[Anatomy of the Cavernous Sinus].

The cavernous sinus is the crossroad of veins from various embryological origins, including the brain, eye, pituitary gland, dura, and cranium. Embryologically, the cavernous sinus is mainly formed from the pro-otic sinus; secondary anastomosis between the cavernous sinus and primitive tentorial sinus results in various anatomical variations in the drainage patterns of the superficial middle cerebral vein. Moreover, connections between the cavernous sinus and basal vein via the uncal vein, bridging vein, and petrosal vein from the superior petrosal sinus may exist. Retrograde drainage from the cavernous sinus into the cerebral veins is often observed in arteriovenous shunts involving the cavernous sinus, such as dural and carotid-cavernous fistulas, which are primarily treated using transvenous embolization. Understanding the anatomy of the cavernous sinus and its associated veins is essential for safe and reliable endovascular treatment.

Three-dimensional Images Fusion Method Useful for Preoperative Simulation of Clipping Surgery for Cerebral Aneurysms.

This study aimed to introduce a three-dimensional (3D) images fusion method for preoperative simulation of aneurysm clipping. Consecutive unruptured aneurysm cases treated with surgical clipping from March 2021 to October 2023 were included. In all cases, preoperative images of plain computed tomography (CT), CT angiography, magnetic resonance imaging (MRI) 3D fluid-attenuated inversion recovery, 3D heavily T2-weighted images, and 3D rotational angiography were acquired and transported into a commercial software (Ziostation2 Plus, Ziosoft, Inc. Tokyo, Japan). The software provided 3D images of skull, arteries including aneurysms, veins, and brain tissue that were freely rotated, magnified, trimmed, and superimposed. Using the 3D images fusion method, two operators predicted clips to be used in the following surgery. The predicted clips and actually used ones were compared to give agreement scores for the following factors: (1) type of clips (simple or fenestrated), (2) shape of clips (straight, curved, angled, or bayonet), and (3) clipping strategy (single or multiple). The agreement score ranged from 0 to 3 because a score of 1 or 0 was given for agreement or disagreement on each factor. Interoperator reproducibility was also evaluated. During the study period, 44 aneurysms from 37 patients were clipped. All procedures were successfully completed, thanks to the precisely reproduced surgical corridors with the 3D images fusion method. Agreement in clip prediction was good with mean agreement score of 2.4. Interobserver reproducibility was also high with the kappa value of 0.79. The 3D images fusion method was useful for preoperative simulation of aneurysm clipping.

[Dural Arteriovenous Fistula:Indications and Outcomes].

The diagnosis of dural arteriovenous fistulas(DAVF)has advanced with the development of imaging techniques. The indication for treatment of DAVF is generally based on classification according to the venous drainage pattern, which determines whether the presentation is benign or aggressive. In recent years, with the introduction of Onyx, transarterial embolization has been increasingly used, and outcomes have improved, although some conditions are more suitable for transvenous embolization. It is important to select an optimal approach based on location and angioarchitecture. Since DAVF is a rare vascular disease with limited evidence, further validation of clinical results is needed to provide more established treatment guidelines.

Plasma SPARC Elevation in Delayed Cerebral Ischemia After Aneurysmal Subarachnoid Hemorrhage.

Matricellular proteins have been implicated in pathologies after subarachnoid hemorrhage (SAH). To find a new therapeutic molecular target, the present study aimed to clarify the relationships between serially measured plasma levels of a matricellular protein, secreted protein acidic and rich in cysteine (SPARC), and delayed cerebral ischemia (DCI) in 117 consecutive aneurysmal SAH patients with admission World Federation of Neurological Surgeons (WFNS) grades I-III. DCI developed in 25 patients with higher incidences of past history of hypertension and dyslipidemia, preoperative WFNS grade III, modified Fisher grade 4, spinal drainage, and angiographic vasospasm. Plasma SPARC levels were increased after SAH, and significantly higher in patients with than without DCI at days 7-9, and in patients with VASOGRADE-Yellow compared with VASOGRADE-Green at days 1-3 and 7-9. However, there were no relationships between plasma SPARC levels and angiographic vasospasm. Receiver-operating characteristic curves differentiating DCI from no DCI determined the cut-off value of plasma SPARC ≥ 82.1 ng/ml at days 7 - 9 (sensitivity, 0.800; specificity, 0.533; and area under the curve, 0.708), which was found to be an independent determinant of DCI development in multivariate analyses. This is the first study to show that SPARC is upregulated in peripheral blood after SAH, and that SPARC may be involved in the development of DCI without angiographic vasospasm in a clinical setting.

