Liver electrolysis: pH can reliably monitor the extent of hepatic ablation in pigs

Electrolysis is a method of tissue ablation that creates chemical species and a pH gradient in response to direct current. Initial studies of electrolysis in animal models and humans have shown that it is a safe, predictable and effective process for destroying normal and tumour-bearing liver in a linear, dose-dependent manner. Presently, the amount of current that is applied (in coulombs) has to be calculated using historical data, with inherent inaccuracy. The present study tested whether pH could be used as a real-time monitor in order to predict more accurately the extent of necrosis. A total of 70 electrolytic lesions were created in 14 pigs, with pH monitoring of the lesion edge. The normal range of pH values was 6.5-8.7. A pH of less than 6 (at the anode) or more than 9 (at the cathode) reflected total cellular necrosis. When a pH value was recorded between 6.0 and 6.5 at the anode or between 8.7 and 9.0 at the cathode, the presence of necrosis was variable. In conclusion, during electrolytic ablation, pH measurement can monitor the extent of the induced necrosis.