Objective: Recently, dual-antiplatelet therapy (DAPT) including clopidogrel (CLP) with endovascular treatment for unruptured cerebral aneurysm has been widely accepted. However, patients who are poor metabolizers of CLP (CLP-PMs) are more frequent in East Asians than in Caucasians, and an adequate antiplatelet effect may not be achieved with a normal dose in such patients. Prasugrel, which is a novel thienopyridine antiplatelet drug that is less likely to be poorly metabolized than CLP, is used widely for percutaneous coronary intervention, but its efficacy and safety with neuroendovascular treatment have not been elucidated. From this point of view, the purpose of this study was to elucidate the safety and efficacy of prasugrel with endovascular treatment for unruptured cerebral aneurysm.

Methods: We investigated 108 consecutive patients with an unruptured cerebral aneurysm who underwent endovascular treatment from March 2015 to January 2016 in our hospital. All patients received DAPT with 100 mg aspirin and 75 mg CLP daily, and antiplatelet function was evaluated by VerifyNow (Accumetrics, San Diego, CA, USA). In patients with P2Y12 reaction units (PRU) over 230, prasugrel was administered with a loading dose of 20 mg and a maintenance dose of 3.75 mg daily.

Results: Prasugrel was administered to 12 patients in our series. Of these patients, the mean age was 63.1 ± 13.0 years, and the mean PRU was 272 ± 20. Eleven patients received endovascular treatment with intracranial stents, of which four patients received treatment with flow diverters. The mean observational period was 5–13 months (median: 6.5), and no symptomatic hemorrhagic and ischemic complications occurred. Mean PRU was decreased to 159 ± 63 in the six patients in which PRU were re-examined.

Conclusion: Prasugrel is safe and effective with endovascular treatment for unruptured cerebral aneurysm in CLP-PMs.

Objective: Neurosurgeons are known as a high-risk group for malpractice litigation in western countries. Besides, based on our previously reported study, neurosurgeons are also in a high-risk group in Japan. Increasing risk of malpractice litigation is a big problem in Japanese healthcare system and several court decisions related to the neuroendovascular procedures are known. Herein, we reviewed the past court decisions regarding the neuroendovascular procedures and investigated the factors affected to the court decisions focusing on the prevention of allegations.

Methods: Court decisions related to neuroendovascular procedures between 2001 and 2015 were extracted from the database in Courts in Japan, and the reasons for the decisions were explored in each case.

Results: Ten cases regarding the neuroendovascular procedures were found among 446 retrieved healthcare-related court decisions. Five out of those 10 cases were attributed to the embolization of unruptured aneurysms, two were correlated with the embolization of arteriovenous malformations (AVMs), one was related to the carotid stenting, and two were associated with the diagnostic angiography. Negligence was identified in five out of the 10 cases, and dismissed in the other five cases. In the five court decisions in favor of plaintiffs, one identified negligence in clinical decisions, one in technical skills, and three in process of informed consent. In one case, defendants could not prove their contentions in technical skills for absence of intraprocedural video records and negligence was confirmed. In two out of five court decisions in favor of the defendant, the claim was dismissed based on the well-described clinical records or documents pertaining to the informed consent.

Conclusion: Neuroendovascular procedures are one of the high-risk groups for malpractice litigation. Sufficient informed consent, documentation, and storage of the clinical data are indispensable prerequisites to reduce the risk of malpractice litigation.

Objective: The results of thrombectomy in people aged 80 years and above were reviewed, and the necessity of an age limit was evaluated.

Methods: Seventy eight patients who underwent thrombectomy at our hospital between July 2014 and September 2016 were divided into those aged <80 years and those aged ≥80 years, and the therapeutic results and outcome were evaluated.

Results: The patients consisted of 25 aged ≥80 years (≥80 years group) and 53 aged <80 years (<80 years group). The mean time from puncture to recanalization was 56 and 65 minutes, respectively, and thrombolysis in cerebral infarction score of 2b or better recanalization was observed in 96.0 and 88.7%, respectively, with no significant difference in either parameter. Change of the approach route was necessary in five patients aged ≥80 years (20.0%). A favorable outcome with a modified Rankin scale (mRS) score of ≤2 was observed 3 months after the onset in 44.0 and 64.2%, respectively, being slightly lower in the ≥80 years group (P = 0.151). In the ≥80 years group, the time from the onset to recanalization was a poor prognostic factor (P = 0.048).

Conclusion: In the patients aged ≥80 years, the recanalization rate, procedural time, and complication rate in thrombectomy were comparable to those in the patients aged <80 years, and no significant difference was observed in the outcome. Therefore, aggressive intervention without an age limit is considered recommendable in preoperatively activities of daily living (ADL)-independent elderly patients expected to be good candidates for simple thrombectomy. However, with the possibility of change in the approach route in mind, it is necessary to achieve recanalization more promptly in older patients.

Objective: Changes in the VerifyNow (Accumetrics, San Diego, CA, USA) assay results before and after neuroendovascular therapy and complications were evaluated.

