1. Indications of laser treatment of airway diseases
Obstruction caused by new organisms in the airway can be seen through bronchoscope, and laser therapy can be applied to all parts that can be accurately aligned with optical fibers and easy to operate. At present, laser therapy is rarely used for airway diseases.
1) Primary and metastatic malignant tumors of trachea and bronchus: including primary bronchial lung cancer, sarcoma, carcinosarcoma, teratoma, lymphoma, plasmacytoma, carcinoid, adenoid cystic carcinoma, etc. It is generally used for malignant tumors or advanced tumors that have lost the opportunity for surgery. If the airway is blocked by pathological tissue hyperplasia, laser can melt the blocked tissue, improve ventilation and relieve or cure dyspnea.
2) Benign tumors of trachea and bronchus: including hamartoma, papilloma, polyp, chondroma, lipoma, fibroleiomyoma, fibroma, endometriosis, bronchial stones, induration, hemangioma, neurilemmoma, etc. Benign tumors are generally limited, easy to be removed by laser, and rarely recur, so laser treatment of benign tumors is excellent, and it can replace surgery to treat benign tumors in some parts.
3) Tracheobronchial granuloma: It mainly includes foreign body granuloma, tuberculous granuloma and inflammatory granuloma caused by surgical suture and tracheotomy. Laser has a good effect on foreign body granuloma, but it has a poor effect on tuberculous granuloma and inflammatory granuloma, but at least it can reopen the airway and improve lung ventilation. It is best to treat tuberculous granuloma after anti-tuberculosis treatment stabilizes the lesion.
4) Organic tracheobronchial stenosis: Scar stenosis is mainly caused by tracheotomy or tracheal intubation, diphtheria, trauma, endobronchial tuberculosis and other reasons, especially iatrogenic tracheotomy or tracheal intubation. Laser treatment is effective for cartilage ring without damage, but ineffective for bottleneck and external pressure stenosis.
5) Others: such as tracheobronchial hemorrhage, tracheobronchial fistula and atypical hyperplasia of tracheobronchial intima. Because laser has obvious protein coagulation and blood vessel sealing effects, proper reduction of laser power can be used for airway hemostasis.
2. Contraindications and precautions for laser treatment of airway lesions
The contraindications of laser therapy are similar to those of conventional bronchoscopy, but the contraindications are consistent with general anesthesia because of frequent operation under general anesthesia. However, as far as endoscopic laser technology is concerned, the main contraindications are:
1) Extraluminal tracheobronchial compression stenosis is mainly caused by mediastinal tumor, lymphadenopathy and lobar atrophy. Ablation treatment will cause perforation of tracheobronchial wall, which is an absolute contraindication for ablation treatment.
2) When the airway is long and the funnel-shaped stenosis is accompanied by submucosal infiltration, the ablation treatment effect is poor.
3) When the airway is completely occluded, ablation treatment is also very difficult. It is necessary to evaluate the blocking path and blocking the distal end before operation, otherwise it will easily lead to perforation of the tube wall. In the case of incomplete airway obstruction, the function of the obstructed distal lung tissue must be evaluated before ablation treatment. If the distal lung tissue loses its gas exchange ability, ablation treatment is unnecessary.
4) When the tumor erodes the posterior wall of trachea and affects esophagus, the probability of perforation and sinus formation in ablation treatment is high. Lung cancer patients who have received extensive radiotherapy for a long time are prone to tracheal wall distortion and softening during radiotherapy, and perforation is also prone to occur during ablation treatment.
5) Ablation treatment of upper lobe lesions should be especially careful, because this position is close to large blood vessels, which is easy to cause massive bleeding.
6) Small cell lung cancer and lymphoma are diffuse lesions, often involving the airway. Chemotherapy can achieve good results, so we should seize the opportunity to choose ablation treatment.
7) Patients with bleeding and abnormal coagulation function, electrolyte disorder, hypotension and severe infection should be considered as contraindications.
