Rupture Risk Factors and Strategies for Unruptured Distal Anterior Cerebral Artery Aneurysms.

BACKGROUND: Distal anterior cerebral artery (dACA) aneurysms are rare. Ruptured dACA aneurysms typically present with subarachnoid hemorrhage in conjunction with intracerebral hematoma and cause neurological deterioration. This study aimed to determine their risk of rupture and examine associated factors. METHODS: We retrospectively analyzed patients with dACA aneurysms to compare patient and aneurysm characteristics between ruptured and unruptured aneurysms. Clinical outcome was used the modified Rankin scale. Univariate analyses were performed to identify rupture risk factors. RESULTS: One hundred three patients with dACA aneurysms were examined (51 ruptured and 52 unruptured). The median aspect ratio of ruptured and unruptured aneurysms was 1.69 and 1.22, respectively (P < 0.01). The median maximum diameter of ruptured and unruptured aneurysms was 5.2 and 3.1 mm, respectively (P < 0.01). The median size ratio of ruptured and unruptured aneurysms was 3.32 and 2.17, respectively (P < 0.01). Maximum diameter was <5 mm in 45.2% of ruptured dACA aneurysms. dACA aneurysm, showing size ratio >2.4 and aspect ratio >1.4, had ruptured in 71.4% and 78.6%, respectively. We suggested that these are the threshold of size ratio and aspect ratio for rupture of dACA aneurysms. A total percentatge of 78.1% of aneurysms with aspect ratio >1.4 and size ratio >2.4 had ruptured. CONCLUSIONS: Distal anterior cerebral artery (dACA) aneurysms may rupture, even when small. We found a significant difference between ruptured and unruptured aneurysms with respect to maximum diameter, aspect ratio, and size ratio. Treatment for small aneurysms should be considered based on size ratio and aspect ratio, not just size.

Ruptured Distal Middle Cerebral Artery Aneurysms-Characteristics and Strategy.

BACKGROUND: Distal middle cerebral artery (dMCA) aneurysms are very rare. Most ruptured dMCA aneurysms lead to subarachnoid hemorrhage (SAH) coexisting with intracerebral hematoma (ICH), resulting in a deteriorating state. The risk factors of rupture of dMCA aneurysms remain unknown. To elucidate the risk of rupture, we studied differences between 4 ruptured and eleven unruptured dMCA aneurysms. METHODS: We retrospectively analyzed patients diagnosed with a dMCA aneurysm according to the maximum size of the aneurysm, aspect ratio, and aneurysm size to vessel size (size ratio). RESULTS: Four patients presented with SAH coexisting with ICH, resulting in a midline shift, caused by rupture of the dMCA aneurysm. The median aspect ratio of ruptured and unruptured dMCA aneurysms was 2.38 and 1.65, respectively, with no significant difference. The median maximum diameter of ruptured and unruptured dMCA aneurysms was 2.98 and 3.78 mm, respectively, with nonsignificant difference. The median size ratio of ruptured and unruptured dMCA aneurysms was 3.13 and 1.84, respectively, being significant difference (P < 0.02). The outcomes of 4 patients having ruptured dMCA aneurysm were as follows: one patient died due to the initial attack, and the others were severely disabled due to cerebral infarction caused by vasospasm. CONCLUSIONS: Distal MCA aneurysms, even if they are small, may be likely to rupture leading to SAH complicated by ICH and result in a poor neurological state and unfavorable outcomes. We recommend aggressive treatment for dMCA aneurysms considering morphological factors such as the size ratio even if they are small and unruptured.

Pseudo-continuous arterial spin labeling with short post-labeling delay time sensitively reflects the hemodynamics of symptomatic patients with permanent large vessel occlusion before and after revascularization.

