Temperature distribution in liver tissue during freezing with new cryoprobes

The performance of new cryoprobes was studied by measuring the spatial and temporal patterns of the temperature distribution in liver tissue around one to three active cryoprobes. After 15 min of maximal freezing a tissue region 22 mm in diameter was frozen to temperatures below - 50 degrees C by one active cryoprobe. With three cryoprobes, using the synergistic cooling effect, a tissue region 45 mm in diameter was cooled to temperatures below - 50 degrees C. Optimal placement of the cryoprobes was found to be of critical importance.