery stenosis? A retrospective study.

Objective: This study aimed to explore the dynamic changes of lesion patterns and hemodynamic characteristics in patients with internal carotid artery stenosis (ICAS).

Methods: Patients who had suffered an acute ischemic stroke in the distribution of ipsilateral ICAS were included. Computed tomography (CT) and transcranial doppler ultrasound (TCD) were conducted to evaluate the degree of ICAS and the hemodynamic characteristics of the intracranial and extracranial arteries.

Results: A total of 424 patients were included in the study. With the aggravation of ICAS, blood velocity in ipsilateral ICA was increased, while blood flow in the ipsilateral middle cerebral artery (MCA) was decreased. In the same degree of ICAS, patients with opened communicating arteries showed relatively higher blood perfusion in MCA compared with those without communicating arteries. In the average stage of ICAS, small lesions (D=0-1.5cm), middle lesions (1.5cm3.0cm) commonly existed. The number of small and large lesions significantly increased when the blood flow of ipsilateral MCA decreased. In the same degree of stenosis, the number of small lesions and large lesions, and the total area of all lesions, evidently increased with the decrease of ipsilateral MCA blood velocity.

Conclusions: Hypoperfusion is an independent risk factor for ischemic lesions in patients with ICAS. Whether or not the communicating arteries are open influences the blood flow of the intracranial arteries. TCD was a convenient and rapid tool to assess intracranial perfusion and vascular compensatory status.