Objective: To evaluate published papers concerning dural arteriovenous fistula involving the superior sagittal sinus (SSS dAVF) treated with endovascular intervention.

Methods: A literature review was performed to identify studies reporting the clinical characteristics, vascular anatomy, endovascular techniques, embolic materials, angiographical result, and outcomes of SSS dAVF.

Results: The analysis consisted of 40 case reports or series, comprising a total of 51 cases of SSS dAVF treated with endovascular intervention. Clinical symptoms included hemorrhage (29.4%), infarction (17.6%), and seizure (7.8%). The arterial supply included the middle meningeal artery (MMA) (100%), superficial temporal artery (STA) (62.7%), and occipital artery (OA) (49.0%). Bilateral MMAs supplied in 78.4% of the cases. A pial arterial supply was observed in 21.6% of the cases. Stenosis or occlusion of the sinus was seen in 37.3% of the cases. The distribution of the Borden classification was as follows: I (7.8%), II (37.3%), and III (54.9%). The endovascular techniques were transvenous embolization (TVE) alone (11.8%), transarterial embolization (TAE) alone (74.5%), and a combination thereof (13.7%). The types of embolic materials for TAE were a coil (25.5%), n-butyl-2-cyanoacrylate (NBCA) (33.3%), and Onyx (45.1%). The arterial pedicles for TAE included MMA (86.3%), STA (17.6%), and OA (9.8%). Direct surgical exposure for the alternative endovascular access was performed to the SSS (5.9%), MMA (3.9%), STA (5.9%), and OA (3.9%). Sinus angioplasty with or without stenting was done in 9.8% of the cases. Balloon-assisted Onyx TAE was done with proximal flow control (7.8%), collateral devascularization (5.9%), and sinus protection (3.9%). Complete occlusion was achieved in 86.3% of the cases while the number of endovascular sessions varied among patients: single (74.5%), double (15.7%), and triple (9.8%). The rate of a postoperative modified Rankin Scale (mRS) score of 0–2 was 89.3%, with morbidity and mortality rates of 7.8% and 3.9%, respectively. Two patients died, possibly due to postoperative acute SSS occlusion.

Conclusion: The current systematic review disclosed several specific results, namely, the angioarchitectures of the SSS dAVF, the relationship between classification and hemorrhagic presentation, the diversity of treatment techniques, the association between the complete occlusion rate and the SSS condition, and the difficulty of achieving curable occlusion in a single session. These findings underscore the need for the development of endovascular techniques and devices to treat this challenging lesion. Improvements in adjunctive endovascular procedures, such as balloon-assisted techniques for Onyx TAE, may help support to the safe and effective obliteration of SSS dAVF.

Objective: Mechanical thrombectomy (MT) for acute cerebral large vessel occlusion (LVO), which involves a cerebral aneurysm in the target vessel, indicates a risk of rupture of the aneurysm. Safety of the MT for LVO involving cerebral aneurysm was examined.

Methods: In all, 240 consecutive patients with LVO were treated with MT between January 2018 and December 2019. Angiographic images and clinical records of patients with LVO involving cerebral aneurysm in the target vessel were retrospectively analyzed.

Results: Cerebral aneurysms were involved in seven patients (2.9%) in the target vessels. Aspiration thrombectomy was first considered; however, five of seven lesions were difficult to manage with aspiration thrombectomy alone. The stent retriever (SR) was combined with aspiration catheter for elongated vessel lesions and distal lesions. In all lesions, good recanalization was achieved without aneurysmal rupture.

Conclusion: Aneurysms were identified in 2.9% of LVO in this study. Good recanalization was performed in all cases, and no cerebral aneurysmal rupture was observed during the perioperative period, and the procedure was relatively safe. Further case accumulation is needed for MT device selection and procedures for LVO involving cerebral aneurysm.

Objective: Subarachnoid hemorrhage due to ruptured vertebral artery dissecting aneurysm (rVADA) is associated with a high frequency of acute rebleeding and requires early treatment following onset. Parent artery occlusion (PAO) or stent-assisted coiling (SAC) embolization is selected as a treatment option according to the individual patient condition. This report is a retrospective examination evaluating the treatment outcomes for rVADA.

