Sinus surgery using nasal endoscopes and special surgical instruments was pioneered by Austrian rhinologist Messerklinger in the early 1970s, and is therefore also known as the Messerklinger technique. Initially, the main content of this technique was to perform sinus surgery on the basis of endoscopic examination of the nasal cavity and sinuses, with the aim of completely removing hidden lesions in the sinuses by relying on the characteristics of the nasal endoscope’s wide angle of view and refractive vision, which is particularly important for patients with multiple nasal polyps. This procedure is called endoscopic sinus surgery. With the in-depth study of the physiology of the mucosa of the nasal cavity and sinuses and the pathophysiology of sinusitis and nasal polyps, people began to emphasize the importance of the anatomical structure of the nasal cavity and sinuses, and the importance of the specific and nonspecific protective functions in the occurrence and regression of sinusitis. In the mucus cilia transport function, mucosal secretion function, the important role of the middle turbinate, anatomical abnormalities and sinusitis, nasal polyps occurring in the relationship between the lesions of the sinus mucosa after surgery, such as the regression of reliable experimental and clinical basis, and put forward a series of new theories. Therefore, American rhinologist Kennedy was the first to propose the concept of functional endoscopic sinus surgery in 1986. The basic starting point of functional endoscopic sinus surgery is: on the basis of completely removing irreversible lesions, correcting the anatomical abnormalities of the nasal cavity and sinuses, opening up the sinus complex and the sinus openings, reconstructing the ventilation and drainage of the nasal cavity and sinuses, as well as preserving the mucous membranes in the sinuses as much as possible and physiological units such as the turbinates as the basic principle of the surgery, so as to create conditions that will improve and restore the morphology and physiological function of the mucous membranes of the nasal cavity and sinuses to cure the sinusitis and the sinuses. The basic principle of surgery is to create conditions to improve and restore the morphology and physiological function of the mucosa of the nasal cavity and sinuses to cure sinusitis. This viewpoint was recognized and rapidly promoted by the international rhinology community in the early nineties, so that more and more nasal surgeons gradually discarded the already accustomed radical surgical methods and adopted a small or limited scope of surgery to solve a wide range of sinus lesions. First, the creation of functional endoscopic sinus surgery and its theoretical basis The theoretical basis of functional endoscopic sinus surgery is based on the physiological function of the nasal cavity and sinus sinus and the regression of sinusitis developed on the basis of pathophysiological mechanisms, including the following six aspects of the problem: the activity and function of the nasal mucus cilia system and its impact on the occurrence of sinusitis and regression. The effect of ventilation and drainage of the nasal sinuses on mucus cilia transport function, gland secretion function, and postoperative mucosal morphology and functional regression. Secretory function of nasal sinus mucosal glands. Reconceptualization of the local immune function of nasal sinus mucosa. An in-depth study of the physiologic function of the middle turbinate. The association between anatomical abnormalities of the nasal cavity and sinuses and the occurrence of sinusitis and nasal polyps. The following are summarized as follows. (A) nasal mucus cilia system In 1836, Sharpy found that the nasal cilia are toward the pharynx, the cilia in the sinuses are toward the sinus mouth movement, which put forward: “the nasal mucus cilia system is related to the transport of secretion and foreign bodies”, laid the mucus cilia system as a nasal sinus non-specific protective function of the theoretical The basis of the mucus cilia system as a non-specific protective function of the nasal cavity and sinuses. Nasal cilia morphology and mode of existence Most of the nasal sinus mucosa belongs to the pseudocomplex columnar hair epithelium, the epithelial surface of the ciliated cells from the growth of the cilia, each ciliated cell about 250-300 cilia, most of the cilia length of 5-6 microns, the root of the root is a little thicker, the tip of the tip of a little thinner in the ciliated surface is covered with a layer of mucus secreted by the cupular cells and other secretory type of cell, the main components are water, inorganic salts, organic salts and other substances, which is the main component of the cilia system. The surface of the cilium is covered with a layer of mucus secreted by cup cells and other secretory cells, the main components of which are water, inorganic salts, mucopolysaccharides, mucin and lysozyme. This layer of mucus is a necessary condition for cilia movement and has a protective effect on cilia and mucosal epithelium. Therefore, it is called mucus cilia system. 2, the distribution of nasal cilia nasal cilia density is the most dense to the lower nasal cavity, with the upper nasal cavity to move, cilia density gradually decreased, in the sinus, to the sinus mouth around the cilia is more dense, sinus mucosal surface for the ciliated cells and secretory cells mixed presence. 