We introduce our technique to treat dural arteriovenous fistulae (dAVFe) under sinus balloon protection. The Kaneka Shoryu 7 × 7 mm balloon was used for sinus occlusion. Initially, the balloon was inflated slowly using 1.5–2.0 mL of saline on the table. A 6F guiding catheter was navigated into the proximal portion of the lesion from the jugular vein of the affected side. The balloon catheter was introduced to the point occluding the shunt. The balloon was temporarily inflated to determine the occlusion point without occluding the outlet of the vein of Labbe. ONYX injection was started from the microcatheter located at just proximal to the shunt point under sinus balloon occlusion. ONYX penetrated the feeding arteries in an antegrade and retrograde manner. After the penetration of ONYX into each feeding artery, the inflated balloon was temporarily deflated to examine the residual shunt. If a small shunt remained, the balloon was inflated again and ONYX injection was continued. To cure dAVF, the location of the balloon is important. The guiding catheter should be placed just proximal to the shunt and the balloon catheter should be gently pulled to stabilize the balloon position.

Objective: In parent artery occlusion (PAO) for ruptured vertebral artery dissecting aneurysms (RVADA), target embolization using coils in a short segment to occlude only the vasodilated area containing the rupture point is selected as a first-choice procedure at our institute. We focused on RVADA involving the posterior inferior cerebellar artery (PICA) and evaluated the treatment results.

Methods: This study consisted of eight cases with RVADA involving the PICA which were treated between October 2007 and January 2020. Based on radiological findings such as the bleb, the rupture points were located at the affected vertebral artery (VA) distal to PICA in all cases. Target embolization, by which only coiling at the dilated segment distal to the VA was performed. We aimed to preserve blood flow to the PICA. The incidence and extent of medullary infarctions, and neurological outcome were retrospectively assessed.

Results: Regarding the diameter of bilateral VA, there were no differences in six cases while the affected VA with RVADA were larger in the remaining two cases. PICA was preserved in all cases but one in which occlusion of complementary PICA was observed. Postoperative medullary infarction was not noted. There was no rebleeding during the follow-up period. However, recanalization of the VA was observed in four cases and additional coil embolization was performed. All patients were discharged with a good outcome (modified Rankin Scale [mRS] 0; seven patients, mRS 2; one patient).

Conclusion: Target embolization preserving the PICA in PICA-involved type RVADA was considered to be an effective treatment method for cases whose rupture point was located in the VA distal to PICA orifice.

Objective: Early recanalization of acute stroke caused by large vessel occlusion (LVO) may improve high signal intensity (HSI) on diffusion-weighted imaging (DWI). In this study, we investigated whether subtraction of reversible ischemic lesions (RIL) from the HSI lesions on DWI improves the diagnostic accuracy for the ischemic core.

Methods: A total of 35 patients from April 2013 and December 2019 were included in this study. These patients presented acute ischemic stroke due to anterior circulation LVO and underwent thrombectomy. All patients underwent DWI within 48 hours after thrombectomy. HSI ratios were calculated, and compared between ischemic lesions and contralateral normal tissue. Ischemic lesions with improvement in the HSI ratio from initial to postoperative DWI were defined as RIL. Based on a receiver operating characteristic (ROC) curve analysis that compared the HSI ratio of all ischemic lesions, the cutoff value of HSI ratio of RILs was calculated.

Results: In all, 127 ischemic lesions were identified in 35 patients. HSI ratios of RILs were significantly lower than those of irreversible ischemic lesions (IILs) (p <0.0001). Based on a ROC curve analysis that compared the HSI ratio of all 127 lesions, the cutoff value of the HSI ratio of RILs was 1.4. After applying this cutoff value to the 127 ischemic lesions of the 35 patients, 20 patients (57%) were identified as having RILs with a HSI ratio of <1.4. In this 20 patients, the postoperative National Institutes of Health Stroke Scale (NIHSS) score at 24 hours was significantly lower (p = 0.007) and improvement in the NIHSS score was significantly higher (p = 0.018) than in the other patients.

Conclusion: A HSI ratio of <1.4 on preoperative DWI may reflect ischemic reversibility. In this study, the HSI ratio correlated with clinical findings associated with cerebral ischemia, and our method may be useful in assessing ischemic cores.

Objective: We investigated the usefulness of 2D-perfusion analysis for the evaluation of cerebral blood flow in unilateral cervical internal carotid artery stenosis.

