Neurological Surgery最新文献

The subtemporal approach offers the advantages of a wide surgical field in the anteroposterior direction and easy access to the proximal basilar artery. This approach can be adapted to treat low-positioned aneurysms using a tentorial incision, known as the subtemporal transtentorial approach. However, a disadvantage of the subtemporal approach is the risk of injury to the temporal lobe. To mitigate this risk, it is important to ensure proper positioning, adequate cerebrospinal fluid drainage, preservation of the bridging veins, and intermittent retraction of the temporal lobe.

Endoscopy offers access to a clear, wide surgical field in deep-brain areas. In recent years, opportunities for the use of endoscopy in endonasal or small keyhole approaches have been increasing. However, ascertaining the tumor-specific suitability of endoscopic surgery remains unclear. In this article, we introduce the general concept of endoscopic surgery for skull base tumors. The optimal goal for all types of skull base surgeries is maximum tumor removal with preservation of function. Therefore, it is important to understand the benefits and limitations of various endoscopic approaches for the skull base.

Among ruptured intracranial aneurysms, aneurysms of the vertebral artery(VA) and posterior inferior cerebellar artery(PICA) are relatively rare, and they exhibit distinct characteristics. These include: 1) a high frequency of diverse aneurysmal morphologies, such as fusiform or dissecting aneurysms; 2) proximity to the lower cranial nerves; 3) the presence of perforators to the medulla oblongata; and, 4) obstruction to the surgical approach by specific bony structures, such as the occipital condyle and jugular tubercle. Consequently, these aneurysms often require interventions that are more complex than simple clipping or coiling, which is typical for anterior circulation aneurysms. Interventions include skull base techniques such as the far-lateral approach and revascularization procedures such as occipital artery(OA)-PICA bypass. Despite these complexities, the rarity of these aneurysms and the recent advancements in endovascular procedures pose challenges for young neurosurgeons in acquiring adequate microsurgical experience. This narrative review addresses the clinical features of VA and PICA aneurysms, the history and variations in the lateral suboccipital approach for these aneurysms, and several bypass techniques for reconstructing the PICA. Lastly, we illustrate our current microsurgical practices through a case presentation accompanied by a surgical video showcasing both the far-lateral approach and the OA-PICA bypass.

The treatment landscape for ruptured cerebral aneurysms is undergoing a paradigm shift. While endovascular therapy is increasingly favored, the future demands minimally invasive approaches that prioritize both safety and a definitive cure. At our center, we meticulously tailor the treatment strategy for ruptured aneurysms to each patient. This strategy considers the aneurysm's morphology, patient characteristics, and the crucial balance between invasiveness, safety, and achieving a cure. Notably, in the hybrid era, we strive to maintain a strong foundation in both direct surgical and endovascular techniques. This ensures that our surgeons can continue to provide future patients with safe and highly curative treatment options.

In aneurysmal subarachnoid hemorrhage, the highest therapeutic priority is to ensure immediate hemostasis without intraprocedural complications. This article outlines the possible intraoperative coil embolization complications for ruptured intracranial aneurysms and discuss strategies for their prevention and treatment.

Delayed cerebral ischemia(DCI) is one of the most significant complications of subarachnoid hemorrhage. Despite significant evolution in understanding DCI pathophysiology, vasospasm affecting cerebral vessels of large and moderate diameters remain the only clinically measurable component of DCI and is therefore the primary target for intervention in the postoperative management of subarachnoid hemorrhage. In Japan, fasudil hydrochloride and ozagrel sodium are widely used to prevent vasospasms; however, their effects are sometimes insufficient. Clazosentan, a selective endothelin receptor subtype A antagonist, reduces vasospasm-related morbidity and all-cause mortality following aneurysmal subarachnoid hemorrhage. This was demonstrated in a recent randomized phase 3 trial, leading to the approval of clazosentan by the Pharmaceuticals and Medical Devices Agency in Japan. Recent advances in our understanding of subarachnoid hemorrhage will facilitate improved management to reduce the incidence of DCI.

Aneurysmal subarachnoid hemorrhage(SAH) causes brain injury and systemic complications, including cardiopulmonary dysfunction, which mutually affect each other. Post-SAH brain injury includes early brain injury(EBI) and delayed cerebral ischemia(DCI). EBI is a non-iatrogenic pathology occurring within 72 h of clinical SAH, primarily induced by increased intracranial pressure, subsequent transient global cerebral ischemia, and extravasated blood components. DCI typically develops between days 4 and 14 after clinical SAH because of erythrolysis(free hemoglobin) and EBI-mediated reactions. EBI and DCI share many pathologies, including large-artery spasm, microvascular spasm, microthrombosis, blood-brain barrier disruption, neuroinflammation, disturbance of venous outflow, and neuroelectric disturbances such as spreading depolarization and epileptic discharge. However, EBI and DCI differ not only in the timing of onset but also in their distribution, with EBI mainly occurring throughout the brain, while DCI occurs locally. Many substances, such as glutamic acid, cytokines, and matricellular proteins, mediate EBI and DCI pathologies. Further elucidation of EBI and DCI pathologies is essential for developing novel treatment strategies.

Aneurysmal subarachnoid hemorrhage(aSAH) is a critical condition that often results in severe neurological deficits. Recent studies have highlighted the role of spreading depolarization(SD) in post-aSAH secondary brain injury. SD comprises rapid and sequential changes in neuronal and glial membrane potentials that disrupt energy metabolism and induce neuronal dysfunction. Implicated in both early brain injury(EBI) and delayed cerebral ischemia(DCI), SD worsens clinical outcomes. This review explores the SD-associated mechanisms in aSAH, ascertains the contribution of SD to EBI and DCI, and identifies potential SD-targeted therapeutic strategies to improve the prognosis of aSAH.

For treating ruptured cerebral aneurysms, it is important to understand the setup and basic technique of coil embolization. Safe and effective embolization relies on preoperative considerations that determine the treatment strategy, guide the optimization of the therapeutic environment, and help in the selection of appropriate device systems. Moreover, during aneurysmal embolization, basic techniques for microcatheter shaping and navigation, safe coil introduction, and precise use of occlusion balloons are indispensable. Microcatheter shaping should be based on three-dimensional digital subtraction angiography findings as well as the axes of the parent artery and aneurysm. The operator must understand the advantages and disadvantages of the two methods for navigating the microcatheter into the aneurysm. Furthermore, it is essential to preoperatively simulate and understand the approaches for managing aneurysmal embolization-related complications, such as intraoperative aneurysmal rupture and thromboembolism. Mastery of these steps is mandatory before undertaking embolization of ruptured cerebral aneurysms.

The debate regarding the role and clinical impact of radiotherapy for meningiomas remains underdeveloped due to insufficient evidence. However, following recent revisions in the WHO classification and the integration of molecular diagnostics, there has been a substantial shift in the stratification of recurrence risks. Nevertheless, the specific circumstances under which radiotherapy proves crucial remain unclear. As risk stratification becomes more refined, the effectiveness of radiotherapy in treating high-risk meningiomas continues to be a contentious issue. Concurrently, there is vigorous discussion regarding the management of 'brain invasion in otherwise benign'(BIOB)meningiomas. The incorporation of PET imaging alongside MRI for defining radiation targets is increasingly acknowledged as advantageous. Boron neutron capture therapy(BNCT), which specifically targets the biological characteristics of tumor cells in invasive regions, is also gaining significant traction as a promising therapeutic approach for meningiomas with infiltrative components.