Quantitative Analysis of Extracranial Arterial Tortuosity in Patients with Sickle Cell Disease

Compared to the intracranial vasculature in sickle cell disease (SCD) patients, the morphologic changes of the extracranial vasculature in SCD patients are less well understood. The purpose of this study was to evaluate the tortuosity of the extracranial carotid and vertebral arteries in patients with SCD compared to age-matched controls.

Following Institution Review Board approval, between January 2004 and December 2013, Magnetic resonance angiogram neck examinations were retrospectively reviewed on 56 patients with SCD and 56 age-matched controls. Vessel tortuosity was measured as curved vector lengths in the common carotid, extracranial internal carotid, and vertebral arteries bilaterally. Correlation of vessel tortuosity with age and hematocrit level was assessed. Paired and unpaired Student's t-tests were performed to determine within and between group differences.

Greater tortuosity in extracranial carotid and vertebral arteries were noted in patients with SCD as compared to age-matched control patients (P < .001). Greater differences in tortuosity between carotid and vertebral arteries were noted in SCD patients as compared to differences in control patients. Incidence of infarction was significantly associated with greater tortuosity of right carotid (P = .002), right (P = .004), and left (P = .020) vertebral arteries.

Extracranial carotid and vertebral arterial tortuosity is increased in SCD patients. This could be related to aberrations in hemodynamics from nonlaminar flow in these vessels. These increases in extracranial vascular tortuosity could potentially lead to alterations in intracranial vascular tortuosity and may be an independent risk factor for cerebral infarct.