Objective: To describe our 1-year experience of the practical use of a mobile communication application by our stroke team.

Methods: The mobile Join application (Allm Inc., Tokyo, Japan) was introduced into our stroke team for the purpose of immediate sharing of the patient information. We analyzed the usage situation for 1 year after the introduction of Join, particularly its efficacy in improving the door-to-puncture time (D2P) for thrombectomy cases, and reported our inter-hospital collaboration with the use of Join.

Results: The total number of events notified by Join was 337, and they included acute stroke potentially leading to reperfusion therapy in 23% (76 events), head trauma in 14%, brain hemorrhage in 12%, other infarction in 10%, subarachnoid hemorrhage in 8%, and the others in 34%. The information of the patients was shared among the team members before arrival to our hospital in 42% of acute stroke cases. Of 31 patients undergoing mechanical thrombectomy, the median interval between arrival and groin puncture for the directly transported patients with/without pre-hospital information was 77.5 min/87 min, respectively, whereas that of the patients transferred from primary hospitals with/without pre-hospital information was 19 min/71 min (p <0.0001), respectively, demonstrating the efficacy of information sharing in advance through Join in improving the timing of endovascular therapy. For inter-hospital collaboration using the telestroke system, we concluded the partnership agreement with three local primary hospitals by communication via Join at a reasonable cost.

Conclusion: Active and effective utilization of the mobile Join application for communication by our stroke team was demonstrated, and it is expected to promote inter-hospital collaboration in stroke treatment.

Objective: This study was performed to clarify the differences in blood flow strength, blood vessel diameter, and post-labeling delay (PLD) by physical experiments, and to examine whether bright vessel appearance (BVA) can be observed by arterial spin labeling (ASL).

Methods: We introduced simulated blood flow (25 cm/sec, 12.5 cm/sec) using a specially made phantom of fixed tubes in a plastic container. At each speed, we scanned at several points of PLD using ASL imaging. We measured the signal in the tube to obtain a signal intensity (SI). We revised the T1 level from the SI and obtained SI_blood. We used SI_tissue with normal perfusion measured from obtained clinical images by ASL and compared it with SI_blood.

Results: In tubes with a narrow inner diameter, the signal slightly decreased. SI also decreased under slow flow compared with fast flow. At each flow rate, SI_blood significantly exceeded SI_tissue.

Conclusion: PLD distinguishes spin in brain tissue from 1525 msec to 2525 msec, and it can be observed. As spin signal decreases when the flow rate is slow, attention is necessary for observation. Assessment at PLD1525–2525 msec where normal perfusion was obtained suggested that BVA can be observed.

Objective: The purpose of this study was to demonstrate the efficacy of a 14-coil (Target XL) for framing in coil embolization of small cerebral aneurysms.

Methods: Between January 2017 and December 2018, 46 patients underwent coil embolization of a small cerebral aneurysm that was less than 5 mm in maximum diameter. They were categorized into 26 patients in whom only 10-coils were used and 20 in whom Target XL was used for framing. The volume embolization rate (VER) and recanalization rate were compared between the two groups.

Results: Although there were two patients in whom Target XL was replaced with a 10-coil for framing, no adverse events associated with the use of Target XL were noted. The mean VER of the first framing coil was significantly higher in aneurysms that were framed with Target XL than in those framed with a 10-coil (Target XL 22.6 ± 4.5%, 10-coil 17.9 ± 8.4%; p = 0.03). Furthermore, the mean VER at the end of the procedure was significantly higher in aneurysms with Target XL used for framing than in those embolized using only 10-coils (14-coil: 36.8 ± 7.8%, 10-coil: 32.0 ± 6.5%; p = 0.03). No recanalization was observed in aneurysms for which Target XL was used for framing, whereas five aneurysms embolized using only 10-coils were recanalized.

Conclusion: Target XL may be safe and feasible as a framing coil in coil embolization of small cerebral aneurysms, which may result in a high VER, low recanalization rate, and good outcome.

Objective: Dural arteriovenous fistula (dAVF) is an abnormal vascular communication between the meningeal artery and vein at the dura mater, with frequent recruitment of collateral arterial pedicles. In recent years, Onyx embolization has become the mainstay intervention for dAVF at various locations, although an unfavorable vascular anatomy often limits effective obliteration of the lesion. Balloon assistance may facilitate curable occlusion of the abnormal shunt with Onyx while preserving the patency of the affected sinus, even in complicated dAVFs.

