Bronchoscopic Cryotherapy. Clinical Applications of the Cryoprobe, Cryospray, and Cryoadhesion.

Cryotherapy is an evolving therapeutic and diagnostic tool used during bronchoscopy. Through rapid freeze-thaw cycles, cryotherapy causes cell death and tissue necrosis or tissue adherence that can be used via the flexible or rigid bronchoscope. This extreme cold can be used through the working channel of the bronchoscope via a specialized cryoprobe or directly with the use of spray cryotherapy. These properties allow for multiple bronchoscopic techniques, each with its own equipment and procedural, safety, and efficacy considerations. Bronchoscopic cryotherapy can be used in a variety of clinical scenarios, including the treatment of malignant and benign central airway obstruction and low-grade airway malignancy, foreign body removal or cryoextraction, endobronchial biopsy, and transbronchial biopsy. The bulk of the experience with bronchoscopic cryotherapy consists of uncontrolled case series of malignant central airway obstruction. There are also controlled data supporting the use of cryoadhesion for endobronchial biopsies, albeit with an increased risk of controllable bleeding. The use of cryoadhesion for transbronchial biopsies is an active area of investigation with limited controlled data. In addition, there are promising future directions using bronchoscopic cryotherapy, including chemosensitizing malignancy with cryotherapy and capitalizing on the synergy between cryotherapy and radiation.