Neurological Surgery最新文献

Intracranial aneurysms occur frequently; however, only a few of these rupture to cause subarachnoid hemorrhage. This presents a dilemma regarding the course of appropriate treatment. In the last decade, the wide utilization of magnetic resonance imaging-based vessel wall imaging(VWI) has facilitated the assessment of aneurysm wall enhancement(AWE), which has garnered significant attention. In 2013, initial reports highlighted that AWE was characteristic of ruptured aneurysms whereas, in 2014, AWE was identified as a characteristic feature of unruptured aneurysms with a high risk of rupture. Several studies have supported these findings since then. VWI, a novel modality that visualizes the inflammation of the aneurysmal wall, is considered highly useful for the diagnosis of aneurysms. This review discusses the key literature on AWE. Long-term prospective studies are warranted to determine whether AWE is an independent risk factor for aneurysmal progression.

Ruptured cerebral aneurysms have a higher incidence of direct surgery-related adverse events compared to unruptured aneurysms owing to challenging surgical conditions, such as difficulties in surgical exposure, cerebral edema, and intraoperative aneurysmal rupture, that increase the intraprocedural difficulty. The most common surgical adverse event is intraoperative rupture, with uncontrolled ruptures(during pre-dissection or from a tear in the aneurysm neck) often resulting in poor clinical outcomes. The key strategies for intraoperative rupture include staying calm, controlling bleeding, and ensuring hemostasis through appropriate methods. Given the advances in endovascular therapy for intracranial aneurysms, the number of microsurgical procedures has been decreasing. Thus, neurosurgeons at each facility need to prepare and gain experience in handling intraoperative ruptures.

In recent years, the association of the microbiome with various diseases has been reported. The oral and gut microbiomes have been linked to cerebral aneurysms and are involved in the systemic inflammatory response, which is mediated mainly via the immune system. Chronic inflammation plays an important role in the pathogenesis and rupture of cerebral aneurysms, and the microbiome is potentially involved in this process. Moreover, the gut microbiome is involved in acute brain injury following subarachnoid hemorrhage. Thus, further studies on microbiome-targeted treatments for cerebral aneurysm are required.

Delayed cerebral vasospasm is a major complication following subarachnoid hemorrhage and a primary cause of delayed cerebral ischemia. While various preventive treatments exist, some patients still develop severe vasospasm, highlighting the need for better rescue therapies. This article explores endovascular treatment as a rescue option for vasospasm, focusing on the clinical characteristics and roles of intra-arterial vasodilator injection therapy and percutaneous transluminal angioplasty(PTA). Despite a lack of strong evidence from large clinical trials, advancements in endovascular technology have positioned both intra-arterial vasodilator injection therapy and PTA as promising and safe rescue options for severe vasospasm. Careful selection of the appropriate approach is crucial for achieving optimal clinical outcomes, considering the unique characteristics, advantages, and limitations of each method. Further clinical trials are necessary to definitively confirm this hypothesis.

The interhemispheric approach is very useful for the safe and reliable clipping of ruptured anterior communicating aneurysms. This approach enables surgeons to directly visualize the aneurysm and the surrounding vessels, including perforators, and provides a wide surgical corridor for clip insertion from multiple directions. Furthermore, in challenging situations, this approach facilitates vascular reconstruction without the need for graft harvesting. However, because of the procedural difficulty, many young and inexperienced neurosurgeons may hesitate to perform this technique. Therefore, this study aimed to provide useful tips, based on intraoperative photography, for skin and dural incisions, prevention of cerebrospinal fluid leakage and olfactory impairment, and fundamental steps for opening tight interhemispheric fissures. Finally, representative challenging cases that were adequately managed using the advantages of this approach are presented.

The transsylvian approach is one of the most commonly used approaches in neurosurgery and is essential for clipping aneurysms located in the anterior cranial circulation, such as the middle cerebral artery, internal carotid artery, and anterior communicating artery. Moreover, basilar artery aneurysms can be clipped using this approach, albeit with some modifications. Important tips for dissecting the Sylvian fissures include reliable visualization, anatomical recognition, and steady manipulation. The actual steps are as follows: determine the affiliation of the arteries and veins, gently move the brain to create a wide space, cut the arachnoid mater, and follow the course of the arteries. In case of subarachnoid hemorrhage, irrigation and flushing out the hematoma is the key step involved in recognizing the structure and safely performing surgery. Here, we describe the basic key operative techniques for performing clipping via the transsylvian approach.

