First-in-human, real-time artificial intelligence assisted cerebral aneurysm coiling: a preliminary experience.

BACKGROUND: Neuroendovascular procedures require careful and simultaneous attention to multiple devices on multiple screens. Overlooking unintended device movements can result in complications. Advancements in artificial intelligence (AI) have enabled real-time notifications of device movements during procedures. We report our preliminary experience with real-time AI-assisted cerebral aneurysm coiling in humans. METHODS: A real-time AI-assistance software (Neuro-Vascular Assist, iMed technologies, Tokyo, Japan) was used during coil embolization procedures in nine patients with an unruptured aneurysm. The AI system provided real-time notifications for 'coil marker approaching', 'guidewire movement', and 'device entry' on biplane fluoroscopic images. The efficacy, accuracy, and safety of the notifications were evaluated using video recordings. RESULTS: The AI system functioned properly in all cases. The mean number of notifications for coil marker approaching, guidewire movement, and device entry per procedure was 20.0, 3.0, and 18.3, respectively. The overall precision and recall were 92.7% and 97.2%, respectively. Five of 26 true positive guidewire notifications (19%) resulted in adjustment of the guidewire back toward its original position, indicating the potential effectiveness of the AI system. No adverse events occurred. CONCLUSIONS: The software was sufficiently accurate and safe in this preliminary study, suggesting its potential usefulness. To the best of our knowledge, this is the first reported use of a real-time AI system for assisting cerebral aneurysm coiling in humans. Large scale studies are warranted to validate its effectiveness. Real-time AI assistance has significant potential for future neuroendovascular therapy.

[Comparison of Bayesian Estimation and SVD Methods for CT Perfusion in Patients with Acute Stroke].

PURPOSE: There are various analysis methods for CT perfusion (CTP). Although the advantages of Bayesian estimation algorithms have been newly suggested, comparisons with other analysis methods on clinical data are still limited. In this study, we compared the Bayesian estimation method with the singular value decomposition (SVD) method in the evaluation of patients with acute cerebral infarction and examined its usefulness. METHODS: CTP data from 13 patients with acute stroke were analyzed using the SVD and Bayesian estimation methods implemented in Vitrea. Evaluation of visual clarity of the ischemic area and quantitative values of the healthy side-affected side ratio using the mean values of the left and right region of interest (ROI) on the images were compared using the SVD and Bayesian estimation methods. RESULTS: In visual evaluation, there were significant differences in CBV in four cases, and in CBF, MTT, and TTP in many cases. The healthy side-affected side ratio of the SVD and Bayesian estimation methods were as follows: CBF 1.19, 1.84; CBV 1.09, 1.02; MTT 1.12, 1.79; and TTP 1.48, 1.19. For CBF and MTT, the Bayesian estimation method had a larger ratio of the healthy side to the affected side, and for TTP, the SVD method had a larger ratio of the test side to the affected side. CONCLUSION: We suggest that the Bayesian estimation method is more useful than the SVD method for assessing CBF and MTT in CTP analysis of patients with acute stroke.

A Case of De Novo Basilar Artery Aneurysm Associated with Proximal Stenosis Treated by Coil Embolization.

Objective: This report highlights a case of a de novo aneurysm assumed to be caused by hemodynamic stress resulting from proximal basilar artery stenosis. Case Presentation: A 76-year-old woman presented at our hospital with tinnitus. Although MRI did not reveal the cause of her tinnitus, it did uncover an incidental finding of basilar artery stenosis. The patient reported a history of cerebral infarction, diabetes, and hypertension. Six years following the initial discovery of basilar artery stenosis, a saccular aneurysm was detected at the bifurcation of the basilar artery and the right anterior inferior cerebellar artery, corresponding to the distal portion of the basilar artery stenosis. Upon revelation of an enlarged aneurysm on the subsequent two-year follow-up MRI, the patient received coil embolization treatment. No signs of recurrence were observed on the next two-year follow-up MRI. Conclusion: It was assumed that proximal basilar artery arteriosclerotic stenosis had caused hemodynamic stress on the distal vessel wall, and that this was responsible for the formation and growth of a de novo aneurysm. This case suggests that cerebrovascular arteriosclerotic changes may be associated with de novo aneurysm formation and therefore requires careful follow-up.

Spinal Cord Infarction after Mechanical Thrombectomy for Acute Basilar Artery Occlusion: A Case Report and Review of the Literature.

Objective: We report a case of spinal cord infarction following mechanical thrombectomy for acute basilar artery occlusion, and describe the pathophysiological mechanism of spinal cord infarction and its possible prevention. Case Presentation: A 70-year-old man developed dysarthria and left-sided sensory impairment and was then diagnosed with acute basilar artery occlusion. Mechanical thrombectomy was performed using a 6-Fr guiding sheath via the left vertebral artery (VA). Complete recanalization was achieved within 1.5 hours. However, toward the end of the procedure, the guiding sheath was wedged in the distal portion of the VA. Postoperatively, left-sided flaccid paralysis and right-sided sensory deficit were observed. Cervical magnetic resonance imaging (MRI) demonstrated an acute spinal cord infarction on the left side, at the level of C3. The cause of infarction was suspected to be the wedging of the guiding sheath during the procedure. Conclusion: Spinal cord infarction is a rare but serious complication of mechanical thrombectomy for acute basilar artery occlusion. The selection of appropriate procedure, device, and safe access route are essential for the success of a mechanical thrombectomy for acute basilar artery occlusion.

