Evaluation of 1.1 mm ultrathin cryobiopsy through a guide sheath for sampling of peripheral pulmonary lesions

Cryobiopsy provides a large amount of specimen with minimal crush artifact, but carries the risk of serious complications such as severe bleeding or pneumothorax. Transbronchial 1.1 mm ultrathin cryobiopsy can be performed through a guide sheath, potentially enabling repeated biopsies from the same location and reducing bleeding complications. This study retrospectively assessed the safety and efficacy of ultrathin cryobiopsy with a 1.1 mm cryoprobe, which can pass through a large guide sheath under radial endobronchial ultrasound (R-EBUS) guidance.

This retrospective observational study evaluated 1.1 mm ultrathin cryobiopsy through a guide sheath (GS-UTCB) for peripheral pulmonary lesions (PPLs), including solitary lesions, pulmonary infiltration, and ground-glass opacity. We compared bronchoscopic parameters between GS-UTCB and conventional endobronchial ultrasound with a guide sheath (EBUS-GS) procedures. In the GS-UTCB group, we analyzed the diagnostic yield of both the 1.1 mm cryoprobe and standard forceps biopsy. Additionally, tissue area and crush artifacts were evaluated for each device.

Between January 2022 and May 2023, 109 patients underwent bronchoscopy; 13 patients received GS-UTCB and 34 received EBUS-GS. The procedure time of the GS-UTCB group was significantly longer than that of the EBUS-GS group (P=0.04). Mild bleeding was significantly more frequent with GS-UTCB group, but there was no significant difference in moderate bleeding. There were no severe or life-threatening complications. In the GS-UTCB group, the diagnostic yield reached 92.3% in total, with 1.1 mm cryoprobe biopsy achieving 84.6% and standard forceps biopsy achieving 69.2%. Tissue area from 1.1 mm cryoprobe specimens was significantly larger than standard forceps (P<0.001), with minimal crush artifacts.

GS-UTCB represents a safe and effective method for sampling of various types of PPLs, demonstrating the potential to complement conventional forceps biopsy with superior tissue quality and diagnostic capability.