Yoshitaka Kurosaki, Kazumichi Yoshida, Ryu Fukumitsu, Nobutake Sadamasa, Akira Handa, Masaki Chin and Sen Yamagata
Plaque characteristics and morphology are important indicators of plaque vulnerability. MRI-detected intraplaque hemorrhage has a great effect on plaque vulnerability. Expansive remodeling, which has been considered compensatory enlargement of the arterial wall in the progression of atherosclerosis, is one of the criteria of vulnerable plaque in the coronary circulation. The purpose of this study was risk stratification of carotid artery plaque through the evaluation of quantitative expansive remodeling and MRI plaque signal intensity.
Both preoperative carotid artery T1-weighted axial and long-axis MR images of 70 patients who underwent carotid endarterectomy (CEA) or carotid artery stenting (CAS) were studied. The expansive remodeling ratio (ERR) was calculated from the ratio of the linear diameter of the artery at the thickest segment of the plaque to the diameter of the artery on the long-axis image. Relative plaque signal intensity (rSI) was also calculated from the axial image, and the patients were grouped as follows: Group A = rSI ≥ 1.40 and ERR ≥ 1.66; Group B = rSI< 1.40 and ERR ≥ 1.66; Group C = rSI ≥ 1.40 and ERR < 1.66; and Group D = rSI < 1.40 and ERR < 1.66. Ischemic events within 6 months were retrospectively evaluated in each group.
Of the 70 patients, 17 (74%) in Group A, 6 (43%) in Group B, 7 (44%) in Group C, and 6 (35%) in Group D had ischemic events. Ischemic events were significantly more common in Group A than in Group D (p = 0.01).
In the present series of patients with carotid artery stenosis scheduled for CEA or CAS, patients with plaque with a high degree of expansion of the vessel and T1 high signal intensity were at higher risk of ischemic events. The combined assessment of plaque characterization with MRI and morphological evaluation using ERR might be useful in risk stratification for carotid lesions, which should be validated by a prospective, randomized study of asymptomatic patients.
Kazumichi Yoshida, Ryu Fukumitsu, Yoshitaka Kurosaki, Takeshi Funaki, Takayuki Kikuchi, Jun C. Takahashi, Yasushi Takagi, Sen Yamagata and Susumu Miyamoto
The purpose of the present study was to investigate the association between carotid artery (CA) expansive remodeling (ER) and symptoms of cerebral ischemia.
One hundred twenty-two consecutive CAs scheduled for CA endarterectomy (CEA) or CA stent placement (CAS) were retrospectively studied. After excluding 22 CAs (2 were contraindicated for MRI, 8 had near-occlusion, 6 had poor image quality, and 6 had restenosis after CEA or CAS), there were 100 CAs (100 patients) included in the final analysis. The study included 50 symptomatic patients (mean age 73.6 ± 8.9 years, 6 women, mean stenosis 68.5% ± 21.3%) and 50 asymptomatic patients (mean age 72.0 ± 5.9 years, 5 women, mean stenosis 79.4% ± 8.85%). Expansive remodeling was defined as enlargement of the internal carotid artery (ICA) with outward plaque growth. The ER ratio was calculated by dividing the maximum distance between the lumen and the outer borders of the plaque perpendicular to the axis of the ICA by the maximal luminal diameter of the distal ICA at a region unaffected by atherosclerosis using long-axis, high-resolution MRI.
The ER ratio of the atherosclerotic CA was significantly greater than that of normal physiological expansion (carotid bulb; p < 0.01). The ER ratio of symptomatic CA stenosis (median 1.94, interquartile range [IQR] 1.58–2.23) was significantly greater than that of asymptomatic CA stenosis (median 1.52, IQR 1.34–1.81; p = 0.0001). When the cutoff value of the ER ratio was set to 1.88, the sensitivity and specificity to detect symptoms were 0.6 and 0.78, respectively. The ER ratio of symptomatic patients was consistently high regardless of the degree of stenosis.
There was a significant correlation between ER ratio and ischemic symptoms. The ER ratio might be a potential indicator of vulnerable plaque, which requires further validation by prospective observational study of asymptomatic patients.
Masaomi Koyanagi, Hitoshi Fukuda, Masaaki Saiki, Yoshihito Tsuji, Benjamin Lo, Toshinari Kawasaki, Yoshihiko Ioroi, Ryu Fukumitsu, Ryota Ishibashi, Masashi Oda, Osamu Narumi, Masaki Chin, Sen Yamagata and Susumu Miyamoto
Shunt-dependent hydrocephalus (SDHC) may arise after aneurysmal subarachnoid hemorrhage (aSAH) as CSF resorptive mechanisms are disrupted. Using propensity score analysis, the authors aimed to investigate which treatment modality, surgical clipping or endovascular treatment, is superior in reducing rates of SDHC after aSAH.
The authors’ multicenter SAH database, comprising 3 stroke centers affiliated with Kyoto University, Japan, was used to identify patients treated between January 2009 and July 2016. Univariate and multivariate analyses were performed to characterize risk factors for SDHC after aSAH. A propensity score model was generated for both treatment groups, incorporating relevant patient covariates to detect any superiority for prevention of SDHC after aSAH.
A total of 566 patients were enrolled in this study. SDHC developed in 127 patients (22%). On multivariate analysis, age older than 53 years, the presence of intraventricular hematoma, and surgical clipping as opposed to endovascular coiling were independently associated with SDHC after aSAH. After propensity score matching, 136 patients treated with surgical clipping and 136 with endovascular treatment were matched. Propensity score–matched cohorts exhibited a significantly lower incidence of SDHC after endovascular treatment than after surgical clipping (16% vs 30%, p = 0.009; OR 2.2, 95% CI 1.2–4.2). SDHC was independently associated with poor neurological outcomes (modified Rankin Scale score 3–6) at discharge (OR 4.3, 95% CI 2.6–7.3; p < 0.001).
SDHC after aSAH occurred significantly more frequently in patients who underwent surgical clipping. Strategies for treatment of ruptured aneurysms should be used to mitigate SDHC and minimize poor outcomes.