Thrombectomy for acute large vessel occlusion in posterior and anterior circulation: a single institutional retrospective observational study.

PURPOSE: Thrombectomy has been the gold standard therapy for anterior circulation occlusion; however, studies regarding thrombectomy in posterior circulation are lacking. In this study, we compared the efficiency of thrombectomy for acute large vessel occlusion between the posterior and anterior circulation at a single institution. METHODS: We retrospectively analyzed consecutive patients who underwent thrombectomy for acute large vessel occlusion at our institution between August 2014 and April 2021. Differences in the clinical background, time course, and treatment technique and outcomes were evaluated between anterior and posterior circulation occlusions. RESULTS: Overall, 353 patients (225 men and 128 women) were included: 314 patients had anterior circulation occlusion and 39 patients had posterior circulation occlusion. Between the patients with anterior and posterior circulation occlusions, the National Institutes of Health Stroke Scale (NIHSS) score (16 [12-21] vs. 29 [19-34], respectively, p < 0.001), door-to-puncture time (65 [45-99] vs. 99 [51-121] min, respectively, p = 0.018), and mortality (22 [7%] vs. 8 [20.5%] patients, respectively, p = 0.010) were significantly different; however, favorable outcome was not significantly different. CONCLUSION: Higher NIHSS score, delayed treatment, and higher mortality were observed in posterior circulation occlusion than in anterior circulation occlusion; successful reperfusion and favorable outcomes were similar between them. Similar favorable outcomes and reperfusion ratio to the anterior circulation might be achieved also in the posterior circulation; however, delayed treatment and the optimal first-pass strategy might need further improvement.

The optimal management of ruptured basilar artery dissecting aneurysms: a case series and scoping review.

The natural history of ruptured basilar artery dissecting aneurysms (BADAs) remains unclear compared to that of ruptured vertebral artery dissecting aneurysms (VADAs). In this study, we investigated the natural history and optimal management of ruptured BADAs. We identified 17 patients with ruptured BADA among 4586 patients with aneurysmal subarachnoid hemorrhage (SAH) treated in seven participating hospitals. A scoping literature review was undertaken to investigate prognostic factors. Six patients among the profiled patients (35.3%) died, all with poor SAH grades (World Federation of Neurological Societies Grade IV and V). Rebleeding after admission was observed in three patients (17.6%) with poor SAH grades. Aggressive treatment and conservative management were initiated in seven and ten patients, respectively. Patients with good SAH grades had significantly higher favorable treatment outcomes than those with poor grades (83.3% vs. 9.1%, P = 0.005). Moreover, based on a scoping review of 158 cases with ruptured BADA, including the patients from our series, approximately 90% of patients with good SAH grades had favorable outcomes. A good SAH grade and no rebleeding after admission were favorable prognostic factors (P < 0.0001 and P = 0.002, respectively). The rebleeding rates were 20.2%, 13.3%, and 6.3% for dilated, pearl and string, and stenotic lesions, respectively. We concluded that the natural history of isolated ruptured BADAs may be better than that of VADAs. Although definitive treatment, if possible, is undoubtedly important, conservative management with careful radiological follow-up for morphological changes might be a viable option for patients in good clinical condition and with non-dilated lesions.

Use of flexible endoscopic aspiration for an intraventricular small floating clot with hemorrhage: a technical note.

BACKGROUND: Although flexible endoscopy is effective for intraventricular lesions, it is less frequently used for hemorrhagic cases. In some hemorrhagic strokes, blood clots may plunge into the cerebral aqueduct and cause acute obstructive hydrocephalus. A flexible endoscope can aspirate clots and prevent acute hydrocephalus. METHODS: Here, we report four cases of hemorrhage: one of intracerebral hemorrhage and three of subarachnoid hemorrhages. RESULTS: In all cases, acute hydrocephalus was not apparent upon admission. Sudden comatose occurred; computed tomography revealed acute obstructive hydrocephalus with a strangulated clot in the cerebral aqueduct. We performed aspiration of the strangulated clot using a flexible endoscope. Consciousness improved in all cases, and acute hydrocephalus was prevented in all cases. CONCLUSION: The use of simple flexible endoscopic aspiration for clots might be a beneficial and less-invasive procedure for acute obstructive hydrocephalus caused by a small clot with hemorrhagic stroke.

Drip-and-Ship Thrombolytic Therapy for Acute Ischemic Stroke.

