Evaluation of the Intracranial Flow Alteration during Manual Syringe and Continuous Pump Aspiration.

GOALS: While mechanical thrombectomy (MT) has been shown to be effective in the treatment of acute large vessel occlusions, adjunctive measures, such as balloon guide catheters (BGC) and aspiration techniques, are utilized heterogeneously. Clarifying the effects of aspiration applied to the anterior cerebral circulation with proximal flow arrest can shed light on embolic protection during MT. MATERIALS AND METHODS: Manual and pump aspiration were applied through a BGC in a synthetic cerebrovascular model with a 60 ml syringe and a Penumbra pump, respectively. Flow direction was observed during the procedure with fluorescent particles and ultraviolet light. Flow rates were monitored at the simulated internal carotid artery and middle cerebral artery (MCA). FINDINGS: Both aspiration methods produced retrograde flow in all the modeled cerebrovascular segments. In the syringe aspiration methods, an interval phase occurred during the experimental trial in which suction forces paused and MCA flow became anterograde through posterior communication artery collateral circulation. CONCLUSION: Flow patterns vary with different methods of aspiration. With proximal flow arrest, continuous aspiration methods induce constant retrograde flow in all vessels, whereas manual aspiration demonstrates various flow changes, including periods of anterograde flow during the procedure, which may be less effective at distal re-embolization prevention.

Novel balloon-and-aspiration method for cerebral venous sinus thrombosis: dental-floss technique.

Cerebral venous sinus thrombosis is sometimes fatal. The standard treatment for sinus thrombosis is anticoagulation, but endovascular intervention must be considered when medical treatment fails. Mechanical thrombectomy is usually required when a large clot burden exits. Unfortunately, in sinus thrombosis attributable to a clot burden larger than that in an intracranial artery, the conventional technique used for intraarterial acute stroke intervention with a stent retriever and/or aspiration is not very effective. The authors describe here their endovascular approach to mechanical thrombectomy for sinus thrombosis using aspiration combined with angioplasty balloon support.

Utility of a Y-configured stentriever technique as a rescue method of thrombectomy for an intractable rooted thrombus located on the middle cerebral artery bifurcation: technical note.

Mechanical thrombectomy with stentriever and/or aspiration is the new gold standard for the treatment of acute strokes with large-vessel occlusion. As many as 20% of cases remain refractory to current stentriever and/or aspiration devices. "Saddle clots" obstructing a bifurcation may be a particular challenge for recanalization with conventional techniques and devices. The authors describe an alternative technique to bifurcation occlusions resistant to the conventional mechanical thrombectomy approach in which they simultaneously deployed 2 stentrievers into both branches of an occluded bifurcation. This stentriever Y-configuration was very effective in managing a challenging intracranial bifurcation occlusion.

Multiple Thromboembolic Cerebral Infarctions from the Aorta in a Patient with Churg-Strauss Syndrome.

BACKGROUND: Ischemic stroke is a rare complication of Churg-Strauss syndrome (CSS) and its pathogenesis has not been well clarified yet. We report a case of cerebral infarction in a patient with CSS due to embolism from a thrombus on the wall of the aorta. CASE: A 39-year-old man had multiple cerebral infarctions with symptoms of mild left hemiparesis and reduced vision. He was clinically diagnosed to have CSS based on remarkable eosinophilia, history of asthma, sinusitis, pulmonary infiltrates, and histologically proven extravascular eosinophilic infiltrates in the specimen of gastric mucosa. Cerebral angiography did not show any stenotic lesions in cerebral arteries. A thrombus was detected on the wall of the aorta by transesophageal echocardiography, which was considered as the source of embolism. The thrombus resolved on follow-up examination 3 months after the onset of the stroke. CONCLUSIONS: This is the first case report on cerebral infarction caused by aortogenic thromboembolism in a CSS patient. Other than cerebral vasculitis, embolism from cardiovascular system, including the wall of the aorta, is a possible cause of cerebral infarctions in a CSS patient.

