Taichiro Kawakami

Dural Venous System in the Cavernous Sinus: A Literature Review and Embryological, Functional, and Endovascular Clinical Considerations

The cavernous sinus (CS) is one of the cranial dural venous sinuses. It differs from other dural sinuses due to its many afferent and efferent venous connections with adjacent structures. It is important to know well about its complex venous anatomy to conduct safe and effective endovascular interventions for the CS. Thus, we reviewed previous literatures concerning the morphological and functional venous anatomy and the embryology of the CS. The CS is a complex of venous channels from embryologically different origins. These venous channels have more or less retained their distinct original roles of venous drainage, even after alterations through the embryological developmental process, and can be categorized into three longitudinal venous axes based on their topological and functional features. Venous channels medial to the internal carotid artery “medial venous axis” carry venous drainage from the skull base, chondrocranium and the hypophysis, with no direct participation in cerebral drainage. Venous channels lateral to the cranial nerves “lateral venous axis” are exclusively for cerebral venous drainage. Venous channels between the internal carotid artery and cranial nerves “intermediate venous axis” contribute to all the venous drainage from adjacent structures, directly from the orbit and membranous skull, indirectly through medial and lateral venous axes from the chondrocranium, the hypophysis, and the brain. This concept of longitudinal venous axes in the CS may be useful during endovascular interventions for the CS considering our better understandings of its functions in venous drainage.

Anomalous Origin of the Anterior Choroidal Artery

We describe a very rare case of anomalous origin of the anterior choroidal artery. In our case the anterior choroidal artery arises from the internal carotid artery proximal to the posterior communicating artery.

Choroid plexus AVM with anomalous origin of the capsulothalamic artery: A case report

Background and importance Traditionally, it has been believed that the plexal segment of the anterior choroidal artery (AChoA) can be sacrificed safely. Here, we present a case of choroid plexus arteriovenous malformation (AVM) in which the capsulothalamic artery originated from distal plexal segment of the AChoA. Clinical presentation A 45-year-old man was diagnosed with arteriovenous malformation involving the left inferior horn in screening MRI. Preceding stereotactic radiosurgery, transarterial target embolization was performed. In this procedure, 20% n-butyl-2-cyanoacrylate (NBCA) was successfully injected from the lateral plexal branch of the AChoA. After embolization, right homonymous hemianopsia developed due to cerebral infarction on the left optic radiation. This infarction was considered to be within the territory of the capsulothalamic artery. Conclusion This anomalous capsulothalamic artery might be formed by hemodynamic compromise of the brain surrounding AVM in early gestation. We must be aware of this unusual anatomical variation to avoid ischemic complication in embolization of the AChoA.

Extracranial internal carotid artery dissection caused by compression from a giant osteophyte due to atlantoaxial osteoarthritis: case report

Deformed osseous structures have been reported as rare causes of extracranial internal carotid artery (ICA) dissection, including the styloid process and the hyoid bone. Here, the authors describe the first known case of symptomatic ICA dissection caused by a giant osteophyte due to atlantoaxial osteoarthritis. The left ICA was fixed at the skull base and at the ICA portion compressed by the osteophyte, and it was highly stretched and injured between the two portions during neck rotation. The patient was successfully treated with ligation of the affected ICA following balloon test occlusion. Atlantoaxial osteoarthritis should be considered in the differential diagnosis of ICA dissection in patients with a severely deformed cervical spine.

An innovative technique for detecting the caudal end of occluded inferior petrosal sinus in cavernous arteriovenous fistula using intravascular ultrasonography—technical note

IntroductionAlthough cavernous sinus (CS) dural arteriovenous fistulas (d-AVFs) are usually treated with transvenous embolization (TVE) via the inferior petrosal sinus (IPS), IPSs are sometimes thrombosed and angiographically invisible. In such cases, the first obstacle to TVE is detecting the entry to the IPS. We report a new technique for TVE via IPS using intravascular ultrasonography (IVUS).MethodsThree consecutive cases of CS d-AVF with ipsilateral or bilateral IPS occlusion were involved in this study. On TVE, the orifice of the IPS was investigated with IVUS placed in the jugular vein or jugular bulb.ResultsThis technique has been successfully adapted in all three cases. In two of these cases, IPS was well visualized with the help of IVUS, and TVE was successfully performed.ConclusionTo our knowledge, this is the first report to mention the usefulness of IVUS for detecting angiographically occult IPS.

The Usefulness of Subcutaneous Infiltration of Epinephrine-Containing Lidocaine for Curative Transarterial Embolization of Dural Arteriovenous Fistula: A Technical Note

Recently, transarterial embolization (TAE) with liquid embolic materials has been recognized as one of the curative therapeutic options for non-sinus type dural arteriovenous fistula (d-AVF). To prevent glue fragmentation and incomplete obliteration, flow reduction of transosseous high-flow feeders is one of the key points of this therapy. However, flow reduction of transosseous feeders is sometimes difficult with previously reported techniques such as particle embolization, manual compression, or proximal balloon occlusion. This report introduces a new technique to reduce the flow of transosseous feeders using epinephrine-containing lidocaine, and describes a case of intracranial d-AVF successfully treated with this technique. The usefulness and efficacy of the technique are discussed.

Pitfalls during the Embolization and Evaluation after the Embolization for the Skull Base Meningiomas

Pitfall during the embolization and evaluation after the embolization for skull base meningiomas supplied by meningeal arteries of internal carotid artery (ICA) are reported. This study includes 15 cases of skull base meningiomas (two males and 13 females) that supplied by meningeal branches of internal carotid artery. The preoperative embolization was performed by these feeders. MRI findings and serum levels of C-reactive protein (CRP) after the embolization were examined. In ten patients among 15 patients the meningeal branches of ICA were dominant feeders. In ten patients out of 15 patients, the embolization from the meningeal branches of ICA was possible. Eight patients out of these ten patients were suffered from high fever and increase of serum level of CRP after the embolization. During the embolization for skull base meningiomas, the existence of collateral pathways between the ICA system and external carotid artery system were identified. The increase of serum levels of CRP might be recognized in the patients that effective embolization were performed.