Objective: The increased surface pressure of the coil mass calculated by computational fluid dynamics (CFD) analysis has been reported to be associated with the recurrence of internal carotid aneurysms after coil embolization. In this study, we investigated the relationship between the pressure on the coil surface and the recurrence of anterior communicating aneurysms.

Methods: Among patients with anterior communicating aneurysms who underwent coil embolization at a volume embolization rate of 20% or more without using a stent, only one proximal anterior communicating artery (A1) was visualized by magnetic resonance angiography (MRA). A virtual post-coiling model was created by eliminating the aneurysm at the neck position from the blood vessel model based on three-dimensional rotational angiography (3D-RA) data before treatment, and the neck plane was defined as the virtual coil plane. Using CFD analysis, the pressure difference (PD) was calculated by subtracting the average pressure of A1 from the maximum pressure on the virtual coil surface and dividing by the dynamic pressure of A1 for normalization. PD was statistically compared between the recurrent group and the non-recurrent group.

Results: Four of 10 patients with anterior communicating aneurysms exhibited recurrence. The PD was 2.54 ± 0.24 and 2.12 ± 0.26 in the recurrent and non-recurrent groups, respectively, and was significantly higher in the recurrent group (p=0.038). In the receiver operating characteristics (ROC) analysis, the area under the curve (AUC) was 0.917, and with a cutoff value of 2.31, the sensitivity was 1.000 and the specificity was 0.833.

Conclusion: PD was considered a predictor of recurrence after coil embolization in anterior communicating aneurysms with asymmetrical A1. Preoperative prediction of recurrence after cerebral aneurysm embolization may be possible using CFD analysis.

Objective: Thrombectomy may be an effective therapy for vertebrobasilar artery (VBA) occlusion in addition to carotid or middle cerebral artery occlusion. Underlying arterial stenosis can be a cause of failure in thrombectomy; however, it is difficult to identify candidates with VBA occlusion before thrombectomy. The purpose of our study was to investigate whether postcontrast computed tomography (pcCT) is useful for identifying candidates with VBA occlusion for thrombectomy.

Methods: In this retrospective study, we included patients who 1) were admitted to our institution between January 1, 2013, and July 1, 2019; 2) underwent pcCT; and 3) underwent emergency endovascular therapy for VBA occlusion. We defined no opacification of the top of the basilar artery (BA) in reconstructed coronal images of pcCT scans as distal BA occlusion and opacification of the top of the BA as distal BA open. We assessed the presence of underlying arterial stenosis at the site of occlusion according to angiographic findings during endovascular procedures. We also evaluated the relationship between the distal BA findings and the presence of underlying arterial stenosis.

Results: Thirty-two patients met our inclusion criteria and were analyzed. Among 19 patients with distal BA occlusion, none (0%) had ischemic stroke with underlying arterial stenosis. Among 13 patients with distal BA open, 4 (31%) were diagnosed with ischemic stroke without underlying arterial stenosis and 9 (69%) with underlying arterial stenosis (p <0.001).

Conclusion: Distal basilar-artery findings in reconstructed coronal postcontrast CT images were useful for identifying candidates with VBA occlusion for thrombectomy.

Objective: In Mexico, the systematic implementation of mechanical thrombectomy has been delayed due to several factors, such as the conditions of the healthcare system. The objective of this report is to explain the experience in our center going through these circumstances, how we have overcome them, our results, and our pending challenges.

Methods: This is a single-center, independent, and retrospective study of prospectively collected data destined to record consecutive patients treated with endovascular techniques at a Mexican hospital that implemented a mechanical thrombectomy program for large vessel occlusion (LVO). Patient selection began in February 2017 and ended in January 2020. Patients selected were between the ages of 18 and 80, and could be treated within 8 hours after onset of symptoms. The timeline of the analysis was divided in half (i.e., 18 months). We prognosticate that our concept of permanent training could have an impact on clinical outcomes.