Successful Balloon-assisted Coil Embolization of Right Subclavian Artery Aneurysm: A Case Report.

Objective: Subclavian artery aneurysms are relatively rare, and have been treated by open surgery and/or endovascular treatment using a stent graft. In this article, we report a case of unruptured right subclavian artery aneurysm successfully treated using balloon-assisted coil embolization. Case Presentation: A 77-year-old man was diagnosed with an asymptomatic unruptured right subclavian artery aneurysm of 8 mm in diameter by follow-up CTA after surgery for thoracoabdominal aortic aneurysms. He also had a history of cerebral infarction and clipping of an unruptured cerebral aneurysm. The subclavian artery aneurysm was treated by balloon-assisted coil embolization because its diameter increased to 17.6 mm in 2 years. Balloon assistance was mainly used to prevent protrusion of the framing coil into the parent artery, and satisfactory framing was achieved. Subsequently, the aneurysm was obliterated using filling and finishing coils. The postoperative course was uneventful, and the follow-up MRI at 18 months after treatment revealed no recanalization of the aneurysm. Conclusion: Balloon-assisted coil embolization may be an effective treatment for subclavian artery aneurysms, but further long-term follow-up and case accumulation are needed.

Case of Hemorrhagic Moyamoya Disease Associated with Von Willebrand Disease.

BACKGROUND: Association of moyamoya disease (MMD) with von Willebrand disease (vWD) is extremely rare. CASE DESCRIPTION: We first report a 27-year-old female case of MMD concurrent with vWD type 1, which presented as hemorrhagic stroke. The patient underwent a revascularization surgery with perioperative replacement therapy of von Willebrand factor and coagulation factor VIII. No hemorrhagic complications occurred. CONCLUSIONS: The patient overcame postoperative transient neurological events and fully recovered. We discuss appropriate perioperative supplementation of coagulation factors for a revascularization surgery for MMD with vWD.

Significance of novel subcortical low intensity score on transient neurological events after revascularization surgery for moyamoya disease.

OBJECTIVES: Transient neurological events (TNEs) are frequently observed after revascularization surgery for moyamoya disease (MMD). Recently, two signs on fluid-attenuated inversion recovery magnetic resonance images, a cortical hyperintensity belt (CHB) sign possibly reflecting vasogenic edema and a transient subcortical low intensity (SCLI) sign possibly reflecting cytotoxic edema, were reported associated with TNEs. The purpose of this study was to create a SCLI score and to investigate the significance of the score in TNEs. PATIENTS AND METHODS: The authors retrospectively analyzed 18 cerebral hemispheres in 16 consecutive patients with revascularization surgery for MMD. The SCLI sign was defined as a transient SCLI in surgically treated hemispheres, and blindly graded as the SCLI score (0-4) based on the extent. The relationships among SCLI, CHB signs and TNEs were evaluated. RESULTS: Postoperative TNEs, SCLI and CHB signs were detected in 8 (44.4%), 9 (50.0%) and 12 (66.7%) hemispheres, respectively. Patients with SCLI and CHB signs had a significantly higher TNE occurrence rate than those without these signs (p = 0.015, and p = 0.013, respectively). Patients with TNEs showed significantly higher SCLI scores than those without TNEs (p = 0.009), while the difference of CHB scores did not reach significance between patients with and without TNEs. For the occurrence of postoperative TNEs, SCLI score with a cut-off value of 1.0 resulted in a specificity of 80.0% and a sensitivity of 87.5%. CONCLUSION: The novel SCLI score may be useful for diagnosing TNEs after revascularization surgery for MMD, although both vasogenic and cytotoxic edema may be involved in postoperative TNEs.