Methods: We retrospectively reviewed the clinical and angiographic findings of patients with dAVF treated endovascularly in our institution between September 2018 and August 2019. Based on the detailed analysis of individual angioarchitecture, we defined complicated dAVF as lesions for which a complete cure is considered difficult to achieve with simple transarterial Onyx embolization alone, primarily due to a high flow and/or diffuse shunt with or without drainage to the functioning but compromised sinus. We evaluated the preoperative symptoms, anatomical classification, endovascular procedure, radiologic results, and clinical outcomes of these patients.

Results: Five patients met our criteria, all of whom were treated with balloon-assisted Onyx embolization (two superior sagittal sinus dAVF, two transverse–sigmoid sinus dAVF, and one torcular dAVF). In four cases, Onyx was injected from a tiny branch of the middle meningeal artery under balloon occlusion of the collateral arteries or balloon devascularization of the competitive inflow. In three cases, balloon sinus protection was performed to prevent the inadvertent occlusion of the vital venous outflow with Onyx. In one case, for the complementary occlusion of the remnant shunt through the previously coiled but recanalized occipital artery, Onyx was injected from the wire lumen of a dual-lumen balloon catheter to avoid undesirable reflux. The angiographic results were an anatomical cure in four cases and near-complete occlusion in one case. No procedural complications were observed in any cases. The clinical outcome was a complete cure in four cases and improvement in one case.

Conclusion: Our cases suggest that balloon devascularization can improve the unfavorable flow environment and simplify the vascular anatomy. Balloon sinus protection can support not only securing the patency of the normal venous outflow but also encourage aggressive intervention. Onyx injection via a dual-lumen balloon catheter can augment the controllability of embolization while preventing reflux. Each of these techniques can facilitate safe and effective Onyx embolization in the treatment of complicated dAVFs, and their combination may further expand the therapeutic horizon.

Objective: Whether coiling is the best treatment option for oculomotor nerve palsy (ONP) induced by posterior communicating artery (PComA) aneurysms remains controversial. In this study, we retrospectively analyzed the recovery of ONP caused by PComA aneurysms.

Methods: Between 2007 and 2019, 8 patients with PComA aneurysms and ONP underwent coiling at our institution. We retrospectively reviewed ONP recovery, duration from onset of ONP to treatment, and complications of procedures.

Results: At the last available clinical follow-up, ONP recovery was complete in 4 patients (50%) and partial in 4 patients (50%). Patients with partial recovery of ONP had sequelae of eye movement impairment that did not affect daily life. In 1 patient, hemiplegia developed due to cerebral infarction of the corona radiata the day after coiling, but it fully recovered 1 year after operation. The delay from the onset of ONP to coiling was significantly related to partial ONP recovery (r = -0.83, p = 0.01).

Conclusion: Endovascular treatment is a relatively safe and satisfactory treatment for PComA aneurysms with ONP.

Objective: Transvenous embolization (TVE) is an effective treatment for cavernous sinus dural arteriovenous fistulas (CS-DAVFs). The facial vein (FV) can be used as an access route for TVE when a trans-inferior petrosal sinus (IPS) approach is difficult. We evaluated the usefulness of combining ultrasonography (US) with computed tomography angiography (CTA) for confirming that the FV is a suitable access route for treating CS-DAVFs.

Methods: Trans-FV TVE was planned for five CS-DAVF patients in whom the shunt point was located in the posterior compartment of the CS and anterior venous drainage predominantly occurred via the superior ophthalmic vein (SOV). The anterior drainage route was examined with CTA and US. We reviewed the relationships between preoperative CTA/US findings and the accessibility of CS-DAVFs via the FV.

Results: The periorbital and perimandibular drainage pathways were clearly more visible on US than on CTA, and the cervical and thoracic drainage pathways were more visible on CTA than on digital subtraction angiography (DSA). CS-DAVFs were accessible via the FV when (1) the entire drainage pathway could be confirmed on CTA and US, (2) the periorbital and perimandibular pathways were unclear on CTA, but could be confirmed on US, or (3) the FV pathway drained into the internal jugular vein (IJV) or external jugular vein (EJV). On the other hand, TVE was challenging to perform via the FV when (1) the periorbital pathway was unclear on CTA and US, (2) the FV pathway drained into the brachiocephalic vein, or (3) the SOV thrombosed intraoperatively. In all five patients, TVE for CS-DAVFs performed via the FV or IPS was successful.

