Objective: To elucidate the current state of in-hospital acute ischemic stroke under the introduction of acute-phase mechanical thrombectomy.

Methods: The study included 18 consecutive patients with in-hospital cerebral infarction who underwent thrombectomy between April 2014 and March 2020 at St. Marianna University School of Medicine Yokohama City Seibu Hospital. We analyzed the primary disease, department responsible for treatment, modified Rankin Scale (mRS) scores before onset and on discharge, status of onset, treatment course, and so on.

Results: The mean age was 79.9 (66–93) years. There were nine females. The admission methods included scheduled admission in 5 patients and non-scheduled admission in 13 patients. The primary diseases consisted of malignant tumors in five patients and heart disease in four patients. The departments responsible for treatment consisted of the Department of Digestive Surgery for six patients and Department of Cardiology for three patients. The mRS score before admission was evaluated as 0–2 in 15 patients and 3–5 in 3 patients. The embolism was evaluated as cardiogenic in 14 patients. Antithrombotic therapy was discontinued before the onset of cerebral infarction in three patients. The mean interval from onset or last well known (LWK) until CT/MRI and puncture was 88.4 and 157.6 minutes. The median Alberta stroke program early CT score (ASPECTS; minimum–maximum) was 8 (2–10). Tissue plasminogen activator (t-PA) was administered to five patients. Concerning the degree of recanalization, the thrombolysis in cerebral infarction (TICI) grade was evaluated as 1 to 2a in 2 patients and 2b to 3 in 16. In the latter, the mean interval from onset or final onset-free confirmation until recanalization was 197.7 minutes. mRS score on discharge was evaluated as 0–2 in four patients, 3–5 in nine, and 6 in five patients. The mortality was related to a primary disease requiring admission in three patients.

Conclusion: In-hospital onset cerebral infarction was markedly influenced by the primary disease requiring admission. Even when favorable recanalization was achieved, the number of patients with a favorable outcome was small.

Objective: We investigated whether thoraco-cervical CTA provided useful information to determine an access route (AR) for mechanical thrombectomy (MT).

Methods: We included acute stroke patients who (1) were admitted between January 2018 and December 2018 and (2) underwent MT for large artery occlusion in the anterior circulation and were able to be treated within 24 hours of the time last known to be well. We evaluated the AR, occlusion site, aortic arch (AA) type, take-off angles (TOA) between the arch and the left common carotid artery (CCA) or the brachiocephalic artery (BCA), successful insertion rate (SIR) of the guiding catheter, puncture-to-initial angiography time (PtIA), and puncture-to-reperfusion time (PtR).

Results: We analyzed 32 patients: femoral-artery access (group F) in 26 and brachial-artery access (group B) in 6 patients. There were no differences in arch types between the two groups, but there were differences in occlusion sites: proximal CCA occlusion in two patients in the B group. Moreover, the TOA of the CCA was less than 25° in two patients in the B group. In the F and B groups, the SIR was 100%, the median PtIA was 9.0 and 9.6 minutes, and the median PtR was 54 and 72 minutes, respectively.

Conclusion: Thoraco-cervical CTA provided useful information to determine the appropriate AR for MT. SIR of 100% and short PtIA were achieved.

Objective: There is a limited understanding of the characteristics of individual intracranial stents used for aneurysm treatment. We used an experimental model to evaluate the physical characteristics of support stents for aneurysm embolization.

Methods: Enterprise 2 VRD 4.0 × 39 mm, Neuroform Atlas 4.5 × 21 mm, and LVIS 4.5 × 32 mm stents were: 1) observed under light microscopy and subjected to measurements of 2) circumferential radial force, 3) strut tension, 4) stent compression, and 5) conformability upon bending.

Results: 1) Light microscopy showed a large structural difference between laser-cut (Enterprise 2 VRD, Neuroform Atlas) and braided (LVIS) stents. 2) Within the range of indicated blood vessel diameters, the radial force of Enterprise 2 VRD was higher than that of Neuroform Atlas. An extremely large force was required to decrease the LVIS diameter. 3) Neuroform Atlas easily deformed compared to Enterprise 2 VRD, while LVIS was extended with a smaller traction force than that required for Neuroform Atlas. 4) The compression strength was in the order of Enterprise 2 VRD >Neuroform Atlas >LVIS. 5) Enterprise 2 VRD showed a decreased cell area on the concave side, and Neuroform Atlas showed deformation with overlapping struts on the concave side. LVIS naturally adhered to the wall of the blood vessel model.

