"The microcatheter contrast injection technique": A novel technique to detect the proximal end of a thrombus in mechanical thrombectomy.

Background: An aspiration catheter needs to attach to a thrombus in order to achieve first-pass recanalization by mechanical thrombectomy (MT) for acute ischemic stroke (AIS), particularly that using a direct aspiration first pass technique. The meniscus sign, which is defined as meniscoid contrast opacification indicating the proximal edge of a thrombus, has been suggested to contribute to successful recanalization. In some cases, the meniscus sign is not detected following an injection of contrast medium through a guiding catheter. To precisely identify the location of a thrombus, we use "the microcatheter contrast injection (MCI) technique," which accurately shows the proximal edge of a thrombus. We herein introduce this novel technique and discuss its efficacy in MT. Methods: In cases without the meniscus sign, a microcatheter was advanced to the distal end of contrast opacification, and contrast medium was injected through the microcatheter to detect the meniscus sign. An aspiration catheter was then advanced to the thrombus indicated by the meniscus sign and slowly withdrawn under aspiration. Results: 29 patients underwent MT for AIS using the MCI technique. Even in cases without the meniscus sign on initial angiography, the MCI technique accurately revealed the proximal edge of the thrombus. Moreover, middle cerebral artery occlusion due to atherosclerotic stenosis and displacement of the aspiration catheter and thrombus axis were detected using this technique. Conclusions: The MCI technique may effectively reveal the exact site of a thrombus and increase the success rate of first-pass recanalization.

Angioarchitecture of the hemorrhagic developmental venous anomaly with stenosis of the collecting vein and cavernous malformation: a case report.

We herein report a case of developmental venous anomaly (DVA) with venous congestion caused by stenosis of the collecting vein that presented with intracerebral hemorrhage (ICH). A 74-year-old woman was referred to our hospital a few days after the onset of motor aphasia. Computed tomography (CT) and magnetic resonance imaging (MRI) showed ICH in the left frontal lobe. Angiography revealed DVA in the left frontal lobe in the late venous phase. Stenosis of the collecting vein of DVA at the entrance to the superior sagittal sinus was detected and accompanied by cavernous malformation (CM) beside DVA. Cone-beam CT revealed the absence of the left septal vein and hypoplastic transverse caudate veins. The patient was treated by blood pressure management and no additional neurological symptoms were detected. DVA develops to compensate for the absence of pial or deep venous systems, and generally benign and clinically asymptomatic. However, the outflow restriction of DVA causes chronic venous hypertension and the formation of CM. These abnormalities are considered to occur during post-natal life and may result in ICH. The risk of hemorrhage needs to be considered in cases of DVA with restricted venous outflow or CM.

Cerebral Infarction Due to Occlusion of Main Trunk of Middle Cerebral Artery in Patient with Accessory Middle Cerebral Artery.

The existence of an accessory middle cerebral artery (AMCA) usually has no pathological significance. Three patients developed cerebral infarction due to thromboembolic occlusion of the main trunk of the middle cerebral artery (MCA). In these patients, AMCA originating from the anterior cerebral artery was intact, and ran to the lateral side along the main MCA. Emergency endovascular treatment to remove the thrombus in the main MCA was performed, and MCA was recanalized. In one patient, the main MCA re-occluded and cerebral infarction developed on the next day. The diameter of AMCA is commonly smaller than that of the main MCA. Therefore, volume of ischemic region depends on the collateral blood flow to the left MCA territory by AMCA. Once an anomalous MCA is detected in a patient with cerebral infarction involving the MCA territory, close examinations to assess the anatomy of both the main and anomalous MCA are mandatory.

Carotid artery stenting for spontaneous internal carotid artery dissection presenting with hypoglossal nerve palsy: A case report.

Background: Some studies reported cases of internal carotid artery (ICA) dissection (ICAD) that was treated by carotid artery stenting (CAS). Symptoms of ICAD resulting from the lower cranial nerve palsy are rare and the treatment strategy is not clearly defined. We report a patient with ICAD showing hypoglossal nerve palsy alone that was treated by CAS. Case Description: A 47-year-old man presented with headache, dysphagia, dysarthria, and tongue deviation to the left. He had no history of trauma nor any other significant medical history. Axial T2-CUBE MRI and MRA showed dissection of the left ICA accompanied with a false lumen. These findings indicated that direct compression by the false lumen was the cause of hypoglossal nerve palsy. Although medical treatment was continued, symptoms were not improved. Therefore, CAS was performed to thrombose the false lumen and decompress the hypoglossal nerve. His symptoms gradually improved after CAS and angiography performed at month 6 showed well-dilated ICA and disappearance of false lumen. Conclusion: CAS may be an effective treatment for the lower cranial nerve palsy caused by compression by a false lumen of ICAD.

