The realm of neurosurgery should be pursued with minimal trauma, comfortable operation, and low cost.
Let’s start with minimally invasive neurosurgery. What is considered minimally invasive? The same criteria are expressed in different ways. Minimal medically induced injury in exchange for maximum therapeutic effect, the smallest possible operational trauma to achieve the most thorough lesion treatment possible. Or anatomically open and anatomically closed, for that matter.
Neurosurgery is mainly surgical treatment of intracranial cavity and intravertebral lesions involving the brain and spinal cord, and the pursuit of minimally invasive results is more obsessive.
The function of the brain is most important. The brain is the regulating organ, the commander of the body, all organs are under its management, eating, drinking, sleeping, breathing, circulation, reproduction, immunity, sensation and movement, all functions are controlled by it; the brain is the organ of thought, the seven emotions and six desires, all mental activities are generated by it. The brain and spinal cord are the most vulnerable to injury, and the consequences of brain and spinal cord injury are the most serious. Brain and spinal cord injuries are the most difficult to repair. Therefore, minimally invasive intracranial and intraspinal surgery is essential.
Only the microoperation of neuronavigation can make minimally invasive neurosurgery possible. Neuronavigation is mainly preoperative for precise positioning and should also involve intraoperative real-time judgment of the surgical scope; microoperation is usually understood as a surgical operation under a microscope, but, today, with the gradual acceptance of endoscopy by neurosurgeons, it should be extended to fine operations performed under any optical instrument.
The location of the brain is the most hidden. The brain is hidden in the cranial cavity, invisible and inaccessible, and the clinical manifestations, which can only suspect intracranial lesions, can only be accurately localized with the help of neuronavigation to locate the intracranial lesions shown by CT, MRI, DSA and other imaging means, and then approach these lesions with small bone windows. The brain has the most complex structure.
The brain receives and processes external information and regulates physical activities in an intricate structure. Although, the brain can be distinguished into functional and non-functional areas and different functional areas manage different physiological functions, the division of functional areas of the brain is relative, and microscopic operations are performed in order to remove as many lesions as possible and injure as little adjacent brain tissue as possible. Since the blood vessels entering and exiting the brain are staggered and anastomosed, and the blood vessels and nerves entering and exiting the skull base are tangled and mixed, microscopic operations can only be performed by optimizing the combination of multiple optical lenses to see the lesions in the cranial cavity clearly and accurately.
Now for the lightweight neurosurgery. Lightweight has two meanings, firstly, the operation should be easy, and secondly, the equipment should be portable. Minimally invasive neurosurgery can be made lighter by simplifying neuronavigation techniques and intraoperative observation techniques.
Neurological navigation includes 3 types of navigation: orienteer frame navigation, ultrasound sonographic navigation and magnetic resonance imaging navigation.
Orientator frame navigation was introduced in neurosurgery as early as 1947. Because of its many defects, it is mainly used for removal of foreign bodies, removal of biopsy specimens, placement of deep brain stimulation electrodes, etc., except for functional neurosurgical applications.
To date, neurosurgery has mainly used magnetic resonance image navigation, so much so that in most people’s opinion, neurological navigation is magnetic resonance image navigation.
However, its disadvantages are obvious.
(1) Structural brain drift cannot be completely corrected, and MRI images cannot be accurately navigated;
(2) Navigation based on preoperative imaging data does not reflect the surgical procedure in real time;
(3) The MRI equipment is bulky, cumbersome and time-consuming to operate, which is not convenient for practical application;
(4) Magnetic resonance equipment is expensive, and the cost of shielding the magnetic field in the operating room and demagnetizing surgical instruments is high.
It was only after the invention and widespread use of real-time B-mode ultrasound examination technology that intraoperative ultrasound acoustic image navigation, which appeared before magnetic resonance imaging navigation, gradually gained importance.
Compared with MRI neurological navigation, ultrasonic sonographic neurological navigation is lightweight and has obvious advantages.
(1) Intraoperative ultrasound has a high probability of detecting the lesion and can precisely locate the lesion and accurately determine its margin and size;
(2) Intraoperative ultrasound-guided intracranial surgery without brain drift and precise navigation;
(3) Intraoperative ultrasound is easy and rapid to operate, taking only 2~3 minutes for each examination, which is a real real-time navigation and can be repeatedly applied to navigate multiple surgeries at the same time;
(4) Intraoperative ultrasound operation protocol is simple, easy to learn and use, and easy to promote;
(5) Intraoperative ultrasound has no special requirements for operating rooms and surgical instruments, and does not increase additional costs;
(6) Ultrasound equipment is simple and inexpensive, and has become a commonly used diagnostic instrument in hospitals at all levels.
