Expansion of Stent and Lumen Diameters on Follow-up after Carotid Artery Stenting in Patients with Carotid Artery Stenosis.

Abstract

Purpose: We examined postoperative stent and lumen expansions after carotid artery stenting (CAS) in patients with carotid artery stenosis. Furthermore, we investigated factors influencing the stent and lumen expansions in a follow-up period. Subjects: 134 cases (128 patients) who underwent CAS and performed follow-up cerebral angiography 12 months after CAS were enrolled into this study. The stenosis rate based on the stent and lumen diameters on follow-up angiography as a percentage of that immediately after CAS was evaluated. Results: Both the stent and lumen diameters were significantly dilated 12 months after CAS (p <0.001). There were no significant stent-type-related differences in the stent expansion rate. In the symptomatic stenosis group, this expansion rate was significantly higher than in the asymptomatic stenosis group (p = 0.02). With respect to the presence or absence of a high signal intensity on time of flight (TOF) magnetic resonance (MR) images, the stent expansion rate was significantly higher in the high signal intensity group (p = 0.006). In patients with a plaque/sternocleidomastoid muscle signal intensity ratio of ≥1.50 on plaque images, it was significantly higher than in those with a value of <1.50 (p = 0.006). However, there were no significant differences in the lumen expansion rate among the groups. Conclusion: Both the stent and vascular lumen were dilated 12 months after CAS. Plaque fragility influenced the stent expansion rate; however, there were no significant factor-related differences in the vascular lumen expansion rate.