Prospective Case Series to Determine the Feasibility, Diagnostic Yield and Safety of Performing EBUS Guided Trans-Bronchial Mediastinal Cryobiopsy (EBUS-TBMC) of Lymph Nodes Using 1.1 mm Cryoprobe Through a Working Channel of Linear EBUS Bronchoscope Versus Conventional En-Bloc Cryobiopsy.

Abstract

EBUS-guided trans-bronchial mediastinal cryobiopsy (EBUS-TBMC) improves diagnostic yield over EBUS-TBNA but conventionally requires en-bloc removal of bronchoscope and frozen specimen, risking loss of airway control and procedural inefficiency. Retrieval of cryobiopsy specimens through-working channel (TWC) may address these limitations, but its feasibility and diagnostic adequacy are uncertain. Prospective evaluation was completed of 13 patients undergoing EBUS-TBMC at a single centre (August 2025 to January 2026). A 1.1 mm Erbe cryoprobe was advanced through an echobronchoscope with a 2.2 mm working channel (BF-UC190F, Olympus Medical, Japan) via needle tract formed via EBUS-TBNA. Fourteen lymph node stations underwent paired en-bloc and TWC biopsies. Paired biopsies were completed in 92.3% of targets. Median specimen size was equivalent (3 mm each; p = 0.197). Diagnostic yield was 93% (en-bloc) versus 79% (TWC); p = 0.48; versus 46% (EBUS-TBNA). There were no post procedural complications. TWC cryobiopsy using a 1.1 mm probe through a standard 2.2 mm working channel is feasible and safe compared to conventional en-bloc cryobiopsy.