Comparison of Three Different Puncture Techniques in EBUS-TBNA

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.

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

The slow-pull capillary technique was performed as follows: after identification and measurement of the target lymph node, a needle was used to puncture the lymph node with the stylet in place.At the same time, the stylet was slowly and continuously pulled to create weak negative pressure.

The operation steps are the same as above, but the negative pressure device of 10ml syringe is connected behind the puncture needle.

The operation steps are the same as above, but there is no negative pressure device behind the puncture needle

The slow-pull capillary technique was performed as follows: after identification and measurement of the target lymph node, a needle was used to puncture the lymph node with the stylet in place.At the same time, the stylet was slowly and continuously pulled to create weak negative pressure.

The operation steps are the same as above, but the negative pressure device of 10ml syringe is connected behind the puncture needle.

The operation steps are the same as above, but there is no negative pressure device behind the puncture needle

The final pathological diagnosis was based on all available cytological and histological samples. In cases with negative pathological results , we continue to follow up the patients for ⩾6months.

Blood contamination was categorized as follows: low (no or few blood cells influencing the diagnosis), moderate (sample partially obscured by blood cells, but pathological diagnosis possible), and high (large numbers of blood cells, rendering pathological diagnosis difficult)

There are three levels of bleeding:Small amount of bleeding（Ⅰ）: Bleeding can stop spontaneously without continuous suction.Moderate bleeding（Ⅱ）: Continuous suction is required, and epinephrine or ice salt water is used locally to stop bleeding.Massive bleeding（Ⅲ）: Patients who need to be used balloon compression, interventional treatment, or blood transfusion treatment or even died of asphyxia due to bleeding.

Acquisition of tissue core of three different puncture methods according to the judgment of the pathologist

Tissue cores were immersed in formalin solution and subjected to histopathological examination. In the absence of a tissue core, the contents were pressed onto a glass slide, immersed in 96% methanol for ⩾10min and subjected to cytopathological examination.Some methods may only obtain cytological specimens, while others may obtain tissue cores. Tissue cores are better for pathologists to diagnose.

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)