Neurological Surgery最新文献

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.

Long-term follow-up results from the International Subarachnoid Aneurysm Trial suggest that coiling is preferable for ruptured aneurysms treatable with both modalities. This finding has led to a growing trend towards coiling for these patients. At our institute, coiling is now the first-line treatment for ruptured aneurysms, with exceptions for middle cerebral artery aneurysms. We also favor direct surgery for small ruptured aneurysms(<3 mm), cases with massive intracerebral hematoma, or situations requiring bypass surgery. While early rebleeding after coiling is uncommon, it carries a certain risk. Therefore, we sometimes choose clipping for ruptured anterior communicating artery or posterior communicating artery aneurysms if clipping poses minimal technical difficulty. To achieve optimal outcomes for ruptured aneurysms, a combined approach is crucial. This involves safe and effective endovascular treatment alongside necessary direct surgical interventions.

Ruptured intracranial aneurysm(IA) leads to aneurysmal subarachnoid hemorrhage(aSAH), which is the most severe type of stroke. Besides age, sex, and alcohol consumption, family history is considered an important risk factor. Approximately 5% of the Japanese population is affected by unruptured cerebral aneurysms. However, their developmental processes and pathologies remain unclear. Familial cerebral aneurysms account for 10% of all cerebral aneurysm cases, and somatic gene mutations are believed to be involved in their development. This review summarizes the recent findings from family-based, genome-wide association, sequencing, and somatic gene mutation studies on IA.