[A Ruptured Vertebral Artery Dissecting Aneurysm Involving the Anterior Spinal Artery:A Case Report].

A 50-year-old woman presented with a subarachnoid hemorrhage caused by a ruptured vertebral artery dissecting aneurysm(VADA)involving the anterior spinal artery(ASA). The ASA branched at the proximal component of the dissecting aneurysm. The rupture point was presumed to be the distal region of the dissecting aneurysm. We performed coil embolization of the distal part only in order to prevent rebleeding and preserve the ASA. The patient showed no neurological deficits. Six months after the procedure, an angiogram demonstrated occlusion of a distal portion of the right vertebral artery. However, the ASA was still patent. No rebleeding occurred, and the patient has remained neurologically symptom-free for 3 years from the treatment. ASA-involved VADAs are extremely rare. Treatment strategy is difficult because there are no options for bypass surgery and occlusion of the ASA may lead to quadriplegia unless there is collateral flow to the ASA. Although the outcome of the patient was good with partial coil embolization in this case, the treatment strategy should be carefully considered for ASA-involved VADAs.

Triple antiplatelet therapy with addition of cilostazol to aspirin and clopidogrel for Y-stent-assisted coil embolization of cerebral aneurysms.

BACKGROUND: Dual antiplatelet therapy for stent-assisted coiling of cerebral aneurysms is essential to prevent thromboembolic complications. There is concern that Y-stent-assisted coiling may increase thromboembolic complications compared with coiling with a single stent. Several reports have demonstrated that cilostazol may improve clopidogrel responsiveness. We investigated whether triple antiplatelet therapy with addition of cilostazol to aspirin plus clopidogrel for Y-stents can prevent thromboembolic events. METHODS: Between July 2010 and October 2012, we treated 40 consecutive aneurysms with coil embolization using Enterprise stents. At the peri-procedural period, dual antiplatelet agents (100 mg aspirin and 75 mg clopidogrel) were used for the single stent group (n = 36), and triple antiplatelet agents (addition of 200 mg cilostazol) were used for the Y-stent group (n = 4). We evaluated post-operative diffusion-weighted imaging (DWI) and any complications. We assessed the following for statistical analysis: age, sex, aneurysm location, shape, and size, neck size, size of parent vessels, and stent length. RESULTS: We found two neurological peri-procedural complications: one transient ischemic attack and one infarction. Both complications belonged to the Y-stent group, which was a significant factor of thromboembolic events (P = 0.008). There were no other significant factors related to neurological complications or positive DWI. For subgroup analysis of the single stent group, stent length was significantly longer in positive DWI than negative DWI (P = 0.04). In the follow-up period of 20 ± 8.6 months, there were no symptomatic late complications in any patients. CONCLUSIONS: Although the number of patients in the Y-stent group is small, this group had a significantly higher risk of thromboembolic complications. While our protocol of a routine dose of dual antiplatelet therapy may be sufficient for single stent therapy, our protocol of a routine dose of triple antiplatelet therapy for Y-stents may not prevent thromboembolic events. This suggests that evaluation of platelet function may be essential, especially for Y-stents.

Rapid ventricular pacing for flow control during transarterial Onyx embolization of tentorial dural arteriovenous fistulas.

We report transarterial Onyx embolization with flow control using rapid ventricular pacing (RVP) in a middle-aged male patient with tentorial dural arteriovenous fistulas (TDAVFs). The patient completed angiographic obliteration in one session without any complications, and the 6-month postangiographic obliteration follow-up showed no evidence of residual or recurrent dural arteriovenous fistulas. RVP may be a novel treatment option of flow control to facilitate the embolic agent penetrating into the venous side and to achieve complete cure in transarterial embolization of TDAVFs.

T-Stent or Half T-Stent-Assisted Embolization of Wide-Necked Aneurysms at the Internal Carotid-Posterior Communicating Artery Bifurcation.

