1.What is interventional therapy? You may know about medication in internal medicine, surgery in surgery, radiation therapy in radiotherapy …… but you may not have heard of interventional therapy. What is interventional therapy? Interventional therapy is a minimally invasive treatment using modern high-tech means – under the guidance of medical imaging equipment, special catheters, guidewires and other precision instruments are introduced into the human body to diagnose and locally treat internal pathologies. Interventional therapy applies digital technology to expand the doctor’s field of vision and extend the doctor’s hands with the help of catheters and guidewires. Its incision (puncture point), which is only the size of a grain of rice, can treat many diseases that could not be treated in the past, had to be treated surgically or had poor efficacy of internal medicine treatment, such as tumors, hemangiomas, and various bleeding, without cutting into human tissues. Interventional therapy has the characteristics of no incision, small trauma, fast recovery and good effect. Interventional therapy: Interventional therapy is an emerging borderline discipline combining medical imaging and clinical therapeutics, which started to develop in the 1970s, and is said by some scholars to be one of the three major diagnostic techniques alongside internal medicine and surgery. Due to its rapid development in the past 10 years, it has opened up new effective treatment pathways for many diseases that were previously considered incurable or difficult to treat clinically. Especially in the treatment of tumors, interventional radiology is playing an increasingly important role. At present, interventional therapy has become one of the main means of clinical treatment in modern hospitals, and will become one of the most promising clinical medical specialties in the 21st century. Interventional physicians have been able to intervene with catheters or other instruments into almost all branches of blood vessels and other luminal structures of the body (digestive tract, bile duct, trachea, nasal duct, etc.), as well as certain specific sites, to implement limited treatment for many diseases. For example, in the case of tumors, interventional therapy can pair several of the most effective anti-cancer drugs together, find the feeding artery of the tumor through catheter technology, and inject the anti-cancer drug and embolic agent directly into the tumor tissue. This therapy has two main advantages: on the one hand, the high concentration of drugs is directly applied to the local area to exert the maximum anti-tumor effect with less toxic side effects on the whole body, making the treatment acceptable to the vast majority of patients; on the other hand, the blood supplying vessels of the tumor are blocked so that the tumor is deprived of blood supply and “starved to death”. This chemoembolization technique is especially suitable for malignant tumors of liver, lung, stomach, kidney, pelvis, bone and soft tissues that have lost the chance of surgery or are not suitable for surgery. 3, the indications for interventional therapy: embolization therapy in interventional therapy has a high cure rate for various benign tumors, such as hepatic hemangioma; it has an immediate effect on hemostasis for various bleeding diseases, such as hemoptysis and oral bleeding caused by bronchial dilatation or lung cancer, hemorrhage caused by obstetrical and gynecological diseases or postpartum, and internal bleeding caused by trauma, which has basically replaced surgical treatment. There are many “ducts” in the human body. In addition to the widely distributed blood vessels, there are also various ducts such as esophagus, trachea, bile duct, ureter and nasal duct. Narrowing of human ducts can cause many diseases, such as blood vessel narrowing can cause hypertension, esophageal narrowing can cause dysphagia, biliary narrowing can cause obstruction jaundice ……, these narrowed ducts are difficult to unblock by taking medicine, and surgery is very traumatic and risky. Interventional treatment can use balloons to dilate the narrowed ducts, or metal stents can be placed in the duct lumen to create artificial ducts. In the case of stenting for renal artery stenosis, for example, after puncturing the femoral artery, the doctor places a special catheter into the renal artery stenosis under the guidance of a high-definition X-ray machine and then pushes out the stent compressed inside the catheter; once the stent is pushed out, it expands to the original design size and holds open the stenosis steadily and evenly; after the blood vessel is open, the blood circulation of the kidney can be effectively improved. (1) Digestive system – Interventional chemotherapy and embolization of medical malignant tumors of liver, stomach, pancreas and intestines; expansion and stenting of benign and malignant stenosis and obstruction of esophagus and bile duct; interventional embolization of hepatic hemangioma, liver cyst and hypersplenism. (2) Respiratory system – interventional chemotherapy and embolization of lung cancer; interventional embolization of hemoptysis; dilation and stenting of benign and malignant stenosis and obstruction of airway. (3) Circulatory system – dilation and stenting of arterial and venous stenosis; thrombolytic treatment of acute and chronic peripheral arterial and venous thrombosis; embolization treatment of peripheral aneurysm and cavernous hemangioma. (4) Neurological system – embolization of cerebrovascular disease (aneurysm, arteriovenous malformation, cavernous sinus fistula, etc.); thrombolysis of cerebral thrombosis in the acute stage. (5) Bone and soft tissue system – interventional chemotherapy and embolization for malignant tumors of bone and soft tissue; vertebroplasty (for vertebral collapse and vertebral hemangioma caused by osteoporosis and metastatic tumors); interventional treatment of disc herniation; interventional treatment of aseptic necrosis of the femoral head. (6) Genitourinary system – interventional chemotherapy and embolization of malignant tumors of kidney, pelvis and breast; intravascular embolization of uterine fibroids;, interventional treatment of renal cysts, interventional treatment of pelvic hemorrhage. Thus, with the continuous progress of clinical medicine and the development of modern science and technology, interventional therapy can undoubtedly bring a new dawn to mankind in conquering persistent diseases, and at the same time discover a broad prospect for the development of human life science. 