The principle of ultrasonic tracheoscopy: Combining bronchoscopy and ultrasonic probe, the ultrasonic probe is installed at the front of the tracheoscope to directly observe the lesions under the mucosa of trachea and bronchus, extra-tracheal lesions and enlarged lymph nodes outside the trachea. It is a new technique of tracheoscopic biopsy with high safety, high diagnostic rate, high repeatability and very low surgical trauma.
Trans-ultrasound bronchoscopic needle aspiration biopsy (EBUS-TBNA) can obtain mediastinal lymph that is not available with conventional bronchoscopy. The biopsy is performed directly under endotracheal ultrasound guidance, with accurate site, satisfactory sampling, few complications, and minimal trauma.
Clinical application of ultrasonic bronchoscopy (EBUS) in the diagnosis and treatment of lung cancer
Current situation of lung cancer diagnosis: 75% of lung cancer patients are clinically diagnosed with tumor at advanced stage, and many patients have no obvious symptoms at the initial stage. Some patients develop lung shadows, severe cough and even cough up blood. One examination can take several months, which often delays the disease. Many examinations need to remove samples from the body under general anesthesia to complete, which is risky, and the examination procedure can also cause wounds to the patient, which has a high rate of misdiagnosis.
Mediastinal lymph nodes: Mediastinal lymph node enlargement is often a diagnostic challenge for lung oncologists. 28% specificity, 75% sensitivity, 51% accuracy for CT; 100%, 89%, 94% for EBUS. In the past, the diagnosis of such diseases was usually made by transbronchial lymph node biopsy or mediastinoscopy under bronchoscopy, but these two modalities suffer from poor accuracy, unsatisfactory sampling, high risk, trauma, and long hospital stay.
The features of ultrasound bronchoscopy: it can show the intraluminal and extraluminal structures through dual channels, and at the same time can observe and check the blood flow, submucosal lesions, evaluate the depth of intratracheal tumor infiltration, and whether endoluminal treatment is possible, and at the same time can guide the biopsy of perihilar lung lesions. EBUS-guided lymph node biopsy (EBUS-TBNA) can observe the size of lesions and the extent of lymph node invasion, and provide a more accurate basis for the staging of lung cancer It can also guide the selection of the most correct treatment plan.
Indications for ultrasound bronchoscopy.
u Submucosal lesions of trachea and bronchus (to understand the spread of tumor in the submucosa and the distance from the bulge, to predict the surgical margin and avoid incomplete surgical resection);
u Tracheal and bronchial stenosis;
u normal surface mucosa but suspected infiltrative disease in the wall or outside the tube (to assess the depth of tumor infiltration in the tracheobronchial wall);
u Intradiastinal lesions: mainly the nature of the enlarged lymph nodes is identified (nature of hilar and mediastinal masses or enlarged lymph nodes)
Mediastinal, tracheal and bronchial lesions requiring puncture localization;
Evaluation of the efficacy of treatment of tracheal and bronchial lesions;
u lung cancer for mediastinal and hilar lymph node staging;
u Understanding the relationship between lung lesions and mediastinal structures to determine the indications for surgery;
To differentiate between mediastinal tumors and tracheobronchial primary tumors, especially to determine whether solid tumors are exocytotic or invasive, and to further define the cause of exocytotic changes in the airway (tumors, lymph nodes, pleural fluid, or abnormally enlarged cardiovascular chambers);
u Small nodular lesions in the peripheral bronchi;
u to determine whether there is tracheobronchial invasion in esophageal cancer.
Application scope: mainly used for biopsy of mediastinal occupancy and pathological staging of lung cancer.
n High sensitivity and specificity for determining mediastinal lymph node metastasis of malignant tumors;
n High accuracy and sensitivity in the determination of benign mediastinal lesions such as nodal disease;
n To improve the standardized treatment of lung cancer and the diagnosis of mediastinal disease to a new level;
n For lung cancer patients preparing for surgery, this test is especially important because it can determine whether the tumor is metastatic and accurately predict the postoperative effect in order to avoid unnecessary surgery, and the whole examination process is non-invasive and less painful for patients.