A case of arteriovenous fistula of the cauda equina fed by the proximal radicular artery: anatomical features and treatment precautions.

PURPOSE: Arteriovenous fistula (AVF) of the cauda equina (CE) fed by the proximal radicular artery (PRA) is very rare, and the differentiation from that of the filum terminale (FT) is important to avoid treatment-related injury to the CE when endovascular treatment is selected. The authors describe a case of AVF of the CE fed by the PRA, demonstrate the anatomical features and discuss the treatment precautions. METHODS: A 69-year-old man presented with a transient weakness of lower limbs. Spinal angiography and magnetic resonance (MR) imaging revealed AVF, of which the feeding artery arose from the anterior spinal artery (ASA), forming the fistula at L2 level to be drained into the longitudinal venous trunk. Under a tentative diagnosis of AVF of the FT, endovascular treatment was attempted but failed due to impossible catheterization into the ASA. Therefore, surgery was performed. RESULTS: Intraoperative finding revealed that the feeding artery and draining vein were not on the FT but on the CE, resulting in the proper diagnosis of AVF of the CE. Surgical clips were applied to the draining vein closest to the fistula, and postoperatively the symptom improved gradually. Although we thoroughly reevaluated spinal angiography and MR images postoperatively, AVF of the CE fed by the PRA and that of the FT were not distinguishable. CONCLUSIONS: The authors described a case of AVF of the CE fed by the PRA and demonstrated the difficulty of the differentiation from that of the FT. The utmost precautions are necessary when endovascular treatment is selected.

Preventive effects of cilostazol against the development of shunt-dependent hydrocephalus after subarachnoid hemorrhage.

OBJECTIVE Chronic hydrocephalus develops in association with the induction of tenascin-C (TNC), a matricellular protein, after aneurysmal subarachnoid hemorrhage (SAH). The aim of this study was to examine if cilostazol, a selective inhibitor of phosphodiesterase Type III, suppresses the development of chronic hydrocephalus by inhibiting TNC induction in aneurysmal SAH patients. METHODS The authors retrospectively reviewed the factors influencing the development of chronic shunt-dependent hydrocephalus in 87 patients with Fisher Grade 3 SAH using multivariate logistic regression analyses. Cilostazol (50 or 100 mg administered 2 or 3 times per day) was administered from the day following aneurysmal obliteration according to the preference of the attending neurosurgeon. As a separate study, the effects of different dosages of cilostazol on the serum TNC levels were chronologically examined from Days 1 to 12 in 38 SAH patients with Fisher Grade 3 SAH. RESULTS Chronic hydrocephalus occurred in 12 of 36 (33.3%), 5 of 39 (12.8%), and 1 of 12 (8.3%) patients in the 0 mg/day, 100 to 200 mg/day, and 300 mg/day cilostazol groups, respectively. The multivariate analyses showed that older age (OR 1.10, 95% CI 1.13-1.24; p = 0.012), acute hydrocephalus (OR 23.28, 95% CI 1.75-729.83; p = 0.016), and cilostazol (OR 0.23, 95% CI 0.05-0.93; p = 0.038) independently affected the development of chronic hydrocephalus. Higher dosages of cilostazol more effectively suppressed the serum TNC levels through Days 1 to 12 post-SAH. CONCLUSIONS Cilostazol may prevent the development of chronic hydrocephalus and reduce shunt surgery, possibly by the inhibition of TNC induction after SAH.

Aneurysm Organization Effects of Gellan Sulfate Core Platinum Coil with Tenascin-C in a Simulated Clinical Setting and the Possible Mechanism.