Conclusion: CTA and US are useful for confirming the anterior access route for trans-FV TVE for CS-DAVFs and predicting the feasibility of such treatment. Our findings suggest that CS-DAVFs can be accessed via the FV if the periorbital drainage pathway can be confirmed on US, even if the pathway is unclear on CTA.

Objective: In cases of cerebral arteriovenous malformation (AVM) in which perforators are involved as feeder, hemostasis is difficult during surgical removal and postoperative hemorrhage may develop. If possible, presurgical embolization should be performed. However, when the anterior choroidal artery (AChA) is the feeder, the risk of embolization is particularly high, and there are few reports describing this situation. Authors report the treatment results of five cases of AVM in which a single operator performed presurgical embolization through the AChA and describe the technique with a review of the literature.

Case Presentations: Of the five total cases (three men and two women; average age was 43.4 years [28–68 years]), one case presented with hemorrhage, two with epilepsy, the other ones with headache and trigeminal neuralgia, respectively. The lesions were located in the frontal lobe in one case and in the temporal lobe in four cases. On the Spetzler-Martin (SM) grading scale, four cases were grade III and one was grade IV. The eloquent area was involved within the nidus in four cases. Multimodal treatment was planned because all cases were high-grade AVM. Authors thought that performing presurgical embolization through the AChA would reduce the overall risk of treatment and performed the presurgical embolization. The embolization was possible in all cases, and the AVM was not angiographycally visible through the AChA in three cases. The blood flow through the AChA was reduced in two cases. All cases were awake immediately after embolization and no case had neurological symptom after embolization. CT or MRI after embolization revealed asymptomatic infarction in two cases. The AVM was removed safely without difficulty including hemostasis.

Conclusion: In this series, there were no morbidity and embolization was performed relatively safely. Embolization through the AChA was suggested to be an effective treatment, but careful consideration is required in each individual case.

Objective: We described a rare hemifacial spasm (HFS) caused by compression of a vertebral artery (VA) aneurysm that was consequently improved by stent-assisted coil embolization.

Case Presentation: A 60-year-old man presented with a chief complaint of left HFS that had persisted for 1 month. It had initially appeared in the orbicularis oculi, spread to the orbicularis oris, and severely disrupted his quality of life. Both MRI and MRA revealed a wide-necked aneurysm of the left VA (neck 8.5 mm, dome 6.0 mm) compressing the left facial nerve root exit zone (REZ). We performed stent-assisted coil embolization because the VA was dominant at this side of the aneurysm and we tried to preserve normal antegrade flow. The HFS disappeared immediately after embolization without complications. After 6 month follow-up, the patient had no recurrence of symptoms and MRA showed no recurrence of the aneurysm.

Conclusion: Stent-assisted coil embolization was effective for treating HFS caused by compression of a VA aneurysm and it might be the treatment of choice for this type of aneurysmal HFS.

Objective: Clear cell ependymoma (CCE) is known to be very similar to hemangioblastoma (HB) in regards to neuroimaging and histopathology. We report a rare case of CCE in which successfully underwent preoperative embolization with a prior diagnosis of HB.

Case Presentation: A 58-year-old woman presented with vertigo for several months. MRI showed the right cerebellar tumor mimicking solid HB. DSA revealed the hypervascular tumor supplied by branches of the posterior inferior cerebellar artery (PICA). To reduce intraoperative bleeding, preoperative embolization was performed using n-butyl-2-cyanoacrylate (NBCA). A flow-guided microcatheter was guided to the proper feeders, and diluted NBCA was injected. Sufficient devascularization was achieved. The tumor was totally resected with minimal blood loss the next day. Postoperative pathological diagnosis was CCE.

Conclusion: This is the first report that preoperative embolization was performed to CCE with careful techniques and recent advanced devices. Since CCE has a poorer prognosis, preoperative embolization for safety total resection may be more important.

Objective: A patient with a ruptured distal medial lenticulostriate artery (mLSA) aneurysm presenting with intraventricular hemorrhage was successfully treated using endovascular treatment.

Case Presentation: A 60-year-old woman presented with impaired consciousness. Radiological examination revealed intraventricular hemorrhage caused by a rupture of a distal mLSA aneurysm. Using endovascular technique, approaching contralaterally through the anterior communicating artery (AComA), complete occlusion of the aneurysm was achieved by N-butyl-2-cyanoacrylate (NBCA) injection. The postoperative course was uneventful.

Conclusion: Intraventricular aneurysms at a distal site of the perforating arteries are rare. Although there have been reports on patients with distal mLSA aneurysms treated by open surgery or conservative therapy, endovascular therapy should also be considered as a treatment option.