Bow hunter's syndrome treated by anterior decompression with fusion: A case report.

Background: Bow hunter's syndrome (BHS) is a rare condition induced by occlusion or compression of the vertebral artery (VA) during head movement or rotation. Here, we report a patient with BHS effectively treated with an anterior cervical discectomy and fusion (ACDF). Case Description: A 75-year-old male experienced recurrent embolic strokes to the posterior circulation. This was attributed angiographically to transient stenosis of the right VA due to a right-sided C5-C6 osteophyte when the head was rotated to the right; the stenosis was improved when the patient rotated his head to the left. The patient successfully underwent a C5-C6 ACDF for removal of the right-sided lateral osteophyte which resulted in no further transient right-sided VA occlusion. Conclusion: Following a C5-C6 ACDF for removal of a right lateral osteophyte, a 75-year-old male's intermittent right-sided VA occlusion responsible for multiple posterior circulation emboli was relieved.

Usefulness of rapid MR angiography using two-point Dixon for evaluating carotid and aortic plaques.

PURPOSE: Recently, various magnetic resonance imaging (MRI) modalities have been developed to easily detect carotid and aortic plaques, but these techniques are time-consuming and vulnerable to motion artifacts. We investigated the utility of a gradient echo MRI technique known as liver acquisition with volume acceleration flexible (LAVA-Flex) to detect carotid and aortic atherosclerotic plaques. METHODS: Ten patients who underwent carotid endarterectomy (CEA) were assessed regarding the correspondence between LAVA-Flex findings and the histopathology of excised carotid plaques. In addition, 47 patients with cryptogenic ischemic stroke underwent LAVA-Flex and transesophageal echocardiography (TEE) for detection of embolic sources in the thoracic aorta. We analyzed the relationship between the thickness of the aortic plaque measured by TEE and the presence of high-intensity lesions on LAVA-Flex. RESULTS: Nine of 10 patients (90.0%) who underwent CEA showed a high-intensity carotid lesion on LAVA-Flex, which corresponded pathologically to plaques containing large lipid cores and hemorrhage. Twenty-four (51.1%) of 47 cryptogenic stroke patients showed a high-intensity lesion in the thoracic aorta on LAVA-Flex; of these, 21 (87.5%) also demonstrated a large plaque (thickness ≥4 mm) on TEE. Twenty-two (95.7%) of 23 patients without a high-intensity lesion on LAVA-Flex demonstrated no large plaque on TEE. LAVA-Flex had a sensitivity of 95.5% and a specificity of 88.0% in patients with large plaques. CONCLUSION: This study showed that LAVA-Flex successfully detected carotid and aortic plaques. This imaging technique may be useful to rapidly diagnose and evaluate carotid and aortic plaques, which are critical risk factors for aortogenic stroke.

Characteristics and Management of Ruptured Aneurysms Originating from the Penetrating Artery of the Distal Middle Cerebral Artery.

We report a rare case of an aneurysm originating from the penetrating artery of the distal middle cerebral artery (MCA). A 76-year-old man without a notable past history presented with sudden-onset severe headache, left hemiparesis, and a decreased level of consciousness. Computed tomography (CT) revealed subarachnoid hemorrhage (SAH) with intracerebral hemorrhage (ICH) in the right temporal lobe extending into the ventricle. Contrast-enhanced CT (CE-CT) demonstrated a focus of contrast enhancement (CE) adjacent to the hematoma in the right frontal lobe. An aneurysm fed by a penetrating artery branching off from the right distal MCA was found on angiography. The patient underwent emergency resection of the aneurysm and hematoma evacuation. Histological analysis revealed that arterial dissection may be an associated factor in the pathogenesis of this peripheral aneurysm formation. A focus of CE within or adjacent to the hematoma may be useful for diagnosing this peripheral aneurysm. ICH can result in a life-threatening situation. Therefore, microsurgery may be the first treatment choice for aneurysms in this location.

Hemifacial spasm caused by vertebral artery aneurysm treated by endovascular coil embolization.