BACKGROUND: Neuroendovascular therapy is a common treatment for patients with acute ischemic stroke of the anterior circulation who fail to respond to recombinant tissue plasminogen activator. However, although most hospitals can provide recombinant tissue plasminogen activator therapy, many cannot perform neuroendovascular therapy. Thus, use of a drip-and-ship treatment-liaison system allowing recombinant tissue plasminogen activator-treated patients to be transferred to facilities offering neuroendovascular therapy is important. METHODS: We retrospectively analyzed 16 drip-and-ship patients transferred to our hospital for additional neuroendovascular therapy after they received intravenous recombinant tissue plasminogen activator at prior hospitals between June 2009 and March 2017. RESULTS: The mean patient age was 68 ± 17 years. Ten patients had cardiogenic embolism and 6 had atherothrombosis. Additional neuroendovascular therapy was performed in 14 patients. Median National Institute of Health Stroke Scale and diffusion-weighted image-Alberta Stroke Program Early Computed Tomography Scores before recombinant tissue plasminogen activator therapy were 14 and 8, respectively. Occluded or stenotic lesions of the cerebral arteries were detected by magnetic resonance angiography in the internal carotid artery (n = 4), middle cerebral artery (n = 10), and basilar artery (n = 3) (1 patient had tandem lesions). Mean intervals from onset-to-recombinant tissue plasminogen activator, recombinant tissue plasminogen activator-to-our hospital (door), door-to-puncture, and onset-to-recanalization were 166, 65, 32, and 334 minutes, respectively. No patients showed symptomatic intracranial hemorrhage. CONCLUSIONS: Magnetic resonance imaging/angiography performed in previous hospitals allows initiation of reperfusion therapy immediately after transfer. Thus, drip-and-ship plus neuroendovascular therapy is a safe and useful system for treatment of patients with acute infarcts.

Duplicate origin and extremely long P1 segment of the posterior cerebral artery diagnosed by MR angiography.

We present what we believe is the first report of a patient with an anomalous artery arising from the distal basilar artery and fusing with the mid-portion of an extremely long P1 segment of the left posterior cerebral artery that was diagnosed on magnetic resonance (MR) angiography. Careful review of MR angiographic images is important to detect rare arterial variations, and partial maximum-intensity-projection images aid their identification on MR angiography.

[Usefulness of Bilateral rSO2 Monitoring for Predicting Cerebral Hyperperfusion Syndrome after Carotid Artery Stenting].

OBJECTIVE: Cerebral hyperperfusion syndrome(CHS)and cerebral hyperperfusion phenomenon(CHP)induce intracranial hemorrhage and can become critical complications after carotid artery stenting(CAS). The purpose of the present study was to predict and avoid CHS after CAS using bilateral rSO2 intraoperative monitoring. METHODS: We retrospectively analyzed 100 consecutive patients who underwent CAS between January 2012 and May 2014 in our institution. We performed continuous bilateral rSO2 monitoring from anesthetic induction to the day following CAS. CHS was defined as the deterioration of neurological conditions post-CAS, no ischemic changes on post-CAS head CT or brain MRI, an increase in cerebral blood flow(CBF)and cerebral blood volume(CBV), and shortening of the mean transit time(MTT)or time to peak(TTP)on CT perfusion. To compare the CHS/CHP group and non-CHS/CHP group, we defined four parameters:rSO2 difference(rSO2 at the endpoint of the procedure-baseline rSO2), ΔrSO2 difference(affected side rSO2 difference-unaffected side rSO2 difference), rSO2 ratio(rSO2 at the endpoint of the procedure/baseline rSO2), and ΔrSO2 ratio(affected side rSO2 ratio/unaffected side rSO2 ratio). RESULTS: There were 2 CHS cases(2.2%)and 3 CHP cases(3.3%). In the CHS/CHP group, the ΔrSO2 difference and ΔrSO2 ratio were significantly higher than those in the non-CHS/CHP group(p value<0.05);however, no significant differences were found in the affected side rSO2 difference(p value=0.063)and affected side rSO2 ratio(p value=0.054)between the groups. CONCLUSION: We could promptly detect CHS and CHP in all cases by using continuous bilateral rSO2 monitoring and analysis of the ΔrSO2 difference and ΔrSO2 ratio.

Rupture of an aneurysm of the superior cerebellar artery feeding a dural arteriovenous fistula.

