Mediastinal "deep freeze"-transcarinal lymph node cryobiopsy

The diagnostic yield of endobronchial ultrasound-transbronchial needle aspiration (EBUS-TBNA) from mediastinal lymph nodes ranges from 66%-89%. However, in many cases cytologic material is not sufficient for full molecular evaluation. A novel method of transcarinal cryobiopsy aims to provide bronchoscopically obtained, larger specimen samples from mediastinal lymph nodes. We aimed to assess the efficacy and safety of transcarinal EBUS-guided lymph node cryobiopsy.

Patients referred for EBUS-TBNA, based on abnormal mediastinal clinical and radiographic findings, were enrolled into this prospective interventional study between July 2020 and August 2021. All EBUS-TBNA procedures were performed using ProCore 22G needle (Cook Medical) to create, both a transcarinal tract for the cryoprobe and to obtain TBNA samples. For EBUS guided transcarinal cryobiopsy, we used flexible 1.1 mm or 1.7 mm cryoprobe inserted into the working channel of the EBUS scope and into the target subcarinal lymph node.

Twenty-four patients with male predominance 2:1 and mean age of 60.12 ± 10.16 years were enrolled. All target lymph nodes had hypoechoic, homogenic consistency with demarcated borders, without central structures. Cryobiopsy provided pathological diagnosis in 20 cases (83.33%), with 1.1 mm cryoprobe in 14 and with 1.7 mm cryoprobe in 6 cases. In one case each, pathology was provided by TBNA or by cryoprobe alone. No immediate or late complications were encountered during the procedures.

Transcarinal EBUS guided lymph node cryobiopsy following EBUS-TBNA proved to be efficient with a high diagnostic yield and can be considered safe, because no immediate or late complications occurred.