Purpose: It is difficult to predict lens radiation dose of the patients during neuroendovascular treatment due to various factors potentially affecting radiation dose such as a various working projection for individual procedures. The purpose of this study was to examine the association between the patient lens entrance dose (lens dose) during cerebral endovascular treatment and displayed dose on a system, as well as the influence of 3D imaging on lens exposure, and clarify factors influencing lens exposure.

Methods: In patients who underwent cerebral endovascular treatment under general anesthesia between February and December 2017, the lens dose was measured using a real-time scintillation optical fiber dosimeter. The correlation between the lens dose and displayed dose on each system was analyzed. Furthermore, dose data were divided into fluoroscopy, DSA, and 3D imaging, and respective values as a percentage of the lens dose were calculated.

Results: There was a strong correlation between the lens dose and Kerma Area Product (KAP) value. The lens dose was weakly correlated with the Air Kerma (AK) value and duration of fluoroscopy. 3D imaging for the visualization of a stent increased the value of 3D imaging as a percentage of the lens dose, and the lens dose increased with the frequency of imaging. In patients with a large field of irradiation after the establishment of a working angle, the lens dose increased.

Conclusion: We evaluated the characteristics of the lens dose. In the future, the management of the lens dose should be examined.

Objective: Carotid artery stenting is performed using a device for preventing distal embolism because vasodilation-related debris may cause cerebral infarction. Concerning filters for preventing embolism, membrane-type filters have been used, but mesh-type filters became commercially available. We have selected filter-assisted stenting as a first-choice procedure. We examined post-treatment filters under a microscope, and reviewed the pathogenesis of distal embolism.

Methods: The subjects were 83 patients in whom carotid artery stenting with a filter was performed, and filters could be examined after surgery (Angioguard XP [AG; Cordis Corporation, Miami Lakes, FL, USA]: 25 patients, Filterwire EZ [FW; Boston Scientific, Natick MA, USA]: 32, and Spider FX [Spider; Covidien, Dublin, Ireland]: 26). After treatment, the filters were stained with hematoxylin and eosin (HE), separated from the struts, and embedded in preparations for microscopic observation. Debris was classified into plaque-derived and fibrin-formation types, and quantified as an area using computer software. Distal embolism was evaluated based on intraoperative flow impairment, postoperative symptoms, and perioperative diagnostic imaging findings.

Results: Intraoperative flow impairment was noted in six patients (24%) in the AG group, five (15.6%) in the FW group, and one (3.8%) in the Spider group. Cerebral infarction was observed in three (12%), two (6.3%), and two (7.6%) patients, respectively. There were no differences in the volume of plaque-derived debris, but the volume of fibrin-formation-type debris was more in the AG group. As a result, the volume of debris collected was more. In the Spider group, the volume of fibrin-formation-type debris was minimum.

Conclusion: Functions differed between the membrane-type and mesh-type filters. Considering their performance, these filters should be used.

Objective: Preoperative transarterial feeder embolization (TAE) may contribute to the safe surgical removal of hyper-vascular tumors such as cerebellar hemangioblastomas (CHBs). We examined the usefulness of preoperative TAE of CHBs in our series.

Methods: We retrospectively analyzed the results of treatment in seven patients with CHBs who had undergone preoperative TAE and subsequent surgery in our hospital between 2005 and 2015 (four males and three females, mean age: 45 years).

Results: The embolized feeders consisted of the posterior inferior cerebellar artery in five patients, superior cerebellar artery (SCA) in one patient, and occipital artery (OA) in one patient. The embolic materials consisted of polyvinyl alcohol (PVA) in two patients, n-butyl-2-cyanoacrylate (NBCA) in four patients, and the combination of PVA and NBCA in one patient. Surgery was performed 1–4 days after embolization. The mean volume of intraoperative blood loss was 593 mL. In all patients, total surgical removal of the tumor was possible in the absence of non-autologous blood transfusion. Furthermore, embolic blood vessels could be identified during surgery in all patients, contributing to intraoperative orientation. Periprocedural complication related to TAE, cerebellar infarction related to embolic-material migration into a normal blood vessel occurred in one patient (13%).

Conclusion: The results suggest that preoperative TAE of CHBs using NBCA contributes to a decrease in the volume of intraoperative blood loss, intraoperative orientation, and safe surgical removal of CHBs.

Objective: We devised a method to readily create an ultra-small shape at the microcatheter tip using a sheath dilator. In the present study, we introduce the creation method and report its usefulness.

