Objective: To evaluate cerebral blood flow immediately after reperfusion following thrombectomy for acute large vessel occlusion, and to examine whether cerebral blood flow after reperfusion is related to hemorrhagic transformation.

Methods: The patients with acute large vessel occlusion in the anterior circulation who obtained reperfusion by thrombectomy were included. Cerebral blood flow was evaluated using single photon emission computed tomography (SPECT) within 6 hours after reperfusion. The patients were divided into two groups with or without hemorrhagic transformation, and basic characteristics, the ratio of cerebral blood flow (affected-side to unaffected-side ratio) in the perfusion area of the middle cerebral artery (MCA asymmetry index), and functional prognosis were compared among two groups.

Results: In all, 23 patients were included; 11 presented hemorrhagic transformation, and 12 did not. The hemorrhagic group exhibited significantly higher MCA asymmetry index than the non-hemorrhagic group (median: 1.54 [1.30–1.83] vs. 1.12 [1.07–1.24], respectively, P = 0.02), and a lower rate tendency of modified Rankin Scale (mRS): 0-2 after 3 months (1 patient [9%] vs. 6 patients [50%], respectively, P = 0.06).

Conclusion: In patients with successful reperfusion by thrombectomy, hemorrhagic transformation is predisposed to occur when high MCA asymmetry index is presented. Care should be taken in periprocedural management of blood pressure and sedation for those with high MCA asymmetry index.

Objective: After internal trapping for ruptured vertebral artery dissection (VAD), serious complications related to medullary infarction influence the prognosis.

Methods: The subjects were 15 patients with ruptured VAD who had undergone internal trapping between 2004 and 2017. Targeted embolization of dilated segment was performed while neither adjacent stenotic sites nor normal segments were embolized. We retrospectively analyzed the incidence and extent of medullary infarctions, neurologic sequelae, and outcome.

Results: In all patients, endovascular procedures were successful. There were no intraoperative complications. In two patients, embolization with the double-catheter method through bilateral approaches was performed. Postoperative medullary infarction was noted in two patients, but they had dorsolateral-type minor infracted foci. There were no serious sequelae in any patient, and there were no rebleedings during the follow-up period.

Conclusion: The results suggest that internal trapping in which the extent of embolization is limited to the site of morbid dilation prevents rebleeding, reducing the risk of postoperative medullary infarctions. Tight packing of a dilated segment with the preservation of perforators from vertebral arteries (VAs) is extremely important. The double-catheter method through bilateral approaches may be useful for tight packing of the dilated segment of ruptured VAD.

Objective: In this study, we report a patient in whom a dural arteriovenous fistula (dAVF) developed after mechanical thrombectomy for acute ischemic stroke, and embolization was performed.

Case Presentation: The patient was a 44-year-old male. He was brought to the emergency room of our hospital by ambulance with cervical pain. Head MRI revealed ischemic stroke related to right internal carotid artery occlusion. Mechanical thrombectomy was performed and thrombolysis in cerebral infarction (TICI) 2b recanalization was achieved. Middle cerebral artery (M2) occlusion and internal carotid artery dissection were observed. Follow-up was conducted. The postoperative course was favorable, and he was referred to another hospital for rehabilitation. However, cerebral angiography 4 months after surgery showed a dAVF. Transarterial embolization was performed. The postoperative course was uneventful and she was discharged.

Conclusion: In the present case, dissection-related dilation/elevation of the internal carotid artery may have resulted in venous compression, leading to the development of a dAVF. We could confirm these serial changes in images before and after its development.

Objective: Reperfusion by endovascular mechanical thrombectomy has been proven effective for patients with acute ischemic stroke. Although most embolization sources are thrombi, other types of clots could also be embolic sources. We report a sporadic case of acute ischemic stroke caused by mobilization of cardiac papillary fibroelastoma (CPF).

