Partially thrombosed giant basilar tip aneurysm that remarkably decreased in size after stent-assisted coiling associated with the disappearance of neovascularization.

Endovascular treatment for partially thrombosed giant basilar tip aneurysms has not been established because of its low cure rate and numerous associated comorbidities. Although some authors reported the growth mechanism of partially thrombosed aneurysm, there is no report for the process of its shrinkage after treatment. We describe a case of a partially thrombosed giant basilar tip aneurysm presenting with disturbance of consciousness because of a mass effect and brain edema. The patient underwent stent-assisted coiling using a low-profile visualized intraluminal support stent (Terumo). Although pre-operative magnetic resonance imaging (MRI) and angiography revealed prominent neovascularization of the inner aneurysmal layer, this vessel was absent on follow-up angiography 1 month after treatment. Repeat angiography demonstrated the gradual recanalization of the aneurysm. However, repeat MRI examinations showed remarkable shrinkage of the thrombosed aneurysm, and the complete disappearance of the thrombosed component was noted 6 months after treatment. The disappearance of neovascularization 1 month after the treatment may have contributed to the shrinkage of the thrombosed aneurysm. Stent-assisted coiling combined with alteration caused a hemodynamic change in this aneurysm, and the flow-diverting effect might have controlled this partially thrombosed giant aneurysm.

[Percutaneous Transluminal Sinus Stenting for Sigmoid Sinus Stenosis Associated with Transverse-Sigmoid Sinus Dural Arteriovenous Fistula:A Case Report].

We report a case of transverse sinus-sigmoid sinus dural arteriovenous fistula(T-S dAVF)with venous flow congestion, which was accompanied by sigmoid sinus stenosis and treated with percutaneous transluminal sinus stenting. A 76-year-old woman presented with dementia and disturbance of consciousness. Magnetic resonance imaging(MRI)on admission revealed subcortical edema in the left occipital lobe and angiography demonstrated a left T-S dAVF with right transverse sinus occlusion and sigmoid sinus stenosis. Hemodynamics of the shunt flow from several feeders demonstrated retrograde flow to the straight sinus and superior sagittal sinus, and antegrade flow into the left internal jugular vein. These hemodynamics caused cortical venous congestion and intracranial venous hypertension. We performed percutaneous transluminal sinus stenting for left sigmoid sinus stenosis. Immediately after stent placement, retrograde shunt flow to the straight sinus and superior straight sinus dramatically disappeared and cortical venous congestion improved. Follow-up angiography 1 year after treatment showed neither new development of T-S dAVF nor re-stenosis of the stent in the left sigmoid sinus, although some shunt flow remained. Percutaneous transluminal sinus stenting for sinus stenosis associated with dAVF appears effective to improve venous congestion and intracranial venous hypertension.

[A Case of Tentorial Dural Arteriovenous Fistula Treated with Transvenous Embolization Using NBCA].

We report a case of tentorial dural arteriovenous fistula(dAVF)treated with transarterial and transvenous embolization using n-butyl-2-cyanoacrylate(NBCA). A 70-year-old man presented with dysarthria and trunk ataxia. Computed tomography(CT)on admission revealed right cerebellar hemorrhage. Right external carotid angiography demonstrated a tentorial dAVF fed by the marginal tentorial artery, petrosquamous branch of the middle meningeal artery, ascending pharyngeal artery, and artery of foramen rotundum. Right internal carotid angiography demonstrated a shunt fed by the meningohypophyseal trunk. The draining vein was the right basal vein with a varix, which drained into the straight sinus. Thin-slice axial images on magnetic resonance angiography demonstrated a shunt point located on the right tentorial incisura. The lesion was diagnosed as Cognard type IV tentorial dAVF. It was initially treated with transarterial embolization using 25% NBCA, which was injected into the marginal tentorial artery and the petrosquamous branch of the middle meningeal artery. However, owing to partial persistence of the shunt after the procedure, transvenous embolization using NBCA was performed. A microcatheter was navigated through the straight sinus into the basal vein, and a balloon catheter was also navigated to the confluence of the straight sinus and the basal vein to interrupt blood flow and prevent the NBCA from flowing back to the sinus. 80% NBCA was injected into the draining vein near the shunt point. Angiography performed immediately after the procedure revealed complete occlusion of the shunt, and postoperative CT showed no evidence of hemorrhage. Transvenous embolization of tentorial dAVF can be an effective method if a microcatheter can be safely advanced close to the shunt point.

[A Case of Percutaneous Transluminal Angioplasty and Stenting for Dacron Bypass Graft Stenosis with Cerebral Infarction].