Conclusion: Laser-cut and braided stents showed different physical characteristics that were visualized and shown as numerical data. These findings improve the understanding of the proper use of these stents in clinical applications.

Objective: Asymptomatic intracranial dural arteriovenous fistula (DAVF) is a rare disease that is often undiagnosed before symptom onset. The present study aimed to examine the detection rate and radiological features of asymptomatic intracranial DAVF using brain MRI data obtained from the Japanese brain check-up system.

Methods: We retrospectively identified 11745 individuals who underwent brain MRI between January 2010 and December 2014. After a routine brain MRI screening, a definite diagnosis was made based on DSA. Data regarding sex, age, disease location, classification type, and treatment method were extracted from the system database and patients’ medical records.

Results: Six individuals (0.05%; mean age, 61.0 ± 9.7 years) were diagnosed with definite intracranial DAVF. The intracranial DAVFs were located in the transverse sinus, confluence, and tentorial sinus in 2, 1, and 3 case(s), respectively. Cortical venous reflux was confirmed in four cases (66.7%), and none of the cases had intracranial hemorrhage or venous congestion. All cases had infratentorial lesions and two-thirds were Borden type II/III.

Conclusion: The detection rate of asymptomatic intracranial DAVF was 0.05% based on the analysis of MRI data from the brain check-up system. Low-flow shunt and tiny cortical venous reflux were likely missed on MRI.

Objective: The recurrence rate of coiled ruptured cerebral aneurysms is greater than that of clipped aneurysms. The aim of this study is to determine the factors that relate to the recurrence of embolized, ruptured cerebral aneurysms, and the evidence thereto.

Methods: From April 2007 through July 2017, we treated 134 ruptured cerebral aneurysm cases by coiling. DSA and/or MRI were done in 98 saccular aneurysm cases one year after the coiling. Recurrence was defined as enlargement of the aneurysm neck or contrast opacification along the aneurysm wall. A chi-square test and a logistic regression analysis were done to analyze the relationship between aneurysm recurrence and clinical factors.

Results: The median follow-up period was 58 months (interquartile range [IQR]: 33–107). Ten cases (10.2%) were subjected to aneurysm recurrence. Internal carotid artery (ICA) aneurysms proximal to the posterior communicating artery, incomplete obliteration of an aneurysm at initial embolization and postoperative DSA during day 9 ± 2, and increased contrast medium in the aneurysm at postoperative DSA during day 9 ± 2 were all statistically related to the recurrence of the aneurysm. Logistic regression analysis showed that the increased contrast medium in the aneurysm at day 9 ± 2 was statistically related to aneurysm recurrence (p <0.0001). Recurrence or retreatment of the aneurysm did not influence the outcome.

Conclusion: Complete obliteration of the aneurysm at the first session is important. Recurrence of an embolized ruptured aneurysm can be estimated by postoperative DSA at day 9 ± 2 days.

Objective: Endovascular therapy (EVT) is a well-documented treatment for acute occlusion of major cerebral arteries. We carried out in-hospital triage using the emergency large vessel occlusion (ELVO) screen, a pre-hospital scale for acute stroke, to diagnose EVT cases and considered its efficacy.

Methods: We investigated stroke cases examined within 24 hours of onset in a 6-month period beginning on March 15, 2019. The results of ELVO screen were retrospectively considered with the presence of atrial fibrillation and treatment of EVT.

Results: A total of 146 cases were included. Of the 65 positive ELVO screen cases, 33 (51%) had large vessel occlusion (LVO). Of the 81 negative ELVO screen cases, 11 (14%) had LVO (sensitivity, 75%; specificity, 69%; positive predictive value, 51%; negative predictive value, 86%; accuracy, 71%; P <0.001). Among LVO cases, 16 of the 33 (48%) positive ELVO screen cases and 2 of the 11 (18%) negative ELVO screen cases were treated by EVT. Complications of atrial fibrillation were significantly more common in positive ELVO screen cases (P = 0.001). EVT was carried out in nearly half of the positive ELVO screen cases of atrial fibrillation, being a significantly higher rate (10 of 24 cases, 42%; P = 0.02).

Conclusion: The accuracy of EVT use increased in positive ELVO screen cases, particularly in those with atrial fibrillation. In-hospital triage using ELVO screen, a pre-hospital scale, significantly aided in selecting patients requiring EVT.

