Dural arteriovenous fistulae of the cavernous sinus (CS) (previously often referred to indirect carotid cavernous fistulas) are rare vascular shunts involving meningeal branches and osseous branches of the external or internal carotid arteries and the CS. They typically present with ocular symptoms including pain, conjunctival injection, and proptosis. Left untreated there may be a risk of vision loss, and fistulas with cortical venous reflux through either the deep or superficial venous system may cause intracranial venous congestion or hemorrhage. Endovascular embolization is the standard treatment, and while transarterial routes may appear possible, transarterial embolization has considerable risks of ischemic complications. Conversely, transvenous routes achieve a high rate of fistula occlusion with a low risk of peri-procedural morbidity. Procedural success depends on identification of the venous outflows from the fistula and localization of the fistulous point, to select the best route of access to the CS, including the inferior petrosal sinus (IPS), intercavernous sinus, or superior ophthalmic vein, among others. Even if the IPS is not visualized, it may be possible to recanalize it to gain access to the CS. Embolization can be performed with a combination of coils, fibered coils, and liquid embolic agents, focusing on occlusion of the fistulous point or blocking high-risk venous outflow pathways. In this review we will highlight procedural pearls and potential pitfalls and our typical approach to these lesions based on illustrative examples.

Objective: The purpose of this study was to report the results of stent-assisted embolization performed at our hospital for acutely ruptured aneurysms.

Methods: This study consisted of 19 patients (4 men and 15 women) with acutely ruptured wide neck aneurysm who underwent stent-assisted coil embolization in acute stage between December 2016 and October 2020. Stent-assisted embolization in the acute stage was performed for very wide neck ruptured aneurysm only when balloon-assisted embolization was failed or was thought to be impossible. Factors related to poor clinical outcome were examined.

Results: There were nine internal carotid artery (ICA) aneurysms, four anterior communicating artery (AcomA) aneurysms, three basilar artery (BA) aneurysms, two vertebral artery (VA) aneurysms and one anterior cerebral artery (ACA) aneurysm. The stents used were one Neuroform EZ and 18 Neuroform Atlas (Stryker). The contrast of the bleb disappeared in all cases with obvious bleb. Complete obliteration was achieved in two cases, neck remnant was in ten, and body filling was in seven. Both of the complete obliteration cases developed thrombotic complications. Modified Rankin score of 0–2 was observed in eight patients (good clinical outcome), whereas that of 4–6 was observed in 11 patients (poor clinical outcome). Several factors possibly affected to poor clinical outcome were examined and only age over 80 years was statically different. Complications related to procedure occurred in five patients; two cases of in-stent thrombosis, one case each of MCA perforation, stent occlusion, and coil fracture.

Conclusion: Stent-assisted coil embolization using Neuroform EZ and Neuroform Atlas could be considered as an emergency treatment for acutely ruptured cerebral aneurysms with very wide neck. It is rarely indicated in patients with age over 80 years.

Objective: Multiple spontaneous arteriovenous fistulas (AVFs) of the external carotid artery (ECA) are rare. We present a case of multiple spontaneous AVFs treated by coil embolization using a combination of the transarterial and transvenous approach.

Case Presentation: A 59-year-old woman complained of right pulsatile tinnitus and a mass lesion at the ventral region of the right ear. 3D CTA and cerebral angiography revealed two AVFs on the superficial temporal artery (STA) with an aneurysm 9.8 mm in diameter. A balloon guiding catheter was navigated to the right STA via the right femoral artery. Another balloon guiding catheter was navigated to the right external jugular vein. The STA distal to the aneurysm was embolized with platinum coils by a transvenous approach. The STA proximal to the aneurysm was embolized transarterially and draining veins were embolized transvenously. Her symptoms were cured after endovascular embolization. MRA at 1 day and 6 months postoperatively showed no recurrence of AVFs or aneurysm.

Conclusion: Coil embolization of multiple spontaneous AVFs of the ECA using a combined transarterial and transvenous approach is a curable treatment option. Transvenous embolization of an STA distal to an aneurysm is useful.

Objective: We report a case of embolic occlusion of the common carotid artery (CCA) in which a giant thrombus was retrieved using the parallel stent retriever technique.

Case Presentation: An 84-year-old woman without anticoagulant therapy despite a history of cardioembolic stroke presented to our hospital because of left hemiparesis after developing sudden vision loss in her right eye. Emergency angiography revealed a giant thrombus in the right CCA. After arresting flow in the CCA using a balloon-guided catheter (BGC), we deployed two stent retrievers in parallel from the internal carotid artery to the CCA, and slowly retrieved them simultaneously under manual aspiration through the BGC. As a result, complete recanalization was achieved.

Conclusion: Thrombi causing acute embolic occlusion of the CCA are often too large to be completely retrieved using conventional thrombectomy techniques. The parallel stent retriever technique may be effective in such cases.

Objective: We report a case of internal carotid artery (ICA) occlusion caused by en bloc distal embolization of carotid free-floating thrombus (FFT) treated by mechanical thrombectomy.

Case Presentation: A 57-year-old woman was brought to our hospital with dysarthria, right hemiparesis, and motor aphasia. MRI and MRA revealed acute infarction due to middle cerebral artery occlusion. Carotid ultrasonography demonstrated a pedunculated mobile plaque in the left ICA. We diagnosed embolic infarction due to the carotid FFT and started medical treatment. However, on the second hospital day, the carotid FFT detached from the arterial wall en bloc, resulting in left ICA occlusion. The occluded ICA was successfully recanalized by mechanical thrombectomy.

Conclusion: FFT is associated with a high risk of embolic ischemic stroke and the primary treatment strategy must be carefully considered.