Treatment Outcomes of Stent-Assisted Coil Embolization for Ruptured Vertebral Artery Dissecting Aneurysms: The Preservation of Branches May Improve the Prognosis.

Objective: Subarachnoid hemorrhage due to ruptured vertebral artery dissecting aneurysm (rVADA) is associated with a high frequency of acute rebleeding and requires early treatment following onset. Parent artery occlusion (PAO) or stent-assisted coiling (SAC) embolization is selected as a treatment option according to the individual patient condition. This report is a retrospective examination evaluating the treatment outcomes for rVADA. Methods: The subjects were 20 rVADA patients (16 men and 4 women) who underwent endovascular treatment at our institution. The mean patient age was 52.9 years. Ten patients each were allocated to the PAO group and SAC group. We evaluated and compared the following parameters: presence of hemorrhagic complications, presence of ischemic complications, requirement of retreatment, and Glasgow Outcome Scale (GOS) after 90 days. Results: The reasons for selecting SAC were contralateral occlusion or a small diameter in three patients, the posterior inferior cerebellar artery (PICA) involvement in three patients, perforating artery from dissected lesion in five patients, and anterior spinal artery in one patient. There was no rebleeding in any patient. Symptomatic ischemic complications were observed in four patients in the PAO group and in one in the SAC group. Hyper-intense lesions in the brainstem on MRI DWI were noted in five patients in PAO group and in one in the SAC group. Retreatment was required for three patients in the PAO group and for four in the SAC group. Favorable outcomes (GOS 4, 5) after 90 days were observed for three patients in the PAO group and for eight patients in the SAC group (p = 0.0257). Conclusion: SAC that can preserve branches is a useful treatment option for rVADA. Further studies on a greater number of subjects are required to establish the optimal dose of antiplatelet agents and anticoagulants, and for stent selection.

[Cryptococcal Meningitis in a Patient with Breast Cancer Receiving Everolimus: A Case of Successful Treatment with Continuous Cerebrospinal Fluid Drainage].

Cryptococcosis is a fungal infection that mainly occurs in immunocompromised patients. We present the first case of cryptococcal meningitis in a patient who was being administered everolimus for breast cancer. Everolimus, a selective inhibitor of mammalian target of rapamycin, is a molecular targeting agent that is administered not only as an immunosuppressive agent, but also as an anticancer therapeutic. A 72-year-old woman with recurrent breast cancer had been receiving everolimus. She was admitted to our hospital with headache and vomiting. Lumbar puncture revealed high opening pressure, and cerebrospinal fluid (CSF) evaluation diagnosed cryptococcal meningitis. She was administered liposomal amphotericin-B, followed by fosfluconazole. Daily lumbar puncture was insufficient to reduce the high intracranial pressure; thus, continuous lumbar drainage was needed to improve her symptoms. The indwelling catheter was replaced regularly to prevent bacterial infection. She was treated successfully with extracorporeal CSF drainage for 86 days and fosfluconazole administration over 17 weeks. The patient recovered fully and was discharged on day 153 of hospitalization. As patients who receive everolimus are potentially immunocompromised hosts, we recommend that the medicine be administered with caution considering opportunistic infections when used in patients with cancer. (Received April 19, 2018; Accepted August 9, 2018; Published November 1, 2018).

Unique Diagnostic Features and Surgical Strategy for Intracranial Carotid Sympathetic Plexus Schwannoma: Case Report and Literature Review.

BACKGROUND: Intracranial carotid sympathetic plexus schwannoma (CSPS) is extremely rare; thus differential diagnostic criteria, optimal surgical strategies, and even a precise definition are lacking. Here we describe a case of CSPS and propose a definition and classification for previously reported cases. CASE DESCRIPTION: A 54-year-old man presented with hypacusis and abducens nerve palsy. Radiologic examinations revealed a well-enhanced mass at the right medial temporal base with erosion of the petrous apex and intact perilesional cortical bone. Preoperative findings, such as spontaneous improvement of diplopia, absence of xerophthalmia or facial palsy, and laterally displaced internal carotid artery (ICA), suggested the atypical origins of the petrous apex schwannoma. The tumor was exposed using the subtemporal extradural approach and completely resected. Intact foramen ovale, rostrolateral displacement of the greater superficial petrosal nerve within the outer membrane of the tumor, eroded petrous apex and carotid canal, superolaterally displaced ICA, and lack of an obvious tumor attachment to any of the suspected nerves suggested that the tumor originated from the carotid sympathetic plexus of the petrous ICA. The patient fully recovered without neurological complications. CONCLUSIONS: Preoperative diagnosis of petrous apex schwannoma is difficult: characteristic findings such as diplopia, hypacusis, and laterally displaced ICA may help. In addition, assessment of the relationship between the tumor and cavernous sinus could be useful in the determination of the surgical approach. Complete resection with good clinical outcome could be expected using Dolenc's approach (type A) and by the middle fossa extradural approach (type B) for intracavernous and extracavernous CSPS, respectively.