Quality of transbronchial biopsy with large forceps compared to cryobiopsy: a randomized controlled, single blinded live animal study

Background: Transbronchial forceps biopsy is the widely accepted modality for obtaining tissue specimens for the evaluation of unexplained lung parenchymal abnormalities. However, cryoprobe biopsy provides large specimen sizes and higher yield performance. Utilization of cryoprobe biopsy remains limited by its need to be performed under rigid bronchoscopy and subsequent required operator expertise. We evaluated whether a larger, 2.8 mm forceps could be utilized for parenchymal biopsies. A larger size would surrogate the cryoprobe's large sample size and forceps mechanism to obviate the need for rigid bronchoscopy and its requirement for removing the sample en bloc. Methods: This prospective, randomized controlled, single-blinded porcine study compared a 1.9 mm cryoprobe, a 2.4 mm cryoprobe, and a 2.8 mm forceps. Assessment of histopathologic quality, sample quality and surface area, attempts to retrieve specimen samples, fluoroscopy activation time, overall procedural time, and complications were compared. Results: Although cryoprobe yielded larger specimens, there was no statistical difference amongst all tools with respect to alveolar tissue surface area. There was bleeding on all cryoprobe biopsies. No bleeding was observed with forceps. Out of 32 potential combinations of interventions for bleeding control, 18 (56.3%) were made. There was no significant difference in sample quality between all three modalities. There was one pneumothorax in the forceps arm. Conclusions: Large forceps (LF) biopsy is a feasible technique while providing high diagnostic yield without the need for advanced therapeutic tools. Human studies are needed to further corroborate this technique.