Methods: Of the 124 neuroendovascular procedures at our hospital between June 2014 and June 2015, 15 patients received elective treatment with dual-antiplatelet therapy (DAPT) consisting of aspirin at 100 mg/day and clopidogrel at 75 mg/day continued from at least 7 days before the procedure to the postprocedural period. Of these patients, those who underwent the VerifyNow assay before treatment and within 1 month after the procedure were included. Changes in the results of VerifyNow assay and complications were retrospectively evaluated.

Results: Thirteen patients were included. The treatment was coil embolization of intracranial aneurysm in five patients (stent-assisted in four patients), carotid artery stenting in seven patients, and angioplasty and stenting for intracranial atherosclerosis in one patient. No significant change was observed in the aspirin reaction units (ARU) value after compared with before treatment. The P2Y12 reaction units (PRU) value decreased significantly after treatment (152 [interquartile range (IQR): 126–157] vs. 9 [IQR: 6–61], p = 0.001). Hemorrhagic events were observed in eight patients (61.5%) after treatment.

Conclusion: Continuation of DAPT after neuroendovascular treatment may induce delayed clopidogrel hyper-response, which may lead to hemorrhagic complications.

Objective: We report a patient with acute-phase cerebral embolism related to Trousseau’s syndrome (TS) in whom thrombectomy was performed, and white thrombi were captured.

Case Presentation: The patient was a 65-year-old female. Sudden-onset dizziness and progressive consciousness disorder were noted. Diagnostic imaging led to a diagnosis of occlusion of the basilar artery (BA). In the acute phase, thrombectomy was performed, and white thrombi were captured, differing from standard-type embolism. After surgery, the symptoms rapidly reduced, but systemic investigation suggested advanced gastric cancer as an etiologic factor for embolism. Subsequently, embolism recurred, and the patient died of hemorrhagic cerebral infarction 31 days after onset.

Conclusion: If a white thrombus is captured during thrombectomy, TS should be differentiated as an etiologic factor.

Objective: We report a case of superior sagittal sinus (SSS) dural arteriovenous fistula (dAVF) treated with transarterial Onyx injection under flow control using two balloon guiding catheters and a dual-lumen balloon microcatheter.

Case Presentation: A 54-year-old man previously diagnosed with SSS dAVF with cortical venous reflux at 4 years prior, who did not request treatment as he was asymptomatic. During follow-up, he developed right temporal lobe subcortical hemorrhage and showed an occlusive change in venous drainage. We performed transarterial Onyx injection with assistance using multiple balloons placed in the bilateral external carotid and right middle meningeal arteries. Using this technique, we were able to sufficiently fill the proximal part of the venous drainage with Onyx and achieved complete obliteration. No treatment-related complication was observed, and follow-up angiography performed at 8 months after the treatment showed no recurrence.

Conclusion: Multiple balloon-assisted transarterial Onyx embolization is useful for adequate fillings of shunt and the proximal part of the venous drainage.

Objective: Ingenuity is required in treating carotid artery stenosis associated with persistent primitive hypoglossal artery (PPHA) because of anatomical singularity.

Case Presentation: A 69-year-old male presented with right thalamic infarction and was found to have marked stenosis of the right internal carotid artery (ICA). PPHA extending from a site distal to the stenosed area of the right ICA to the right vertebral artery was observed. Since there were few collateral channels for the posterior circulation, one FilterWire EZ (Boston Scientific, Natick, MA, USA) each was placed in the ICA and PPHA, and carotid artery stenting was performed.

Conclusion: The effectiveness of the double distal filter protection technique for ICA stenosis associated with PPHA and tips for the retrieval of the filter devices are reported.

Objective: Carotid artery stenting is performed increasingly with increases in atherosclerotic diseases. Since cerebral embolism is a problematic complication of stenting, preventive methods have been devised, and filters for distal protection have recently begun to be used. We have examined filters after the procedure and evaluated the relationships of the findings with preprocedural symptoms, imaging diagnosis, and flow impairment during treatment. While membrane filters have initially been used, mesh-type filters have also been introduced. Since mesh-type filters have an elastic structure in which wires are woven in, modifications of the conventional observation method are necessary.

Case Presentation: A 73-year-old man developed right hemiparesis and was referred to our department with a diagnosis of cerebral infarction. Marked stenosis was noted at the origin of the left internal carotid artery and was considered a responsible lesion as a result of close examination. On the 26th day of illness, stent placement was performed using a mesh-type filter. After stent placement, the filter was stained with hematoxylin and eosin. The mesh part was cutoff, mounted on a glass slide, a mounting medium was dripped, and a cover glass was applied. Both sides of the cover glass were fixed with clips. After the embedding medium dried (about 1 week), the clips were removed, and the completed preparation was examined microscopically. Many pieces of thrombotic debris were captured. At high magnification, organized components and slight precipitation of fibrin were also observed.

Conclusion: Examination of filters is useful because it makes the evaluation of debris properties and their relationships with preprocedural images and intraprocedural complications possible.