BACKGROUND: Hemifacial spasm (HFS) caused by vertebral artery (VA) aneurysms is rare. Several cases of HFS caused by VA aneurysms treated by endovascular parent artery occlusion (PAO) have been reported. Recently, we treated a rare case of HFS caused by a saccular VA aneurysm at the bifurcation of the posterior inferior cerebellar artery (PICA), which was successfully treated by endovascular coil embolization, preserving the parent artery, and PICA. We discuss endovascular treatment for HFS induced by VA aneurysms with a literature review. CASE DESCRIPTION: A 59-year-old man presented with the left HFS persisting for 2 months. Magnetic resonance imaging revealed a left saccular VA-PICA aneurysm and demonstrated that a left facial nerve was compressed by the aneurysm at the root exit zone. Angiography revealed that the PICA was branching from the aneurysm neck. Endovascular coil embolization was performed using the balloon remodeling technique to preserve the left VA and PICA. HFS disappeared after treatment. CONCLUSION: Although microvascular decompression was commonly accepted for the standard treatment of HFS, coil embolization of aneurysms without PAO may be an effective treatment for HFS caused by VA aneurysms.

Morphological Change of Cerebral Aneurysm with Possible Pseudoaneurysm at A2/3 of the Anterior Cerebral Artery on Three-dimensional Computed Tomographic Angiography.

Intracranial pseudoaneurysm formation due to a ruptured nontraumatic aneurysm is rare. We describe a case of ruptured aneurysm, which showed morphological change on radiological examinations. An 83-year-old woman developed subarachnoid hemorrhage (SAH) with ventricular rupture and intracerebral hematoma in the corpus callosum. Contrast-enhanced computed tomography (CE-CT) demonstrated an aneurysm at the right A2/3 junction of the anterior cerebral artery. CE-CT repeated 17 h after the initial one showed shortening of the lesion on both three-dimensional and raw images. The aneurysm was surgically clipped. In cases of SAH with a hematoma or thick SAH, there is a possibility that a pseudoaneurysm will form at the tip of the true aneurysm in an adjacent thrombus or existence of intraluminal thrombus. The morphology may change during the period between initial radiological evaluation and the operation in these cases. We should be aware that the intraoperative findings or subsequent radiological findings might be different from those observed on preoperative radiological examinations.

Bilateral Chronic Subdural Hematoma Presenting with Pseudo-Subarachnoid Hemorrhage Sign on Computed Tomography.

BACKGROUND: On rare occasions, cisterns are demonstrated as high-density areas on computed tomography (CT) and misdiagnosed with subarachnoid hemorrhage (SAH). This false-positive finding is called pseudo-SAH. PATIENTS AND METHODS: From April 2014 to August 2018, a total of 161 patients with chronic subdural hematoma (CSDH) were treated in our hospital. For these cases, the existence of a pseudo-SAH sign on CT was retrospectively examined. RESULTS: One patient with bilateral CSDH showed pseudo-SAH and a further examination to evaluate vascular abnormalities causing true SAH was necessary. In three patients, the Sylvian fissures were demonstrated as high-density areas due to an atherosclerotic middle cerebral artery; however, the condition was not misdiagnosed with SAH. CONCLUSION: In cases of CSDH, there is a possibility that CT demonstrates a pseudo-SAH sign. In such cases, close examinations to exclude true SAH are mandatory.

De novo Aneurysm Formation on Internal Carotid Artery at Origin of Thick Posterior Communicating Artery: 7 Years after Transient Occlusion of Contralateral Internal Carotid Artery.

The incidence of de novo intracranial aneurysm formation has been reported to be 0.84% per year. It is rare for de novo aneurysm formation to be observed on serial radiological examinations. A 64-year-old male with a history of right internal carotid artery (ICA) occlusion 7 years ago had subarachnoid hemorrhage (SAH) due to a ruptured left ICA aneurysm at the bifurcation of the posterior communicating artery (PComA). At the time of ICA occlusion, the left PComA was thick, about 3.0 mm in diameter, and no aneurysm was detected on radiological examinations. Thirty-eight months later, a small aneurysm was detected on the left ICA on magnetic resonance angiography (MRA). At the onset of SAH, the aneurysm was larger than that observed on the previous MRA. Left frontotemporal craniotomy was performed, and the aneurysm was clipped. A thick PComA might contribute to the development of an aneurysm at its origin due to hemodynamic stress. Persistent hemodynamic stress may cause enlargement of an aneurysm in 4 years and its subsequent rupture. In patient with a thick PComA, close observation is necessary to screen for de novo formation of a cerebral aneurysm.

Persistent Primitive Hypoglossal Artery Associated With Multiple Cerebral Aneurysms.

