Feasibility and Safety of 1.1-mm Cryobiopsy for Acute Rejection Surveillance in Lung Transplant Recipients: A Comparative Study and Review of the Literature

BACKGROUND: Identifying graft rejection after lung transplantation remains challenging, and no consensus exists on the optimal surveillance strategy. Transbronchial forceps biopsy (FBx) is the conventional method but is limited by small sample size and crush artifacts. Sheath-guided cryobiopsy (CBx) using a novel 1.1-mm probe has emerged as a promising alternative. This study evaluates the feasibility and safety of the 1.1-mm cryoprobe and provides a focused review of current literature.

METHODS: We conducted a retrospective observational single-center study between October 2022 and January 2023 of adult lung transplant recipients who underwent transbronchial biopsies for surveillance. Procedures were performed using either standard FBx or the 1.1-mm cryoprobe. Descriptive analyses compared feasibility and safety between groups.

RESULTS: We identified 72 lung transplant recipients who underwent 109 surveillance biopsies. A total of n = 56 CBx and n = 53 FBx procedures were performed. The median procedure time was 20 min (IQR 17-26) in the CBx group versus 22 min (IQR 15-33) in the FBx group. We found a statistically higher median sample area for CBx compared with FBx (11 vs. 6 mm 2, p < 0.01). No pneumothorax or postprocedural respiratory failure occurred in either group.

CONCLUSION: CBx with a 1.1-mm probe provides larger histological samples than FBx, with comparable safety and potentially shorter procedural times. These findings support its feasibility for lung transplant surveillance.