2016 年 10 巻 4 号 p. 190-195
Objective: To assess the selection of carotid endarterectomy (CEA) or carotid artery stenting (CAS) and the choice of embolic protection device (EPD) on the basis of a preoperative magnetic resonance (MR) plaque image such as Sp/Sm (signal intensity ratio of carotid plaque against sternocleidomastoid muscle).
Methods: Between August 2011 and August 2015, 180 patients who underwent CEA or CAS at our institution were retrospectively analyzed. CEA was selected when soft plaque was suspected by a plaque image of Sp/Sm ≥2, in contrast, CAS was indicated for patients with a surgically high-risk condition and for patients with a plaque image of Sp/Sm <2. Moreover, EPD was chosen by means of the plaque characterization such as Angioguard XP for Sp/Sm <2, Filter wire EZ or Spider FX for 2 ≤ Sp/Sm <3, and balloon (GuardWire PS/Mo.Ma Ultra) for 3 ≤ Sp/Sm. Then, we compared the peri-operative complication rate and hyperintensity rate on diffusion-weighted image (DWI) post-operatively.
Results: In 80 cases with 3 ≤ Sp/Sm, CEA was performed for 30 cases and CAS using balloon for 50 cases. In 88 cases with 2 ≤ Sp/Sm <3, CEA was performed for nine cases and CAS using Filter wire EZ or Spider FX for 79 cases. The residual 12 cases with Sp/Sm <2 were treated with CAS using Angioguard XP. The complication rate was 2.1% in CAS and 0% in CEA. Asymptomatic hyperintensities on DWI after revascularization were detected in 24% of CAS patients and 0% of CEA patients. As for EPD, 27 of 79 CAS patients treated with Filter wire EZ or Spider FX had hyperintensities on DWI and hyperintensities were mostly observed in 21 of 39 patients with 2 ≤ Sp/Sm <3 on both T1- and T2-weighted imaging, but not in 6 of 40 patients with 2≤ Sp/Sm <3 on either T1- or T2-weighted imaging.
Conclusion: The clinical outcome of patients treated with CEA was acceptable regardless of their carotid plaque components, if SAPPHIRE CEA high-risk group is accurately excluded. Considering that balloon protection should be used as EPD against soft plaque with 2 ≤ Sp/Sm <3 on both T1- and T2-weighted imaging, selection of CEA or CAS and EPD based on the MR plaque characteristics such as Sp/Sm is a useful strategy.