We experienced a very rare case of bleeding from an aneurysm of a branch of the superior cerebellar artery, which feeds a dural arteriovenous fistula (DAVF) of the posterior fossa. The aneurysm was not detected on initial angiography and 2 episodes of rebleeding resulted in deterioration of the patient's condition. Although rare, aneurysms of the pial feeding arteries should be considered as a cause of bleeding in cases of DAVF.

Agenesis of the internal carotid artery with paraclinoid-supraclinoid anastomosis and basilar artery-posterior communicating artery anastomosis diagnosed by magnetic resonance angiography.

The several types of agenesis of the internal carotid artery (ICA) are classified based on the aplastic segment of the ICA and types of collateral circulation. On magnetic resonance angiography, we incidentally found an extremely rare case in which the patient had 2 types of collateral circulation-anastomosis between the paraclinoid and supraclinoid segments of the contralateral ICA and anastomosis between the tip of the basilar artery and the posterior communicating artery. This is the first report of a case of ICA agenesis with 2 such types of collateral circulation.

Subdural and intracerebral hemorrhage caused by spontaneous bleeding in the middle meningeal artery after coil embolization of a cerebral aneurysm.

Nontraumatic acute subdural hemorrhage (SDH) with intracerebral hemorrhage (ICH) is rare and is usually caused by severe bleeding from aneurysms or arteriovenous fistulas. We encountered a very rare case of spontaneous bleeding from the middle meningeal artery (MMA), which caused hemorrhage in the temporal lobe and subdural space 2 weeks after coil embolization of an ipsilateral, unruptured internal cerebral artery aneurysm in the cavernous portion. At onset, the distribution of hematoma on a computed tomography scan led us to believe that the treated intracavernous aneurysm could bleed into the intradural space. Emergency craniotomy revealed that the dura of the middle fossa was intact except for the point at the foramen spinosum where the exposed MMA was bleeding. Retrospectively, angiography just before and after embolization of the aneurysm did not show any aberrations in the MMA. Although the MMA usually courses on the outer surface of the dura and is unlikely to rupture without an external force, physicians should be aware that the MMA may bleed spontaneously and cause SDH and ICH.

Mechanical thrombectomy in acute in-stent thromboembolism.

Following the implantation of a carotid artery stent (CAS), the aetiology of in-stent occlusion typically shifts from embolic events in the acute phase to intimal hyperplasia in the chronic phase. A man in his 70s with a history of CAS implantation (performed 5 years ago) for left internal carotid artery (ICA) stenosis was admitted to our hospital with a chief complaint of left-sided transient scotoma. MRI revealed an acute occlusion of the left ICA, and an urgent digital subtraction angiography (DSA) was performed. The DSA results suggested the presence of an in-stent thrombus instead of in-stent stenosis. An urgent endovascular thrombectomy was performed, and the thrombus was successfully retrieved from the carotid stent. Full reperfusion was achieved, and no damage occurred to the carotid stent. This case highlights the importance of thorough examination of MRI and DSA findings for accurate differentiation between the causes of vessel occlusion.

A Study of Factors Affecting Functional Outcomes in Patients With Successful Recanalization by Mechanical Thrombectomy.

BACKGROUND AND PURPOSE: Reperfusion therapy is typically performed in cases with acute cerebral infarction. Mechanical thrombectomy (MT) achieves superior recanalization and favorable outcomes. However, some patients have poor functional prognosis despite successful recanalization. We investigated factors affecting functional prognosis after MT with good reperfusion. METHODS: Among the 205 consecutive cases with ischemic stroke treated with MT at our center from January 1, 2019 to March 31, 2021, 168 with successful recanalization were included. Factors affecting early neurological improvement (ENI) and modified Rankin Scale (mRS) scores were reviewed retrospectively. RESULTS: There were 93 (55%) cases with ENI and 75 (45%) without ENI. The times from onset to recombinant tissue-type plasminogen activator administration and recanalization in ENI cases were shorter than those in non-ENI cases. However, non-ENI cases had significantly higher Fazekas grades for white matter lesions. In multivariate analysis, the Fazekas grade was related to ENI (odds ratio [OR]=0.572, 95% confidence interval [CI]=0.345-0.948). The mRS score at discharge was 0-2 in 64 cases (good outcome) and 3-6 in 104 cases (poor outcome). Patients with a poor outcome had a significantly higher age, National Institutes of Health Stroke Scale (NIHSS) score, and Fazekas grade. Multivariate analysis revealed that the NIHSS score (OR=1.073, 95% CI=1.020-1.129) and Fazekas grade (OR=2.162, 95% CI=1.458-3.205) at hospitalization affected the mRS score at discharge. CONCLUSION: There is a correlation of greater severity of white matter lesions with poorer ENI and clinical outcomes at discharge post-MT.