Methods: We conducted a 2D-perfusion analysis during cerebral angiography and ¹²³I-iodoamphetamine (IMP) single photon emission computed tomography (SPECT) for unilateral cervical internal carotid artery stenosis without contralateral stenosis. The relationship between the ratio of the lesion side to the normal side in the parameters obtained by 2D-perfusion and the value calculated by stereotactic extraction estimation (SEE) analysis of SPECT was statistically examined.

Results: The ratios of the lesion side to the normal side regarding the peak arrival time (AT; time to peak [TTP]) of the contrast agent and the mean filling time (mean transit time [MTT]) of the contrast agent in 2D-perfusion significantly correlated with the area of Stage II and increase ratio (I.R) ≤30% in the SEE analysis (p = 0.002, 0.003).

Conclusion: 2D-perfusion analysis can be used to estimate the extent of impaired cerebrovascular reserve (CVR) area in unilateral internal carotid artery stenosis.

Objective: We report the usefulness of the adjunctive technique using a 3.4-Fr TACTICS catheter, which is a distal access catheter (DAC) for coil embolization.

Methods: Patients who underwent coil embolization with an adjunctive technique using a TACTICS catheter between October 2018 and May 2019 were retrospectively analyzed.

Results: In all, 64 aneurysms in 51 patients were treated. Among them, 18 aneurysms in 15 patients (4 ruptured aneurysms and 14 unruptured aneurysms) required an adjunctive technique using a TACTICS catheter. The methods of embolization were the double catheter technique (DCT) for five aneurysms, stent-assisted coiling (SAT) for seven, DCT + SAC for one, and balloon-assisted technique (BAT) for five aneurysms. Aneurysms were located in the anterior communicating artery (Acom A) in three cases, distal anterior cerebral artery (dACA) in one, middle cerebral artery (MCA) in five, internal carotid artery (ICA) in six, basilar artery (BA) in one, and vertebral artery (VA) in two cases. It was easy to access distal intracranial vessels using the TACTICS catheter. In all cases, guiding of the microcatheter, coiling, and stent placement were improved. There were no complications associated with using the TACTICS catheter.

Conclusion: Compared with conventional DACs, distal intracranial vessels were more easily accessed using the TACTICS catheter. A TACTICS catheter is useful because DCT and SAC require sufficient operability of the microcatheter.

Objective: In-stent thrombosis (IST) is a known complication after stent-assisted coil (SAC) embolization. We report a case of mechanical thrombectomy using a stent retriever (SR) for IST and share our experience with this treatment to prevent a poor outcome in future cases.

Case Presentation: The patient was a 62-year-old man. SAC embolization for an unruptured left internal carotid artery (ICA) aneurysm was performed. Three weeks after discharge, right hemiparesis and aphasia developed. Magnetic resonance imaging (MRI) demonstrated cerebral infarction in the left middle cerebral artery (MCA) territory and the left ICA was occluded. His relatives told us that the patient discontinued taking antiplatelet drugs. IST was diagnosed and emergency thrombectomy was performed. First, we tried to introduce an aspiration catheter or balloon catheter into the occluded lesion, but they were unable to be sufficiently inserted to the distal site. Therefore, we used a SR even though it carried a risk of friction on the deployed stent. The occluded artery was finally recanalized using the SR, but the stent became shortened. For the treatment strategy, sufficient medication (antithrombogenic agents and edaravone) should be administered first, followed by mechanical treatment. In mechanical treatment, thrombus fragmentation with a guidewire or balloon and aspiration should be attempted first. New aspiration catheters to carry the devices to the far distal site easily are now available.

Conclusion: SRs cannot be utilized for thrombectomy with a stent. In emergency situations, careful consideration during troubleshooting rather than using a SR is needed.

Objective: We describe a rare patient with a cavernous sinus dural arteriovenous fistula (CS DAVF) in whom diagnostic rotational angiography (RA) caused sinus arrest and bradycardia.

Case Presentation: A 79-year-old woman with no previous history of cardiovascular diseases presented with left oculomotor nerve paresis. Conventional angiography confirmed a bilateral CS DAVF. During a three-dimensional RA (3DRA) examination of the left internal carotid artery, sinus arrest occurred. Subsequently, the use of 3DRA to image the left external carotid artery and the use of cone beam computed tomography (CBCT) to image the left internal and external carotid artery also caused transient sinus bradycardia. Two weeks later, we inserted a temporary transvenous pacemaker and completed the transvenous embolization of the left CS DAVF. The left oculomotor paresis improved without any perioperative complications.

