Objective: Neurofibromatosis type 1 (NF1) is associated with vascular fragility, which results in aneurysms, arteriovenous fistulas, and dissections. Here, we describe a case of endovascular treatment of a ruptured occipital artery aneurysm that occurred after a craniotomy in a patient with NF1.

Case Presentation: A 46-year-old man with a history of NF1 underwent a right lateral suboccipital craniotomy to remove a cavernous hemangioma in the right middle cerebellar peduncle. Severe bleeding occurred in the occipital artery during the craniotomy. Due to vessel fragility, coagulation and ligation were not possible, and pressure hemostasis was achieved using cellulose oxide and fibrin glue. On postoperative day 12, the patient developed a sudden swelling on the right side of the neck as well as tracheal compression. Contrast-enhanced CT revealed a ruptured aneurysm in the right occipital artery. Transarterial embolization was performed under general anesthesia the same day. Right external carotid angiography showed an 18-mm-diameter fusiform aneurysm in the occipital artery. The aneurysm ruptured inferiorly to form a large pseudoaneurysm with significant jet flow. An arteriovenous fistula was also observed in a nearby vein. A microcatheter was inserted into the fusiform aneurysm under proximal blood flow control, and embolization was performed using coils and N-butyl-2-cyanoacrylate.

Conclusion: Compared to surgical repair of ruptured occipital artery aneurysms, endovascular treatment appears to be safe, effective, minimally invasive, and rapid. Ruptured occipital artery aneurysms in NF1 patients can cause neck swelling and airway compression and should be recognized as a potentially lethal condition.

Optimal platelet inhibition is critical in patients with carotid and intracranial artery stenosis undergoing carotid artery stenting (CAS) and intracranial artery stenting (ICS). Many reports have highlighted the importance of dual antiplatelet therapy (DAPT) in reducing adverse neurological outcomes without a significant increase in bleeding complications during CAS. DAPT has commonly used CAS and ICS, typically with aspirin and clopidogrel, but clopidogrel resistance occurs in approximately 20% of Japanese and other Asian populations. One solution to clopidogrel resistance is using adjunctive cilostazol to suppress the frequency of stroke events and in-stent restenosis after CAS. Other antiplatelet agents such as prasugrel, ticagrelor, cangrelor, and glycoprotein (GP) IIb/IIIa inhibitors are under investigation. The duration of DAPT after CAS remains controversial, as a longer duration of DAPT after CAS is associated with lower rates of readmission for stroke, but increased risk of hemorrhagic complications. Regarding antithrombotic therapy in CAS with concomitant atrial fibrillation, the use of direct oral anticoagulants plus a P2Y12 inhibitor may be suggested for the optimal safety and efficacy of antithrombotic management. For emergent CAS in acute ischemic stroke (AIS), intraprocedural DAPT loading and GP IIb/IIIa inhibitors, as necessary, may improve stent patency without increasing the risk of intracranial hemorrhage. In ICS, aggressive antiplatelet therapy based on an assessment of platelet aggregation is also important to improve clinical outcomes. In addition, rescue stenting for AIS caused by intracranial atherosclerotic stenosis-related large vessel occlusion is gaining attention. GP IIb/IIIa inhibitors have shown promise, but are not approved in Japan. In conclusion, DAPT is essential for the perioperative management of CAS and ICS. Specific perioperative antithrombotic management remains unclear, but the potential benefits of antithrombotic agents must be weighed against the corresponding increased risk of bleeding complications.

Objective: Carotid artery stenting embolic protection devices offer various options, among which distal filter protection is the simplest and easiest to handle. However, compared to balloon protection systems, distal filter protection has more embolic complications. Therefore, we explored the risk factors of distal filter protection, intending to achieve a safer carotid artery stenting. This retrospective study was conducted to identify prognostic factors following carotid artery stenting with only distal filter protection from July 2010 to June 2021.

Methods: Information on patient background, procedures and devices, and complications was collected using medical records. The data pertaining to 187 patients were analyzed after excluding the data of patients in whom other protection devices (8 cases) were used. We used FilterWire EZ as the first choice for embolic protection device and SpiderFX when the patients had difficult-to-cross lesions.

Results: The patients' mean age was 71.9 ± 6.9 years, and 72 (38.5%) were symptomatic. Symptomatic (odds ratio: 2.02, p = 0.035) and difficult-to-cross lesions (odds ratio: 3.63, p = 0.0013) were factors independently associated with symptomatic complications.

