At the “New Concept of Minimally Invasive Surgery Symposium” held in Beijing in 2001, more than 10 academicians from both academies proposed that minimally invasive surgery is the sublimation of surgery in the 21st century, and “minimally invasive” is the new realm of surgery. Minimally invasive” is the new realm of surgery. Any treatment measure that minimizes the surgical damage to tissues, lifts the patient’s lesion to the maximum extent, and preserves the patient’s physiological function to the maximum extent should belong to minimally invasive surgery. Minimally invasive neurosurgery, as a branch of surgery, is the belief of neurosurgeons to minimize the trauma to the patient’s body surface and body tissues when dealing with neurological patients, and to do their best to pursue the “minimally invasive” surgery. This is a new development in the field of neurosurgery. With the continuous progress of neurobiological research, the research and application of human genome project and neural stem cells, the rapid development of computer information technology, new discoveries in material science, these all provide the theoretical basis and technical guarantee for the renewal of the concept of neurosurgery, and promote the development of modern neurosurgery. Following the 1950s, classical neurosurgery tended to mature; in the second half of the 20th century, international microscopic neurosurgery techniques developed rapidly and became popular; in the 1990s, neurosurgery entered the minimally invasive era. Minimally invasive neurosurgery includes six aspects: (i) image-guided surgery; (ii) micro-bone window surgical access; (iii) neuroendoscopy-assisted surgery; (iv) intravascular intervention; (v) three-dimensional radiosurgery; (vi) molecular neurosurgery (neural stem cells and gene therapy and other technologies). In the past 10 years, minimally invasive neurosurgery has been gradually developed in China, and in some economically developed regions, minimally invasive neurosurgery techniques have reached or are close to the international advanced level, but on a national scale, the development is still unbalanced, and it is necessary to update the concept of minimally invasive neurosurgery, popularize relevant minimally invasive basic knowledge and standardize minimally invasive neurosurgery techniques.
A hundred-year history of neurosurgery
In 2001, archaeologists found a human skull about 5000 years old in Gaorao, Shandong Province, with clear cranial traces on the right occipital area. However, the history of human neurosurgery in the world with available records for academic research has developed most rapidly in the 20th century. The history of neurosurgery in the last 100 years can be roughly divided into three stages, namely classical neurosurgery, microneurosurgery and minimally invasive neurosurgery. The classical neurosurgery stage was represented by Cushing (1869-1939) and Dandy (1886-1946). At this stage, the diagnostic means for neurological disorders were primitive, and only when patients had obvious neurological deficits, neurologists could make anatomical localization diagnosis based on the symptoms of neurological deficits and determine the approximate location of intracranial lesions before the surgeons opened the skull for surgical treatment. The cranial surgery of neurosurgery in this period was formed based on anatomical brain lobes, classical standard craniotomy, and the location of intracranial lesions was determined according to the neurological localization, combined with pneumocephalus (ventricle) and cerebral angiography, and the surgical maneuver was selected. At that time, deep surgical field illumination relied on lighted brain pressure plates, which were poorly lit, and large bone flap craniotomy was generally used to ensure the reliability of probing. Since the accuracy of preoperative localization was relatively poor, the surgical space was often obtained by removing lobes of the brain to search for deep tumors. after the 1950s, the stage of micro-neurosurgery was entered. The generation of neurosurgeons represented by Yasargil, after more than 20 years of efforts, established and developed and perfected the micro-neurosurgery technique, which pushed the treatment level of neurosurgery to a brand new stage. At this stage, there was an in-depth understanding of brain function and the application of neurological function monitoring during surgery, which increased the functional protection of brain and nerves. At the same time, epoch-making revolutionary changes in diagnostic techniques occurred, with the successive emergence of CT, MRI and DSA, which provided reliable imaging assurance for early detection and accurate localization of intracranial lesions. In the early 1970s, after more than 10 years of research and training, the international neurosurgical community was able to develop a series of microsurgical instruments and devices, such as high-speed cranial drills, controlled operating beds and headstocks, automatic retractors, ultrasonic aspirators, bipolar electrocoagulation, and hemostatic gauze, which solved the problems of lighting, narrow operating space, and hemostasis that confused neurosurgery. completed practical research and training in micro (brain) dissection, laying a reliable foundation for the popularization and standardization of micro neurosurgery. Microscopic neurosurgery advanced the classical neurosurgical “lobar surgery” to focal resection surgery, minimizing damage and disturbance to brain tissue, and explored new approaches: the pterygoid point approach, the transcranial bony approach, and the frontal orbitozygomatic approach, the common feature of these surgical approaches is to sacrifice part of the skull base bone structure, reducing the pull on the brain, and to reach the lesion through the extracerebral to reach the lesion. Following the establishment of microscopic neurosurgery in the 1950s, after nearly half a century of development and improvement, microscopic neurosurgery has been popularized in the international neurosurgery field and gradually stepped into the era of minimally invasive neurosurgery.
