Yusuke Nishikawa

Surgical Treatment for Carotid Stenoses with Highly Calcified Plaques

BACKGROUND The aim of this study was to clarify both the present status of treatment for carotid stenosis with highly calcified plaques and the appropriate treatment. METHODS A total of 140 consecutive treatments for carotid stenoses (carotid endarterectomy [CEA]:carotid artery stenting [CAS] 81:59) were enrolled in the study. We classified the patients into low-calcified plaque (LCP) and high-calcified plaque (HCP) groups by calcium score, determined by a receiver operating characteristic analysis, and we compared the results after both treatments. RESULTS The mean degree of residual stenosis and improvement rates of the stenosis after CAS for the HCP group were 9.7% ± 13.3% and 87.0% ± 16.8%, respectively, whereas those for the LCP group were 1.7% ± 6.1% and 97.9% ± 7.9% (both P < .001). A multiple logistic regression analysis revealed that only the calcium score was an independent pre-CAS predictor of residual stenosis. Restenosis at 6 months was observed frequently in the HCP group after both CAS and CEA (18.8% and 20.0%, respectively). Cerebral hyperperfusion syndrome was observed in 2 cases of CAS, 1 for each plaque group. The 30-day and 6-month rates for any stroke or death after CAS were 2.3% and 12.5% for the LCP and HCP groups, respectively, whereas those after CEA were 1.6% and 0%. CONCLUSIONS Carotid stenoses with HCP (calcium score ≥420) treated by CAS showed a disadvantage in the degree of stent expansion compared to carotid stenoses with LCP, suggesting that CEA may be recommended as a surgical option.

Efficacy and safety of single versus dual antiplatelet therapy for coiling of unruptured aneurysms.

BACKGROUND Although the efficacy of antiplatelet therapy for coiling of unruptured cerebral aneurysms has been reported, regimens for this therapy are not yet well established. The aim of this retrospective study was to analyze correlations among the modes of antiplatelet use, aneurysmal configuration, coiling methods, and complications to elucidate the optimal antiplatelet therapy for coiling. METHODS The study population comprised 154 patients with unruptured aneurysms who underwent coiling with antiplatelet therapy at our institution between 2001 and 2009. The patients were categorized by mode of antiplatelet therapy (single [n = 64] or dual [n = 90]), neck size (wide [n = 80] or narrow [n = 74]), and technique used (simple [n = 42] or adjunctive [n = 112]). The incidences of hemorrhagic/ischemic complications and abnormalities on postprocedural diffusion-weighted magnetic resonance imaging (DWI) in each group were statistically assessed. RESULTS Hemorrhagic complications occurred in 1 case (1.5%) with single antiplatelet therapy and in 2 cases (2.2%) with dual antiplatelet therapy. Symptomatic ischemic complications occurred in 5 cases (7.8%) with single therapy and in 4 cases (4.4%) with dual therapy. Abnormalities were detected by DWI in 27 cases (42%) with single therapy and in 31 cases (34%) with dual therapy. No significant difference was found between modes of antiplatelet therapy even when the technique used was taken into account. In cases of wide neck, however, there were significant differences in the rate of symptomatic ischemic complications (single, 21.7%; dual, 3.5%; P = .014) and DWI abnormalities (single, 37.8%; dual, 20.9%; P = .048). CONCLUSION Our data suggest that dual antiplatelet therapy may better prevent ischemic complications from coiling for wide-necked aneurysms compared with single antiplatelet therapy.

Calcification in original plaque and restenosis following carotid artery stenting

Background: The relationship between calcification in primary plaque and recurrent stenosis after carotid artery stenting (CAS) is not established, but an inverse association with restenosis following carotid endarterectomy (CEA) has been suggested. Methods: We retrospectively analyzed 75 plaques of 109 consecutive CAS with regard to calcification, using the calcium score and shape, location, and other characteristics of original plaques together with stenting-related factors. CAS was performed in a standard fashion with an embolic protection device. Greater-than-moderate restenosis (≥50%) was assessed by peak systolic velocity (PSV) with duplex ultrasonography (≥130 cm/s, internal/common carotid or distal/proximal PSV ratio ≥2.0). Results: Univariate analysis revealed percentages of dyslipidemia treated with statins (P = 0.03), calcification in distal ICA (P = 0.02), and immediate residual stenosis (P = 0.02) were significantly higher in patients with greater-than-moderate restenosis, whereas calcification in carotid bulb and usage of open-cell stent were rather less frequent (P < 0.001 and P = 0.02, respectively). Multivariate logistic regression analysis showed that rarity of calcification in carotid bulb was a sole independent predictor for greater-than-moderate recurrent carotid stenosis 1 year after CAS (OR = 0.21, CI = 0.06–0.77, P = 0.02). Conclusions: Calcium score was not significantly related to restenosis at 1 year after CAS, as was previously found following CEA, though scarcity of calcification in carotid bulb was suggested as a predictor of in-stent restenosis. Compared to post-CEA restenosis, carotid plaque calcification may be inversely but tenuously associated with recurrent stenosis 1 year post-CAS. No other stenting factors (e.g., stent design, pre-/post-dilation, or protection devices) showed a significant association with recurrent stenosis post-CAS.

