Neurological Surgery最新文献

Neurosurgeons of the future must possess the ability to engage in preoperative simulation. However, given the changing medical practices and redistribution of tasks among physicians, the significance of radiological technologists is increasing. In this article, we describe the collaboration between radiological technologists and the hospital system to simplify preoperative simulation for young physicians. Preparation for preoperative simulation is a collaborative process with radiological technologists, aiming to facilitate mutual learning and risk management. It involves recognizing and utilizing the expertise of certified radiological technologists for imaging and additional surgical support, with due consideration given to the additional fees. The creation of an in-hospital arrangement system for preoperative simulation ensures more efficient and safer workflow.

This study aimed to evaluate the clinical usefulness of zero-echo time(ZTE)-based magnetic resonance imaging(MRI)in planning an optimal surgical approach and applying ZTE for anatomical guidance during transcranial surgery. P atients who underwent transcranial surgery and carotid endarterectomy and for whom ZTE-based MRI and magnetic resonance angiography(MRA)data were obtained, were analyzed by creating ZTE/MRA fusion images and 3D-ZTE-based MRI models. We examined whether these images and models could be substituted for computed tomography imaging during neurosurgical procedures. Furthermore, the clinical usability of the 3D-ZTE-based MRI model was evaluated by comparing it with actual surgical views. ZTE/MRA fusion images and 3D-ZTE-based MRI models clearly illustrated the cranial and intracranial morphology without radiation exposure or the use of an iodinated contrast medium. The models allowed the determination of the optimum surgical approach for cerebral aneurysms, brain tumors near the brain surface, and cervical internal carotid artery stenosis by visualizing the relationship between the lesions and adjacent bone structures. However, ZTE-based MRI did not provide useful information for surgery for skull base lesions, such as vestibular schwannoma, because bone structures of the skull base often include air components, which cause signal disturbances in MRI. ZTE sequences on MRI allowed distinct visualization of not only the bone but also the vital structures around the lesion. This technology is minimally invasive and useful for preoperative planning and guidance of the optimum approach during surgery in a subset of neurosurgical diseases.

With the advent of high-resolution imaging and advancements in computational fluid dynamics(CFD)and computational structural mechanics(CSM)analyses, clinical simulation of endovascular intervention has gradually become feasible. Virtual stents have become indispensable for coil embolization. For braided stents, such as those with low-profile visualized intraluminal support and flow diverters, predicting postplacement elongation and contraction is challenging; however, software development has enabled more precise treatment planning. Additionally, simulations utilizing three-dimensional(3D)printer models can enable realistic simulations of procedures such as intracranial stents and Woven EndoBridge placement. This approach is beneficial for shunt disorders such as arteriovenous malformations and dural arteriovenous fistulas, offering 3D visualization of shunt access routes and intuitive treatment strategy planning, even for beginners. Furthermore, it can be applied to procedures such as open surgical clipping and nidus resection, aiding in the selection of suitable clips and considerations for ideal resection based on nidus curvature. Simulations using CFD, CSM, and 3D printers are crucial for training surgeons and handling new devices. Harnessing medicine-engineering synergy is essential, and regulatory approval(insurance coverage)and appropriate commercialization of simulations are paramount for the future.

In this section, we defined virtual reality(VR)surgical simulations using fusion three-dimensional(3D)images, which are 3D images created by fusing multiple medical image data. The more detailed the fusion of 3D images, the more knowledge and effort are required. In addition, 3D fusion images vary greatly with each case and depend on the skill and orientation of the image creator and the image processing software used. Some creators produce a fused 3D image with ample details to simulate tissue deformation, whereas others are limited to rough observations and use two-dimensional cross-sectional images for detailed anatomical information. Thus, there is no gold standard for creating fused 3D images or VR surgical simulations. Therefore, it is important to clarify the objective of a VR surgical simulation. An understanding of image-processing technology is useful in terms of software selection and image-processing efficiency. This section outlines the construction of fused 3D images and the use of VR surgical simulations based on actual clinical applications.

Industry-academia Collaboration is an academic activity within academia(educational institutions such as universities, research institutes, etc.)formed to research and develop new technologies, create new businesses and knowledge, and recruit outsourcing human resources. There is a collaboration between an industry(a private company, a group that engages in broad commercial activities and links research and development directly to economic activity)and academia. Amidst the dramatic changes in the environment surrounding the goals of research and development of new technologies and the creation of new businesses, there are changes in what academia can do complementarily. We will outline the changes and current situation, including the efforts of the Tohoku University Hospital.

