Ultrasound-guided Cryobiopsy of Mediastinal/Hilar Lymph Nodes

Transbronchial EBUS-guided TBNA and Cryobiopsy of Mediastinal Lymph Nodes in Patients Nonsuspicious for Lung Cancer, Using Different Cryoprobe Freezing Times

EBUS-guided cryobiopsy of mediastinal and hilar lymph nodes has shown to be a useful diagnostic tool to obtain tissue for histological analysis and further targeted therapies in lung malignancies. Due to the large size and better quality of the tissue samples, a higher diagnostic yield than with transbronchial needle aspiration (TBNA) can be expected, especially in non-solid tumors. In previous studies different biopsy protocols were used. The freezing time of cryoprobe (which defines the sample sizes) ranged from 3 to 7 s and the number of biopsies was between 1 and 4 samples. It is therefore unclear what freezing times and biopsy frequency are required to obtain the best histological information.

EBUS-guided cryobiopsy of mediastinal and hilar lymph nodes has shown to be a useful diagnostic tool to obtain tissue for histological analysis and further targeted therapies in lung malignancies. Due to the large size and better quality of the tissue samples, a higher diagnostic yield than with transbronchial needle aspiration (TBNA) can be expected, especially in non-solid tumors. In previous studies different biopsy protocols were used. The freezing time of cryoprobe (which defines the sample sizes) ranged from 3 to 7 s and the number of biopsies was between 1 and 4 samples. It is therefore unclear what freezing times and biopsy frequency are required to obtain the best histological information. This study will analyze whether the freezing time influences the diagnostic yield in CB of mediastinal lymphadenopathies. Additionally we will evaluate the influence of the number of biopsies on the diagnostic yield.

Inclusion Criteria:

• At least one mediastinal lesion or hilar 1 cm or longer in the short axis requiring diagnostic bronchoscopy
• Age between 18 and 90 years
• Written informed consent after participant's information

Exclusion Criteria:

• Age < 18 and > 90 years
• Lacking ability to form an informed consent (including impaired judgement, communication barriers)
• Contraindication against bronchoscopy (e.g. co-morbidities)
• Mediastinal abscess or cyst
• Extraordinary blood supply of the lesion visualized by EBUS bronchoscope
• INR > 1.5 or Thrombocytes < 100 G/l
• Clopidogrel or other new antiplatelet drugs within 7 days before biopsy (salicylic acid alone allowed)
• Anticoagulation with NOAC within 48 hours before biopsy
• Pulmonary lesions suspicious of lung carcinoma