Conclusion: This retrospective single-center study established independent prognostic factors for carotid artery stenting with distal filter protection. For patients with symptomatic lesions and severe stenosis or bends that are difficult to pass through, it is necessary to be careful when performing carotid artery stenting with distal filter protection.

Objective: To report the rare case of a patient with a perianeurysmal cyst following stent-assisted coil embolization of an unruptured vertebral artery aneurysm.

Case Presentation: A 63-year-old woman underwent stent-assisted coil embolization for an unruptured vertebral artery aneurysm embedded in the brainstem (pons). Complete occlusion of the aneurysm was successfully achieved. However, subsequent magnetic resonance imaging (MRI) conducted 8 months after the procedure showed perilesional edematous changes surrounding the aneurysm, and at 20 months, cyst formation was observed in the vicinity of the aneurysm. Progressive enlargement of the cyst eventually led to the development of paralysis and dysphagia, necessitating cyst fenestration surgery. Although postoperative reduction in the cyst size was achieved, the patient experienced complications in the form of aspiration pneumonia and bacterial meningitis, which resulted in a life-threatening condition.

Conclusion: Aneurysms embedded in the brain parenchyma should be carefully followed up, recognizing the risk of perianeurysmal cyst formation after coil embolization.

Objectives: We have been performing preoperative coronary artery assessments and implementing coronary revascularization or intraoperative adjunctive therapies as needed in patients scheduled for carotid artery stenting (CAS) to prevent ischemic heart disease. In this study, we report the results of a retrospective observation of patients who underwent CAS under our treatment strategy to prevent perioperative coronary ischemic complications.

Methods: A total of 224 cases from January 2014 to December 2021 were included. Following preoperative coronary artery CTA, preoperative coronary artery treatment or intraoperative adjunctive therapy (temporary transcutaneous cardiac pacemaker [TTCP] or intra-aortic balloon pumping [IABP]) was performed based on the degree of stenosis. We analyzed the outcomes of patients treated with CAS under this strategy at our institution.

Results: Coronary artery disease was detected preoperatively in 143 cases (64%), with 91 cases (41%) indicated for coronary revascularization. Preoperative coronary artery treatment was performed in 76 cases (34%) prior to CAS, and adjunctive therapy with TTCP or IABP was provided in 28 cases (13%) during the procedure. No case developed perioperative coronary ischemic complication.

Conclusion: In patients who have undergone CAS, perioperative coronary ischemic complications might be reduced by evaluating the risk of ischemic heart disease preoperatively, performing pre-CAS coronary artery intervention based on the severity of the lesions, and administering intraoperative adjunctive therapy.

Objective: In recent years, the transradial artery approach has gained prominence and is increasingly employed in neurovascular angiography and therapy due to its safety, reduced complications, and minimal invasiveness. While various venous approaches, including the conventional transfemoral vein approach, exist for procedures such as transvenous embolization, recent reports have highlighted methods involving upper extremity cutaneous veins. However, the practicality and efficacy of these approaches remain unclear.

Case Presentations: This study presents our experience with three cases of dural arteriovenous fistulas, where transvenous embolization was performed via upper limb cutaneous veins. In all instances, the arteriovenous approach was successfully executed using a single upper extremity, leading to the successful completion of treatment.

Conclusion: This technique demonstrates significant advantages, not only in terms of its minimal invasiveness but also due to its simplicity and safety. Anticipating broader acceptance in the future, this approach offers a promising avenue for further exploration in neurovascular interventions.

Objective: Mechanical thrombectomy (MT) is the gold standard treatment for acute ischemic stroke. During these interventions, a thrombus frequently obstructs a guiding catheter. The obstructed guiding catheter should be withdrawn before distal embolism occurs; however, albeit infrequently, the thrombus occludes even a sheath introducer (SI). While conventionally new SI placement is required for continuation of treatment, we propose a viable alternative for recanalization of the occluded SI, termed vacuum-assisted delivery of thrombus (VADT), with a clinical report of our cases. The usefulness of this technique was also evaluated in simulation experiments.