BACKGROUND: This study aimed to deliver gellan sulfate core platinum coil with tenascin-C (GSCC-TNC) into rabbit side-wall aneurysms endovascularly and to evaluate the organization effects in a simulated clinical setting. METHODS: Elastase-induced rabbit side-wall aneurysms were randomly coiled via a transfemoral route like clinical settings with platinum coils (PCs), gellan sulfate core platinum coils (GSCCs), or GSCC-TNCs (n = 5, respectively). Aneurysm-occlusion status was evaluated angiographically and histologically at 2 weeks post coiling. As each rabbit coiled aneurysm provided only 2-3 tissue slices due to technical limitations and prevented immunohistochemical evaluations, a PC, GSCC, or GSCC-TNC was randomly implanted in a rat blind-ended model (n = 3, respectively) and the organization effects were immunohistochemically evaluated for expressions of tenascin-C (TNC), transforming growth factor-beta (TGF-ß), and matrix metalloproteinase-9 (MMP-9) 2 weeks later. RESULTS: Coil handling was similar among the 3 kinds of coils. GSCCs showed a significantly higher ratio of organized area to the aneurysmal cavity than PCs, but GSCC-TNCs had the greatest organization-promoting effects on aneurysms (the ratio of organized area/aneurysmal luminal area: PC, 17.9 ± 7.1%; GSCC, 54.2 ± 18.3%; GSCC-TNC, 82.5 ± 5.8%). GSCC-TNCs had intense immunoreactivities for TNC, TGF-ß, and MMP-9 in the organized thrombosis and tunica media. GSCCs also showed intense immunoreactivities for TNC, TGF-ß, and MMP-9, although the extent was less than GSCC-TNCs. The immunoreactivities were hardly found in unorganized thrombus and the tunica media of aneurysm wall in the PC group. CONCLUSIONS: This study first showed that GSCC-TNCs promote intra-aneurysmal clot organization in simulated clinical settings using rabbits possibly through the TGF-ß and MMP-9 upregulation.

Gellan sulfate core platinum coil with tenascin-C promotes intra-aneurysmal organization in rats.

The aims of this study were to develop a new coil, gellan sulfate core platinum coil (GSCC), that delivers tenascin-C (TNC) to an aneurysm (GSCC-TNC) and to evaluate the effects on intra-aneurysmal organization. We performed in vitro adsorption tests of TNC to gellan sulfate (GS). GSCC-TNC was produced by immersing GSCC in TNC solution under the following conditions (TNC concentration 10, 50, or 100 µg/mL; TNC immersion time 15, 30, or 60 min) by monitoring intra-aneurysmal organization in a rat blind-ended aneurysm model. In addition, 20 rats randomly underwent implantation of a platinum coil or the GSCC-TNC produced under optimum conditions into an aneurysm, whose organization effects were compared in a blind fashion at 2 weeks post-surgery. GS demonstrated a high affinity to TNC in a dose-dependent fashion (affinity constant = 1.79 × 10(10) (M(-1))). GSCC immersed in 10 µg/mL of TNC solution for 30 and 60 min induced similar and better organization of aneurysmal cavity compared with that for 15 min (the ratio of the organized areas in an aneurysmal cavity-15 min, 27.2 ± 11.8 %; 30 min, 75.6 ± 11.9 %; 60 min, 82.6 ± 19.7 %, respectively) with the preservation of the aneurysmal wall structure, while higher TNC concentrations caused the destruction of the aneurysmal wall. GSCC-TNC produced under 10 µg/mL of TNC solution for 30 min showed a significantly better organization of aneurysms compared with bare platinum coils in rats. A newly developed coil, GSCC-TNC, may be effective for improving intra-aneurysmal organization after coil embolization.

Development, clinical presentation and endovascular management of congenital intracranial pial arteriovenous fistulas.

