In-channel cryoprobe extraction for mediastinal and transbronchial cryobiopsy: a novel technique (cross-sectional...

Cryobiopsy has revolutionized mediastinal and lung parenchymal sampling, offering superior diagnostic yields compared to traditional techniques. However, the need for en bloc removal of the bronchoscope and cryoprobe during sample retrieval compromises the procedural safety and efficiency. We introduced a novel in-channel cryobiopsy extraction method that preserves continuous airway visualization and simplifies the procedural workflow.

In this prospective study, we evaluated 30 cases of mediastinal cryobiopsy through the working channel guided by endobronchial ultrasound (C-Cryo-EBUS) and 10 cases of transbronchial cryobiopsy through the working channel (channel-guided transbronchial cryobiopsy (C-TBCB)], using 1.1 and 1.7 mm cryoprobes. After a standardized 3-s freeze, all tissue samples were extracted directly through the bronchoscope's working channel without removing the scope. The outcomes assessed included procedural feasibility, diagnostic yield, procedure time, complication rate, and sample quality.

All cryobiopsies were successfully retrieved through the working channel, achieving a 100% diagnostic yield in both mediastinal and transbronchial settings. No complications or bronchoscopic damage was observed. Mean procedure times were 15.7 ± 6.3 min (C-Cryo-EBUS) and 14.6 ± 5.8 min (C-TBCB). Continuous visualization throughout the procedure enhanced control, minimized airway trauma, and enabled the immediate management of potential bleeding. The extracted specimens maintained excellent architecture and diagnostic adequacy, comparable to those of traditional methods, but with reduced procedural complexity.

The in-channel cryoprobe extraction technique is a feasible, reproducible, and safe alternative to conventional cryobiopsy. It maintains endoscopic visualization, reduces procedure time, and preserves diagnostic sample quality. Its implementation may optimize clinical workflows and promote safer and more efficient cryobiopsy practices in interventional pulmonology.