3, nasal mucus ciliary system function, including the contents of two parties, one is the ciliary activity, the second is the cilia through the ciliary transport rate. Ciliary activity refers to the characteristics of the cilia themselves swinging, normal human nasal mucosa cilia swinging frequency of 700-1200 times per minute. Ciliary transmission rate refers to the cilia swing through the formation of a regular wave-like movement to send liquid and micro-particle material speed, the normal human nasal mucus cilia system transmission rate of 7-11 millimeters per minute distance. It is generally recognized that although the ciliary transport rate is based on ciliary activity, the ciliary transport rate is more clinically significant than the ciliary activity. It is not the case that the faster the frequency of ciliary oscillations, the higher the transmission rate. If the transmission rate slows down while the ciliary oscillations remain unchanged, it is most often the result of ciliary dyskinesia, which most often occurs, for example, when bilateral mucosal contact occurs at any one site of the sinonasal complex. The cleansing effect of the nasal mucus cilia system is an important mechanical protective function of the human upper respiratory tract, which transports inhaled dust, bacteria, and other harmful substances out of the nasal cavity and sinuses by means of cilia. The direction of cilia transportation in the nasal cavity is toward the back of the nostrils, and the cilia transportation in the sinuses is from the sinus wall around toward the sinus opening. The cilia in the frontal sinus are transported in a slightly different way from the other sinuses, starting from the medial wall of the frontal sinus opening and winding upwards through the upper and lower walls to reach the frontal sinus opening, which is equal to one week’s circulation in the frontal sinus. Nasal mucus cilia system function and the nasal cavity, sinus infectious diseases and regression are closely related to the cilia immobility syndrome patients suffer from intractable, recurrent sinusitis is an example. In patients who have undergone radical sinus surgery, the purulent discharge is often difficult to subside, which is related to the destruction of the mucociliary system. The basic argument for functional surgery for sinusitis is to improve and restore the function of the mucus hair system of the nasal cavity and sinuses as a starting point. 4, Ciliary pathology associated with functional endoscopic sinus surgery. (1) Nasal cilia movement rate disruption, cessation and reverse movement Any part of the nasal cavity, if the mucous membranes on both sides are in contact with each other, can cause local cilia movement disruption or cessation, and this phenomenon is prominently manifested in the region of the sinonasal complex. Under normal circumstances, the middle turbinate is free in this area, and its internal, external, anterior, and inferior surfaces do not come into direct contact with any of the surrounding pouches. Once the mucous membranes on both sides come into contact with each other, the ciliary movement of the frontal sieve fossa and the middle nasal passages will be disrupted, reversed, or stopped. Therefore, freeing the middle turbinate, solving the mutual contact between the mucosa of the sinonasal complex, and improving and restoring the normal ciliary transport in this area is a very important part of functional endoscopic sinus surgery. (2) The effect of sinus opening obstruction on the function of ciliary transport in the sinus Reimer (1981) has experimentally confirmed that blocking the maxillary opening, the ciliary movement in the sinus is weakened, and after opening the sinus opening, the ciliary movement is restored. Thus unblocking the sinus opening improves and restores the mechanical air and oxygen partial pressures in the sinus. It is another important content of functional endoscopic sinus surgery. (3) The effect of inflammation and pus accumulation on cilia movement During the pathophysiological process of chronic inflammation, some qualitative changes will occur in the mucosa of nasal cavity and sinus, such as epithelial degeneration, squamous epithelial hyperplasia, etc., the cilia on the mucosal surface will be partially or completely detached, and the function of mucus cilium system can be seriously affected due to the changes in morphology and secretion function. Therefore, controlling local infection is an important part of improving and restoring the function of the nasal mucus ciliary system. Long-term failure of purulent secretions to subside after surgery is often directly related to extensive mucosal damage during surgery, local inflammation not being effectively controlled, and failure to restore the function of the mucus ciliary system. This is why it is important to emphasize the importance of preserving those mucous membranes that are less diseased and expected to recover as much as possible during surgery, and it is very important to master this principle during surgery. (ii) Ventilation and drainage of the nasal cavity and sinuses From the point of view of functional endoscopic sinus surgery, ventilation and drainage include both the nasal cavity and the sinuses. The degree of nasal ventilation is directly related to the degree of sinus ventilation, and nasal ventilation is the basis of sinus ventilation. However, good or bad nasal ventilation does not directly reflect good or bad sinus ventilation, for example, in the case of good nasal ventilation, sinus ventilation can be affected by the sinus-nasal tract complex and sinus obstruction. Drainage is an important factor in ensuring normal physiologic function of the nasal cavity and sinuses, especially for the sinuses. The sinus orifices are the channels for drainage, and the ciliary transport function is essential for drainage. The pathophysiologic regression of sinusitis depends largely on whether the