A 62-year-old man presented to the emergency room with mild dysarthria and right motor weakness. The patient was diagnosed with aortic dissection (DeBakey type III) in the cardiovascular department of our institution two years ago and was then treated with left carotid-bilateral subclavian bypass with collagen-seated Dacron graft followed by thoracic endovascular aortic repair (TEVER) with stent-graft placement. Magnetic resonance imaging on admission showed cerebral infarction with left proximal middle cerebral artery occlusion in the left cerebral hemisphere. Three-dimensional computed tomography angiography (3D-CTA) demonstrated a stenotic lesion at the anastomosis of the right subclavian artery and the bypass graft. It also showed the partial left common carotid artery, suggestive of an endoleak in the thoracic stent graft. The patient was diagnosed with artery-to-artery embolism due to bypass graft stenosis or endoleak in the thoracic stent graft and was treated with conservative therapy. He gradually recovered from the neurological deficit and underwent endovascular angioplasty with a balloon-expandable stent for bypass graft stenosis by using the distal balloon protection method and the left proximal common carotid artery occlusion with coils 1 month later. One-year follow-up 3D-CTA showed good patency of the stent in the bypass graft. No recurrence of cerebral infarction was observed during the postoperative course.

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.

Carotid artery stenting for stenosis after carotid artery replacement: An illustrative case report.

Background: There are few reports on the treatment of carotid artery stenosis after arterial vessel replacement. We report and discuss an illustrative case of carotid artery stenting (CAS) performed for stenosis after carotid artery replacement. Case Description: A woman in her 20s experienced injury to the right carotid artery during an operation for removal of a carotid body tumor 6 years before presentation. The right common carotid artery and internal carotid artery were replaced with an artificial vessel graft at that time. Intraluminal stenosis in the graft was not identified 3 years after surgery; however, 4 years after surgery, stenosis was recognized at the non-anastomotic site inside the artificial vessel graft. Subsequently, antiplatelet therapy was initiated. The stenosis was noted to progress gradually in follow-up appointments. Therefore, we decided to intervene because of the patient's young age and the risk of long-term hemodynamic stress. Angiography revealed pseudo-occlusion in the artificial vessel. Percutaneous transluminal angioplasty was performed for stenosis with distal protection; subsequently, CAS was performed. The patient was discharged without neurological deficits 4 days after the operation, and no apparent restenosis was observed as of the 1-year follow-up. Conclusion: Stenosis after cervical artery replacement can be safely treated with CAS. Inflation pressure and stent should be selected according to the pathology of the stenosis.

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.

Two patients of visual disturbance and optic perineuritis after placement of a flow diverter.

The pathogenesis of new visual symptoms after flow diverter stent placement in the ophthalmic artery for internal carotid artery aneurysms remains unclear. We report two cases of patients who developed visual field disturbance and decreased visual acuity following flow diverter placement. The "doughnut sign" was found around the optic nerve on magnetic resonance imaging. The patients had progressive visual field defects and impairment on the side where the flow diverter was placed. Short tau inversion recovery coronal images showed a doughnut-shaped high-signal around the optic nerve on the affected side. Both patients were treated with steroid pulse therapy, and 1 received endovascular therapy. Their symptoms gradually improved, and the "doughnut sign" disappeared. The "doughnut sign" observed around the optic nerve on magnetic resonance imaging may be found alongside visual disturbance symptoms after paraclinoid aneurysm treatment. It is recommended that short tau inversion recovery sequences be performed preoperatively in patients presenting with visual impairment and in whom the possibility of postoperative exacerbation is suspected.

Initial clinical experience using the two-stage aspiration technique (TSAT) with proximal flow arrest by a balloon guiding catheter for acute ischemic stroke of the anterior circulation.

BACKGROUND: Our initial experience using the two-stage aspiration technique (TSAT) with proximal flow arrest by a balloon guiding catheter is presented. In TSAT, aspiration is applied with the 5MAX ACE and also with the 3MAX catheter with a Penumbra aspiration pump, while arresting proximal flow by balloon inflation. METHODS: In patients treated with TSAT, clinical data including National Institutes of Health Stroke Scale (NIHSS) score at admission and the modified Rankin Scale (mRS) score at discharge, as well as procedural data including the Thrombolysis in Cerebral Infarction (TICI) score, procedural time, and complications were analyzed. RESULTS: Thirty-four consecutive patients (19 men (56%); mean age 73 years) were treated with TSAT using a balloon guiding catheter. The patients presented with a mean NIHSS score of 17.4 and 23 (68%) patients received IV tissue plasminogen activator. Median time from groin puncture to successful recanalization was 41 min (range 15-160 min). All patients were successfully revascularized; TICI 2b or better recanalization was achieved in 30 (88%) patients. No patient required an additional procedure such as use of a stent retriever. Procedure-related complications occurred in two (5.9%) patients (vessel injury and guidewire perforation). Symptomatic intracranial hemorrhage occurred in one patient and asymptomatic hemorrhagic infarction occurred in two patients. There were no cases of embolization to new territory (ENT). The mean NIHSS score at discharge improved to 6.1. Sixteen patients (47%) achieved a good outcome with an mRS score of 0-2 at discharge (mean hospitalization period 20 days). CONCLUSIONS: TSAT with proximal flow arrest by a balloon guiding catheter is an effective and safe method to achieve good clinical and angiographic outcomes. This method may reduce ENT in the direct aspiration first-pass thrombectomy (ADAPT) technique.