Objective: Acute pulmonary embolism (PE) is a life-threatening cardiovascular event associated with high mortality and morbidity. The presence of a patent foramen ovale (PFO) in patients with acute PE represents a risk factor for mortality. Furthermore, a thrombus-in-transit via a PFO with impending paradoxical embolism carries a high mortality rate.

Case Presentation: An adult patient with ischemic stroke caused by paradoxical embolism following PE underwent mechanical thrombectomy and achieved successful recanalization. Initial CT pulmonary angiography (CTPA) showed not only pulmonary thromboemboli but also bilateral atrial thromboemboli. During hospitalization, transesophageal echocardiography (TEE) revealed the PFO with a right-to-left shunt. Two months after rehabilitation undergone by the patient, PE completely disappeared and PFO closure was conducted to reduce the recurrence risk of ischemic stroke.

Conclusion: Not only cardiologists but also interventional neurologists should understand that CTPA can demonstrate the thrombus-in-transit through the PFO and provides a reliable prediction of the sudden onset of ischemic stroke in patients with symptomatic PE. When identified, considering a case-by-case treatment approach by multidisciplinary teams is essential for preventing further life-threatening paradoxical embolization.

Objective: The authors describe a case of the so-called dural arteriovenous fistula (DAVF) around the posterior condylar canal (PCC).

Case Presentation: A 71-year-old woman presented with pulse-synchronous bruit on the left side. Conventional DSA demonstrated the following: There were many feeders, including the ascending pharyngeal artery (APA), the occipital artery (OA), and the vertebral artery (VA), to the DAVF around the PCC. Shunt flow from the posterior condylar vein (PCV) drained the suboccipital cavernous sinus (SCS) and sigmoid sinus (SS), and there was venous reflux into the inferior petrosal sinus (IPS). The patient was diagnosed with PCC DAVF and underwent transvenous embolization (TVE) with coils. Intraoperative 3D-rotational angiography (RA) and axially reconstructed images revealed an osseous shunt within the occipital bone adjacent to the PCC. The arteriovenous (AV) shunt and other symptoms disappeared after occluding the drainage route from the osseous shunt to the PCV.

Conclusion: There are only three previous reports of PCC DAVF, being rare. However, no report clearly described the shunt point of PCC DAVF. 3D-RA and axially reconstructed images were useful to find and treat the shunt point.

Objective: Accurately determining the clot position is highly important for immediate recanalization when endovascular mechanical thrombectomy is performed using a stent retriever and aspiration catheter. We describe a new method that facilitates the precise identification of the clot position called pull the trigger sign (PTS).

Case Presentation: Selective angiography was performed through a 0.027-inch microcatheter that penetrated the clot into the distal lumen. Although the contrast media highlighted the occluded artery, it often stagnated in the distal artery. It was washed away at a certain point when a stent clot retriever was deployed over the potential clot site. We hypothesized that this point represented the exact position of the clot’s proximal end and used in vitro analyses to assess this hypothesis. Briefly, a circulation-enabled silicone vascular model in which colored water was used to simulate stagnation beyond a fake clot was developed and utilized to investigate PTS six times. The rate of identifying PTS in the vascular model was 100%. As hypothesized, stagnant fluid was washed away when the deployed stent reached the clot’s proximal position. The clinical efficacy of PTS was also confirmed.

Conclusion: PTS was useful in revealing the precise position of clot’s proximal end, which enabled safer contact aspiration when using an aspiration catheter. Thus, PTS led to a higher success rate and faster recanalization in the first attempt than conventional methods.

Objective: Endovascular treatment for complex wide-necked basilar tip aneurysms is challenging. Multiple stenting may be an option to deal with such aneurysms; however, the risk of ischemic complications is reported to be relatively high. Here, we report a case of unruptured basilar tip aneurysm treated using the intentional stent herniation technique to preserve the aneurysmal neck branches.

Case Presentation: A 65-year-old woman presented with a growing unruptured basilar tip aneurysm associated with bilateral posterior cerebral arteries (PCAs) arising from the aneurysmal dome. We intentionally selected a large-sized Neuroform Atlas stent (Stryker, Kalamazoo, MI, USA) compared to the parent artery and deployed it along the right PCA to the basilar artery. The stent was herniated into the aneurysmal dome near the origin of the left PCA, resulting in the preservation of the left PCA. Successful coil embolization was achieved with acceptable obliteration.

Conclusion: The intentional stent herniation technique may be an effective approach to treat complex wide-necked basilar tip aneurysms.