sinus opening is blocked or not and whether the drainage of the sinus can be reestablished, which can be most powerfully proved in the pathogenesis of exudative otitis media and the regression of the lesion. There are a variety of clinical reasons affecting sinus ventilation, such as hypertrophy of the inferior turbinate, curvature of the nasal septum, vesicular middle turbinate, edema or polypoid degeneration of the middle turbinate, reverse curvature of the middle turbinate, hypertrophy of the leptomeninges, overdevelopment of the perifrontal airspace, swollen, hypertrophic hyperplasia of the mucosa of the sinus-oral-nasal tract complex, growth of one’s own meatus, and so on. It should be noted that, at the time of surgery, lesions that prevent nasal and sinus ventilation and drainage should be treated simultaneously, i.e., while surgery is performed to improve sinus ventilation and drainage, attention must be paid to the improvement of nasal ventilation and vice versa. It has been shown that within 3-6 months after the improvement of nasal and sinus ventilation and drainage, the mucosa of the middle turbinate and sinus meatus, which is watery, thickened, or even mildly polypoid, can return to its normal morphology, and there is regrowth of cilia on the surface of the mucosa that has lost its cilia. For this reason, the biggest difference between functional endoscopic sinus surgery and traditional radical surgery is that the middle turbinate and sinus mucosa are preserved as much as possible, and the focus of the surgery is on how to improve the ventilation and drainage of the nasal cavity and sinuses. Improvement of nasal and sinus ventilation and drainage can promote the normalization of the morphology and function of certain already diseased inflammatory mucosa, which is the most important theoretical basis for functional endoscopic sinus surgery. Surgery of the maxillary sinus is actually surgery of the lateral wall of the nasal cavity, and surgery of the frontal sinus is surgery of the frontal recess. Both use a small range of minimally invasive surgery to solve a wide range of sinus lesions. (C) nasal cavity, sinus gland secretion function 1, nasal mucosa in the glands nasal mucosa is very rich in glands, in the olfactory region of the olfactory glands, in the respiratory region of the unicellular glands (cup cells) and the lamina propria in the plasma glands, mucous glands. 2, sinus mucosa in the glands Sinus mucosa is also a pseudo-complex layer of columnar ciliated epithelium, the number of submucosal glands than the nasal cavity is less than the number of mainly distributed around the sinus openings connected with the nasal cavity. Normal secretion of the nasal cavity and sinus mucosa depends on good ventilation. Nasal obstruction or sinus obstruction once occurred, will certainly affect the mucosal secretion function. 3, chronic rhinitis, sinusitis mucosal glandular pathology Inflammatory stimulation can make glandular hyperplasia, mucosal basal cells can be chemotaxis for cup-shaped cells, this change to the sinuses around the natural mouth and the lower wall of the maxillary sinus is the most obvious, so that the sinuses for the patient’s mucosal lesions are from the mouth of the sinus began to gradually spread to the whole sinus. (D) the nasal cavity, sinus mucosa free function The epithelial cells of the nasal mucosa (cup cells), submucosal glands (plasma gland cells, mucous gland cells), blood vessels and mucous membranes within certain secretory cells (plasma cells, mast cells, lymphocytes, fibroblasts) not only produces secretion, and plasma proteins from the blood vessel exudate, or by the cells of the full bloom and secretion of the important free substances, which is the nasal mucosa free of the This is the histological basis of nasal mucosal immunity. This is the histologic basis for the immunity of the nasal mucosa. It can be seen that the mucosa is the most basic condition for the protective mechanism of the nasal cavity and sinuses. For this reason, maximizing the preservation of the mucosa as well as improving its form and function has become the primary point of departure in functional endoscopic sinus surgery, and is the main difference from conventional radical surgery. Various substances originating from the nasal mucosa with immunity defense function can be divided into two categories: non-specific and specific; the former are natural immunity substances, while the latter are produced under the stimulation of antigens (pathogenic bacteria/viruses), which together constitute the immune barrier of the nasal mucosa. (E) Reconceptualization of the function of the middle turbinate 1. Secretory function. The middle turbinate bears the main secretory function of the nasal cavity. It can provide mucus felt for the activity of cilia, which is favorable to the transport function of ciliary system. 2.Temperature and humidity regulation. 