Takeo Nishida

Cardiac Cycle-Related Volume Change in Unruptured Cerebral Aneurysms A Detailed Volume Quantification Study Using 4-Dimensional CT Angiography

Background and Purpose— The hemodynamic factors of aneurysms were recently evaluated using computational fluid dynamics in a static vessel model in an effort to understand the mechanisms of initiation and rupture of aneurysms. However, few reports have evaluated the dynamic wall motion of aneurysms due to the cardiac cycle. The objective of this study was to quantify cardiac cycle-related volume changes in aneurysms using 4-dimensional CT angiography. Methods— Four-dimensional CT angiography was performed in 18 patients. Image data of 1 cardiac cycle were divided into 10 phases and the volume of the aneurysm was then quantified in each phase. These data were also compared with intracranial vessels of normal appearance. Results— The observed cardiac cycle-related volume changes were in good agreement with the sizes of the aneurysms and normal vessels. The cardiac cycle-related volume changes of the intracranial aneurysms and intracranial normal arteries were 5.40%±4.17% and 4.20±2.04%, respectively, but these did not differ statistically (P=0.12). Conclusions— We successfully quantified the volume change in intracranial aneurysms and intracranial normal arteries in human subjects. The data may indicate that cardiac cycle-related volume changes do not differ between unruptured aneurysms and normal intracranial arteries, suggesting that the global integrity of an unruptured aneurysmal wall is not different from that of normal intracranial arteries.

Brain metastasis from small-cell neuroendocrine carcinoma of the urinary bladder: A case report

Eight months after radical surgery for small-cell neuroendocrine carcinoma (SCNC) of the urinary bladder, a 69-year-old man was admitted with a brain tumor in the left frontal lobe. The tumor, about 5 cm in diameter, was intensely but heterogeneously enhanced on computed tomography and magnetic resonance imaging. The tumor was subtotally removed, leaving only the portion adjacent to the anterior horn of the left lateral ventricle. Microscopically, the tumor was composed of diffuse sheets of small tumor cells with round to spindle-shaped nuclei, indistinct nucleoli, scant or absent cytoplasm, and indistinct cell margins. Immunohistochemically, the tumor cells were positive for synaptophysin, neuron-specific enolase, chromogranin A, and keratin. Ultrastructurally, the tumor cells showed classic neurosecretory granules and microvilli in the cytoplasm. The tumor was diagnosed as a brain metastasis from SCNC of the urinary bladder. After surgery, whole-brain radiation therapy of 40 Gy was performed, which succeeded in controlling the residual tumor. However, 4 months after surgery, the patient died of meningeal carcinomatosis. To our knowledge, this is the first report focusing on brain metastasis from SCNC of the urinary bladder. The clinicopathological features and pathological diagnosis of this tumor are discussed.

Brachial–Ankle Pulse Wave Velocity as a Predictor of Silent Cerebral Embolism after Carotid Artery Stenting

BACKGROUND In neuroendovascular therapy, the effect of arterial stiffness on postprocedural cerebral thromboembolism is unknown. In this observational study, we examined the relationship between cerebral thromboembolism after carotid artery stenting and arterial stiffness. METHODS From April 2015 to February 2017, we enrolled consecutive patients undergoing scheduled carotid artery stenting in our institution. In all patients, preprocedural brachial-ankle pulse wave velocity was used to assess arterial stiffness, whereas the number of new cerebral ischemic lesions on diffusion-weighted magnetic resonance imaging was assessed after treatment. We also analyzed patient data and details of procedures in patients with carotid artery stenting. RESULTS Twenty-one patients completed the study. The mean brachial-ankle pulse wave velocity was 1879 cm/s. There was no association of cerebral thromboembolisms with age, unstable plaque, protection device, or type of stent. However, the brachial-ankle pulse wave velocity was an independent predictor of cerebral thromboembolisms (P = .0017). CONCLUSIONS Brachial-ankle pulse wave velocity is predictive of silent cerebral embolisms on diffusion-weighted magnetic resonance imaging after carotid artery stenting.

Transarterial Sinus Embolization for a Dural Arteriovenous Fistula in a Sinus of the Lesser Sphenoid Wing: A Case Report

Dural arteriovenous fistula (DAVF) in a sinus of the lesser sphenoid wing (SLSW) is rarely reported. Here, we report a case of an isolated SLSW DAVF treated by coils placed into the sinus through the feeding artery. A 68-year-old man was admitted to our hospital with headache. Magnetic resonance images and an angiogram showed a varix in the right middle cranial fossa. A DAVF, consisting of three main feeders and the isolated SLSW, was diagnosed based on the angiogram findings. Retrograde leptomeningeal venous drainage to the deep middle cerebral vein was observed. Given the remarkable extent of cortical venous ectasia together with the presence of headache and right abducens nerve paralysis, endovascular treatment was initiated. A transvenous approach through the right inferior petrosal sinus was not feasible because of difficulty associated with inserting the microcatheter into the SLSW. Thus, we tried a transarterial approach and were able to advance the microcatheter beyond the fistula into the isolated SLSW, through the artery of the foramen rotundum. The isolated sinus and feeding arteries were embolized with coils. The postoperative angiogram showed the total occlusion of the SLSW DAVF. This case demonstrates the feasibility of transarterial sinus packing for an isolated SLSW DAVF.