Case Presentations: The VADT procedure is as follows: 1) insert a peel-away sheath, originally attached to a balloon-guiding catheter (BGC), into the SI to continuously open the hemostatic valve; 2) advance the BGC into the peel-away sheath while applying mechanical aspiration; and 3) remove the peel-away sheath/BGC assembly slowly. In a simulation environment using an artificial thrombus, we repeated the VADT procedure five times and reproducibly achieved SI reopening within only 10–20 seconds. From March 2013 to September 2022, 204 patients were treated with MT at our stroke center and SI occlusion occurred in three patients (1.5%). These events occurred exclusively in patients with extracranial internal carotid artery occlusion. All three patients with SI occlusion underwent successfully thrombus extraction in the SI using the VADT on the first try.

Conclusion: The results of clinical experience and simulation experiments strongly support VADT as a reliable option for recanalization of an occluded SI.

Antithrombotic therapy plays a crucial role in secondary prevention following ischemic stroke from the acute phase. Numerous trials, along with a meta-analysis, contributed to establishing aspirin as the primary medication for secondary stroke prevention. According to the Cochrane Database of Systematic Review 2022, initiating antiplatelet therapy with aspirin at a dose of 160 mg to 300 mg daily within 48 hours of stroke onset reduces the risk of death or dependency at the end of follow-up. Other antiplatelet drugs, such as clopidogrel, cilostazol, prasugrel, and intravenous ozagrel sodium, are also available within the Japanese Health Care Insurance System. Two pivotal trials from the 2010s underscored the effectiveness and safety of dual antiplatelet therapy (DAPT) using aspirin and clopidogrel, administered for 21 days to 3 months following acute ischemic stroke or transient ischemic attack. However, the extension of DAPT with aspirin and clopidogrel beyond 3 months may result in substantial bleeding risks. Although prasugrel offers a rapid, potent, and consistent inhibition of platelet aggregation and can be used in place of clopidogrel, there is a lack of substantial real-world clinical data on its use in acute ischemic stroke. It is important to recognize that antiplatelet drugs might not be beneficial and could even increase the risk of hemorrhagic events in cardioembolic stroke. In cases of ischemic stroke with nonvalvular atrial fibrillation, direct oral anticoagulants are the primary choice if applicable. Warfarin continues to be the anticoagulant of choice for secondary stroke prevention in patients with mechanical valve replacements. In patients who have undergone intravenous thrombolysis, antithrombotic therapy is generally delayed for up to 24 hours, although there are no definitive guidelines for the period during and immediately after mechanical thrombectomy. This review provides an overview of the current status of antithrombotic therapy for acute ischemic stroke.

Objective: The double origin of the posterior inferior cerebellar artery (DOPICA) is a rare variant of PICA. Vertebral artery dissecting aneurysm (VADA) with DOPICA is an extremely rare occurrence. Herein, we report a case of VADA located between DOPICA that was successfully treated with endovascular internal trapping.

Case Presentation: A 48-year-old male, found collapsed at his workplace, was admitted to our hospital for emergency medical assistance. Head CT revealed a subarachnoid hemorrhage (Fisher group 3), and cerebral angiography revealed right VADA with DOPICA. The VADA was located distal to the proximal component of the posterior inferior cerebellar artery (PCPICA) and just proximal to the hypoplastic distal component of PICA (DCPICA). Emergency endovascular internal trapping was performed using a total of 13 coils from the distal end of the VADA to just the distal of the branching point of PCPICA. VADA was not visualized, and antegrade flow through DOPICA to the basilar artery was confirmed. Head magnetic resonance angiography (MRA) showed antegrade flow via DOPICA, and the patient was discharged home on Day 46 with a modified Rankin Scale 0.

Conclusion: Endovascular internal trapping for VADA with DOPICA was considered useful, especially when VADA is distal to PCPICA and proximal to DCPICA.

