Neurological Surgery最新文献

Veins at the craniocervical junction are complex network structures. They empty into two main brain venous drainages, the internal jugular vein and internal vertebral venous plexus, and reroute venous blood according to postural changes. They are also involved in the etiology of dural arteriovenous shunts in this region. Hence, regional venous anatomy is crucial for interventional neuroradiologists to understand the pathophysiology and formulate therapeutic strategies. This article aims to provide a summary on venous anatomy, radiological findings, and related pathological conditions, especially for young and inexperienced interventional neuroradiologists.

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.

Primitive anastomotic arteries temporarily exist between the future internal carotid and vertebrobasilar arteries during the early embryonic period(between 28 and 32 days of life). The primitive trigeminal, otic, hypoglossal, and proatlantal intersegmental arteries serve as major blood channels to the developing vertebrobasilar circulation at this stage. These arteries are replaced by the posterior communicating and vertebral arteries, and the primitive anastomotic arteries rapidly regress following the development of the definitive vertebrobasilar circulation. Occasionally, these primitive anastomoses persist and are incidentally discovered after birth. Physicians who treat cerebrovascular diseases should be familiar with the anatomy and functions of these vessels. In this review, we discuss the embryonic basis of the carotid-vertebrobasilar anastomoses and the clinical significance of their persistent forms in adults.

This chapter outlines the cerebrovascular developmental anatomy with emphasis on the internal carotid artery(ICA), which is important for optimal endovascular treatment of cerebrovascular system disorders. Gene expression, neural crest cells, and pharyngeal arches play key roles in the embryonic development of the carotid arteries. Evolutionary inheritance in vertebrates contributes to the formation, regression, and segmental structure of these arteries. We present examples of current mutations with regard to their segmental nature; ICA mutations are discussed primarily with regard to their developmental origin from the first to third pharyngeal arches and the role of the ductus caroticus. This comprehensive review highlights the importance of understanding the developmental and anatomical nuances of the ICA to aid with accurate diagnosis and management of vascular anomalies in the clinical setting. We have focused on the complexity associated with ICA mutations, particularly those associated with the third pharyngeal arch and the need for a solid foundation of developmental and anatomical knowledge to accurately identify and interpret their significance in the adult phenotype.

The ascending pharyngeal, accessory meningeal, and lingual arteries branch from the proximal segment of the external carotid artery. These branches give rise to smaller branches that contribute blood supply to the pharyngeal mucosa, parapharyngeal tissue, middle ear, submandibular tissues, tongue, and dura mater of the middle and posterior fossa. These arteries may also supply the cranial nerves and have potential anastomotic channels that function with the internal carotid and vertebral arteries. M igration of embolic material into the vasa nervorum and potential anastomoses may cause complications. Therefore, knowledge of these functional anatomies is crucial for neuro-interventionalists.

The basal vein of Rosenthal, the vein of Galen, and the straight sinus are important venous communication routes connecting the deep, superficial, and dural sinuses. The basal vein is divided into three parts since it originates secondarily from three different areas and its venous areas are diverse. However, care should be taken because disconnection between these segments causes variations that change the venous flow path. Endovascular treatment warrants a proper understanding of this anatomical area and requires consideration of vascular occlusion and venous drainage changes.

The middle cerebral artery divides into the cortical and perforating branches that supply blood to the extensive cerebral cortex and basal ganglia. In addition to an understanding of the normal vessel diameter and length, endovascular physicians should be familiar with anatomical variations. Understanding the perfusion territory is important for accurate diagnosis of the disease type.

The superior petrosal sinus and petrosal vein are important drainage routes for the posterior cranial fossa, with some variations and collateral vessels. An anterolateral-type tentorial dural arteriovenous fistula, which occurs around the petrosal vein, often develops aggressive symptoms due to venous reflux to the brainstem and cerebellum. Neuroendovascular treatment of this fistula is usually challenging because transarterial embolization has a high risk and indications for transvenous embolization are limited. In the cavernous sinus and transverse sinus/sigmoid sinus dural arteriovenous fistulas, venous reflux to the petrosal vein is dangerous, and a treatment strategy with the occlusion of the petrosal vein is indispensable. Furthermore, attention should be paid to venous approaches through the superior petrosal sinus.

3D printers have been applied in bone-based surgeries, including craniofacial, plastic, oral, and orthopedic surgeries. The improved capabilities of diagnostic imaging equipment and 3D printers have enabled the development of more precise models, and research on surgical simulations and training in the field of neurosurgery is increasing. This review outlines the use of 3D printers in neurosurgery at our institution in terms of modeling methods and surgical simulations. Modeling with the powder-sticking lamination method using plaster as the material allows drilling, which is a surgical procedure. Therefore, it is useful for simulating skull base tumors, such as petrosectomy in a combined transpetrosal approach or anterior clinoidectomy in an orbitozygomatic approach. The color coding of each part of the model facilitates anatomical understanding, and meshed tumor modeling allows deep translucency. As shown above, the 3D printer's modeling ingenuity allows for useful surgical simulations for each case.

In STA-MCA bypass surgery, it is important to select the optimal recipient using preoperative simulation to avoid complications. We report a preoperative simulation for STA-MCA bypass using the Brain LAB iPLAN platform^®BRAIN LAB)and the 3DCG simulation software GRID^®Kompath). Here, we introduce the basics and applications of preoperative simulation for occlusive atherosclerotic lesions and present a target bypass for periventricular anastomosis and peripheral vessels of aneurysms in Moyamoya disease. By creating and visualizing 3D fusion images, the optimal donor and recipient can be selected. Determining the skin incision and extent of craniotomy according to the case is also applicable to the minimally invasive STA-MCA bypass. Preoperative simulations enable accurate pinpoint bypass surgery and prevent complications.