Recurrent Stroke with Rapid Development of Intracranial Artery Stenosis and Subsequent Successful Mechanical Thrombectomy in Essential Thrombocythemia.

Essential thrombocythemia is a myeloproliferative neoplasm. Ischemic stroke is frequently the first manifestation of essential thrombocythemia. We herein report a patient with JAK2V617 mutation-positive essential thrombocythemia who developed recurrent ischemic stroke with rapid development of intracranial artery stenosis and subsequently underwent successful mechanical thrombectomy. The high JAK2V617F allele burden in our patient (58.4%) may have affected the patient's condition. We discuss similar reports in the literature and the possible pathophysiologic mechanism of large artery involvement in these patients.

Reversed-Image Mechanical Thrombectomy for Acute Ischemic Stroke in a Situs Inversus Totalis Patient.

An 85-year-old female with situs inversus totalis presented with right hemiplegia, right facial nerve palsy, eye deviation to the left, and aphasia. Magnetic resonance imaging revealed acute ischemic lesions in the left insular cortex and the frontal lobe. Magnetic resonance angiography revealed an occlusion of the left internal carotid artery. Reversed-image mechanical thrombectomy achieved complete reperfusion in three passes within 54 minutes. Six months post-intervention, the patient could walk indoors independently. Our technique, which replicates the normal arterial anatomy by inversion and angulation, was adapted to situs inversus totalis.

Recovery of Oculomotor Nerve Palsy After Surgical and Endovascular Repair of Unruptured Internal Carotid-Posterior Communicating Artery Aneurysms.

OBJECTIVE: Unruptured posterior communicating artery (Pcom) aneurysms cause oculomotor nerve palsy (ONP). However, the time course of recovery after aneurysm repair remains unclear. We aimed to evaluate the ONP course after clipping and coiling for unruptured Pcom aneurysms. METHODS: We retrospectively reviewed the medical records of 25 consecutive patients with ONP due to unruptured Pcom aneurysms, undergoing aneurysm repair at our institution during 2010-2022. We analyzed the clinical data, angiographic results, and surgical complications. The time to ONP recovery was evaluated using the Kaplan-Meier method. RESULTS: This study included 14 patients undergoing surgical clipping and 11 undergoing endovascular coiling. The two groups exhibited no significant differences in complete or partial ONP percentage or in symptom presentation (ptosis, diplopia, ocular paralysis, pupillary light reflex disorder, or mydriasis). All patients achieved complete or partial recovery during the follow-up period. The median time to partial or complete improvement in ONP was significantly shorter for clipping compared to coiling (2 days vs. 33 days; P = 0.009). Preoperative partial and complete ONP were stratified; clipping improved significantly earlier than coiling in the complete ONP group (P = 0.010). In the early treatment group (based on the median duration of treatment), clipping resulted in earlier improvement than coiling (P = 0.014). In the small aneurysm group (based on the median of the aneurysm maximum diameter), clipping resulted in earlier improvement than coiling (P = 0.005). CONCLUSION: In ONP caused by an unruptured Pcom aneurysm, clipping may provide faster recovery than coiling, particularly in cases of early onset, complete palsy, and small aneurysms.

Fenestration of the superior cerebellar artery diagnosed by magnetic resonance angiography.

We herein report a case of fenestration of the superior cerebellar artery (SCA), which was incidentally diagnosed by magnetic resonance (MR) angiography. A 65-year-old woman was referred to our hospital for unruptured cerebral aneurysms. MR angiography revealed 2 unruptured aneurysms. It also showed fenestration of the left SCA near its origin from the basilar artery, as well as several other vascular variations: a left common carotid artery arising from the brachiocephalic trunk, and a right vertebral artery terminating to the right posterior inferior cerebellar artery. Yearly observation was chosen as a treatment strategy due to the small size of the cerebral aneurysms. According to previous reports, SCA fenestration is an extremely rare variation. This is the second case of SCA fenestration diagnosed by MR angiography in the relevant English-language literature.

Ischemic stroke in a young adult with a known epileptogenic arteriovenous malformation: illustrative case.