3. Specific operation steps and methods
Treatment through flexible bronchoscope can be performed under local anesthesia or general anesthesia. Preoperative preparation under general anesthesia is the same as general anesthesia, and preparation under local anesthesia and preoperative preparation is the same as general bronchoscopy. First, preheat the laser therapeutic instrument, with laser power 100W and wavelength 1064nm. Conventional anesthesia, anesthesia as shallow as possible, as far as possible to reduce the inhibition of patients' breathing to the lowest degree, while using 2% lidocaine for airway surface anesthesia to reduce irritation. Insert endotracheal tube, perform bronchoscopy treatment through endotracheal tube, insert bronchoscope into lesion, insert optical fiber through bronchoscopy biopsy hole, extend the distal end of bronchoscope at least 65438±0cm, locate with visible red light, aim at ablation target 4 ~ 65438±00mm, and irradiate with Nd: YAG laser. The foot switch is controlled by the operator, and the power used is generally 20-40 watts. Each irradiation (pulse time) is 0.5- 1 sec, and the interval is 0. 1-0.5 sec. The energy used depends on the size of the lesion, and it is safer to irradiate larger lesions in stages, with an interval of 1-2 weeks. Argon plasma coagulation (APC) has been widely used in the treatment of respiratory diseases and has become an important technical means to treat respiratory diseases.
Argon is an inert gas, which is ionized by high frequency current. The ionized argon plasma beam has conductivity, which can guide the current from the high-frequency output electrode to the tissue and concentrate it at a point in contact with it. The argon plasma beam tends to move, and its moving direction depends on the shortest distance from the nozzle to the tissue in order to minimize the moving impedance of the argon plasma beam.
Argon knife treatment through bronchoscope is mainly suitable for local bleeding of trachea and bronchus, growth bulge lesions in respiratory tract, lumen stenosis and foreign bodies, such as benign stenosis of respiratory tract (scar stenosis of anastomotic mouth), cancerous obstruction of main airway and left and right tracheal mouths, granulation hyperplasia of respiratory tract, fixed suture foreign bodies in respiratory tract, food foreign bodies in respiratory tract, and extensive exfoliative lesions of respiratory mucosa (fungal infection of respiratory mucosa after bone marrow transplantation). Those who are not suitable for bronchoscopy and those who are not bleeding in the respiratory system (such as bronchiectasis and tumor invading the great vessels of the chest) are absolute contraindications. High-frequency electrotherapy, electrocoagulation and electric shock are used for endoscopic treatment. High-frequency electric energy generates heat energy, which acts on tissues, making them coagulate, necrotic, carbonize and vaporize, and at the same time occluding blood vessels. There are generally three kinds of high-frequency electrotherapy treatments: electrotomy, electrocoagulation and mixed electrotomy.
High-frequency electrotherapy is suitable for palliative treatment of malignant tumors of trachea and bronchus that have lost the opportunity of operation. Radical treatment of various benign tumors in tracheobronchial cavity: clearing inflammation, surgery, trauma and foreign body granuloma. Patients with pacemakers can't use high-frequency electrotherapy, so as not to make pacemakers fail or cause myocardial burns and other injuries. Cryotherapy was mainly used to treat a variety of skin diseases in the early stage, and then it was widely used in the treatment of various tumors with the development of various cryoinstruments. The damage caused by freezing can occur at the level of molecules, cells, tissues and organs. The speed of local cooling and dissolution and the lowest temperature can determine whether the cells can survive. The sensitivity of tissue to freezing is usually related to its water content. Tissue with more water content is relatively sensitive to freezing, while tissue with less water content has better tolerance to freezing. General tumor tissues are more sensitive to freezing than ordinary cells.
Cryotherapy is suitable for palliative treatment of tracheal and bronchial malignant tumors. Radical treatment of benign tumors of trachea and bronchus: treatment of restenosis at both ends and in the cavity after stent implantation; Removal of foreign bodies or blood clots from trachea and bronchus.
After cryotherapy, complete intravascular thrombosis occurred 6-12 hours after treatment. In the next few days, the cells will degenerate and necrosis, and non-hemorrhagic necrosis of the tissue will appear 8- 15 days after treatment. Cryotherapy is not suitable for relieving acute airway obstruction because of its delayed effect. Balloon dilatation via bronchoscope (high pressure) is mainly used to treat central airway stenosis. The principle is that the balloon is placed in a narrow airway and inflated with a high-pressure gun pump, so that many small longitudinal lacerations are produced around the trachea at the narrow part, and the lacerations are filled with fibrous tissue, thus achieving the purpose of expanding the narrow part.