Case Presentation: A 79-year-old man presented was hospitalized with chronic heart failure due to disdialysis syndrome. He developed sudden consciousness disturbance and was diagnosed with basilar artery occlusion. Mechanical thrombectomy with only one pass of the Penumbra 5MAX ACE (Penumbra Inc., Alameda, CA, USA) was successful with a direct aspiration first-pass technique. Histopathological examination of the papilla-shaped fragile clot with white granular surface, revealed papillary fibroelastoma. Slight improvement in his clinical symptoms was seen after thrombectomy, but the patient died of deterioration of the disdialysis syndrome. CPF diagnosis was based on the pathological findings of the embolus, not on transesophageal echocardiography (TEE) or open heart surgery due to disdialysis syndrome in our patient. In addition, the presence of cardiac tumor could not be confirmed in the autopsy.

Conclusion: CPF is a rare benign cardiac tumor, which might cause cerebral infarction either directly or through thrombus formed by platelets and fibrin. While mechanical thrombectomy is safe and effective, but histopathological diagnosis of the aspirated clot can be recommended, especially if the appearance of the embolic material is unusual.

Objective: In this report, we discuss the cases of two patients with a ruptured blood blister-like aneurysm (BBA) of the basilar trunk, who we treated with overlapping stent-assisted coil embolization (SACE).

Case Presentations: Case 1: The first patient was a 52-year-old male with a World Federation of Neurosurgical Societies (WFNS) Grade IV subarachnoid hemorrhage (SAH). A 2 mm anterior wall BBA of the basilar artery (BA) was detected on cerebral angiography on day 10 and treated with overlapping SACE. No recanalization was observed at 12 months after surgery. Case 2: The second patient was a 62-year-old female with WFNS Grade I SAH. A 1.7 mm posterior wall BBA of the BA was detected on cerebral angiography on day 5, which was treated with overlapping stents alone, but a residual aneurysm was noted on day 14, and SACE was additionally performed. Infarction of the perforating branch was noted after surgery, but the aneurysm was completely occluded on follow-up after 1 week. No recanalization was observed at 10 months after surgery.

Conclusion: Although overlapping SACE may be effective for ruptured BBAs of the basilar trunk, attention should be paid to the damage of the perforating branch after surgery in cases of aneurysm of the posterior wall of the BA. For appropriate multiple overlapping stents, accumulation of cases and further investigations are necessary.

Objective: We herein report a new technique using double microcatheters to treat a wide-necked aneurysm in which the neck is incorporated with the parent artery.

Case Presentations: Case 1: The patient was a 71-year-old woman with a large, wide-necked unruptured aneurysm of the basilar bifurcation area with the right posterior cerebral artery (PCA) incorporated in the aneurysm sac. We previously placed a scaffolding coil around the right PCA orifice via a microcatheter placed near the right PCA to avoid a framing coil via another microcatheter involving the right PCA orifice. After confirming that the framing coil did not obstruct the right PCA flow, the “scaffolding” coil was repositioned in the framing coil. Complete occlusion of the aneurysm was achieved with the stable frame of these two coils. Case 2: The patient was a 68-year-old woman who presented with subarachnoid hemorrhaging due to a ruptured aneurysm with a wide neck of the basilar bifurcation. Coiling with a conventional double-catheter technique failed to form suitable framing because the tips of both microcatheters faced the same direction (posterior) even after changing the shapes of the tips. After leading the tip of one microcatheter to face the anterior direction by inserting part of the first coil via the microcatheter, we placed the second coil via another microcatheter with its tip facing posteriorly. The second coil then came to functions as the scaffolding, holding the tip of the first catheter anteriorly. A stable frame was made when the remaining part of the first coil was deployed.

Conclusion: We termed this method the “scaffolding technique.” This technique is an effective and safe option for treating wide-necked aneurysms.

Objective: A newly developed application for cerebral C-arm computed tomography perfusion imaging (C-arm CTP) using an angiography system was investigated.

Case Presentation: C-arm CTP protocol continuously collects X-ray projection images during 10 back and forth C-arm rotations. From the collected data, cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), and time to peak (TTP) images and multiphase vascular images are reconstructed. C-arm CTP images acquired in patients with acute and chronic major artery occlusion are presented.

Conclusion: C-arm CTP using an angiography system is capable of evaluating perfusion parameters in real time, similar to conventional evaluation using multi-detector row CT perfusion (MD-CTP), suggesting its usefulness for examination of ischemic stroke in the angiographic suite.