Minimally invasive neurosurgery
1.Overview
Minimally invasive neurosurgery (minimally invasive neurosurgery) is established and developed on the basis of micro-neurosurgery. In the late 20th century, with the support of many high-technology, the emergence of
positron emission tomography (PET), functional magnetic resonance (fMR), three-dimensional cerebral angiography (3d-DSA) and magnetoencephalography (magneto-
phalogram (MEG), which not only allows early, accurate and rapid diagnosis of neurological diseases, but also localizes important brain functions such as limb movement and language in images that are directly visible, providing reliable imaging to avoid damage to these neurological functions during surgery. At the same time, the combination of imaging and computer technology, newly developed engineering materials for medical clinical use has led to the emergence of a large number of new high-quality surgical equipment and instruments, such as image-guided surgery, neuroendoscopy, stereotactic radiotherapy (x-knife, γ-knife), cerebral blood flow and electrophysiological monitoring, and other equipment, which strongly promote the development of minimally invasive surgery. In addition, with the progress of society, the concept of treatment is gradually changing from purely disease-centered to patient-centered, and the concept of treatment in the 21st century is changing to a “social-psychological-biological” model.
2.Minimally invasive concept
Minimally invasive neurosurgery concept is in the diagnosis and treatment of neurosurgical disorders, to minimize the medical source of injury, with the least invasive operation, the maximum protection, restoration of brain nerve function, to solve the patient’s pain. The concept of minimally invasive neurosurgery should be understood comprehensively. The one-sided perception of minimally invasive neurosurgery as small incision craniotomy or the application of a certain surgical instrument during surgery is a misinterpretation of the concept of minimally invasive neurosurgery. Minimally invasive neurosurgery is characterized by miniaturization, intelligence and closure, making the surgery safer and more reliable, while shortening the patient’s hospital stay and recovery period, and also reducing medical costs.
Minimally invasive neurosurgery techniques
1.Image-guided neurosurgery
Image-guided neurosurgery (IGS), also known as neuronavigation technology or frameless stereotactic surgery, is an important part of minimally invasive neurosurgery and is a modern technology developed from brain stereotactic surgery. In the early 20th century, from 1906 to 1908, Henry and Clarke designed a head frame device for the study of deep brain anatomy in animals. Based on this, in 1912, Clarke first designed the frame apparatus for human use. Since then, research on brain stereotactic instruments has not stopped. in 1949, Leksell designed a semi-arching cephalic frame that laid the foundation for the development of brain stereotactic surgery. in the early 20th century, early brain stereotactic surgery used imaging data from cranial plain films and pneumoencephalography to locate lesions based on geometric principles, expecting to accurately detect intracranial lesions. In 1980, Leksell designed an image-guided device for CT & MRI with frames. 1980s, frameless brain stereotactic surgery emerged, changing the traditional craniotomy approach and accelerating the development of minimally invasive neurosurgery. development process. The image navigation system instrumentation is composed of infrared camera array, computer work platform and tracking instruments. It includes: (1) infrared camera array; (2) computer work platform; (3) reference ring; and (4) navigation probe (power parameter frame). Application of image guidance in surgery: ① Cranio-cerebral surgery: In the operation of tumor removal, the image guidance system provides information on the extent of tumor resection lesion, accurately removes the lesion and avoids damage to the normal brain tissue aspect, which improves the surgical effect. The transsphenoidal human pathway to remove pituitary adenoma can replace the intraoperative monitoring of C-arm to avoid radioactive contamination. At the same time, neuronavigation can assist in marking important intracranial structures to avoid injury during craniotomy. ②Spine surgery: Image guidance is used for implant surgery of the spine to safely implant screws and fixation plates, especially in the implantation of cervical joint replacement screws, anterior displacement of the spine, spinal trauma and corrective fusion surgery. It assists in the removal of tumors and reduces damage to the spinal cord.
