Proposal for a standardized methodology for performing endobronchial ultrasound-guided mediastinal cryobiopsy: a four-step approach

Endobronchial ultrasound (EBUS)-guided mediastinal cryobiopsy is a novel technique that increases the accuracy of diagnosing most pathologies that affect the mediastinum. Although EBUS-guided transbronchial needle aspiration (EBUS-TBNA) is the first choice in the diagnosis of mediastinal pathology, mediastinal cryobiopsy offers a larger and higher quality biopsy with minimal artifacts and no crushing when compared to conventional cytological samples obtained through EBUS-TBNA. It is particularly valuable in pathologies where EBUS-TBNA has diagnostic limitations, such as lymphoproliferative diseases, benign granulomatous conditions like sarcoidosis and silicosis, some rare infectious processes, metastases from rare non-pulmonary tumors, and in advanced stages of non-small cell lung cancer (NSCLC) where immunohistochemistry and molecular analysis are essential for personalized treatment. Therefore, mediastinal cryobiopsy seems to play a crucial role in these challenging scenarios. However, there is ongoing debate in the field of interventional pulmonology regarding the best approach for obtaining a mediastinal cryobiopsy. Some interventional pulmonologists use a high-frequency needle knife to create an incision in the tracheobronchial wall adjacent to the mediastinal lesion before inserting the cryoprobe, while others use a needle to create a pathway to the target area. There are also variations in the use of endoscopic or ultrasound imaging for guidance. In this article, we aim to review the current literature on different methods of performing mediastinal cryobiopsy and share our own clinical experience and methodology in a systematic way for its implementation in a safe, fast, and effective way.