BACKGROUND: Brain arteriovenous malformations (AVMs) usually manifest as hemorrhages or seizures. They rarely present with ischemic symptoms, especially in young patients. We present a case of an epileptogenic AVM that led to cerebral infarction due to paradoxical embolic occlusion of the middle cerebral artery (MCA) involving the main feeder of the lesion. OBSERVATIONS: A 35-year-old male had been suffering from AVM-associated epilepsy for 10 years and was scheduled for surgery. He suddenly developed right-sided hemiconvulsions followed by hemiparalysis and impaired consciousness. Computed tomography revealed no intracerebral hemorrhage, and symptoms were initially thought to indicate epilepsy and Todd's palsy. Because of his prolonged symptoms, he underwent magnetic resonance imaging, which revealed a large cerebral infarction due to occlusion of the MCA involving the main feeder of the AVM. The patient underwent AVM resection, and the partially thrombosed nidus was completely removed. Histopathological investigation revealed a fresh thrombus in totally occluded nonarteriosclerotic feeders. He had no atrial fibrillation; however, subsequent transesophageal echocardiography revealed a patent foramen ovale, suggesting a paradoxical embolism. LESSONS: This case serves as a reminder that AVMs can present with considerable variability. Acute cerebral infarction should be considered a possible mechanism of seizures, even in patients with epileptogenic AVM.

Simplified Transradial Access for Aneurysms Treatment: A Guiding System Using Solo Distal Access Catheter and Anatomical Considerations.

OBJECTIVE: The recent shift from transfemoral access to transradial access in neurointervention has led to gaps in guiding systems. We propose a useful guiding system, the solo distal access catheter system without a conventional guiding catheter or a sheath in transradial access for aneurysms treatment. We also assessed the anatomical features required for suitable patient selection. METHODS: We retrospectively collected data from consecutive patients with aneurysms treated with the solo distal access catheter system at our institution between April 2022 and April 2023, and evaluated the anatomical factors that appeared to affect the procedure. RESULTS: Of the 20 patients who underwent transradial access, 11 were treated using the solo distal access catheter system, and 10 (90.9%) completed the procedure. No radial artery occlusion was detected. The entry angle of the target vessel ranged from 37° to 139°, and the mean proximal parent artery diameter was 9.34 ± 1.48 mm. A double subclavian innominate curve was observed in 3 of 5 patients whose target vessels were the right common carotid artery. CONCLUSIONS: Using a solo distal access catheter as a guiding system for treating aneurysm proved effective and feasible with appropriate patient selection. Anatomical assessment of the entry angle of the target vessel, proximal parent artery diameter, and tortuosity may be important factors for the success of this method.

Three cases of middle cerebral artery occlusion emergently revascularized with a balloon-expandable coronary bare stent after intravenous tissue plasminogen activator.

BACKGROUND: Revascularization with emergency stent placement in patients with acute middle cerebral artery occlusion is still controversial in Japan. METHODS: We placed balloon-expandable coronary bare stents in 3 patients in whom revascularization was not obtained after intravenous tissue plasminogen activator therapy (IV t-PA) for acute ischemic stroke (middle cerebral artery M1 occlusion). RESULTS: Patient 1 was an 87-year-old woman with left hemiplegia. Her National Institutes of Health Stroke Scale score (NIHSS) was 12, and her magnetic resonance imaging diffusion-weighted image Alberta Stroke Programme Early Computed Tomography Score (MRI DWI-ASPECTS) was 8. Adequate revascularization was not obtained with IV t-PA and adjunctive percutaneous transluminal angioplasty (PTA) for right M1 occlusion, and a stent was placed 368 minutes after onset. Her Thrombolysis in Myocardial Infarction Trial (TIMI) score was 2. After 90 days, her modified Rankin scale (mRS) score was 4. Patient 2 was a 65-year-old woman with left hemiplegia. Her NIHSS score was 16, and MRI DWI-ASPECTS was 9. A stent was placed 337 minutes after onset after IV t-PA and adjunctive PTA for right M1 occlusion. Her TIMI score was 3. After 90 days, her mRS score was 3. Patient 3 was a 61-year-old woman with left hemiplegia. Her NIHSS score was 18, and MRI DWI-ASPECTS score was 7. Arterial dissection was found after IV t-PA and adjunctive PTA for the right M1 occlusion, so a stent was placed 312 minutes after onset. Her TIMI score was 2. After 90 days, her mRS score was 0. CONCLUSIONS: Revascularization with emergency stent placement seems likely to be successful in patients with acute middle cerebral artery occlusion, but clinical symptoms do not always improve in some cases and care is needed in selecting patients for the procedure.