INTRODUCTION: Pial arteriovenous fistulas (AVF) are vascular disorder of the brain consisting of a direct connection between arteries and veins without a nidus located in the subpial space, and are frequently associated with venous varix. MATERIALS AND RESULTS: This study reviewed a series of 16 children with congenital pial AVF, treated between January 2005 and August 2011. All cases presented before 5 years of age and the mode of presentation varied with age. Fourteen had a single fistula while two had multiple fistulas, one among them had cutaneous features suggestive of RASA1 mutation. MRI is the preferred initial imaging, to demonstrate anatomical location, feeders, venous varix and regional, hemispheric or diffuse cerebralmalacia. Digital subtraction angiography performed during the first therapeutic attempt showed venous varix along with arterial enlargement as the most common angio-architecture. All cases were embolized with N-butyl-cyanoacrylate (NBCA) with or without coiling of the venous sac to attain flow control. Hypotension and a higher concentration of glue were used to aid controlled glue injections. Dural AVF and reactive angiogenesis are not uncommon sequlae found on follow-up angiogram. Outcomes were excellent in 75% and good in 19%. CONCLUSION: Congenital pial AVF are caused by a missed step in vascular development during the early embryonic stage. Transarterial endovascular embolizaiton using NBCA with or without using coils to attain flow control is the treatment of choice, with low morbidity. The efficacy of treatment is high as demonstrated by the high cure rate. Follow-up angiogram is mandatory to look for recanalization, reactive angiogenesis and denovo dural AVF development.

De novo development of dural arteriovenous fistula after endovascular embolization of pial arteriovenous fistula.

BACKGROUND: The development of de novo dural arteriovenous fistula(s) following endovascular embolization of a prior high-flow pial arteriovenous fistula (PAVF) has not previously been reported and the natural history is unknown. The anatomic basis, pathophysiologic mechanism, management and outcome are discussed. METHODS: Treatment-completed congenital PAVFs treated at our center between January 2005 and August 2011 were analyzed retrospectively. Among 16 cases of PAVFs treated by endovascular embolization, four developed de novo dural arteriovenous fistulas during treatment or on follow-up that were not present before treatment. Information was collected from the clinical case records, imaging by MRI on presentation and during follow-up, all angiographic images and records during each of the procedures and during follow-up. RESULTS: The time interval between the last embolization and identification of a dural fistula ranged from 3 to 14 months. Ten fistulas were identified in four patients, seven of which were embolized, four with glue, two with Onyx18 and one with absolute alcohol. None recanalized, while one patient developed fistula in an adjacent location that was subsequently treated with radiosurgery. Not all fistulas need treatment; small fistulas with a minimal flow can safely be observed. CONCLUSIONS: De novo dural fistulas following endovascular embolization of high-flow PAVFs is not an uncommon development. They are mostly asymptomatic and develop anywhere along the drainage of the fistula, maturing over time and diagnosed during follow-up studies, emphasizing the need for follow-up angiography. They can be effectively treated by endovascular embolization. Localized refractory dural fistulas can be dealt with by radiosurgery.

Cerebral ischemic lesions detected with diffusion-weighted magnetic resonance imaging after carotid artery stenting: Comparison of several anti-embolic protection devices.