Methods: For mandrel formation, 7 Fr. or 4 Fr. sheath dilators were used. 1) A small, round loop was prepared by rolling a mandrel on a sheath dilator. 2) The mandrel with an ultra-small loop was inserted into the tip of a straight-type microcatheter. 3) The microcatheter tip was heated using a heat gun. 4) The mandrel was removed from the microcatheter tip. Using the catheter which has ultra-small shaped tip, coil embolization was performed.

Results: The mandrel loop diameter was 3 mm when a 7 Fr. sheath dilator was used. It was 2 mm when a 4 Fr. sheath dilator was used. It was possible to create various ultra-small shapes, such as J, S, and pigtail shapes, at the catheter tip. Ultra-small shaped catheters were used to treat 25 cerebral aneurysms. In all patients, catheters could be readily guided into the aneurysms, and their stability after insertion was favorable.

Conclusion: The ultra-small catheter shaping method with a sheath dilator facilitated the creation of various ultra-small shapes measuring 2–3 mm in diameter at the microcatheter tip.

Objective: We report a patient in whom vascular straightening was achieved after stent-assisted coil embolization, leading to complete occlusion of an intracranial aneurysm after 1 year.

Case Presentation: The patient was a 60-year-old female. A medical checkup of the brain showed a posterior inferior cerebellar artery (PICA) aneurysm. Under general anesthesia, coil embolization was performed. During surgery, a coil deviated onto the PICA side, and a stent was deployed so that the aneurysmal neck might be located at its center. Finally, incomplete occlusion of the aneurysm was achieved. Cerebral angiography 1 year after surgery indicated a sharper branching angle of the blood vessel in comparison with the preoperative angle and complete occlusion of the aneurysm.

Conclusion: A braided stent inserted to a site where a thin parent vessel is not fixed by the peripheral structure may make the parent vessel straight, contributing to complete occlusion of an aneurysm.

Objective: To describe a case of dural arteriovenous fistulas (DAVFs) involving the isolated transverse sinus (TS) treated by transvenous embolization (TVE) via the mastoid emissary vein (MEV) with the femoral venous approach.

Case Presentation: An 86-year-old woman presented with cerebral hemorrhage. Angiography showed DAVFs involving the left isolated TS with retrograde cortical venous drainage. Transvenous approach through the occluded sigmoid sinus into the affected sinus failed; however, we could easily advance a microcatheter into the isolated sinus via the MEV. The DAVFs were completely occluded by selective TVE combined with transarterial embolization, and reconstruction of antegrade cerebral venous drainage from the vein of Labbe’ to the MEV was obtained.

Conclusion: The MEV can be an alternative approach route for TVE of transverse-sigmoid sinus DAVFs when an approach through the occluded sinus is difficult or failed.

Objective: We report a patient in whom a devised stent-assisted internal trapping was effective to eliminate the mass effect of a symptomatic giant vertebral artery (VA) aneurysm.

Case Presentation: A 63-year-old female. Detailed examination of gait disorder showed a brainstem-compressing, non-thrombotic, giant, fusiform aneurysm at an area distal to the posterior inferior cerebellar artery (PICA) bifurcation of the left VA. Endovascular internal trapping was planned, but the exacerbation of mass effects related to the coils inserted into the aneurysm cavity was concerned. Thus, before the usual internal trapping procedure, a self-expanding stent was deployed across the aneurysm to limit the coils in the stent during the internal trapping procedure. Six months later, the aneurysm decreased markedly in size with a complete relief of neurological symptom.

Conclusion: Our devised stent-assisted internal trapping method, coiling-in bridging-stent technique, was successful to exclude a symptomatic giant VA aneurysm from the circulation with a minimum amount of coil in the aneurysm cavity. With this method, marked decrease in size could be expected since coils would not interfere with the shrinkage of the aneurysm. This method would be useful in giant cerebral aneurysms which need endovascular internal trapping.

Objective: We report a case of superior sagittal sinus thrombosis, where aspiration of the thrombus using a 6 Fr coaxial catheter (CC) resulted in prompt and complete recanalization.

Case Presentation: A 69-year-old female was brought to our hospital by ambulance due to headache and left hemiparesis. MRI images revealed superior sagittal sinus thrombosis. Endovascular treatment was performed in addition to anticoagulant therapy to prevent clinical deterioration and to achieve an early improvement. Unfortunately, neither intrasinus chemical thrombolysis nor mechanical thrombectomy with a balloon led to recanalization. Therefore, we used a CC, 6 Fr Cerulean catheter DD6 (Medikit co. ltd., Tokyo, Japan), as an aspiration catheter, which resulted in prompt and complete recanalization. Consequently, her symptoms disappeared shortly thereafter.

Conclusion: As the endovascular treatment of venous sinus thrombosis, thrombus aspiration through a 6 Fr CC may be an effective option.