5.Vascular interventions for malignant tumors: Vascular interventions for malignant tumors include tumor artery embolization and chemoembolization. Although selective arterial infusion chemotherapy is an important method for treating substantial malignant tumors, there are still characteristics such as rapid metabolism and excretion of infused drugs from the drug delivery organ and failure to significantly reduce the toxic side effects of normal tissue cells throughout the body. The tumor supply artery is temporarily or permanently blocked by vascular embolic agents, such as gelatin sponge, stainless steel ring and autologous blood clot, to reduce the size of the tumor and facilitate surgical resection and intraoperative bleeding. For patients with inoperable advanced malignant tumors and arterial perfusion therapy, it can play a better palliative effect, relieve patients’ pain and bleeding symptoms, and prolong survival time. However, these embolization methods generally embolize larger arteries and branches, which can easily form collateral circulation to restore blood supply to tumor tissues within a short period of time, and the therapeutic effect is still unsatisfactory. In recent 10 years, many scholars have researched on new drug formulations, i.e. drug carriers, which can combine anti-cancer drugs and embolic agents into target arteries to embolize the terminal branches of tumor tissues and block blood supply, and slowly release chemotherapeutic drugs to play the role of local chemotherapy, and significantly reduce the drug concentration in body circulation and systemic chemotherapy toxicity, which is called chemoembolization and has achieved obvious results. The effect is obvious. The theoretical basis of chemoembolization is to combine the ischemic effect of tumor caused by embolization and the antitumor effect of chemotherapeutic drugs to achieve the purpose of killing tumor tissue. The main superiority of its synergistic effect is to increase the local drug concentration and prolong the local drug action time, while decreasing the systemic drug concentration and reducing the toxic side effects. There are certain side effects and complications of malignant tumor chemoembolization: there are two major side effects and complications of malignant tumor chemoembolization: firstly, complications caused by general interventional techniques and side effects of chemotherapeutic drugs; secondly, complications caused by embolization, mainly in the following three aspects: ① Post-embolization syndrome: it can occur in most of the tumor after embolization, and the causes are usually thought to be organ ischemia, edema and tumor tissue necrosis. Necrosis. The main manifestations are nausea, vomiting, fever, pain and paralytic intestinal stasis. The fever usually does not exceed 38 degrees Celsius, but severe cases may have high fever, which may gradually return to normal within 1 week. Pain can occur at the time of bolus injection, and in severe cases, the bolus has to be discontinued. Treatment includes analgesia, antiemetic drugs, oxygen and other symptomatic treatment. To prevent infection, broad-spectrum antibiotics can be administered preoperatively and postoperatively. ② Misembolization and ectopic embolization: The catheter cannot be inserted super-selectively, the embolic agent is not selected properly, and the pressure of the injected contrast agent is too high, which can cause the embolic agent to reflux and misembolize other organs. Ectopic embolism can be caused by the collateral circulation between the target artery of embolization and other organs. Such as brain and lung infarction, ischemic necrosis of skin, gallbladder, intestine, nerves and limbs. Preventive and treatment measures are: a. Perform detailed angiography before embolization to observe whether there are other normal organs with collateral vessels or arteriovenous fistulae, and if so, try to further super-selective cannulation to the target artery or use larger proximal embolic agents to block collateral vessels or arteriovenous fistulae. b. Select appropriate embolic agents and embolization techniques. c. If misembolization or ectopic embolization occurs, give immediate vasodilator, anticoagulant, hormone and other drugs to reduce the extent and degree of tissue infarction. ③Infection and abscess formation: It is less common, and the reason is mostly due to necrosis and liquefaction of tumor tissue after embolization, coupled with poor sterilization of surgical instruments, catheters and embolic agents or not strictly aseptic operation. The preventive measures are strict aseptic operation, autoclave treatment of embolization agent if necessary, preoperative and postoperative use of broad-spectrum antibiotics for prevention, etc. Once the abscess is formed, it should be treated by percutaneous puncture and drainage. 6.Non-vascular interventional treatment for malignant tumor: Percutaneous non-percutaneous interventional treatment is a technique to diagnose and treat many diseases by using various instruments under the guidance of medical imaging equipment such as X-ray, CT, B-ultrasound, MRI, through pathways other than blood vessels, such as through the natural openings of human physiological cavities or directly through the organs. In recent years, with the advancement of equipment and devices, the scope of clinical application has become more and more extensive, and the technique has become increasingly perfect. Percutaneous non-transvascular interventional techniques have the advantages of safety, effectiveness and few complications in the diagnosis and treatment of tumors. At present, many large and medium-sized hospitals in China have carried out this technology one after another, and in some aspects it is close to the international level. The former has been applied to the diagnosis and differential diagnosis of tumor diseases in various parts of the body, while the latter is mainly applied to the diagnosis of obstruction in the biliary system and urinary system. The application of non-vascular interventional techniques involves various systems throughout the body. For example, balloon catheter dilation and stent placement for malignant stenosis of the esophagus, gastroduodenum, colon and biliary tract in the digestive system, gastrostomy, ultrasound and CT-guided direct drug injection therapy for liver cancer, direct puncture injection or direct current therapy for lung cancer in the respiratory system, metal endoprosthesis for malignant tracheobronchial stenosis, intraluminal perfusion therapy for malignant pleural effusion, percutaneous nephrostomy and stent drainage in the urinary system for malignant ureteral obstruction, intracavitary perfusion therapy for bladder cancer; craniopharyngioma aspiration and sympathetic nerve block for central nervous system; MRI-guided percutaneous laser resection of deep malignant tumors, etc. Proper selection of guidance devices and techniques is the key to interventional treatment. Whether it is percutaneous biopsy, or percutaneous internal and external drainage and stent placement, convenient and accurate guidance is required to ensure the success of the procedure. The guiding methods for percutaneous non-transvascular techniques include fluoroscopy, B-ultrasound, CT, and MRI, and the principle of choosing the guiding method depends on the location of the lesion, the purpose of treatment, and the interventional technique used, and can be determined on a case-by-case basis before surgery.