1, an indication of balloon dilatation
Balloon dilatation has no therapeutic effect on the etiology, and is mainly used for the main airway stenosis caused by benign scar lesions, and only as an auxiliary treatment for airway stenosis caused by malignant diseases.
1) Tuberculous tracheobronchial stenosis is mainly caused by scar contraction after bronchial tuberculosis is cured.
2) Iatrogenic airway stenosis: anastomotic stenosis after tracheotomy, long-term tracheal intubation, radiotherapy and lung surgery (such as lung transplantation, sleeve resection and tracheotomy).
3) Inflammatory diseases involving airway, such as sarcoidosis and Wegener granulomatosis.
4) Post-traumatic airway stenosis.
5) Congenital airway stenosis.
6) Malignant airway stenosis: external pressure or combined external pressure airway stenosis, assisting airway expansion, is beneficial to the extension of airway stent and the placement of therapeutic airway catheter.
2. Contraindications of balloon dilatation
1) loss of lung function at the distal end of stenosis. Although the trachea was opened, the lung function could not be improved.
2) Severe bleeding and coagulation dysfunction.
3) Severe cardiopulmonary insufficiency makes the patient unbearable and loses the treatment opportunity; However, if it is cardiopulmonary insufficiency caused by main tracheal stenosis, it should be treated actively, and the cause should be solved as soon as possible to achieve the purpose of treatment.
4) After surgical cannula anastomosis, the tension of trachea is inconsistent, which is easy to cause anastomotic laceration during dilation treatment, so the dilation treatment should be cautious.
5) Tracheomalacia is not an indication of balloon dilatation. The destruction of bronchial cartilage leads to the disappearance of tracheal wall support. During balloon dilation, the lumen can be dilated, but once the balloon is released, the lumen will contract.
3, the timing of treatment and matters needing attention
For bronchial stenosis caused by tuberculosis, anti-tuberculosis treatment should be fully carried out before operation. It is suggested that regular anti-tuberculosis treatment should be adhered to 9 months after operation; There was no obvious active tuberculosis in the bronchus during treatment. Do not use hyperthermia or stent to treat bronchial tuberculosis; If obvious infection or active tuberculosis lesions are found after dilatation, the dilatation treatment should be stopped immediately and changed to anti-inflammatory or anti-tuberculosis treatment, and then the dilatation treatment should be carried out after the inflammation is absorbed; Patients with obvious tracheal contraction in anti-tuberculosis treatment should be closely observed, and the lumen must be kept intact in order to strive for the opportunity of expansion treatment.
4, the specific steps of operation and matters needing attention
1) anesthesia: patients with tracheal trunk lesions and long-term severe stenosis choose general anesthesia; The lesion is located in the main bronchus, but the contralateral lung function is poor, so it may not be possible to complete the dilation operation under local anesthesia. General anesthesia is recommended.
2) Choose a suitable balloon catheter: know the diameter and length of normal trachea and bronchus: the diameter of trachea is 16-20mm and the length is10-325px; Right main bronchus diameter 12- 15mm, length 1-50px. The right middle bronchus has a diameter of 12mm and a length of 75px. Left main bronchus diameter 10- 14mm, length 125px. At present, balloons produced by Boston Scientific Company are commonly used. According to the inner diameter of the working hole of therapeutic bronchoscope and the diameter and length of the balloon, the appropriate balloon catheter is selected.
3) Catheter placement and expansion: At present, the balloon catheter is usually placed through the working channel under the guidance of bronchoscope, the expansion position is determined under direct vision, and water is pumped into the balloon with a pressure gun. The pressure can be 3-8 atmospheres to achieve different expansion diameters, and the pressure should be increased from low to high. Each expansion operation lasts about 30-60 seconds, and the effect is observed. If it doesn't work, the lesion can be treated by cryotherapy and then expanded. If it still doesn't work, you can use high-frequency electroacupuncture to cut off the scar and then expand it. Be careful not to cut the tracheal membrane. Depending on the degree of expansion, each operation can be repeated 1- 10 times. When there is no therapeutic bronchoscope, fluoroscopy and bronchoscopy can be combined. Firstly, the guide wire and balloon catheter were inserted under fluoroscopy to determine the position of the corresponding stenosis, and bronchoscopy was inserted to observe the balloon catheter and stenosis, which was beneficial for the operator to observe the process of balloon direct expansion.
