Since these events simultaneously damage the targeted tissue's vascular elements, post-freeze thrombotic events lead to severe ischemia and necrosis. The above description is not new. What is missing from this simple story are accepted explanations of both the causes of cryosurgical failure and the sometimes observed ablative effects in non-targeted lesions, the concept of cryoimmunology. Accordingly, the damaging effects of this therapy occur over time and space. For example, intracellular freezing, which is totally destructive, occurs close to the probe but quantitatively declines with distance toward the periphery of the ice ball.
Osmotic stress is experienced by cells throughout the freeze zone.
Since cells near the freeze zone margin are not subjected to extensive intracellular ice formation, we know that these peripheral regions experience less destructive effects. In this outer region of the frozen lesion not all cells experience intracellular ice formation. Many cells, depending on their unique physiology and proximity to the freeze zone edge, only experience transient hypothermia and osmotic stress, which may be collectively insufficient to cause total cell destruction. If, however, the vascular tissue within this region escapes destruction due to continued blood flow, it is possible for some areas within the ice ball periphery to recover during the post-thaw period. Freezing kills, sometimes.