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Purpose To determine cryoprobe spacing requirements in order to achieve overlapping ablation zones using the same ablation protocol in porcine liver, lung, and kidney. Materials and methods Six female pigs underwent cryoablation of the liver, lung, and kidney. Two 2.4-mm cryoprobes were spaced 20-mm apart with seven 16-gauge thermometers placed linearly and in axis with the cryoprobes at 5-mm increments from one another. The placement of the thermometers was such that three were placed between the two probes and two were placed laterally to each probe. Simultaneous use of the cryoprobes, using 12- and 8-minute double-freeze cycles, was performed with intratissue temperature monitoring during the procedure. Results The center temperatures between the two cryoprobes in kidney, lung, and liver were –25.87 ° C ± 1.91, –6.47 ° C ± 3.94, and 0.48 ° C ± 6.69, respectively. Dual 2.4-mm cryoprobes in our model achieved acute pathological complete coagulative necrosis zone at the center of the ablation zone between the cryoprobes only in the kidney tissue where a mean diameter of the acute complete coagulative necrosis zone was 39.6 mm ± 0.76 mm. Conclusions The critical temperature of −20°C was not reached at the midpoint between the probes with the 20-mm spacing arrangement in the lung and liver. These results emphasize the need for individualized organ ablation treatment protocols.

Patients with ulcerative colitis in Hong Kong are diagnosed at an older age and have a more extensive disease at diagnosis than patients in Melbourne. The high proportion of patients with extensive disease has implications for disease control, type of medications required, cancer risk, and surveillance requirements. Drug treatment in Hong Kong was less intense; in particular immunosuppressive treatment was often not used prior to colectomy. Phenotypic and management differences between East and West should serve to highlight areas of clinical and resource needs.