Persistent primitive hypoglossal artery is a rare anastomosis between the carotid and basilar arteries, and sometimes associated with cerebral aneurysms. However, association of persistent primitive hypoglossal artery with aneurysms located on arteries other than persistent primitive hypoglossal artery itself or posterior circulation is very rare. An 80-year-old woman suffered from subarachnoid hemorrhage, whose angiography demonstrated aneurysms on the left middle cerebral artery and anterior communicating artery, and the left persistent primitive hypoglossal artery. The middle cerebral artery aneurysm was the origin of hemorrhage. Although repeated craniotomy was necessary for the left middle cerebral artery aneurysm, both aneurysms were successfully clipped. In our case, neither aneurysm was located on an artery related to the persistent primitive hypoglossal artery. There is a possibility that cases of persistent primitive hypoglossal artery are accompanied by cerebral aneurysms on arteries other than the persistent primitive hypoglossal artery or in the posterior circulation.

Duplicated middle cerebral artery associated with aneurysm at M1/M2 bifurcation: a case report.

BACKGROUND: A duplicated middle cerebral artery arises from the internal carotid artery and supplies blood to the middle cerebral artery territory. A duplicated middle cerebral artery is sometimes associated with an intracranial aneurysm. Most aneurysms associated with duplicated middle cerebral artery are located at the origin of the duplicated middle cerebral artery. An aneurysm located at the distal middle cerebral artery is not common. CASE PRESENTATION: We encountered a 62-year-old Asian man with duplicated middle cerebral artery associated with aneurysms at the M1/M2 junction of the duplicated middle cerebral artery and top of the internal carotid artery. CONCLUSIONS: In cases of duplicated middle cerebral artery, association with a distal aneurysm on the duplicated middle cerebral artery is rare. However, the aneurysm may be formed on the thicker middle cerebral artery due to hemodynamic stress.

Aneurysm of lenticulostriate artery in a patient presenting with hemorrhage in the caudate nucleus and lateral ventricle-delayed appearance and spontaneous resolution.

BACKGROUND: An aneurysm of distal lenticulostriate artery is very rare. The natural course and management of this rare aneurysm are not clear. CASE DESCRIPTION: An 81-year-old woman developed consciousness disturbance. Computed tomography revealed hemorrhage in the right caudate nucleus and lateral ventricles. Three-dimensional computed tomographic angiography demonstrated only an aneurysm at the basilar artery. On angiography, on the sixth day, an aneurysm at the right lenticulostriate artery was demonstrated. Then, the aneurysm disappeared on three-dimensional computed tomographic angiography on the 15th day. Subsequent radiological examinations revealed no vascular anomaly in the right lenticulostriate artery. CONCLUSION: An aneurysm at this location can show dynamic changes based on radiological findings. Close radiological observation is necessary.

Dissecting Vertebral Artery Aneurysm Presenting Regrowth After Stent-Assisted Coil Embolization in Acute Stage.

For a case of dissecting vertebral artery aneurysm (DVAA) in a dominant vertebral artery (VA) or posterior inferior cerebellar artery (PICA)-involving lesion, stent-assisted coil embolization (SACE) is an effective technique to preserve blood flow of the VA. A 41-year-old man presented with subarachnoid hemorrhage. Angiography demonstrated DVAA on the left VA just distal to the PICA, and the right VA was thinner than the left. For this case, SACE was performed to preserve the left VA and PICA. On the 10th day, angiography showed recurrence of the dissection. The dissected portion had thickened and extended to both distal and proximal sides involving the PICA origin and proximal portion to the PICA. A second endovascular embolization was performed and the recurrent dissecting aneurysm was embolized including the main VA cavity. In cases of DVAA, there is a possibility of recurrence after SACE, if a dissecting cavity remains unembolized. Therefore, total embolization is necessary under close observation from multiple angles, including the down-the-barrel view.

Thromboembolic complications during endovascular treatment of ruptured cerebral aneurysms.

