What is the first phase of cryoablation?

The first phase of cryoablation involves extracellular ice formation. During this initial phase, the temperature of the tissue is lowered, leading to the formation of ice crystals outside of the cells. This process is crucial as it alters the osmotic balance, causing water to migrate out of the cells and concentrate in the extracellular space. As the temperature continues to decrease, this can lead to physical damage to the tissue, paving the way for the subsequent phases of cryoablation where cellular effects, such as intracellular ice formation, begin to occur. Understanding this phase is critical for appreciating the overall impact of cryoablation on targeted tissues and how subsequent phases follow the extracellular freezing process.