Trigeminal neuralgia is characterized by severe lancinating pain in the face and hemifacial spasms displayed by continuous facial muscle twitching, which may impair a patient's quality of life. Before 1960, in the United States of America, the treatment of such symptoms was only partial rhizotomy of the cranial nerves, which resulted in postoperative complications.^{1, 2)} Afterwards, in the late 1960s, it became evident that the etiology of symptoms was an elicited arterial compression of the cranial nerves at the "Root Entry/Exit zone." Microvascular decompression(MVD)was introduced and finally became largely popularized by Gardner and Jannetta et al.^{3, 4)} In 1978, at the Neurosurgical Meeting in New York, I incidentally witnessed slides of MVD proposed by Jannetta, which gave me a big surprise since we were then treating such patients by old-fashioned rhizotomy. Despite much ignorance displayed even in the neurosurgical meeting, I started MVD in 1980.⁵⁾ In addition, in 1998 we held an Annual Meeting of the Japan Society for Microvascular Decompression Surgery, which has become more active in the fields of microsurgical techniques, diagnosis, monitoring, and long-term follow-up studies.^6-8) MVD is a functional neurosurgery and satisfactory results should entail a complete and permanent cure of symptoms without any postoperative sequelae. This makes MVD a sustainable surgery.

During microvascular decompression(MVD)for hemifacial spasm(HFS), trigeminal neuralgia(TN), and glossopharyngeal neuralgia(GPN), brainstem auditory-evoked potential monitoring is widely used to preserve hearing function. In MVD for HFS, abnormal muscle response monitoring is useful for identifying the offending vessels compressing the facial nerve and confirming the completion of decompression intraoperatively. The amplitude of facial motor-evoked potential by transcranial electrical stimulation in the orbicularis oculi muscle is reported to decrease after completing MVD. The Z-L response(ZLR)probably confirms the true offending vessels by stimulating the culprit vessels; then, the ZLR could disappear after decompressing the offending vessels away from the compression sites. Spontaneous electromyographic activities obtained from the mentalis muscles by injection of saline into the facial nerve reportedly decreased after MVD compared with those before MVD. In MVD for the GPN, glossopharyngeal motor-evoked potential by transcranial electrical stimulation is used to preserve swallowing function and not to assess the completion of MVD. Because MVD for both the TN and GPN can result in normalization of the hyperactivity of the sensory nerve, it may be difficult to develop any monitoring to confirm the completion of MVD during surgery.

In this feature article, we underscore the advantages of Transposition over Interposition in the management of trigeminal neuralgia and hemifacial spasm. Interposition, while effective, has raised concerns owing to long-term complications associated with the use of artificial materials, such as Teflon and silicone sponges. Transposition, on the other hand, mitigates these issues, showcasing adaptability to a range of anatomical and pathological conditions and affirming its standing as a safer and more effective treatment alternative. Each technique has distinct applications that are governed by the patient's specific anatomical and pathological needs. While Transposition is emerging as a favored option, Interposition remains relevant in specific cases, underscoring the necessity for a personalized approach to neurovascular decompression. In offering a comprehensive overview, this article is not just an academic exercise, but also a practical resource. A nuanced exploration of these surgical interventions is meant to provide readers with actionable insights, blending the current findings with real-world applicability. The goal is to foster a deeper understanding and aid practitioners in making informed decisions that are finely attuned to each patient's unique needs and conditions, ensuring optimal outcomes, while prioritizing safety and effectiveness.

Although carbamazepine is the first-line treatment option for trigeminal neuralgia, it may not be sustained long-term. The benefits of carbamazepine are offset by adverse effects that lead to its withdrawal. The alternatives to carbamazepine include gabapentin, pregabalin, and microgabalin. Although used off-label in Japan, baclofen, lamotrigine, intravenous lidocaine, and botulinum toxin type A are also effective. Clinical experience has shown that alternative treatments are less effective than carbamazepine. Therefore, they can be used instead of or in addition to carbamazepine. The adverse effects of drugs include drowsiness, dizziness, rash, bone marrow suppression, and liver dysfunction. Carbamazepine and lamotrigine are particularly likely to cause severe drug eruptions such as Stevens-Johnson syndrome and toxic epidermal necrolysis. Low-dose titration is important to avoid the development of rashes and adverse effects.

Preoperative surgical simulation via three-dimensional fusion computer graphics models have been widely accepted as a legitimate means of securing the diagnosis and treatment effectiveness of neurovascular compression. The authors discussed three factors of surgical simulation as being 1. Knowing the anatomical relationship, 2. Knowing the desirable end result of surgical intervention, and 3. Knowing how to design surgical interventions to achieve such desirable end results. Satisfying each factor requires distinct functionality from the software used in the surgical simulation. As per the imaging study used to construct the multimodal computer graphic models, CT scan and MR are usually sufficient, although renal function-permitting contrast enhancement can be a feasible option for depicting minute vessels in particular. There are three major steps in building three-dimensional fusion computer graphics models:1. Image interpretation, 2. co-registration, and 3. Segmentation. Each step comprises an essential part that must be handled with care. The segmentation step is where rigorous technological advancement takes place, although classical techniques, such as the seeded region growing method or the multi-threshold method, are still practically important. Regarding surgical simulation after three-dimensional model construction, technical challenges concerning large deformations should be recognized to ensure non-nonsense surgical simulation.