Background In cases of subarachnoid hemorrhage due to aneurysm rupture, the administration of an anticoagulant or antiplatelet agent involves the risk of rebleeding from the aneurysm. There is a possibility of inducing thromboembolic events during the endovascular embolization of ruptured cerebral aneurysms. Patients and methods From April 2006 to March 2017, we treated a total of 70 patients with ruptured cerebral aneurysms with an endovascular technique. Among them, five patients (7.1%) showed intra-arterial thrombus formation. The aneurysms were located at the anterior communicating artery and basilar artery in two patients each, and on the internal carotid artery at the bifurcation of the anterior choroidal artery (AChoA) in one. In these patients, the clinical course, radiological findings, and management were retrospectively reviewed. Results Thrombus formation was observed in the posterior cerebral artery, anterior cerebral artery (A2), AChoA, and middle cerebral artery. The timing of thrombus formation was during coil delivery in four cases, and guiding catheter advancement in one. As for thrombus management, for all patients, administrations of heparin and antiplatelet agents were performed. For four patients, urokinase injection into the affected arteries was added after the completion of embolization. Cerebral infarction was postoperatively identified in two patients, but no hemorrhage was noted. Conclusion Administrations of heparin and antiplatelet drugs should be performed appropriately during procedures, and close observation of the arterial condition on angiography is necessary. Once thromboembolism occurs during the endovascular embolization of ruptured cerebral aneurysms, adequate heparinization, and antiplatelet therapy should first be performed.

Pseudoaneurysm at M3 of the middle cerebral artery: Morphological changes on serial radiological examinations.

A 20-year-old man presented with consciousness disturbance and hemiparesis, and computed tomography demonstrated subarachnoid and intracerebral hemorrhage. Angiography on admission demonstrated a slight irregularity of the middle cerebral artery (MCA) branch. Angiography on the 12th day showed a suspicious lesion at M3 of the left MCA. Angiography performed 24 days after the onset disclosed an aneurysm at M3. The aneurysm was trapped and resected after superficial temporal artery-MCA bypass. Pathological examinations revealed that this distal aneurysm was a pseudoaneurysm without vascular components in its dome. Although a lesion that may cause subarachnoid or intracerebral hemorrhage was not detected on the initial angiography, repeated examinations revealed the atypical vascular lesion in distal MCA.

Agenesis of the Left Internal Carotid Artery Associated with Dolichoectatic Intracranial Arteries.

A 28-year-old man without a significant medical history visited our hospital complaining of a headache. Computed tomography (CT) demonstrated thick, calcified vertebral artery (VA) and basilar artery (BA), despite the patient being young. Magnetic resonance angiography demonstrated the absence of the left internal carotid artery (ICA). The right ICA, the bilateral VA, and the BA were well developed and dolichoectatic. CT revealed the absence of the carotid canal on the left side. The condition was diagnosed as congenital agenesis of the left ICA with dolichoectatic changes in 3 other arteries. In a young patient with thick, calcified intracranial arteries, close examination is necessary, because vascular anomalies such as ICA agenesis may exist.

Right Aortic Arch Associated with Left Internal Carotid Artery Agenesis.

We report the rare case of a right aortic arch associated with agenesis of the left internal carotid artery. A 75-year-old woman with a medical history of tetralogy of Fallot presented with dizziness. Magnetic resonance angiography revealed agenesis of the left internal carotid artery in addition to a previously diagnosed right aortic arch. The left common carotid artery was present, but it was thin. Computed tomography showed the absence of the left carotid canal. The left anterior cerebral artery was fed via the anterior communicating artery. The left middle cerebral artery was fed via a thickened posterior communicating artery originating from the left posterior cerebral artery. Although a right aortic arch and agenesis of the internal carotid artery are both very rare, association of the two conditions may occur. Both anomalies depend on the abnormal regression of the dorsal aorta during embryonic development. In such a situation, the presence of other anomalies in the cardiac or central nervous system should be taken into consideration.

Superficial Temporal Artery-Middle Cerebral Artery Bypass Using a Thick STA after Endarterectomy: A Rescue Technique.

Background and Objective Superficial temporal artery (STA)-middle cerebral artery (MCA) bypass is a procedure to reconstruct cerebral blood flow in the MCA territory. In some cases, the STA wall is thickened and the size discrepancy between STA and MCA is apparent. In such a situation, STA-MCA bypass is challenging. We present two patients who underwent STA-MCA bypass using STA in which a thickened intima was removed. We discuss the usefulness of this rescue technique. Patients and Results A patient with an atherosclerotic MCA occlusion and another with an occluded internal carotid artery are included. Endarterectomy of STA was performed before or during anastomosis, and the intima-resected STA was anastomosed to MCA. In both cases, the STA was thick and hard, and it was difficult to anastomose the STA as it was to the MCA. Patency of the bypass was confirmed by postoperative angiography. Conclusion Endarterectomy of a thickened STA might be an effective rescue technique in cases with severely atherosclerotic STA in STA-MCA bypass.