The sphenoid wing dural arteriovenous fistulas (DAVFs) are clinically rare. They often present as non-sinus-type arteriovenous fistulas (AVFs) and may be associated with focal neurological deficits, intracranial venous hypertension, and intracranial hemorrhage. These cases are classified as lesser or greater sphenoid wing lesions. We searched the PubMed databases for studies evaluating the clinical presentation, surgical treatment, and endovascular treatment of these lesions and analyzed 37 cases from 22 papers. A total of 17 cases had lesser sphenoid wing AVFs, and the localization of the shunts could be divided into the sinus of the lesser sphenoid wing (SLSW) or the superficial middle cerebral vein (SMCV). Most SLSW AVFs drained into the cavernous sinus, but two cases drained directly into the deep middle cerebral vein via a bridging vein. All cases with shunts directly into the SMCV had reflux into the SMCV with varices. A total of 20 cases had shunts in the greater sphenoid wing, and the localization of the shunts varied, with shunt localization, and venous return morphology dependent on variations in middle fossa venous return. Most cases had shunts in the sphenobasal vein near the foramen ovale. However, some cases had shunts in the superior ophthalmic vein, sphenopetrosal vein, and laterocavernous sinus. Many were associated with cortical venous reflux. These lesions have been treated by surgical ligation of the drainage vein and transarterial or transvenous embolization. Recently, embolization has become the standard treatment for DAVFs due to advances in endovascular techniques. This paper reviewed and discussed the angioarchitecture, clinical presentation, and treatment of these lesions to clarify the characteristics of sphenoid wing DAVFs.

The clinical manifestations of dural arteriovenous fistulas (dAVFs) are highly variable and dependent on the hemodynamic properties and location of the fistula. The locations of the fistula are numerous and include the cavernous sinus, transverse–sigmoid sinus, superior sagittal sinus, inferior and superior petrosal sinuses, anterior condylar confluence, tentorium, anterior cranial fossa, middle fossa, foramen magnum, cranio-cervical junction, convexity, and spinal cord. These dAVFs can be divided into two types, “sinus type” and “non-sinus type,” based on their communication with dural shunts and cerebral veins. The sinus type involves direct communication between the arterial dural branch and one dural sinus, sometimes leading to recruitment of cortical veins. On the other hand, the non-sinus type is embedded into the dura, with the drainage always involving a cerebral vein and no communication with any sinus. Treatment options for these types of dAVFs differ; sinus-type dAVFs require normally sinus obliteration and occlusion of recruited veins, while non-sinus-type dAVFs require embolization of the drainage vein. Accurately classifying the type of fistula, sinus type or non-sinus type, is critical for developing a proper treatment plan. This review describes clinical characteristics and treatment of those non-sinus-type dAVFs involving unusual locations with illustrative cases.

Dural arteriovenous fistula (dAVF) of the foramen magnum (FM) region is rare. Moreover, the terminology of dAVF is very confusing in this region. In the narrow sense, the FM dAVF is the non-sinus-type dAVF with direct venous reflux to the medulla oblongata or spinal cord via the bridging veins (BVs) of the FM. Previous literature was systematically reviewed to investigate the clinical characteristics, angioarchitecture, and effective treatment of the FM dAVF. From the literature review, almost all the feeders of FM dAVF were dural branches. Spinal pial arteries were rarely involved as the feeder. All lesions had venous reflux to the medulla oblongata via medullary BVs. The FM dAVF is characterized by a significant male predominance and a high incidence of aggressive symptoms. The most common symptom is congestive myelopathy, followed by hemorrhage. The FM dAVF differs from the craniocervical junction (CCJ) arteriovenous fistula (AVF) and is similar to the thoracolumbar spinal dAVF. Direct surgery for the FM dAVF is effective and safe. Endovascular treatment for the FM dAVF may be more effective and has lower complication rates than that for the CCJ AVF.

Anterior cranial fossa (ACF) dural arteriovenous fistula (DAVF) is a rare lesion among cerebral DAVFs. This lesion shows significant bleeding risk because of the angioarchitecture, involving direct leptomeningeal retrograde venous drainage, as a nonsinus-type DAVF. Over the years, direct surgery has been considered the primary treatment for ACF DAVF, offering favorable clinical outcomes compared to a low complete obliteration rate with endovascular treatment and the relatively high risk of blindness due to central retinal artery occlusion with transophthalmic artery embolization. In recent years, however, significant improvements in DSA and 3D reconstruction imaging quality have allowed a much more precise understanding of the angioarchitecture of the shunt and vascular access route. In addition, advances in endovascular devices, including catheters and embolic materials, have facilitated microcatheter navigation into more distal vessels and more reliable closure of the fistulous point. Supported by such technological innovations, endovascular approaches to the treatment of ACF DAVF have been becoming successful first-line treatments. This article reviews the evolution of treatment strategies and the current status of endovascular treatment for ACF DAVF, with a particular focus on transarterial embolization.