Prospective, Randomised Multicenter Study Comparing the Efficacy of Transbronchial Forceps Biopsy With Cryobiopsy to Diagnose Interstitial Lung Disease.

Endoscopic biopsy currently plays only a minor role for the diagnosis of interstitial lung disease. However, in some cases obtaining lung tissue is necessary to establish a final diagnosis. The current standard procedure is transbronchial forceps biopsy - if not sufficient: surgical lung biopsy. Transbronchial lung biopsy bears essential limitations however:

• Small tissue sample
• Limited evaluability of the material caused by forceps-induced crush artifacts

In cryobiopsy the cryoprobe´s tip is being cooled and thereby cools the surrounding tissue to approximately minus 89 degrees Celsius. Subsequently, the frozen probe is retracted with the frozen tissue being attached onto the frozen probe's tip. When applied in the central airways, cryobiopsy proved to deliver large specimens of good quality, which may exceed forceps biopsies in terms of diagnostic yield. Pilot studies on transbronchial cryobiopsy showed that same advantages as seen in the endobronchial use.

Inclusion criteria

• Clinical indications for biopsy of interstitial lung disease
• Age over 18 years
• Signed consent

Exclusion criteria

• Risk of bleeding / ongoing anticoagulation
• Oxygen saturation <90% - despite delivery of 2l oxygen / min
• Underlying cardiac disease (unstable angina, myocardial infarction during the last month, congestive heart failure)
• Pulmonary hypertension, PAP sys> 50mmHg