Objective: Middle meningeal arteriovenous fistula (MMAVF) is typically post-traumatic or iatrogenic in origin, but it can have an idiopathic origin in rare cases. Here, we report a case of idiopathic MMAVF complicated by segmental arterial mediolysis (SAM).

Case Presentation: The patient was a 63-year-old woman admitted to our hospital with symptoms of right pulsating tinnitus for the past 2 months. She had no significant medical history. MRI and DSA revealed a right MMAVF. Selective embolization using coils was performed. Seven years later, when she underwent laparotomy for intestinal perforation, multiple aneurysms were found in the abdominal cavity. Left hemicolectomy was performed, and an aneurysm of the gastroepiploic artery was resected. Based on a pathological examination of the aneurysm, the patient was diagnosed with SAM. Coil embolization was performed to prevent rupture.

Conclusion: This case report shows that MMAVF may be associated with SAM. Fistula embolization with coils is an effective treatment of MMAVF associated with SAM. Therefore, it is important to check for systemic diseases, such as SAM when idiopathic MMAVF is detected.

Objective: We herein report two cases of transient cerebral vasoconstriction after carotid artery stenting (CAS).

Case Presentation: An 81-year-old man presented with asymptomatic severe stenosis in the right carotid artery accompanied by a slight reduction in cerebrovascular reactivity. CAS was performed, but the patient had a generalized seizure because of transient cerebral ischemia caused by intolerance to carotid artery occlusion with balloon protection. Confusion and left hemiparesis persisted. DSA suggested cerebral ischemia due to vasoconstriction as the cause of these prolonged symptoms. A 66-year-old man presented with asymptomatic severe stenosis in the right carotid artery with slight hypoperfusion. CAS was performed. The patient developed left hemispatial neglect, dysarthria, and left hemiparesis 12 hours after the procedure. DSA revealed cerebral vasoconstriction in the responsible territory. The conditions of both patients improved within several days with medical treatment and they were discharged without neurological deficits.

Conclusion: The cases presented herein show that transient ischemic complications caused by cerebral vasoconstriction may develop after CAS.

Objective: Trousseau syndrome (TS) is a condition of systemic thrombosis generally associated with an underlying malignancy. An ischemic stroke is a representative thrombotic event. Thrombectomy is a useful procedure for the treatment of cerebral large vessel occlusion, and anticoagulation therapy is the main preventive treatment for TS. This case report describes a woman with terminal pancreatic tumor presenting with repeated occlusions of cerebral and coronary arteries necessitating multiple thrombectomies.

Case Presentation: A 67-year-old woman was admitted to our hospital with severe right hemiplegia and global aphasia. MRI revealed left M1 occlusion; therefore, a thrombectomy was performed. Her symptoms recovered completely. Body contrast CT revealed pancreatic cancer with multiple metastases, and she was diagnosed with TS. On day 4 after thrombectomy, the same neurological symptoms occurred and re-occlusion of the left M1 was confirmed. Endothelial injury was suspected, and thrombectomy was repeated. Despite continuing anticoagulation therapy, the coronary artery was occluded and she underwent percutaneous coronary intervention on day 13. To treat the primary pancreatic lesion, she was transferred to the Surgery unit on day 20.

Conclusion: Hypercoagulability associated with TS and endothelial damage due to rough procedure resulted in repeated vessel occlusions in this case. Careful thrombectomy and anticoagulation therapy with strict monitoring are needed in TS patients.

Objective: We report a case of pure acute subdural hematoma (SDH) caused by a diploic arteriovenous fistula (AVF) and it is a first case report as far as we researched it.

Case Presentation: A 19-year-old man was admitted as an emergency to our hospital with headache and nausea. CT scan on hospital admission showed a right acute SDH. Because there was no history of head trauma, MRI, MRA, and DSA were performed to identify a source of bleeding. DSA disclosed an AVF. The shunt was located between a frontotemporal branch of the middle meningeal artery (MMA) and a diploic vein, and its shunting point formed an aneurysmal sac, which was considered to have ruptured. Endovascular treatment was administered rather than surgical treatment to prevent re-bleeding because the patient was conscious and alert, CT showed a small SDH, and the left MMA near the shunting point was accessible for catheterization. A diluted mixture of 25% n-butyl-2-cyanoacrilate was injected into a left frontoparietal branch just before the shunting point and the shunt, including the aneurysmal sac, was obliterated. The patient’s postoperative course was uneventful and he was discharged without neurological deficits.

Conclusion: We experienced a patient with a pure acute SDH caused by diploic AVF. In patients with non-traumatic acute SDH, DSA is recommended to determine its underlying cause. Our review of published reports yielded few instances of non-traumatic pure acute SDH in young people. Possible causative factors should be investigated promptly and appropriate treatment provided immediately.

Objective: Transvenous embolization (TVE) is typically used in combination with the residual shunt of transarterial embolization (TAE) for the treatment of direct carotid-cavernous fistulas (direct CCFs). This report is about our additional embolization method using combination therapy.

Case Presentation: Five consecutive cases of direct CCF were presented; two were caused by aneurysms and three by head injuries. The treatment for each was started with TAE, with the addition of TVE if a shunt remained. At the time of TVE, a microcatheter positioned in the internal carotid artery passing from the cavernous sinus through the aneurysm neck or fistula was pulled back (pull-back method). It was then placed in the coil mass with TAE, and additional coils were filled. In two cases, the shunt disappeared by using only TAE, whereas it disappeared after being additionally embolized by the pull-back method in the remaining cases. All patients recovered with no postoperative complications.

Conclusion: The TAE and TVE combination therapy with the pull-back method could efficiently embolize the residual shunt after TAE.