Objective: We report the usefulness and pitfalls of coil embolization using the T or half T-stent technique for aneurysms located at internal carotid artery-posterior communicating artery (ICA-P-com) bifurcation in which the neck is wide and the P-com must be kept patent due to it being the fetal-type with a hypoplastic P1 segment. Case Presentations: Two cases were treated using the T-stent technique and two were treated using the half T-stent technique. The average age of the patients was 70.3 years and all were females. One aneurysm ruptured. The average size of aneurysms and neck was 12 mm and 8.5 mm, respectively, in the T-stent group, and 7.4 mm and 6.7 mm, respectively, in the half T-stent group. An S- or pigtail-shaped microcatheter (MC) was used to navigate into the P-com. Stent deployment was successful in all the cases. Retreatment was required in one case treated using the T-stent technique due to major recurrence. Conclusion: T or half T-stent-assisted coil embolization can be an alternative endovascular treatment method for wide-necked ICA-P-com aneurysms in which the P-com must be kept patent due to it being the fetal-type with a hypoplastic P1 segment.

Usefulness of preoperative cone beam computed tomography and intraoperative digital subtraction angiography for dural arteriovenous fistula at craniocervical junction: Technical case report.

BACKGROUND: Direct surgery is commonly selected for the treatment of cranio-cervical junction dural arteriovenous fistula and its outcome is more satisfactory than that of embolization. Intraoperative treatment evaluation is relatively easy in embolization, whereas in direct surgery it can be difficult. CASE DESCRIPTION: A 67-year-old male suffered a subarachnoid hemorrhage. On three-dimensional (3D) images of preoperational cone-beam computed tomography (CBCT), the structure of the draining vein was depicted in detail along with the surrounding bone structures. The radial artery penetrated the dura mater, and it was found that there were two veins derived from the radiculospinal vein; one was the anterior radicular vein descending toward the dorsal side (the shallow layer of the surgical field) and the other was the anterior spinal medullary vein ascending toward the ventral side (the deep layer of the surgical field) and flowing out to the anterior spinal vein. CONCLUSION: Without detailed assessments with preoperative CBCT, the surgery might have been done with dissection of only the anterior radicular vein in the shallow layers. For identification of the draining vein located deep in the surgical field, such as the cranio-cervical junction, careful assessments using 3D CBCT images are important.

Assessment of human placenta as an ex-vivo vascular model for testing of liquid embolic agent injections with adjunctive techniques.

PURPOSE: This project sought to test the utility of post-delivery human placenta (HP) as a vascular model for liquid embolic agent (LEA) simulation, along with adjunctive techniques. MATERIALS AND METHODS: Twelve LEA injections were performed under fluoroscopy in HP with two reflux control methods: dual lumen 'mini' balloon-catheter (n=9); and injection after proximal nBCA plug formation through a second microcatheter ('pressure cooker') (n=3). Measured outcomes included liquid embolic agent (LEA) advancement and reflux. Reflux was categorized into three grades: grade 0=no reflux; grade 1=occlusion of side branches without reflux beyond the balloon or plug; and grade 2=reflux beyond the balloon or plug. RESULTS: Simulation success was greater when a balloon was used rather than with a nBCA plug (89% vs 33%, P=0.054). In eight successful balloon-assisted injections, the reflux grades were: 50% grade 0; 12.5% grade 1; and 37.5% grade 2. The one successful nBCA plug injection had grade 2 reflux. All grade 2 balloon injections occurred when the balloon was positioned across a vessel bifurcation. CONCLUSIONS: HP provides excellent simulation for liquid embolic agents with a dual lumen balloon catheter.

An Onyx tunnel: reconstructive transvenous balloon-assisted Onyx embolization for dural arteriovenous fistula of the transverse-sigmoid sinus.