BACKGROUND AND PURPOSE: This study evaluated the feasibility of arterial spin labeling (ASL) for diagnosing hemodynamic stroke due to permanent anterior circulation large vessel occlusion. METHODS: Three-dimensional pseudo-continuous ASL data at two post-labeling delay (PLD) times (1.5 and 2.5 s) in patients with unilateral permanent middle cerebral artery (MCA) segment 1 (M1) or internal cerebral artery (ICA) occlusion were acquired during routine magnetic resonance angiography. Sixty-one patients with symptomatic occlusion (M1, 24; ICA, 37) and 69 patients with asymptomatic occlusion (M1, 21; ICA, 48) were enrolled. Regions of interest were automatically placed in the MCA region using a template. The respective scans were compared with asymptomatic M1 or ICA occlusion scans. The ratio of signal intensity (occlusion side/non-occlusion side) in the perfusion area of MCA (asymmetry index [AI]) was compared between both groups. RESULTS: In both PLD groups, AI was significantly lower in symptomatic patients than in asymptomatic patients. The receiver operating characteristic curve showed moderate capacity for the prediction of symptomatic AI in both groups (area under the curve, 0.739 and 0.712, respectively). As a result of extracranial-intracranial bypass operation in 28 symptomatic (M1, eight; ICA, 20) patients, AI was significantly higher postoperatively in the PLD 1.5 s group than in the PLD 2.5 s group. CONCLUSION: In symptomatic patients with permanent large vessel occlusion, the signal intensity ratio of pseudo-continuous ASL with short PLD sensitively reflects the hemodynamics before and after revascularization; therefore, this technique may be an alternative method in situations where PET or SPECT cannot be performed.

A Case of Intracranial Vertebral Artery Dissection Undetected by CT, MRI, and MRA at the Onset of Headache That Caused Subarachnoid Hemorrhage Seven Days Later.

Objective: We report a patient with normal imaging findings at the onset of preceding headache who developed subarachnoid hemorrhage (SAH) due to intracranial vertebral artery dissection 7 days later. Case Presentation: A 51-year-old woman with a history of chronic headache visited our emergency outpatient department with a complaint of mild to moderate right nuchal pain. CT, MRA, and MRI (diffusion-weighted image, T2-weighted image, FLAIR, MR cisternography, and basi-parallel anatomical scanning) were normal. Seven days later, she was admitted to our hospital with sudden disturbance of consciousness. CT revealed SAH and CTA demonstrated dilatation of the right vertebral artery (VA). The dilated lesion with an intimal flap on the right VA proximal to the posterior inferior cerebellar artery was confirmed on DSA. The dilated lesion and the proximal VA were occluded endovascularly using coils. The condition of the patient improved gradually, and she was transferred to the rehabilitation hospital on day 45 with a modified Rankin Scale score of 2. Conclusion: The clinical course of the presented case, although rare, should be kept in mind in daily clinical practice.

Non-Sinus-Type Laterocavernous Sinus Dural Arteriovenous Fistula Treated by Transarterial Venous Coil Embolization: A Case Report.

Objective: Laterocavernous sinus dural arteriovenous fistulas (DAVFs) are rare and not always accessible transvenously due to their angioarchitecture. We report a case of non-sinus-type laterocavernous sinus DAVF treated by endovascular transarterial venous coil embolization. Case Presentation: A 78-year-old woman was admitted to our hospital with loss of consciousness, right hemiparesis, and motor aphasia. CT demonstrated intracerebral hematoma in the left frontal lobe and subarachnoid hemorrhage. On CTA and MRA, a DAVF was found in the left laterocavernous sinus region associated with the accessory meningeal artery (AMA) and draining directly into the superficial middle cerebral vein. The diagnosis was confirmed by DSA, which revealed a DAVF fed by the large and straight AMA and the internal carotid artery's meningohypophyseal trunk. Endovascular transarterial venous coil embolization was performed through the AMA. A microcatheter was advanced beyond the shunt point into the origin of the draining vein, and coils were placed in the venous and arterial sides of the fistula. The fistula was completely occluded, and 15-month follow-up angiography demonstrated stable obliteration of the fistula. Conclusion: Transarterial venous coil embolization may be a treatment option for non-sinus-type laterocavernous sinus DAVF with a large fistula size and a large and straight feeding artery.

