Transbronchial cryobiopsy: a new tool for lung biopsies.

BACKGROUND: Specimens from transbronchial lung biopsies lack sufficient quality due to crush artifact and are generally too small for diagnosis of diffuse lung diseases. Flexible cryoprobes have been shown to be useful in therapeutic bronchoscopy. We introduce a novel technique for obtaining lung biopsies bronchoscopically, using a flexible cryoprobe.
OBJECTIVES: The purpose of this study was to show the feasibility of using a cryoprobe to obtain lung biopsies during flexible bronchoscopy.
METHODS: Forty-one patients with radiographic signs of diffuse lung disease were selected for transbronchial biopsy. During flexible bronchoscopy, conventional transbronchial biopsies using forceps were done first. Then a flexible cryoprobe was introduced into the selected bronchus under fluoroscopic guidance. Once brought into position, the probe was cooled and then retracted with the frozen lung tissue being attached on the probe's tip. The tissue was processed for histology. After establishing a diagnosis, the specimen area was measured using a digital morphometry system.
RESULTS: We evaluated the biopsy samples of 41 patients. The mean specimen area was 5.82 mm(2) (0.58-20.88 mm(2)) taken by forceps compared to 15.11 mm(2) obtained using the cryoprobe (2.15-54.15 mm(2), p < 0.01). Two patients had a pneumothorax which resolved with tube thoracostomy. Biopsy-associated bleeding did not require any intervention. Transbronchial cryobiopsy contributed in a substantial number of cases to a definitive diagnosis.
CONCLUSIONS: Transbronchial cryobiopsy is a novel technique which allows to obtain large biopsy samples of lung parenchyma that exceed the size and quality of forceps biopsy samples. Prospective trials are needed to compare this technique with surgical lung biopsy for diagnosis of diffuse lung diseases.