Results: In all, 73 patients gathered, of which 60.3% were women and 39.7% were men, with an average patient age of 62 years old. The average Onset-Door time was 248 minutes, and mean Door-Recanalization time was 91.7 minutes, where 29.6% (27.2 min) were used in the endovascular procedure per se. The results obtained were as follows: five (6%) patients with a thrombolysis in cerebral infarction (TICI) <2B and nine patients (12.3%) with a TICI 2B. TICI 2C and 3 were considered optimal results and found in 59 (80.8%) patients. It was found that 17 (23%) patients treated in the first 18 months had favorable outcomes (modified Ranking Scale [mRS] <3), and in the last 18 months, 45 (33%) patients had favorable outcomes (p = 0.0001).

Conclusion: Developing countries such as Mexico usually present particular conditions that are not part of the algorithms generated in developed countries. Nevertheless, with logistic adaptation, creativity, and above all, permanent training, similar results to those in other parts of the world can be achieved.

Objective: We describe an instructive case of post-thrombectomy subarachnoid hemorrhage (PTSAH) by sylvian hematoma removal.

Case Presentations: An 83-year-old female presented with an acute cardiogenic right M1 occlusion. After the thrombectomy with combined stent retriever and aspiration technique with total five passes, TICI 2b reperfusion was achieved; however, CT imaging displayed subarachnoid hematoma (SAH) along the right sylvian fissure. Throughout the approach, contrast extravasation was not confirmed. The SAH grew up to become the sylvian hematoma; therefore, removal of the sylvian hematoma was conducted. An abrupt arteriole tear around the distal M2 of parietal artery was confirmed as bleeding point and those teared arteriole’s stumps were electrically coagulated not to re-bleed.

Conclusion: We suggest that the PTSAH is possible even in invisible-extravasation cases and the sylvian hematoma removal is effective to elucidate the etiology of the PTSAH, and is a reliable method to prevent the re-bleeding and is anticipated to improve the prognosis. Craniotomy is required for medically resistant PTSAH after thrombectomy, and avulsion of the pial artery can be the cause.

Objective: We report a case of paradoxical cerebral embolism caused by patent foramen ovale (PFO) that was treated by the direct aspiration first pass technique (ADAPT).

Case Presentation: The case involved a 12-year-old boy who had symptoms of dizziness and vomiting the day prior to being admitted to the emergency department. The following morning, consciousness disorder, dysarthria, and right paresis were observed, and he was transferred to our hospital. Computed tomography (CT) and magnetic resonance imaging (MRI) lead to the diagnosis of acute cerebral infarction due to basilar artery (BA) occlusion. Mechanical thrombectomy was performed, and Thrombolysis in Cerebral Infarction (TICI) 3 was obtained. Postoperatively, his consciousness was improved, but echocardiography revealed PFO. Percutaneous PFO closure was performed at our department of pediatric cardiology.

Conclusion: For our patient with paradoxical cerebral embolism of the BA caused by PFO more than 6 hours after onset, mechanical thrombectomy with ADAPT using a Penumbra 5MAX ACE68 resulted in a good outcome.

Objective: We report a rare case of a ruptured anterior spinal artery (ASA) aneurysm caused by bilateral vertebral artery (VA) occlusion.

Case Presentations: A 78-year-old man suddenly developed severe headache and slight hemiparesis, and was admitted to our hospital. Computed tomography (CT) revealed subarachnoid hemorrhage, mainly in the posterior fossa. On emergency angiography, the right VA terminated at the origin of the posterior inferior cerebellar artery (PICA), and anastomoses between the PICA and the anterior inferior cerebellar artery (AICA) were observed, in addition to a saccular 3-mm aneurysm with bleb originating from the PICA-AICA anastomosis. Left vertebral arteriography demonstrated that the left VA was occluded segmentally at the V4 level and revealed a tortuous arterial network filling the distal VA. Based on the location of the bleeding, the right VA aneurysm was considered to have ruptured. After balloon test occlusion of the right VA, parent artery occlusion was performed without complications. The patient had no neurological changes immediately after surgery, but several hours later, he stopped breathing. Retrospective analysis revealed an ASA aneurysm, which was determined to be the bleeding source. Although conservative treatment was performed, he died the fourth day after onset without neurological improvement.