Outcome and effect of endovascular treatment in stroke associated with acute extracranial internal carotid artery occlusion: Single-center experience in Japan.

BACKGROUND: Positive data from several randomized controlled trials (RCTs) of endovascular treatment (EVT) for acute ischemic stroke (AIS) patients with anterior circulation large vessel occlusion (ACLVO) have emerged. However, little evidence exists on EVT for acute extracranial internal carotid artery (EC-ICA) occlusion. We therefore analysed the outcome and effect of EVT on AIS due to ACLVO caused by EC-ICA occlusion, including tandem occlusion compared with that caused by pure intracranial artery occlusion. METHODS: A total of 135 consecutive AIS patients with ACLVO between July 2014 and December 2017 were identified. We retrospectively analysed the efficacy of EVT for ACLVO after introducing a stent retriever (SR). We classified ACLVO into the following categories: group A, intracranial artery occlusion without EC-ICA occlusion (pure intracranial artery occlusion), and group B, ipsilateral EC-ICA occlusion with/without intracranial artery occlusion. RESULTS: In total, 65 patients were enrolled. Group A comprised 71% (46/65) of all cases. No difference was observed in terms of age, National Institute of Health Stroke Scale (NIHSS) score, Alberta Stroke Program Early Computed Tomography Score-Diffusion Weighted imaging (ASPECTS-DWI), several clinical time intervals, rate of successful revascularization (74% versus 84%), and rate of functional independence (42% versus 39%) between groups A and B. In all patients, an ASPECTS-DWI ≥6 and an onset-to-door time ≤6 h were associated with good outcome, whereas intracranial artery occlusion without EC-ICA occlusion (pure intracranial artery occlusion) was not. CONCLUSIONS: The outcomes support the efficacy of EVT in stroke associated with acute EC-ICA occlusion. In the EVT of AIS due to ACLVO, there was no significant difference in the results between ipsilateral EC-ICA occlusion with/without intracranial artery occlusion and intracranial artery occlusion without EC-ICA occlusion (pure intracranial artery occlusion).

[Successful Treatment of Repeated Bilateral Middle Cerebral Artery Occlusion by Performing Mechanical Thrombectomy in a Patient with Trousseau Syndrome].

We report a patient with Trousseau syndrome who presented with repeated acute middle cerebral artery (MCA) occlusion, which was successfully treated by performing mechanical thrombectomy. A 66-year-old man with a lung lesion and abdominal lymph node swelling experienced a sudden onset of left hemiparesis. Magnetic resonance angiography (MRA) revealed a right MCA occlusion. Perfusion-weighted imaging revealed reduced cerebral blood flow in the right MCA territory. Complete recanalization of the occluded vessel was achieved by performing mechanical thrombectomy, and his symptoms remarkably disappeared. Twenty days after the procedure, he experienced right hemiparesis and total aphasia. MRA revealed a left MCA occlusion, which was located on the contralateral side of the first occlusion. The second mechanical thrombectomy was successfully performed, and complete recanalization was successfully achieved. Right hemiparesis improved after the procedure. Histological examination of the retrieved clots revealed coagulated fibrin and platelets. Cytodiagnosis of pleural effusion revealed adenocarcinoma, and he was diagnosed with lung adenocarcinoma and cancerous pleurisy. Trousseau syndrome was the presumed primary cause of the patient's tendency for thrombogenesis. To the best of our knowledge, there were no reports regarding the repeated use of mechanical thrombectomy for patients with bilateral MCA occlusion caused by Trousseau syndrome. Neuroendovascular therapy can offer good neurological outcomes even in patients with malignant lesions.