Coil and Single Stent Placement for Ruptured Dissecting Aneurysm of Middle Cerebral Artery: a case report.

BACKGROUND Ruptured dissecting aneurysms located at the middle cerebral artery (MCA) are rare, and their standard treatment has not been defined. Furthermore, lenticulostriate artery involvement in the dissecting segment makes treatment extremely difficult, and no previous reports have described successful treatment for such conditions. CASE DESCRIPTION We herein report the case of a 74-year-old woman who presented with sudden severe headache from subarachnoid hemorrhage due to dissection in the proximal M1 segment of left MCA involving lenticulostriate arteries. Digital subtraction angiography on day 6 showed that the dissecting aneurysm had enlarged despite strict blood pressure control. On day 8, the patient was treated successfully with a self-expanding closed cell stent and coil embolization, preserving blood flow in the lenticulostriate arteries as well as the MCA. CONCLUSIONS Follow-up digital subtraction angiography performed 5 weeks after endovascular therapy showed healing of the dissecting lesion, and the patient was discharged neurologically intact.

X-ray angiography perfusion imaging with an intra-arterial injection: comparative study with 15O-gas/water positron emission tomography

Background X-ray angiography perfusion (XAP) is a perfusion imaging technique based on conventional DSA. Objective In this study, we aimed to validate parameters derived from XAP by comparing them with 15O-gas/water positron emission tomography (PET), using data from patients with chronic ischemic cerebrovascular disease. Methods 18 consecutive patients were included. XAP was performed with intra-arterial infusion of contrast media, and a time–density curve was constructed for each cerebral hemisphere. From the curves, the relative values of mean transit time (rMTT) and wash-in rate (rWiR) were obtained by dividing the values of the right hemisphere by those of the left hemisphere. These were then compared with the relative values of cerebral blood flow (rCBF) and rMTT calculated from the PET data. Results XAP rWiR correlated strongly with PET rCBF (r=0.86, P<0.0001). rMTT measurements from the two modalities were also strongly correlated (r=0.85, P<0.0001). Bland–Altman analysis revealed a bias of 0.14±0.18 (95% limits of agreement −0.22 to 0.51) for PET rCBF versus XAP rWiR, and 0.016±0.093 (95% limits of agreement −0.17 to 0.20) for rMTT between the two modalities. Conclusions The relative values obtained from XAP were validated across a population of patients with chronic ischemic cerebrovascular disease.

Carotid artery stenting for patients with occipital–vertebral anastomosis

Background and purpose We report the outcomes of carotid artery stenting for patients with angiographically visible occipital artery–vertebral artery anastomosis. Methods Among 47 consecutive patients who underwent carotid artery stenting from January 2007 to December 2010, seven patients for whom cerebral angiograms clearly showed occipital artery–vertebral artery anastomosis were selected. Four different protection methods were used: distal internal carotid artery protection; carotid flow reversal; seatbelt and airbag technique; and double protection method of protecting both the external and internal carotid artery. Results One patient with distal internal carotid artery protection showed a high-intensity lesion at the border of the upper thalamus, internal capsule and lateral ventricle wall after carotid artery stenting. The other patient with the double protection method did not show any high-intensity lesions on postoperative diffusion-weighted imaging in the vertebrobasilar territory. All seven patients with visible occipital artery–vertebral artery anastomosis showed ipsilateral vertebral artery severe stenosis or occlusion. Conclusion Large occipital artery–vertebral artery anastomosis may be a pathway for embolic materials during carotid artery stenting. External carotid artery protection is recommended for carotid artery stenting in such patients.

Overlapping stent-assisted coil embolization for a ruptured intracranial vertebral artery dissection

Abstract Ruptured intracranial vertebral artery dissection is a cause of non-traumatic subarachnoid hemorrhage. Urgent intervention should be considered to prevent fatal rebleeding. Endovascular parent artery occlusion, which is the initial treatment of choice, is not suitable for patients with a hypoplastic or occlusive contralateral vertebral artery. We report a case of ruptured vertebral artery dissection, which was successfully treated with double overlapping stent-assisted coiling.