4) Precautions: For the expansion of upper tracheal stenosis, pay attention to protecting vocal cords; Gradually increase the pressure during the operation to avoid tearing the tracheal wall; The balloon must completely enter the airway to avoid damaging the bronchoscope; Be careful not to insert the bronchiectasis too deeply, so as not to damage the distal normal airway.
5. Common complications
1) wall bleeding: bleeding is the most common complication. But in general, there is not much bleeding and there is no need to deal with it; If the bleeding time is long, it can be diluted with thrombin or adrenaline (locally with 1: 10000), and the bleeding point can be electrocoagulated locally with APC.
2) Bronchial rupture: After treatment, the patient developed subcutaneous emphysema in mediastinum or neck, which was caused by tracheal rupture during dilation. Generally, most people can heal themselves after rest. At this time, we should pay attention to let patients minimize cough and give infection prevention treatment.
3) Stenosis and restenosis: It is necessary to distinguish between the recurrence caused by uncontrolled tuberculosis infection and restenosis caused by scar hyperplasia and contracture caused by patients' scar constitution. The first case is active anti-tuberculosis treatment. In the second case, repeated expansion and freezing are needed, and some patients can inhibit scar hyperplasia through radiotherapy. Even after the above treatment, some patients still have uncontrollable stenosis and need other treatment methods. Airway stents can be divided into silica gel tubular stents and metal mesh stents (coated or uncoated) according to the manufacturing materials, each with its own advantages and disadvantages.
Compared with metal mesh stent, silicone tubular stent is cheaper; It is easy to adjust and take out the position of the stent during implantation, but the stent implantation needs to be carried out under general anesthesia with a rigid bronchoscope, which affects the function of removing mucocilia and easily causes secretions to block the lumen and the stent to shift, especially for stenosis with short conical airway, poor adhesion, irregular airway or uneven surface. At present, there is no silicone stent in China.
Compared with silicone tubular stent, metal mesh stent is more convenient to implant, and most patients can implant flexible bronchoscope under local anesthesia. Metal mesh stent has good elasticity, so the incidence of displacement after implantation is relatively low; The stent itself is thin and has a high ratio of inner diameter to outer diameter, and at the same time, it can retain the mucus clearance function of the airway to a certain extent. The disadvantage of metal mesh stent is that the restenosis rate caused by tumor or granulation tissue growing through the mesh is high. Because the metal mesh stent is not easy to move out after implantation, it should be used with caution for patients with benign airway stenosis, especially patients with acute inflammation. At present, the use of detachable metal brackets (such as Lee's bracket) is advocated.
The indications of tracheal and bronchial stent implantation mainly include three aspects: ① lumen reconstruction of organic stenosis of central airway (including trachea and bronchus above segment). ② Support for chondromalacia of tracheomalacia and bronchimalacia. ③ Blocking tracheal and bronchial fistula or fissure.
The etiology of central airway organic stenosis includes malignant tumor and benign lesion. For airway stenosis caused by malignant tumor, if the chance of surgical treatment is lost, in most cases, the tumor tissue in the cavity needs to be removed by laser, argon knife, high frequency electrocautery or freezing under bronchoscope. If the patient suffers from airway obstruction and dyspnea due to extensive infiltration of tumor in the tube wall or compression of extraluminal tumor and metastatic lymph nodes, temporary stent placement can be performed at the airway obstruction site. At present, malignant airway stenosis is considered as an indication of airway stent implantation. The etiology of benign airway stenosis is relatively complicated. In China, the most common cause is tracheobronchial tuberculosis and mucosal injury caused by high balloon pressure of tracheal intubation or incision intubation. For benign airway stenosis, stent implantation should be cautious. The principle of stent implantation should be to consider laser, high-frequency electrocautery or freezing, and stent implantation in the airway after balloon expansion, and it is difficult to maintain the curative effect. At the same time, the application of detachable support is advocated.
Destruction and defect of trachea and bronchial cartilage caused by inflammation or mechanical compression such as bronchial tuberculosis and recurrent polychondritis often lead to abnormal movement of airway wall at cartilage defect. For such patients, stent implantation is sometimes the only option.