2.Micro bone window approach
The “keyhole approach”, which is directly translated as “lockhole approach”, is a metaphor for a tiny cranial opening, and is one of the important symbols of minimally invasive neurosurgery, which has been used in neurosurgery since 1990. Its advantages are small surgical trauma, reduction of medically induced injuries, improvement of surgical results, and raising the micro-neurosurgery technology to a new level. During craniotomy, it is harmful to expose brain tissues in a wide range in a non-physiological environment. Reducing the extent of craniotomy reduces the chance of complications such as postoperative epilepsy and postoperative hematoma. The microbony window approach can be used for surgery of intracranial tumors and cerebrovascular disease, especially for the treatment of skull base lesions such as intracranial aneurysms, pituitary tumors, craniopharyngiomas, auditory neuromas, and cavernous hemangiomas. The general microbone window maneuver has a bone flap of about 2.5×3.0 cm, and the commonly used microbone window maneuvers are.
(1) longitudinal fissure maneuver.
(2) Inferior temporal foramina maneuver (pterygoid point maneuver).
(3) supraorbital foramen maneuver (brow arch maneuver).
(4) Individualized surgical approach: according to the different conditions (size and nature) of each patient’s lesion, the best surgical approach is selected.
3.Neuroendoscopic-assisted surgery
It can reduce the scope of craniotomy and enlarge the images of anatomical structures in the surgical field, enhance local lighting, and improve the surgical effect. The advantages of neuroendoscopy: Compared with the operating microscope, neuroendoscopic surgery has three advantages: ① The endoscopic view tube itself can have a lateral view, so when the lesion is reached, a panoramic view can be obtained, and the lesion can be “close-up”, and the image can be magnified to identify the important nerve and vascular structures lateral to the lesion and around the lesion, and guide the removal of the surrounding lesion tissue. The endoscope can be angled to reveal some surgical procedures. The angled endoscope shows some corners of the pontocerebellar horn and basal pool that cannot be reached by the operating microscope. ②In deeper fields, the light source brightness of the operating microscope has decayed, while the neuroendoscope is close illumination, although the stereoscopic image is slightly different than the microscopic simple image, but the clarity of the deep field is significantly better than the operating microscope; local illumination can be increased and the light brightness is softer; ③The endoscope body is long and small in cross-section, which is suitable for operating in narrow cavities and orifices. The application of neuroendoscopic techniques in neurosurgery includes three forms of endoscopic surgery alone (ES), endoscope-assisted microneurosurgery (EAM) and endoscope-controlled microneurosurgery (ECM). ② Complications of neuroendoscopic surgery: The complication rate of neuroendoscopic surgery is low, among which the main ones related to the endoscope itself are: ① side injuries caused by improper operation; ② infections: in addition to incomplete sterilization of instruments, contamination during the interaction of endoscope a microscope.
