The purpose of this study was to compare the accuracy and sensitivity of slow-pull capillary technique, traditional suction aspiration and non negative pressure puncture in the diagnosis of mediastinal and/or hilar lymph node enlargement by ultrasound bronchoscopic lymph node biopsy.

EBUS-TBNA has been widely used in the diagnosis of diseases involving lung hilar and mediastinal lymph node enlargement.But different puncture methods are still controversial. Research shows that there was no significant difference in sample adequacy, diagnostic specificity and accuracy between the no negative pressure aspiration and traditional negative pressure aspiration technique.Slow-pull capillary technique is a relatively new operating method of endoscopic ultrasound guided fine needle biopsy in recent years. At present, this technology is widely used in pancreatic space occupying lesions. Compared with the traditional negative pressure aspiration method, our previous retrospective study found that the slow-pull capillary technique can improve the diagnostic accuracy of patients. Therefore, the purpose of this study is to prospectively and randomly compare the advantages and disadvantages of three puncture methods in EBUS-TBNA.

Inclusion Criteria:

• Age 18-80years
• Chest computed tomography showing hilar or mediastinal lymph node enlargement
• No contraindications for bronchoscopy
• Signed informed consent provided by the patient
• Disease needs to be diagnosed through the EBUS-TBNA

Exclusion Criteria:

• Severe coagulation dysfunction
• Severe cardiopulmonary dysfunction
• Acute asthma attack or massive haemoptysis
• Poor general condition
• Physical weakness without tolerance for anaesthesia or allergy to narcotic drug
• Disease can be diagnosed by other less invasive methods (such as skin or peripheral superficial lymph node biopsy)

The operator knows which puncture technique to be used, but the subject and the outcomes assessor does not know the technique.