The fistula between esophagus and trachea or bronchus can be congenital, but the clinical manifestations are mostly caused by malignant tumors. The clinical symptoms of tracheoesophageal fistula mainly include choking cough, dyspnea, aspiration pneumonia when drinking and eating, etc. Esophageal tumor infiltrates airway, causing tracheoesophageal fistula. Esophageal stent implantation can improve the quality of life of patients, but generally it can not completely and effectively block the fistula. Implantation of esophageal and airway double-coated stent can achieve more ideal clinical results.
The fistula or rupture of bronchial stump and bronchial anastomosis is a common complication of lobectomy and bronchial sleeve resection for central lung cancer. In addition to local sealing with gelatin sponge, cellulose and medical adhesive under bronchoscope, placing covered stent or filling with gelatin sponge before fixing with common metal stent is also an effective method to block tracheobronchial fistula or fissure in recent years. Generally, the establishment of artificial airway is done by anesthesiologists, but it is often difficult for some patients to intubate, such as cervical spondylitis, myasthenia gravis, acromegaly and severe head trauma. At this time, using bronchoscope to guide intubation is the only option. In addition, due to the intuitive visibility of bronchoscope, the injury caused by routine blind intubation can be avoided, especially for patients who may have abnormal upper airway and difficult intubation. When mechanical ventilation is needed, double-lumen tracheal intubation is necessary, and bronchoscopy is a good method. Bronchoscope is the most reliable tool to determine the position of double-lumen tracheal intubation.
Bronchoscope is also a very useful tool to replace tracheal intubation. In ICU ward, due to airbag rupture, oversize tracheal intubation and other reasons, it is often necessary to replace tracheal intubation, or when oral intubation needs to be replaced by nasal intubation, bronchoscopy can not only observe the original tracheal intubation and airway, but also facilitate the timely discovery of abnormal conditions, re-establish artificial airway in the shortest time, and reduce the impact of hypoxia on critically ill patients.
Clinically, some patients suddenly suffer from respiratory distress after extubation, partly due to upper airway obstruction (UAO), which mostly occurs under or at the glottis. When UAO occurs, the artificial airway must be rebuilt. Although the patient's respiratory distress symptoms were quickly relieved after re-intubation, the cause of UAO is still unclear. For patients who may have UAO, bronchoscope should be inserted before extubation, so that bronchoscope and tracheal intubation can be extubated together, so that the cause of UAO can be found, and tracheal intubation can be reinserted immediately to avoid the influence of UAO on patients. Then look for a solution according to what happened. The occurrence of UAO is generally related to patients' previous intubation difficulties, repeated intubation attempts and long mechanical ventilation time. Acute and chronic lung abscess, pneumonia, bronchial infectious diseases and other factors, such as blood-bronchial barrier, tissue wrapping, physical and chemical properties of pus, often lead to poor curative effect of systemic medication. Drainage and administration through bronchoscope can increase the local drug concentration. Generally, the bronchoscope is inserted into the directional lung segment and lobar bronchus, and sputum is fully sucked first, and then washed with a small amount of normal saline. After cleaning the washing liquid, inject antibiotics sensitive to respiratory tract and having no irritation, such as penicillin, amikacin, cephalosporin, etc., dissolve them in normal saline 10ml, and inject them into the focus as standby therapeutic drugs. The total lavage volume should not exceed 100 ml. If the condition is critical, the operation time should be limited to 15 minutes without irrigation.
Patients with chronic obstructive pulmonary disease complicated with respiratory failure or other critically ill patients often block the airway due to thick sputum or blood clots, resulting in atelectasis of one lung segment, lobe or one lung. At this time, the patient's condition is often acute and life-threatening. When the measures such as stimulating cough, deep breathing exercise, patting the back and body position drainage are still ineffective, bronchoscope can be used for aspiration and lavage, which can effectively relieve atelectasis and save patients' lives. Some patients, such as rib fracture, hemothorax, pneumothorax and postoperative patients, can't stimulate cough by patting their backs, so bronchoscopy has become the only effective tool to relieve atelectasis. Generally, most atelectasis can be relieved after aspiration and irrigation through bronchoscope.