A Randomized Controlled Trial of a Novel Sheath Cryoprobe for Bronchoscopic Lung Biopsy in a Porcine Model

Transbronchial forceps biopsy (FBx) has been the preferred method for obtaining bronchoscopic lung biopsy specimens. Cryoprobe biopsy (CBx) has been shown to obtain larger and higher quality samples, but is limited by its inability to retrieve the sample through the working channel of the bronchoscope, requiring the bronchoscope to leave the airway for sample retrieval.

We evaluated a novel device using a sheath cryobiopsy (SCBx). This method allows for specimen retrieval through the working channel of the bronchoscope, with the scope remaining inside the airway.

This prospective, randomized controlled, single-blinded porcine study compared a 1.1-mm SCBx probe, a 1.9-mm CBx probe, and 2.0-mm FBx forceps. Assessment of histologic accessibility, sample quantity and quality, number of attempts to acquire and retrieve samples, cryoprobe activation time, fluoroscopy activation time, technical feasibility, and complications were compared.

Samples adequate for standard pathologic processing were retrieved with 82.1% of the SCBx specimens, 82.9%% of the CBx specimens, and 30% of the FBx specimens. The histologic accessibility of both SCBx (P = .0002) and CBx (P = .0003) was superior to FBx. Procedure time for FBx was faster than for both SCBx and CBx, but SCBx was significantly faster than CBx (P < .0001). Fluoroscopy time was lower for both SCBx and CBx compared with FBx. There were no significant bleeding events.

SCBx is a feasible technique providing a higher quality lung biopsy specimen compared with FBx and can successfully be retrieved through the working channel. Human studies are needed to further assess this technique with additional safety data.