Tatsuro Takada

Prediction of cerebral hyperperfusion syndrome after carotid artery stenting by CT perfusion imaging with acetazolamide challenge

IntroductionCerebral hyperperfusion syndrome (HPS) is an uncommon but serious complication of carotid artery stenting (CAS). The purpose of this study was to investigate the efficacy of CT perfusion imaging (CTP) with acetazolamide challenge to identify patients at risk for HPS after CAS.MethodsWe retrospectively analyzed 113 patients who underwent CTP with rest and acetazolamide challenge before CAS. CTP maps were assessed for absolute and relative cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and change of each parameter before and after acetazolamide challenge. Patients were divided into two groups according to the HPS after the CAS. Receiver-operating characteristic (ROC) curve analysis was performed to determine the most accurate CTP parameter for the prediction of HPS.ResultsNine of 113 patients had HPS. There were significant differences for absolute and relative values of resting CBF (p = 0.001 and p = 0.026), resting MTT (p < 0.001 and p = 0.004), post-acetazolamide CBF (p < 0.001 and p = 0.001), post-acetazolamide MTT (p < 0.001 and p = 0.002), and %changes of CBF (p = 0.009) between the HPS and non-HPS groups. ROC curve analysis showed that the CTP parameters with the maximal area under the receiver-operating characteristic curve (AUC) for HPS was the absolute value of post-acetazolamide MTT (AUC 0.909) and the absolute value of resting MTT (AUC 0.896).ConclusionPretreatment CTP with acetazolamide challenge could identify patients at risk for HPS after CAS. Although the CTP parameter that most accurately identified patients at risk for HPS was the absolute value of post-acetazolamide MTT, resting MTT was sufficiently accurate.

A case in which contrast-enhanced transoral carotid ultrasonography was useful for pre- and post-procedural evaluation in carotid artery stenting

Contrast-enhanced transoral carotid ultrasonography (CETOCU) is a novel examination modality that is superior to other modalities in the cases of pseudo-occlusion with severe arteriosclerotic stenosis of the distal internal carotid artery (ICA), and is also useful for noninvasively evaluating changes over time in the vessel distal to the stent following carotid artery stenting (CAS). We report a case of a patient who we evaluated with CETOCU for a pseudo-occlusive ICA before and after CAS.

Effects of Pretreatment Cerebral Blood Volume and Time to Recanalization on Clinical Outcomes in Endovascular Thrombectomy for Acute Ischemic Stroke

BACKGROUND Faster time to recanalization leads to better clinical outcomes in patients treated with endovascular thrombectomy. Whether the association between time to recanalization and clinical outcomes depends on cerebral blood volume (CBV) obtained from pretreatment computed tomography (CT) perfusion (CTP) imaging was investigated. METHODS In consecutive patients with acute ischemic stroke who achieved recanalization by endovascular thrombectomy for intracranial internal carotid artery or M1 occlusion, the effects on clinical outcome of time to recanalization and the relative CBV value (rCBV) assessed by pretreatment CTP were evaluated. The patient population was divided into 2 groups according to rCBV: normal rCBV group (rCBV ≥ .9) and low rCBV group (rCBV < .9). In each group, time to recanalization was compared between the good and the poor clinical outcome groups. RESULTS Sixty-four patients were eligible for this study. Twenty-six patients (40.6%) achieved good clinical outcomes. In the normal rCBV group, no association was found between clinical outcome and time to recanalization. In the low rCBV group, time to recanalization from CTP (101 minutes versus 136 minutes, P = .040) was significantly shorter in the good clinical outcome group. On binary logistic regression modeling, CTP to recanalization time (odds ratio 1.035 [1.004-1.067], P = .025) was an independent predictor of good clinical outcome only in the low rCBV group. CONCLUSIONS The association between time to recanalization and clinical outcomes depends on rCBV obtained from pretreatment CTP. Time to recanalization is more important for good clinical outcomes in patients with low rCBV than in patients with normal rCBV.

Contrast‐enhanced transoral carotid ultrasonography for the evaluation of a long stenotic lesion in the internal carotid artery

Contrast‐enhanced transoral carotid ultrasonography (CETOCU) is a novel modality for imaging the distal extracranial internal carotid artery, which is not possible with conventional carotid ultrasonography. We present a representative case that demonstrates the usefulness of CETOCU.

Abstract TP10: Endovascular Treatment for Acute Ischemic Stroke With Intracranial Atherosclerotic Occlusive Disease

Background: Treatment strategy for acute ischemic stroke with intracranial atherosclerotic disease remains unknown. The aims are to evaluate whether revascularization rates, procedural complication...

Long-Term Outcome of Balloon Angioplasty Without Stenting for Symptomatic Middle Cerebral Artery Stenosis

PURPOSE A recent randomized controlled trial demonstrated that aggressive medical management was superior to angioplasty with stenting for intracranial stenosis. The purpose of this study was to assess initial and long-term outcomes of balloon angioplasty without stenting for symptomatic middle cerebral artery (MCA) stenosis. METHODS We retrospectively analyzed the clinical data of 72 patients (mean age, 58.9 years old) with 84 balloon angioplasties without stenting for high-grade (>70%) atherosclerotic stenosis of the main trunk of the MCA. All patients had experienced recurrent transient ischemic attack or minor stroke resistant to medical treatment. We assessed perioperative and long-term outcomes such as restenosis and the recurrence of strokes. The follow-up period was a median of 63 months (range, 6-171 months). RESULTS Balloon angioplasty was successful in 97% of procedures. During the 30-day perioperative period, a total of 3 patients suffered from stroke (4.2%) without death. A total of 23 (31.9%) patients had restenosis at a time point that varied from 6 to 111 months. Diabetes mellitus (DM) was noted significantly more often in the restenosis group (39%) than in the nonrestenosis group (13%). Multivariate logistic regression analysis revealed DM (odds ratio, 4.84; 95% confidence interval, 1.196-19.62; P = .027) as an independent predictor of restenosis. Restenosis and DM were indicated as independent predictors of the recurrence of ischemic stroke and transient ischemic attack. CONCLUSIONS Balloon angioplasty without stenting for symptomatic MCA stenosis can be performed with a high successful rate and a low risk of complications. Long-term outcome data suggest that this procedure reduces the risk of further strokes.

Contrast‐enhanced transoral carotid ultrasonography for the evaluation of plaque protrusion after carotid artery stenting

A 67 year‐old man was admitted to our hospital because of mild left hemiparesis and was diagnosed with cerebral infarction caused by right internal carotid artery stenosis. He was treated with dual antiplatelet therapy and scheduled for carotid artery stenting 14 days after onset. The preoperative right carotid angiogram showed 60% stenosis by the NASCET criteria, with an ulcer. The postoperative angiogram suggested protrusion in the stent, which could not be seen on conventional carotid ultrasonography because of its high location. On transoral carotid ultrasonography, clear delineation of the lesion was not possible due to color blurs. Contrast‐enhanced transoral carotid ultrasonography (CETOCU) clearly demonstrated the protrusion and delineated the lumen within the stent.