Ruptured vertebral artery dissecting aneurysms(VADA) carry a poor prognosis owing to the high rates of rebleeding, stroke, and mortality without appropriate treatment. Various endovascular techniques are employed to treat these aneurysms. Deconstructive techniques, involving internal trapping with coils, often achieve complete angiographic occlusion at higher rates; however, they carry a risk of medullary infarction. Reconstructive techniques using neck-bridge stents preserve the parent vessel and reduce perioperative morbidity. Nevertheless, these techniques are associated with a higher rate of aneurysmal rebleeding or recurrence. Optimal treatment modalities should be chosen based on the anatomical characteristics of the aneurysm and the trade-off between risks and benefits.

Intracranial aneurysms, a major cause of subarachnoid hemorrhage(SAH), pose a significant social burden due to their poor patient outcomes. Recent studies, including those using animal models, have shed light on a new disease concept: intracranial aneurysms as a chronic inflammatory disease. This process is triggered by abnormal hemodynamic forces and mediated by immune cells like macrophages and neutrophils. The initiation of intracranial aneurysms is a two-step process. First, high wall shear stress and mechanical stretch work together to promote macrophage infiltration into the arterial walls. This infiltration is facilitated by endothelial cells and fibroblasts, which are activated to produce chemoattractants. Once the lesions enlarge, low wall shear stress and turbulent flow take over, maintaining macrophage infiltration. As the disease progresses towards rupture, infiltration creates hypoxic conditions that exacerbate the situation. These conditions, in turn, induce the formation of neovessels at the weakest point of the aneurysm and promote specific inflammatory microenvironments rich in neutrophils. The excessive tissue destruction caused by neutrophil-mediated inflammation ultimately leads to lesion rupture. Therefore, intracranial aneurysm rupture requires not only structural changes but also qualitative alterations within the chronic inflammatory environment. This suggests that factors mediating chronic inflammation could be potential targets for predicting or preventing aneurysm rupture.

Despite advancements in neurosurgical techniques, subarachnoid hemorrhage(SAH) caused by the rupture of a partially thrombosed intracranial giant aneurysm remains a challenging clinical entity. This report describes the successful treatment of an 80-year-old male patient with SAH due to a ruptured, partially thrombosed intracranial giant aneurysm. The patient underwent a staged endovascular strategy using a flow diverter. The patient presented with SAH secondary to a ruptured, partially thrombosed intracranial giant aneurysm located at the C2 portion of the internal carotid artery and involving the origin of the posterior communicating artery(Pcom). Imaging revealed a dorsomedial rupture point on the aneurysm. A two-stage endovascular intervention(IVR) was performed. The first stage involved coil embolization aimed at covering the rupture point. Following the resolution of the vasospasm and the acute phase of SAH, the second stage involved the deployment of a pipeline embolization device. Digital subtraction angiography performed one month after the second stage IVR demonstrated a significant reduction in aneurysm filling, with preserved flow to the Pcom artery. We will discuss the technical details and rationale behind the staged endovascular approach in this complex case.

With advances in genetic analysis technology, the genetic and molecular backgrounds of cerebrovascular diseases have become clearer. In moyamoya disease and intracranial artery stenosis, RNF213 p.Arg4810Lys has been identified as a disease susceptibility gene variant(germline variant), and various analyses have been conducted. PDGFRB mutations have been identified as characteristic somatic variants in cerebral aneurysms and are attracting attention. In addition, PIK3CA and MAP3K3 mutaions have been identified in cerebral cavernous malformations as somatic variants. Moreover, KRAS and BRAF mutations have been identified in arteriovenous malformations as somatic variants, respectively. Further studies are in progress. We reviewed the results of recent genetic analyses of cerebrovascular diseases, focusing particularly on genetic mutations.