3.Barrier function. The formation of a natural barrier to protect the entire sinus-oral-nasal complex. (1) The frontal sinus opening is hidden in the crypt behind the vertical part of the middle turbinate. (2) The sieve bubble and sieve sinus are completely covered by the middle turbinate. (3) The maxillary sinus opening is protected by the inferior border of the middle turbinate. (4) The posterior end of the middle turbinate obscures the pterygoid sinus opening. According to the theory of nasal airflow dynamics, only a small amount of air enters the middle nasal passage due to the middle turbinate’s covering. The special position of the middle turbinate determines that it is bound to be the primary target of airflow attack, which may be why the middle turbinate is more prone to lesions than other parts of the nasal cavity. (F) Nasal cavity, sinus anatomical abnormalities and sinusitis, nasal polyps associated with the occurrence of nasal septum curvature: human nasal septum cartilage development is completed later than the craniofacial bone development is completed, can be craniofacial bone development is completed, the nasal septum is still growing, due to the failure to fully develop, resulting in curvature. Therefore, in most people, the nasal septum is slightly curved, but not dysfunctional. However, a small number of people (10-15%) can develop a more severe curvature, and excessive high septal curvature can directly compress the middle turbinate, leading to sinus lesions. It should be corrected. Hypertrophy of leptomeninges: the upper end of leptomeninges constitutes the medial wall of the sieve funnel, and the lower end (caudal end) is involved in constituting the natural mouth of the maxillary sinus; hypertrophy of the upper end can affect the drainage of the frontal sinus, and hypertrophy of the lower end can cause the drainage of the maxillary sinus. Complete excision of the leptomeninges is an indispensable step in surgery. Overdevelopment of the nasal mound airspace: upward overdevelopment can occupy the entire frontal crypt and affect frontal sinus drainage. Reverse curvature of the middle turbinate. Vesicular middle turbinate: also known as a turbinate bubble. Sieve turbinate airspace: it is caused by the overdevelopment of the sieve sinus airspace and its expansion to the root of the middle turbinate, as the determination of the anatomical abnormality of the nasal cavity and sinuses is mainly based on whether it affects the ability of the sinus-oral-nasal complex to air and drainage, which can be accurately determined by the preoperative nasal endoscopy, CT, reading the film and in the operation. Once confirmed, surgical correction should be performed. (A) Evaluation of the meaning of “functional surgery” Messerklinger found in the seventies that when the mucosal surfaces of the nasal cavity come into contact with each other, the local ciliary activity will be disturbed, stopped or reverse movement will occur, which will result in the retention of local secretions and lead to secondary infections in the corresponding area and Supervised secondary infection of the proximal sinuses. The anterior portion of the middle turbinate, the leptomeninges, and the sieve vesicles have the highest prevalence of anatomic abnormalities and are therefore the areas most susceptible to such mucosal contact. Ciliary dyskinesia and tracing of the hundreds is followed by early infection due to secretion retention, and the first to be affected are the anterior group of sieve sinuses. It is also observed that mucosal edema caused by inflammatory lesions in the anterior end of the middle nasal tract and the anterior sieve can gradually spread to other sinus openings, such as the natural opening of the maxillary sinus and the frontal crypt, leading to obstruction of aeration and drainage at the opening of the maxillary sinus and the frontal sinus. Therefore, it is believed that middle nasal tract lesions and anterior sieve sinusitis may be the root cause of the development of other sinuses. It is therefore believed that middle nasal tract lesions and anterior sieve sinusitis may be at the root of the pathogenesis of the other sinuses. Further clinical observations showed that despite lesions in the frontal and maxillary sinuses also gradually regained the mucosal morphology of the party. Based on this yuk observation, it is proposed that the pathway of sinus infection should be: middle nasal tract – anterior group of sieve sinuses – other sinuses. To emphasize the importance of this area, Naumann named the nearby area around the middle nasal tract and the anterior group of sieve sinuses: the sinonasal complex. The main goal of the surgery is to relieve the sinus complex, i.e., to relieve the root cause of the sinus lesions, and to open up the blocked sinus openings to allow good ventilation and drainage, while the maxillary and frontal sinuses are left untouched. The surgery of the maxillary sinuses is the surgery of the lateral wall of the nasal cavity, and the surgery of the frontal sinuses is the surgery of the frontal crypts, which actually means the surgery of the open sinuses. This is the basic theoretical concept of the classic treatment of extensive inflammatory sinus lesions with small, minimally invasive procedures. Later, Kennedy named this procedure: functional endoscopic sinus surgery. According to the differences in the surgical scope, type of surgery, and treatment of transnasal endoscopic sinus surgery should be divided into three types of this type of surgery: 1. classical functional endoscopic sinus surgery; 2. expanded functional endoscopic sinus surgery; 3. radical endoscopic sinus surgery. (ii) Evaluation of the name of the surgery 1. Surgery that is performed in accordance with the principles and modalities of classical functional surgery for the sinonasal complex, the frontal invagination, and the natural opening of the maxillary sinus and that does not injure the mucous membranes in the sinus can be called functional endoscopic sinus surgery. (2) Surgery that preserves or partially preserves the middle turbinate, opens the whole sieve or the whole pterygoid sieve, and preserves all or most of the mucous membrane of the sinus in accordance with the principle of functional surgery can be called transnasal endoscopic sinus surgery. 3. Surgery that removes all or most of the middle turbinate or sinus mucosa on the basis of open surgery is called radical transnasal endoscopic sinus surgery.