Conclusion: In cases of subarachnoid hemorrhage associated with bilateral VA occlusion, an aneurysm formed by hemodynamic stress may be the source of hemorrhage. It is important to suspect aneurysms in the extracranial collaterals, such as the ASA, and intracranial collaterals such as the PICA-AICA anastomosis.

Objective: We report the case of a patient in whom arterial spin labeling (ASL) was useful for assessing the effects of treatment for a transverse–sigmoid sinus dural arteriovenous fistula (TSS-dAVF).

Case Presentation: The patient was a 65-year-old man. Cerebral angiography demonstrated an aggressive dAVF involving the TSS, superior sagittal sinus (SSS), and the sinus confluence, with severe cortical and deep venous reflux. We performed multiple transarterial and transvenous embolizations for the TSS and sinus confluence lesion. The shunt disappeared almost completely after embolization. A high signal intensity that had been apparent in the SSS and straight sinus (StS) on ASL imaging before embolization disappeared after embolization. ASL imaging 3 months after embolization revealed slightly a high signal intensity in the StS, which was considered to be due to recurrence of the lesion. Moreover, recurrence of the confluence and TSS-dAVF was observed on cerebral angiography 6 months after embolization. As additional embolization was considered difficult, radiation therapy was recommended, but the patient refused; therefore, follow-up was performed. As ASL imaging findings were consistent with cerebral angiography findings, careful examination and monitoring of changes on ASL imaging were subsequently performed.

Conclusion: Follow-up using ASL imaging is useful to assess the effects of treatment performed for a dAVF.

Objective: We report a case of a ruptured cerebral aneurysm in which a bifurcation pattern at the tip of the basilar artery was asymmetric fusion type and the superior cerebellar artery (SCA) branched from the posterior cerebral artery (PCA) on the caudal fusion type side.

Case Presentation: A 45-year-old woman presented with a subarachnoid hemorrhage with a headache. Cerebral angiography revealed that the right SCA diverged from the PCA and a small cerebral aneurysm had developed at this site. This cerebral aneurysm was successfully treated by coil embolization.

Conclusion: There have been no previous reports on cerebral aneurysms at the site of this normal variation.

Objective: Intravenous (IV) recombinant tissue plasminogen activator (rt-PA) and mechanical thrombectomy (MT) are effective treatments for acute ischemic stroke (AIS). However, the treatment for AIS in pregnancy is not established because no clinical trials have included pregnant patients. We present a case of middle cerebral artery (MCA) M2 segment occlusion in pregnancy treated with IV thrombolysis and endovascular therapy.

Case Presentation: A 36-year-old woman being 6 weeks pregnant presented with right-sided hemiparesis and aphasia. MRI showed a high-intensity area on diffusion-weighted imaging of the left parietal lobe, and MRA showed left MCA M2 segment occlusion. She underwent IV rt-PA and MT and achieved thrombolysis in cerebral infarction 2b revascularization without complications. The protein S concentration was lower than that in the physiological changes during pregnancy. She was diagnosed with embolic stroke related to coagulopathy in pregnancy, and she underwent anticoagulation. At the 3-month follow-up, the modified Rankin Scale was 0. She miscarried at 4 months, and the fetal death was presumed to be obstetric cause.

Conclusion: IV rt-PA and MT may be effective and safe treatments for pregnant patients. Estimated fetal radiation exposure during MT is low and is presumed not to affect fetal development. We should mitigate the radiation dose and reduce the dose of iodinated contrast agents, particularly in pregnant patients.

Objective: We report the “sheath pull-through technique” for stenting of common carotid artery stenosis (CCAS).

Case Presentations: In this technique, an 8–10 Fr super-long sheath (SLS) 55–65 cm is inserted into the femoral artery and the brachiofemoral pull-through technique is subsequently used, improving the support of the sheath itself. We pulled both ends of a pull-through wire to further improve the support of SLS, stabilizing guiding catheter (GC) during the procedure in two cases.

Conclusion: This technique stabilizes GC during CCAS stenting.