Conclusion: RA is a standard radiological modality for the diagnosis of cerebrovascular disease. Although the physical force generated by the injection of the contrast medium at the carotid bifurcation can theoretically cause hemodynamic instability, no previous reports have described sinus arrest or bradycardia in association with diagnostic carotid angiography. The present case demonstrates that 3DRA and CBCT can provoke rare, but serious, incidences of cardiac arrhythmia.

Objective: Azygos anterior cerebral artery (ACA) is a well-known anomaly of the second segment of the ACA. Although cases of intracerebral aneurysms related to this anomaly have been reported, acute ischemic stroke (AIS) related to the azygos ACA is extremely rare.

Case Presentation: An 84-year-old man developed disturbance of consciousness (Glasgow Coma Scale [GCS] E3V1M5), quadriparesis and aphasia, with a National Institutes of Health Stroke Scale (NIHSS) score of 32. Magnetic resonance imaging (MRI) showed no early ischemic changes, although a head magnetic resonance angiogram (MRA) demonstrated a single A2 trunk without any A3 branches that were suspected bilateral ACA occlusions. Mechanical thrombectomy for the occluded A2 trunk with contact aspiration using a Penumbra 4MAX aspiration catheter was performed, and the clot was retrieved and complete recanalization was achieved after two attempts (Thrombolysis in Cerebral Infarction scale 3) without any complications (onset to recanalization time: 187 min). The final angiogram demonstrated the recanalization of the single A2 and bilateral A3 branches, so we diagnosed as azygos ACA occlusion. MRI performed the next day revealed several small infarctions in bilateral frontal lobes, but ischemic symptoms gradually improved. NIHSS score decreased to two in 2 weeks and modified Rankin Scale (mRS) score at 90 days was one.

Conclusion: In this case, occlusion of the azygos ACA led to a large ischemic penumbra that spread widely and bilaterally in the ACA area, resulting in sudden onset of severe ischemic symptoms, including quadriparesis and aphasia. However, due to complete and rapid recanalization with contract aspiration, a large part of the ACA territory bilaterally was salvaged and the patient recovered extremely well.

Objective: Transarterial embolization (TAE) of the cavernous sinus (CS) via a fistula formed in the internal carotid artery (ICA) is the standard for carotid-cavernous fistulas (CCFs). Depending on the fistula, an adjunctive technique using a balloon or stent is effective. We report a case in which the balloon-assisted technique using the super-compliant balloon catheter “Super-Masamune” was effective.

Case Presentation: A 44-year-old woman who sustained head trauma from a traffic accident 1 month prior presented with diplopia, conjunctival chemosis, and proptosis of the left eye. Digital subtraction angiography (DSA) revealed a left CCF with a reflex to the left superior ophthalmic vein (SOV). During TAE with the Super-Masamune assistance, we tightly embolized around the fistula using a small volume of coils and the CCF was obliterated.

Conclusion: The balloon of the Super-Masamune is made of a styrene-based elastomer, which has excellent compliance. Therefore, it is possible to reduce the volume of coils because the balloon is in close contact with the ICA or fistula. This may reduce the incidence of postoperative cranial nerve palsy and cost of treatment materials.

Objective: We report carotid artery stenting (CAS) using balloon-expandable coronary (BECo) stent. The materials in this study consist of 15 cases of high-grade stenosis in internal carotid artery (ICA) in which self-expanding carotid (SECa) stent was not utilized. There were two groups why BECo stent was used instead of SECa stent: alternative group and intentional group. The alternative group was subdivided into two groups: access difficulty of guiding catheter and access difficulty of SECa stent.

Case Presentation: The alternative group included 11 cases (access difficulty of guiding catheter in 10 and access difficulty of SECa stent in 1), and the intentional group included 4 cases. There were four cases using transbrachial approach. All the intentional group cases were the first stage of staged angioplasty (SAP). The second stage of SAP was PTA in two and SECa stent over the BECo stent in two. There was no complication related to CAS.

Conclusion: CAS using BECo stent is one of the choices for the first stage of SAP, if stent placement instead of PTA is required at the first stage. It is also the useful alternative for the patient having difficulty of SECa stent.