Silent brain infarcts after carotid or vertebrobasilar artery stenting.

BACKGROUND AND PURPOSE: Stenting is an important treatment for preventing stroke. However, the effect of vertebrobasilar stenting (VBS) might be limited because of relatively high periprocedural risks. Silent brain infarcts (SBIs) are known as a predictor for future stroke. Because of anatomical differences, factors for SBIs might be different between carotid artery stenting (CAS) and VBS. We compared the characteristics of SBIs between VBS and CAS.

METHODS: We included patients who underwent elective VBS or CAS. Diffusion-weighted imaging was performed pre- and post-procedure to detect new SBIs. Clinical variables, occurrence of SBIs, and procedure-related factors were compared between CAS and VBS. Moreover, we investigated predictors of SBIs in each group separately.

RESULTS: Ninety-two (34.2%) out of 269 patients had SBIs. SBIs were more frequently observed in VBS (29 [56.6%] vs. 63 [28.9%], p<.001). The risk of SBIs outside the stent-inserted vascular territory was higher in VBS compared to CAS (14 [48.3%] vs. 8 [12.7%], p<.001). Larger-diameter stents (odds ratio: 1.28, 95% confidence interval: 1.06-1.54, p = .012) and prolonged procedure time (1.01, [1.00-1.03], p = .026) increased the risk of SBIs in CAS, whereas only age increased the risk of SBIs in VBS (1.08 [1.01-1.16], p = .036).

CONCLUSIONS: Compared to CAS, VBS was associated with longer procedure time, more residual stenosis, and more SBIs, especially outside the stent-inserted vascular territory. The risk of SBIs after CAS was associated with stent size and procedural difficulty. Only age was associated with SBIs in VBS. The pathomechanism of SBIs after VBS and CAS may be different.