Transvenous embolization is an effective method for treating dural arteriovenous fistulas (DAVFs) of the transverse-sigmoid sinus (TSS). However, in cases of complicated DAVFs, it is difficult to preserve the patency of the dural sinus. The authors describe the technical details of a new reconstructive technique using transvenous balloon-assisted Onyx embolization as another treatment option in a patient with an extensive and complex DAVF of the left TSS. A microcatheter and compliant balloon catheter were navigated into the left internal jugular vein and placed at the distal end of the DAVF in the transverse sinus. The microcatheter was placed between the vessel wall of the TSS and the balloon. After the balloon was fully inflated, Onyx-18 was injected at the periphery of the balloon in a slow, controlled, progressive, stepwise manner; the balloon and microcatheter were simultaneously withdrawn toward the sigmoid sinus, with Onyx encompassing the entirety of the complex DAVF. The Onyx refluxed into multiple arterial feeders in a distal-to-proximal step-by-step manner, ultimately resulting in an Onyx tunnel. The final angiography study revealed complete obliteration of the DAVF and patency of the TSS. The Onyx tunnel, or reconstructive transvenous balloon-assisted Onyx embolization technique, may be an effective treatment option for large, complex DAVFs of the TSS. This technique may provide another option to facilitate the complete obliteration of the DAVF while preserving the functional sinus.

[Carotid artery stenting via a transbrachial artery: techniques and problems].

Recently, carotid artery stenting (CAS) has been reported to be an alternative of carotid endarterectomy (CEA) for internal carotid artery (ICA) stenosis due to the improvement of protection devices. In general, the transfemoral approach has been chosen for CAS because of the sizes of the devices. However, the transfemoral route seems to be unavailable or at high risk, in cases of severe atherosclerotic changes or aneurysm of the femoral, iliac artery or aorta, or after bypass graft placement. In this report, we presented 5 patients who underwent CAS using the transbrachial approach. The mean stenotic rate of 84% before treatment was reduced to 14% after the procedures. The 30-day morbidity and mortality were both 0%. Major local complications at the puncture site were not encountered. There has been no stroke nor death during a mean follow-up period of 6 months. We suggest that CAS via transbrachial route is an effective and safe treatment for ICA stenosis, by use of low-profile devices and bi-plane DSA equipment, especially in patients who are not eligible for the transfemoral access.

A case of a cerebral cavernous malformation of the third ventricle that caused the syndrome of inappropriate secretion of antidiuretic hormone.

BACKGROUND: Cerebral cavernous malformations (CCMs, also known as cavernous hemanigiomas) of the third ventricle are uncommon. Here, we present a rare case of a CCM that caused the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). CASE DESCRIPTION: A 68-year-old man presented with acute-onset cognitive and memory disturbance. Endocrinological examinations revealed hyponatremia due to SIADH. Computed tomography indicated a high-density mass in the third ventricle that caused left unilateral hydrocephalus due to obstruction of the foramen Monroe. On magnetic resonance imaging, the mass showed high intensity in both T1 and T2-weighted images and low intensity in susceptibility-weighted images, suggesting subacute intralesional hemorrhage. We completely excised the mass via a basal interhemispheric translamina terminalis approach. Intraoperatively, the mass adhered tightly to the left hypothalamus, which was supposed to the origin and was well circumscribed from the surroundings. The histopathological diagnosis was CCM, and his SIADH improved after the operation. CONCLUSION: We presented a rare case of a CCM in the third ventricle that caused SIADH, which improved after complete excision of the mass via a basal interhemispheric translamina terminalis approach.

Removal of a malignant cystic brain tumor utilizing pyoktanin blue and fibrin glue: Technical note.

BACKGROUND: The leakage of cystic fluid during metastatic cystic brain tumor resection may cause tumor dissemination. When the cyst wall is thin, excision without removing the wall is often difficult. METHODS: We were able to perform an en bloc resection of a cystic malignant brain tumor after aspirating the cystic fluid, injecting pyoktanin blue into the cyst to stain the cyst walls, and solidifying the empty cyst cavity by filling it with fibrin glue. RESULTS: Pyoktanin blue readily stained the thin cystic walls and enabled visualization of mural damage. Solidification of the tumor made it easier to grasp and facilitated the dissection of tumor margins. CONCLUSIONS: This method has the potential to become a useful technique for the resection of malignant cystic brain tumors.