Methods: The subjects were 20 rVADA patients (16 men and 4 women) who underwent endovascular treatment at our institution. The mean patient age was 52.9 years. Ten patients each were allocated to the PAO group and SAC group. We evaluated and compared the following parameters: presence of hemorrhagic complications, presence of ischemic complications, requirement of retreatment, and Glasgow Outcome Scale (GOS) after 90 days.

Results: The reasons for selecting SAC were contralateral occlusion or a small diameter in three patients, the posterior inferior cerebellar artery (PICA) involvement in three patients, perforating artery from dissected lesion in five patients, and anterior spinal artery in one patient. There was no rebleeding in any patient. Symptomatic ischemic complications were observed in four patients in the PAO group and in one in the SAC group. Hyper-intense lesions in the brainstem on MRI DWI were noted in five patients in PAO group and in one in the SAC group. Retreatment was required for three patients in the PAO group and for four in the SAC group. Favorable outcomes (GOS 4, 5) after 90 days were observed for three patients in the PAO group and for eight patients in the SAC group (p = 0.0257).

Conclusion: SAC that can preserve branches is a useful treatment option for rVADA. Further studies on a greater number of subjects are required to establish the optimal dose of antiplatelet agents and anticoagulants, and for stent selection.

Objective: The purpose of this study was to investigate the efficacy of percutaneous transluminal angioplasty (PTA) for symptomatic middle cerebral artery stenosis by analyzing cerebral blood flow (CBF).

Methods: Between January 2016 and December 2018, six patients with symptomatic middle cerebral artery stenosis underwent CBF analysis by single-photon emission computed tomography (SPECT) with acetazolamide challenge before and after PTA for stenosis. They were retrospectively reviewed, and the blood flow in the area of the affected middle cerebral artery before and after angioplasty was compared.

Results: The mean stenosis rate and length of lesion before angioplasty were 76.4 ± 5.4% and 6.5 ± 2.1 mm, respectively. Balloon angioplasty without stenting was performed on all patients. The mean residual stenosis rate just after angioplasty was 45.4 ± 9.3%. No periprocedual complications developed, and there were no notable cerebral ischemic events during the postprocedural follow-up period. One patient underwent repeat angioplasty for restenosis. Although there was only a mild decrease in blood flow at rest, the cerebrovascular reserve (CVR) in the area of the affected middle cerebral artery was markedly decreased before angioplasty (mean, 3.6 ± 4.3%). After angioplasty, the CVR was significantly improved (mean, 18.0 ± 4.7%, p <0.01).

Conclusions: PTA for symptomatic middle cerebral artery stenosis can be safely performed using appropriate interventional techniques for select patients. Reduced CVR due to stenosis can be improved after angioplasty, which may reduce the risk of cerebral ischemic events.

Objective: We report a rare case of carotid artery dissection leading to fatal epistaxis 12 years after Gamma knife surgery.

Case Presentation: A 65-year-old woman underwent Gamma knife surgery for remnant pituitary adenoma adjacent to the left cavernous sinus after transsphenoidal tumor removal. After 12 years, she developed repetitive critical hematemesis subsequent to cardiopulmonary arrest, and a dissecting aneurysm of the cavernous segment of the left internal carotid artery (ICA) was identified by cerebral angiography after resuscitation and massive blood transfusion. Effective hemostasis was confirmed by endovascular embolization to occlude the affected carotid artery. She was transferred to a rehabilitation facility 1 month after onset.

Conclusion: The etiology of this pathology may have been a collapsed vasa vasorum or fibrosis of adventitia on the carotid wall adjacent to the irradiated site. We need to suspect this rare but serious pathology in patients with histories of irradiation of the cavernous region who develop massive hematemesis of unknown origin.

Objective: We report a case of acute internal carotid artery occlusion in a patient with adult-onset moyamoya disease who underwent mechanical thrombectomy and had a good outcome.

Case Presentation: A 73-year-old woman was diagnosed with moyamoya disease by asymptomatic right middle cerebral artery occlusion at 59 years of age. The patient was transported for stroke symptoms. Magnetic resonance imaging (MRI) demonstrated left terminal internal carotid artery occlusion and low-intensity signal on T2^*-weighted imaging at the occlusion site. Alteplase was administered and endovascular treatment was subsequently performed. A small-diameter microcatheter was guided to the distal end of the occlusion and angiography after deployment of a stent retriever revealed irregular stenosis. Severe stenosis remained after thrombectomy, and balloon angioplasty was added. The treatment resulted in recanalization and good outcome.