Prospects of minimally invasive neurosurgery
1.Gene therapy
The greatest project in human history – the Human Genome Project is not only to decipher the code of human genes, but more importantly to find ways to prevent and treat diseases at the molecular level. The development of cellular and molecular biology has made gene therapy possible in the central nervous system, called cellular molecular neurosurgery. On the one hand, there is the identification of genes responsible for neurosurgical diseases. Neurological diseases that have been clearly identified as genetic genetic disorders such as lysosomal storage disorder, Sandhoff syndrome, Lesch-Nyhan syndrome, cerebral cavernous hemangioma, neurofibromatosis, etc. On the other hand, gene therapy for neurological disorders are.
(1) Total gene replacement of cells in the central nervous system: used to correct hereditary neurodegenerative lesions such as enzyme dysfunction, such as treatment of lysosomal storage disorders. Total gene replacement for enzyme dysfunction requires a viral vector system capable of non-toxic long-term gene expression in neuronal and glial cells, neural stem cells capable of acting as vectors for gene therapy, and gene replacement with normal alleles that can effectively eliminate dominant manifestations of disease in the CNS due to recessive mutations in a single gene.
(2) Gene therapy to restore cellular functions at specific locations in the CNS: used to restore specific subpopulations of nerve cells that have lost function during neurodegeneration. The transfer of viral vector-mediated therapeutic genes to site-specific subpopulations of neuronal cells in the brain, with tight regulation of gene transcription and protein expression, can be used to restore function in site-specific neurodegenerative lesions. Or transplantation of genetically altered cells or embryonic grafts to produce specific neurotransmission or growth factors that restore neurological deficits in specific parts of the central nervous system caused by neurological dysfunction. Examples include gene therapy for Parkinson’s disease and Alzheimer’s disease.
(3) Gene therapy for brain tumors: Gene therapy for brain tumors requires that the transferred genes have special anti-tumor effects and can selectively express toxic genes to cause lysis and necrosis of tumor cells, resist tumor growth, and ultimately kill tumors without causing damage to normal brain tissue. The combination of surgery, radiotherapy and gene therapy can prolong the survival of patients with certain tumors compared with traditional tumor treatments. In addition, immunotherapy can be used, which can improve the efficacy of treating certain tumors.
(4) Gene therapy for stroke: Gene therapy for stroke leads to therapeutic genes that can protect ischemically damaged nerve cells from apoptosis and genes that control the expression of different inflammatory regulatory factors in the brain. 3 to 5 weeks of transient gene expression is beneficial for normal repair processes and angiogenesis in ischemic diseases and can achieve therapeutic purposes.
2.Study of neural stem cells
Neural stem cells have two distinctive features: first, they have a high degree of self-renewal ability and can repeatedly undergo mitosis to produce a large number of daughter cells; second, under certain conditions, they can differentiate into neural cells and glial cells. At present, neural stem cells have three uses: first, they are used for replacement therapy of damaged neural cells. Transplanting neural stem cells into the central nervous system to replace the neural cells missing due to injury or disease is important for restoring their functions. Second, it is used as a carrier for gene therapy; third, it is applied to life science research. At present, it has been possible to expand human neural stem cells to a considerable number in vitro and maintain their proliferation capacity for a certain period of time, but the regeneration of cells in the central nervous system is a very complex process, and the application of neural stem cells in the clinic still requires a lot of preliminary work.
3.Trend of clinical treatment
The integration of brain function, cerebral blood flow and imaging (PET, fMR, MEG, etc.) provides a more reliable guarantee for more accurate removal of CNS lesions and further enhances the level of minimally invasive neurosurgery. The complementary neuronavigation and ultrasound technologies, application of contrast and ultrasound techniques, etc. have resulted in clearer margins for tumors and blood vessels in the brain, not only removing tumors thoroughly but also avoiding damage to important cerebral blood vessels. Medical engineering scientists and technicians have designed Brain Suit, an integrated diagnostic and surgical treatment system, turning a new page in minimally invasive neurosurgery. The emergence of new knowledge and technology has promoted the change of concept of neurosurgical surgery treatment, and the change of concept of neurosurgeons will certainly enrich the knowledge and experience of neuroscience, and will promote the progress of the discipline of neurosurgery.