Cryoablation: Mechanism of Action and Devices

Abstract

Cryoablation refers to all methods of destroying tissue by freezing. Cryoablation causes cellular damage, death, and necrosis of tissues by direct mechanisms, which cause cold-induced injury to cells, and indirect mechanisms, which cause changes to the cellular microenvironment and impair tissue viability. Cellular injury, both indirect and direct, can be influenced by four factors: cooling rate, target temperature, time at target temperature, and thawing rate. In this review, the authors describe the mechanisms of cellular injury that occur with cryoablation, the major advantages and disadvantages of cryoablation compared with other thermal ablation techniques, and the current commercially available cryoablation ablation systems.

Percutaneous ablation of malignant thoracic tumors

“…Whatever the type of energy used, the procedure is usually performed under conscious sedation or general anesthesia, depending on the patient, type of lesion and the choice or experience of the operator (10,11,19). At the minimum, the patient is put under oxygen administration with continuous monitoring of cardiorespiratory parameters.…”

“…Other energy sources are available, including microwave, cryoablation and laser (2,7,10,11). The type of energy that can be used will depend on the patient, location and nature of the tumor, treatment goal, and operator experience or preference.…”

“…5). The anesthetic effect of cold on tissues and nerves is a prominent advantage, making the technique particularly suitable for the treatment of lesions located in the chest wall or close to the pleura (11). Finally, the associated antitumoral immune response would be more important than for other ablation techniques, and preservation of tissue architecture allows better cellular repopulation of healthy peritumoral tissues.…”

Biophysiologic considerations in cryoablation: a practical mechanistic molecular review

“…Thawing eventually results in a decrease in extracellular osmolarity as ice melts, which can result in an influx of water into cells, resulting in cellular swelling and bursting (5). Repeating the freeze-thaw cycle results in markedly increased cell death rates (4).…”

“…These mechanisms are not as well understood as the immediate direct injury caused by the procedure. One hypothesis is that mitochondrial damage may activate caspase cascades, resulting in programmed cell death (5,11). Recognition of the role of the apoptotic pathway of cell death in cryosurgery raises questions regarding the potential for resistance to cryotherapy, particularly in the treatment of prostate cancer, as it is not possible to include the entire prostate in the central necrotic zone to ensure negative margins due to the proximity of neurovascular bundles and the rectum.…”