Distal embolism is an important periprocedural technical complication with carotid angioplasty and carotid artery stenting (CAS). We evaluated the safety and efficacy of protection devices used during CAS by detecting new cerebral ischemic lesions using diffusion-weighted magnetic resonance imaging in 95 patients who underwent 98 CAS procedures: 34 using single PercuSurge GuardWire, 31 using double balloon protection, 15 using proximal flow reverse protection devices, 14 using Naviballoon, and 4 using filter anti-embolic devices. Diffusion-weighted imaging was performed preoperatively and postoperatively to evaluate the presence of any new embolic cerebral lesions. Postoperative diffusion-weighted imaging revealed 117 new ischemic lesions. Three patients had new ischemic stroke, two minor and one major, all ipsilateral to the treated carotid artery. The remaining patients had clinically silent ischemia. The incidence of new embolic lesions was lower using the proximal flow reverse protection device than with the double balloon protection (33% vs. 48.4%), but the volume of ipsilateral new ischemic lesions per patient was 136.6 mm(3) vs. 86.9 mm(3), respectively. Neuroprotection with Naviballoon yielded ipsilateral lesions of large volume (86.6 mm(3)) and higher number (5.7 lesions per patient) than using the filter anti-embolic device (34.8 mm(3) and 1 lesion per patient). New cerebral ischemic lesions after neuroprotected CAS are usually silent. The lower incidence of distal ischemia using proximal flow reverse and double balloon protection devices is limited by the larger volume and higher number of ischemic lesions.

[Vertebral artery dissection due to a bone anomaly of the superior facet of C6: a rare cause of embolic stroke].

We report a rare case of repeated vertebral artery (VA) occlusion. The VA occlusion was due to a distal embolism originating from traumatic VA dissection resulting from mechanical compression due to excessive bone formation of the superior facet of C6. A 39-year-old male suffered from two embolic events in the right VA with a 4-month intervals. Three-dimensional computed tomography (3D-CT) revealed abnormal bone of the superior facet at the level of C6 and the verterbral artery compression. Angiography demonstrated the irregularity and the late clearance of the contrast material at the stenosis of VA, which was diagnosed as the dissection. Dynamic angiography showed right VA occlusion when rotating the patients head to the left and extending it backwards. External orthosis using a cervical collar for 1 month was undertaken, but the dissection remained, so coil embolization of the right VA was performed using an intravascular procedure. Because of the age of the patient, location, radiological features and clinical course, the authors considered the excessive bone formation was a bone anomaly rather than a cervical spondylotic change.

Diffusion-weighted magnetic resonance imaging in carotid angioplasty and stenting with balloon embolic protection devices.

We compared the results of two procedures to protect against distal embolism caused by embolic debris from carotid angioplasty with stent deployment (CAS) using diffusion-weighted magnetic resonance imaging (MRI). The study group comprised 39 men and 3 women (42 and 3 CAS procedures, respectively) with severe carotid stenosis (average age 70.0 +/- 6.6 years). During 20 CAS procedures the internal carotid artery was protected with a single balloon. A PercuSurge GuardWire was used for temporary occlusion. During 25 CAS procedures the internal and external carotid arteries were simultaneously temporarily occluded with a PercuSurge GuardWire and a Sentry balloon catheter, respectively. Diffusion-weighted MRI was performed 1 to 3 days after CAS. Data from 26 patients undergoing conventional angiography for diagnosis of cerebral ischemic disease, cerebral aneurysm or brain tumors were included as controls. Diffusion-weighted MRI after conventional diagnostic angiography showed ischemic spots in 3 of the 26 controls (11.5%). Ischemic spots were observed during 11 of 20 CAS procedures with the internal carotid artery protected with a single balloon (55.0%), and were observed during 9 of 25 CAS procedures with both the internal and external carotid arteries protected (36.0%). This difference was significant (P = 0.0068). Ischemic lesions appeared not only ipsilateral to the carotid stenosis but also in the contralateral carotid artery (31.9%) and vertebrobasilar territory (25.3%). Better protection was obtained with simultaneous double occlusion of both the internal and external carotid artery than with single protection of the internal carotid artery during CAS.

Angioscopic observation during carotid angioplasty with stent placement.

This clinical report is the first to describe angioscopy during carotid angioplasty with stent placement. The average observation time was 3 minutes 43 seconds in 18 cases. The view was clear in 67% of cases. Lesions in the endothelium, rupture of the fibrous cap, clots, debris detaching from plaque, and stent struts were observed. No symptomatic ischemic complications occurred. Diffusion-weighted MR imaging after angioscopy showed asymptomatic ischemic lesions in 47% of cases.