Conclusion: Adults with moyamoya disease may have accompanying atherosclerotic intracranial artery occlusion. Angiography after deployment of a stent retriever was useful for clarifying the etiology of occlusion. It is important to determine the etiology of occlusion based on the medical history or imaging findings and to select an appropriate treatment.

Objective: We report a case of coil embolization using trans-cell technique through mesh of a pipeline embolization device (PED).

Case Presentation: A 55-year-old female developed a left cavernous carotid aneurysm (CCA) with left abducens nerve palsy. The abducens nerve palsy improved gradually after PED deployment for the aneurysm. Sixty-nine days after the procedure, the patient suddenly presented with a severe headache, left abducens nerve palsy, left eyelid edema, and left pulsatile tinnitus. Digital subtraction angiography (DSA) revealed left direct carotid cavernous fistula (dCCF) due to rupture of the aneurysm, and the patient underwent endovascular treatment. A Marathon was guided into the left internal carotid artery, and a guidewire via the Marathon passed through the mesh of the PED. Then the Marathon advanced over the guidewire into the aneurysm through the mesh of the PED, with assistance of a distal access catheter and a balloon catheter. Transarterial intra-aneurysmal coil embolization using trans-cell technique was performed, and the shunt blood flow was diminished. After subsequent transvenous embolization (TVE), the shunt blood flow disappeared, and all neurological symptoms improved. When PED is deployed linearly at a diameter 0.5 mm smaller than the nominal diameter, the average strand spacing is calculated to be approximately 0.2 mm. Since PED is a braided stent, the spacing can be large. It is theoretically reasonable for Marathon with an outer diameter of 0.59 mm to pass through the mesh of the PED.

Conclusion: In some cases, trans-cell technique through mesh of PED can be performed using a small diameter microcatheter.

Objective: We report a case of acute middle cerebral artery (MCA) occlusion caused by tumor embolism.

Case Presentation: A 64-year-old man with lung cancer presented with sudden onset left-sided hemiparesis and sensory disturbance. Diffusion-weighted imaging (DWI) revealed hyper-intense foci in the right MCA territory and magnetic resonance angiography (MRA) demonstrated right MCA M2 segment occlusion. Mechanical thrombectomy (MT) was performed with Thrombolysis in Cerebral Infarction 2B recanalization. On histopathology, thrombus composed of fibrin and squamous cell carcinoma was observed. We diagnosed him with tumor embolism from lung cancer that invaded the pulmonary vein and the left atrium.

Conclusion: Tumor cells may be confirmed by pathological examination regardless of the morphology of the embolus. Pathological examination of the cerebral embolus is useful for the accurate diagnosis of ischemic stroke subtypes.

Objective: We report renal artery injury by a guidewire during coil embolization of a cerebral artery aneurysm, which was successfully treated by transarterial embolization using n-butyl-2-cianoacrylate (NBCA).

Case Presentation: A 65-year-old woman underwent coil embolization for an unruptured cerebral aneurysm, resulting in its complete occlusion. However, her blood pressure decreased during embolization and postoperative abdominal computed tomography (CT) revealed a retroperitoneal hematoma. Intraoperative video revealed that the 0.035-inch guidewire had passed deeply into the right renal artery when the guiding sheath was navigated into the abdominal aorta, suggesting renal artery perforation. Transarterial embolization using NBCA was performed immediately, which resulted in hemostasis.

Conclusion: Although renal artery perforation with a guidewire is a rare complication, it can have severe consequences. Early diagnosis with prompt and definitive hemostasis is important.

Objective: We report a case of dural arteriovenous fistula (dAVF) at the cavernous sinus treated by direct puncture of the superior ophthalmic vein (SOV) using an electromagnetic navigation system.

Case Presentation: The case involved a 70-year-old male patient who presented with mild chemosis, proptosis, and abducens palsy of the right eye. In this case, we used an electromagnetic navigation system for direct puncture of the SOV. Angiographic obliteration of the fistula was confirmed and the visual symptoms recovered well after surgery. There were no complications associated with direct puncture of the SOV using the electromagnetic navigation system.

Conclusion: Direct puncture of the SOV to obliterate a dAVF is a possible alternative choice of treatment when the usual transvenous access route fails. To reduce the risk of complications, an electromagnetic navigation system is useful.