Real time artificial intelligence assisted carotid artery stenting: a preliminary experience.

BACKGROUND: Neurointerventionalists must pay close attention to multiple devices on multiple screens simultaneously, which can lead to oversights and complications. Artificial intelligence (AI) has potential application in recognizing and monitoring these devices on fluoroscopic imaging. METHODS: We report out preliminary experience with a real time AI assistance software, Neuro-Vascular Assist (iMed technologies, Tokyo, Japan), in six patients who underwent carotid artery stenting. This software provides real time assistance during endovascular procedures by tracking wires, guiding catheters, and embolic protection devices. The software provides notification when devices move out of a predefined region of interest or off the screen during the procedure. Efficacy, safety, and accuracy of the software were evaluated. RESULTS: The software functioned well without problems and was easily used. Mean number of notifications per procedure was 21.0. The mean numbers of true positives, false positives, and false negatives per procedure were 17.2, 3.8, and 1.2, respectively. Precision and recall were 82% and 94%, respectively. Among the 103 true positive notifications, 24 caused the operator to adjust the inappropriate position of the device (23%), which is approximately four times per procedure. False notifications occurred because of false positive device detection. No adverse events related to the software occurred. No periprocedural complications occurred. CONCLUSIONS: Neuro-Vascular Assist, a real time AI assistance software, worked appropriately and may be beneficial in carotid artery stenting procedures. Future large scale studies are warranted to confirm.

[Basic and Advanced Techniques of Anastomosis in Deep Surgical Fields:STA-SCA Anastomosis].

This article detailly describes the subtemporal-transtentorial STA-SCA bypass technique. Through temporal base drilling, copious cerebrospinal fluid evacuation before retraction, and sufficient retraction of the temporal lobe preserving the veins of the temporal base would be primodial to obtain an appropriate surgical field. Refrection of the tentrial free edge and identification of recipient SCA posterior to the entry point of the trochlear nerve into the cavernous sinus is a micro-anatomical key. Bilateral bayonet-type needle holders and forceps should be used not to shadow the surgical corridor with one's hands.

Posterior Communicating Artery Hypoplasia: A Risk Factor for Vertebral Artery Dissection Causing Subarachnoid Hemorrhage.

OBJECTIVE: Subarachnoid hemorrhage due to vertebral artery dissection is often fatal; however, its anatomical predictors remain unclear. We conducted a retrospective hospital-based case-control study to evaluate whether variations in the posterior communicating artery are associated with the risk of vertebral artery dissection with subarachnoid hemorrhage. MATERIALS AND METHODS: We obtained data from patients who underwent computed tomography angiography at our hospital between April 2010 and March 2020. Based on the connection between the anterior and posterior circulation of the arterial circle of Willis, the patients were categorized into a separated group (posterior communicating artery hypoplasia) and a connected group (all others). We evaluated the association between the development of posterior communicating artery and subarachnoid hemorrhage due to vertebral artery dissection using multivariate logistic regression analysis. RESULTS: Thirty-eight patients had subarachnoid hemorrhage due to vertebral artery dissection and 76 were identified as age- and sex-matched controls. In conditional multivariate logistic regression analysis, the separated group showed a significant association with subarachnoid hemorrhage due to vertebral artery dissection, with an adjusted odds ratio of 2.8 (95% confidence interval, 1.2-6.5; P = 0.021). CONCLUSIONS: The present study demonstrates that posterior communicating artery hypoplasia may be associated with subarachnoid hemorrhage due to vertebral artery dissection. Our results highlight the importance of anatomical variations in the cerebral artery and provide evidence to help develop preventive measures against strokes.

Unexpectedly Smaller Artifacts of 3.0-T Magnetic Resonance Imaging than 1.5 T: Recommendation of 3.0-T Scanners for Patients with Magnet-Resistant Adjustable Ventriculoperitoneal Shunt Devices.

BACKGROUND: Magnetic resonance imaging (MRI) artifacts of adjustable shunt devices are thought to be similar to metal clip artifacts, in that they are larger with higher field strength scanners. We have published several reports about the artifacts of new MRI-resistant adjustable shunt devices, and we found a case in which a 3.0-T scanner showed smaller artifacts than the 1.5-T scanner. We aimed to clarify whether this claim is true or not. METHODS: Under permission of our institutional Ethical Committee, 2 volunteers underwent imaging studies using 3.0-T and 1.5-T scanners from GE, Siemens, and Philips. Four MRI-resistant adjustable shunt devices-proGAV2.0 (Miethke), Codman Certas Plus (Johnson & Johnson), Polaris (Sophysa), and Strata MR valve (Medtronic)-were fixed on the left temporal scalp. Routine MRI images, including T1-and T2-weighted imaging, fluid-attenuated inversion recovery, diffusion-weighted imaging (DWI), and magnetic resonance angiography (MRA), were obtained. We also compared artifacts between a 3.0-T scanner and a-1.5 T scanner in 4 patients. RESULTS: The 3.0 T-scanners showed smaller artifacts than the 1.5-T scanners on DWI and MRA images for all shunt devices and scanners. In the other sequences, the results depended on the MRI scanner manufacturer; however, the GE 3.0-T scanner showed smaller artifacts in every sequence. This was also true in the 4 clinical cases. CONCLUSIONS: A 3.0-T scanner is recommended over a 1.5-T scanner for patients with MRI-resistant adjustable shunt devices in the diagnosis of acute ischemic condition or when using GE scanners.