Neurological Surgery最新文献

What is the most important factor to achieve successful surgery for deep-seated brain tumors with preservation of brain functions? Definitely, it is to identify the tumor origin site at which a tumor arose and select appropriate surgical approaches that immediately lead directly to the site in the early stage of surgery, minimizing damages of cortices and important white matter bundles, and controlling main arterial supply to the tumor. For this, neurosurgeons must have thorough knowledge of brain anatomy and function, and tailor the best surgical approach for each patient, based on three-dimensional anatomical simulation. For lesions situated in the posterior and lower part of the thalamus and extending to the lateral part, two "cross-court" approaches; the occipital transtentorial/falcine and infratentorial supracerebellar transtentorial approaches, provide a wide corridor to even the lateral aspect of the thalamus and early access to the posterior choroidal arteries, usually main feeders of this territory tumors, without damaging any cerebral cortices and major white matter bundles. Here, we describe the selection of approaches for two representative cases and demonstrate surgical procedures and postoperative courses.

This article detailly describes the subtemporal-transtentorial STA-SCA bypass technique. Through temporal base drilling, copious cerebrospinal fluid evacuation before retraction, and sufficient retraction of the temporal lobe preserving the veins of the temporal base would be primodial to obtain an appropriate surgical field. Refrection of the tentrial free edge and identification of recipient SCA posterior to the entry point of the trochlear nerve into the cavernous sinus is a micro-anatomical key. Bilateral bayonet-type needle holders and forceps should be used not to shadow the surgical corridor with one's hands.

With the development of endoscopic and peripheral instruments, endonasal or transcranial endoscopic surgery for skull-base tumors has become more common. Preoperative simulation makes it relatively easy to understand the anatomical relationship between skull base tumors and the surrounding vital structures, which vary with each case. This may lead to the avoidance of complications and an improvement in the removal rate. Especially in cases of skull base tumors where multiple surgical approaches are possible, the three-dimensional model can be used to confirm the surgical field for each approach and consider the most appropriate. With the development of endovascular treatment and radiotherapy, experience in craniotomy has decreased. Young neurosurgeons need to develop skills to learn as efficiently as possible from their limited experience. Therefore, it is extremely useful to provide an environment that allows for easier preoperative simulations.

Several studies have reported the importance of preoperative simulations. This report describes the methods and utility of neuroendovascular treatment using a three-dimensional(3D)-printed hollow cerebral aneurysm model. This model was created using a stereolithography apparatus-type 3D printer with digital imaging and communications in medicine data from 3D digital subtraction angiograms. The 3D model was used to perform preoperative simulations of microcatheter placement in aneurysms, microguidewire manipulation, and stent deployment. We performed each simulated procedure during surgery. The hollow cerebral aneurysm 3D model can also be used as a training model for surgical trainees. Preoperative simulation using a high-precision hollow cerebral aneurysm model created using 3D printers enables the discussion of specific treatment strategies for each case, including new devices and device sizes, and is expected to develop into "tailor-made medicine" in the future, contributing to safe and reliable treatment implementation.

Preoperative simulation images creates an accurate visualization of a surgical field. The anatomical relationship of the cranial nerves, arteries, brainstem, and related bony protrusions is important in skull base surgery. However, an operator's intention is unclear for a less experienced neurosurgeon. Three-dimensional(3D)fusion images of computed tomography and magnetic resonance imaging created using a workstation aids precise surgical planning and safety management. Since the simulation images allows to perform virtual surgery, a déjà vu effect for the surgeon can be obtained. Additionally, since 3D surgical images can be used for preoperative consideration and postoperative verification, discussion among the team members is effective from the perspective of surgical education for residents and medical students. Significance of preoperative simulation images will increase eventually.

Hemangioblastomas are richly vascular tumors. Therefore, visualizing the vascular anatomy of their feeders and drainers is important for planning surgical excision. Preoperative three-dimensional computer graphic(3DCG)images are useful for determining the number, location, and course of their feeders and drainers.

In patients with intractable epilepsy, seizure focus resection can yield favorable seizure outcomes. First, the localization of the seizure focus is estimated by noninvasive methods such as magnetic resonance imaging(MRI), video-electroencephalography(EEG)monitoring, nuclear medicine examinations, magnetoencephalography, and neuropsychological tests. A subgroup of patients may require additional information obtained from the intracranial EEG. There are two major methods for intracranial EEG: intracranial EEG with subdural grid electrodes(SDG)and stereotactic electroencephalography. If the estimated seizure focus overlaps with the eloquent area in noninvasive studies, the margin and extent of the resection are determined by the results of intracranial EEG and functional mapping by electrical cortical stimulation. Herein, we present a case of lobe epilepsy with subtle MRI lesions in the superior temporal sulcus of the language-dominant hemisphere. The results of the SDG and functional mapping showed that the seizure onset zone overlapped with the language area. Resection of the middle and inferior temporal gyri and multiple transections of the language area resulted in Engel IIB seizure outcomes. In such cases, a thorough preoperative simulation is required to determine the best resection margin for seizure control and functional preservation.

The craniovertebral junction not only contains anatomically important structures such as the medulla oblongata, upper cervical spinal cord, and vertebral artery, but also controls the dynamic movements of flexion, extension, and rotation of the head and neck. Consequently, instability and spinal deformities can easily occur in the craniovertebral region, and appropriate treatment should be selected based on the specificity of the lesion. Basilar invagination often involves bone and vascular anomalies and fusion surgery is often required. Therefore, careful pre-operative simulations are necessary. The creation and use of three-dimensional bone models, including image navigation, are useful for surgical simulation.

Preoperative simulation for endoscopic endonasal approach(EEA)using computed tomography and magnetic resonance imaging evaluates tumor extension and the relationship between adjacent structure(the pituitary stalk, major vessels, and cranial nerves); therefore, preoperative planning of nasal procedure, skull base bony removal, and cranial base reconstruction are possible. Additionally, three-dimensional(3D)fusion image aids surgeons to visualize intraoperative 3D findings. These preoperative simulations are critical to avoid complications and predict pitfalls perioperatively. However, tumor consistency or adhesion with adjacent structure cannot be predicted but is judged perioperatively, which affects the extent of tumor resection. This manuscript describes important points of preoperative simulation for EEA, especially the transplanum-transtuberculum approach for craniopharyngiomas or tuberculum sellae meningiomas, showing some examples in patients.

Recently, three-dimensional(3D)holograms from mixed-reality(MR)devices have become available in the medical field. 3D holographic images can provide immersive and intuitive information that has been reported to be very useful for preoperative simulations. Compared with conventional 3D images on a two-dimensional(2D)monitor, 3D holograms offer a higher level of realism, allowing observation of the images anytime and anywhere if the MR device is operational. Even during surgery, surgeons can check realistic 3D holograms in front of them, above the surgical field, without having to turn their heads toward a 2D monitor on the wall. 3D holograms can also be used for neuronavigation if the hologram is tracked to the patient's real head. This method can be defined as 3D augmented reality(AR)navigation, which shows a hologram of a target, such as a tumor or aneurysm, inside the head and brain. In the future, interventions using these techniques with 3D holograms from MR devices are expected to evolve and develop new types of treatments for endoscopic surgery or fluoroscopy-guided endovascular surgery.