Angiographic Characteristics of Pseudo-occlusion of the Internal Carotid Artery Before and After Stenting.

BACKGROUND: Various definitions of pseudo-occlusion and clinical outcomes after various treatments have been reported, but reports discussing the stenotic characteristics of pseudo-occlusion are rare. OBJECTIVE: To analyze the angiographic characteristics of pseudo-occlusion of the internal carotid artery (ICA) before and after carotid artery stenting (CAS). METHODS: We retrospectively reviewed the angiographic characteristics of 56 patients with pseudo-occlusion of the ICA treated with CAS. Angiographic changes were evaluated from digital subtraction angiography in terms of lesion characteristics of the stenosis and the diameter changes in the distal ICA before and after CAS. RESULTS: Fifty-six patients were successfully treated. Based on angiographic findings of ICA stenosis, 33 and 23 patients were classified into the single-channel and multiple-channel group, respectively. Regarding the diameter changes in the distal ICA after CAS, 31 cases were classified as immediate dilatation and the other 25 as restricted dilatation. Immediate dilatation of the distal ICA beyond the stent and that at a follow-up examination were observed significantly less frequently in the multiple-channel group than in the single-channel group. The use of multiple stents and stent occlusion at a follow-up examination were significantly more prevalent in the multiple-channel group than in the single-channel group. CONCLUSION: Stenotic lesions of pseudo-occlusion of the ICA were classified as single channel and multiple channel. Restricted dilatation of the distal ICA after CAS was more prevalent in the multiple-channel group. Because adverse events tended to be more frequent in the multiple-channel group than in the single-channel group, the indications for CAS should be determined carefully in multiple-channel patients. ABBREVIATIONS: CAS, carotid artery stentingICA, internal carotid artery.

Reappraisal of primary balloon angioplasty without stenting for patients with symptomatic middle cerebral artery stenosis.

There is a controversy regarding the safety and efficacy of intracranial stenting. We describe our experience with primary balloon angioplasty without stenting for symptomatic middle cerebral artery (MCA) stenosis. All patients who underwent balloon angioplasty without stenting for MCA stenosis between 1996 and 2010 were retrospectively reviewed. We evaluated technical success rates, degrees of stenosis, and stroke or death within 30 days. Among patients who were followed-up for > 1 year we evaluated latest functional outcomes, stroke recurrence at 1 year, and restenosis. In total 45/47 patients (95.7%) were successfully treated. Average pre- and postprocedure stenosis rates were 79.9% and 39.5%, respectively. Three neurological complications occurred within 30 days: one thromboembolism during the procedure; one lacunar infarction; and one fatal intraparenchymal hemorrhage after the procedure. Stroke or death rate within 30 days was 6.4%. Thirty-three patients were available for follow-up analysis with a mean period of 51.5 months. The combined rate of stroke or death within 30 days and ipsilateral ischemic stroke of the followed-up patients within 1 year beyond 30 days was 9.4%. Restenosis was observed in 26.9% of patients and all remained asymptomatic. In our retrospective series, balloon angioplasty without stenting was a safe, effective modality for symptomatic MCA stenosis. For patients refractory to medical therapy, primary balloon angioplasty may offer a better supplemental treatment option.

Iatrogenic pneumothorax after ventriculoperitoneal shunt: an unusual complication and a review of the literature.

A patient received a ventriculoperitoneal shunt operation for hydrocephalus after subarachnoid hemorrhage. Postoperative computed tomography incidentally revealed asymptomatic pneumothorax caused by a shunt tube passing through the thoracic space. The patient was observed without removal of the tube or chest drainage, with the expectation of spontaneous recovery. However, the pneumothorax was not cured, and chest drainage was performed and eventually resolved the pneumothorax. The ventriculoperitoneal shunt worked well, and the patient recovered from consciousness disturbance. We discuss treatment strategies for this rare complication and how to avoid it. A review of the literature suggests that female or obese patients may be associated with this complication.