The degree of refinement of neurosurgery is inseparable from the progress of intraoperative observation techniques. Before the invention and application of the optical lens, the neurosurgeon’s eye directly observed the surgical field, using the eye operative surgical technique (EOST), surgery is difficult to achieve minimally invasive results. After the invention and application of the optical lens, the neurosurgeon’s eye viewed the surgical field indirectly through the lens, using the lens operative surgical technique (LOST), and surgery could achieve minimally invasive results.
However, the lens operative technique has many disadvantages. Take the microscope lens surgical mode as an example, and look at the disadvantages of the lens surgical mode.
The microscope lens surgical mode uses a bulky ordinary microscope, which greatly restricts the operation of the hand and the observation of the eye.
(1) The bulky ordinary microscope occupies a lot of space, and the instrument delivery and surgical operation are obviously limited;
(2) In the microscope lens surgery mode, the surgeon must observe the surgical field through the microscope, the surgeon must close the eye to the eyepiece, the eye and the mirror can not be separated, in this “close observation, long-distance operation” condition, the surgeon has little space to move, less opportunity to change posture, long time surgery operation is easy to fatigue;
(3) in the microscope lens surgery mode, instrument nurses, assistants and operators through the microscope to observe the opportunity and effect of the surgical field is different, and the cooperation between each other is difficult.
After the invention and application of digital camera technology, the lens images of the surgical field and surgical procedure can be converted into video screen images, and the video screen images can be used to guide the surgical operation, which is called screen operative surgical technique (SOST).
In contrast, the advantages of the SOST mode are.
(1) It does not restrict the hand operation and eye observation, and the posture can be changed at will during the operation, which makes the operation comfortable;
(2) The operator, assistant and nurse receive the same visual information, so it is easy to cooperate intraoperatively;
(3) Simultaneous observation of the surgical process is possible, which facilitates real-time discussion of surgical difficulties and visual teaching;
(4) The film data of the surgery can be saved, which is convenient for retrospective analysis and teaching research;
(5) Simplify the intraoperative observation system, with lightweight and low-cost equipment;
(6) It can optimize the combination of multiple optical lenses to achieve the best observation effect.
In addition to simplifying the intraoperative observation system, the visual screen surgery mode can also optimize the combination of multiple optical lenses to achieve the best observation effect.
Optical lenses are no more than magnifiers, microscopes, telephoto lenses, exophthalmoscopes and endophthalmoscopes. These optical lenses, the difference lies mainly in the size of the focal length and the thickness of the lens barrel. To put it simply, the magnifying glass continuous zoom into the microscope, microscope focal length extended into the telescope, microscope barrel reduced into the external view, microscope focal length shortened and barrel reduced into the endoscope.
These optical lenses have their own strengths.
(1) the field of view of the microscope three-dimensional, but its focal length is medium, can only be placed in front of the surgeon, will obscure the line of sight; its lens is thick, can only operate in front of the mirror, surgical instruments for will obscure the lens.
(2) endoscope focal length is short, close observation field of view is open and well illuminated, but its lens is easy to be contaminated by blood; its mirror pole is slender, can only be operated in the mirror perimeter, surgical instruments do not obscure the lens, but will collide with the mirror pole.
(3) Telescope is similar to microscope, but its focal length is long, can be suspended over the surgeon’s head, will not block the line of sight.
(4) The external view mirror is also similar to the microscope, but its focal length is long and the mirror rod is thin, so it is placed in front of the surgeon and rarely blocks the line of sight, so it can be operated in front of the mirror – the mirror perimeter, and the surgical instruments do not block the lens or collide with the mirror rod.
The location of lesions in the cranial cavity is deep, the relationship between the adjacent is complex, and the surgery requires high light and vision, so the combination of microscope, telescope, endoscope and exoscope should be optimized, and endoscopy-assisted microscope, telescope or exoscope should be used, and various optical lenses complement each other to produce better observation results. The establishment of the visual screen surgical model has broken through the focal length limitation and enabled various optical lenses to play a role in microscopic (minimally invasive) neurosurgery. In particular, it is no longer a fool’s dream to carry out telescopic neurosurgery.
So far, lightweight minimally invasive neurosurgery has been made, with tiny trauma, comfortable operation, low cost, and win-win situation for both doctors and patients. Doctors do the surgery safely and comfortably; patients receive the surgery with reduced risk, improved efficacy, and lower cost.