Hemodynamic instability increases new ischemic brain lesions on diffusion-weighted imaging after carotid artery stenting.

Hemodynamic instability (HI) may impair the washout of debris during distal intracranial circulation and increase the risk of clinically evident cerebral ischemia. However, the interaction between HI and new ischemic brain lesions detected on diffusion-weighted imaging (DWI) has not been examined. This study evaluated whether HI was significantly associated with the incidence of new ischemic brain lesions on DWI. Data on 128 patients who underwent carotid artery stenting (CAS) with the same devices and procedures between January 2005 and May 2010 were retrospectively analyzed. HI was noted in 31 (24.2%) patients. New ischemic brain lesions were detected on DWI in 25 (19.5%) patients. Ten of 31 (32.2%) patients with HI showed new ischemic brain lesions on DWI. Fifteen of 97 (15.5%) patients without HI showed new lesions. Univariate analysis showed that patients with HI had a significantly higher incidence of new ischemic brain lesions than patients without HI (p = 0.04). A multivariable model showed that age and HI were significantly associated with the incidence of new ischemic brain lesions. In patients with carotid artery stenosis, decreased blood pressure produced no active vascular response, but reduced the cerebral blood volume and velocity due to impaired dynamic cerebral autoregulation. The results of this study suggest that HI with CAS induces impaired clearance of microembolisms and causes an increased number of new ischemic brain lesions detected on DWI.