Analysis of Recurrent Stenosis After Carotid Endarterectomy Featuring Primary Plaque Calcification

BACKGROUND The relationship between calcification in primary plaque and restenosis after carotid endarterectomy (CEA) has been seldom investigated. OBJECTIVE To clarify the relationship between characteristics of calcified carotid plaque and recurrent stenosis after CEA, as well as the diseases natural course. METHODS Ninety-four plaques out of 107 consecutive CEAs were retrospectively analyzed with regard to calcification, employing calcium score as well as shape, location, and other characteristics of original plaques. CEA was performed in a standard fashion with primary closure using an internal shunt. Restenosis was assessed by direct measurement of stenosis mainly using multidetector row computed tomography (CT) angiography. RESULTS Univariate analysis revealed that calcium score and calcification circularity score were significantly lower in more than moderate restenosis (≥50%; 422.1 ± 551.6 vs 84.2 ± 92.0, P < .001; 1.8 ± 1.3 vs 1.1 ± 0.3, P < .001, respectively). Receiver operating characteristic analysis demonstrated a calcium score of 80, which was the optimal cutoff value for restenosis over 50% (sensitivity 0.70, specificity 0.68, pseudopositive ratio 0.32, area under curve 0.71, Youdens index 0.38). Low calcium score (OR 2.88, CI 1.06-7.79, P = .04) and low calcification circularity (OR 5.72, CI 1.42-23.1, P = .01) were independent predictors for more than moderate recurrent carotid stenosis 1 year postoperatively. Cases with decreasing tendency of restenosis showed higher calcium scores than those with increasing or unchanged tendency (217.2 ± 245.3 vs 164.5 ± 155.5, P < .001). Lower calcium score cases showed lower restenosis-free survival. CONCLUSION Carotid plaque calcification may be inversely associated with recurrent stenosis 1 year after CEA or later. Preoperative CT assessment for less calcification will benefit restenosis patients by early prediction and close follow-up.

Lumbar peritoneal shunt containing a programmable valve for intracranial hypertension caused by Borden type 1 dural arteriovenous fistulas.

Three male patients underwent lumbar peritoneal (LP) shunt for intracranial hypertension caused by intracranial Borden type 1 dural arteriovenous fistulas (D-AVFs). Endovascular treatment was performed initially, but it was ineffective in all cases. Before LP shunt, the Mariotte blind spot expanded in all cases and severe papilledema was observed in two cases. We managed the opening pressure of the shunt system in accordance with patient symptoms. Mariotte blind spot expansion and papilledema disappeared after LP shunt. Follow-up cerebral angiography revealed spontaneous closure of D-AVFs in one case and aggressive conversion in two cases. D-AVFs were completely closed by transvenous embolization. Because the angioarchitecture of the fistula frequently worsens without deterioration of the symptom after LP shunt, follow-up angiography and additional treatment are important.

Fatal remote cerebral hemorrhage at a site of a microbleed immediately after intravenous thrombolysis

We report a patient with ischemic stroke who was treated with intravenous alteplase and subsequently developed a fatal pontine hemorrhage during cerebral angiography. An 88‐year‐old woman presented with right hemiplegia and aphasia. Magnetic resonance angiography at onset showed occlusion of the left middle cerebral artery. T2*‐weighted magnetic resonance imaging showed a cerebral microbleed in the pons. She was treated with intravenous alteplase followed by cerebral angiography. Left carotid angiography showed recanalization of the left middle cerebral artery, and neurointervention was not carried out. During the angiography, she became comatose. Computed tomography showed a massive pontine hemorrhage. The hemorrhage was considered to be attributable to the microbleed. The variety of time phases of cerebral microbleeds have been elucidated; there are a subset of lesions reflecting acute or subacute microhemorrhages. It is considered that expansion of a pontine microbleed induced by alteplase caused a fatal remote cerebral hemorrhage in the present case.