The safety of electrolytically induced hepatic necrosis in a pig model.

BACKGROUND: Electrolysis fulfils the criteria for an ideal treatment of patients with unresectable liver tumours. Previous studies in the rat and pig have shown that controlled necrosis can be safely produced by inserting platinum electrodes into normal liver' parenchyma and liver tumours. As with any new treatment it is mandatory to investigate the 'worst-case scenario' of inadvertent intravascular electrode placement in a large animal model before progressing to clinical trials. METHODS: Under ultrasound control in six pigs, electrodes were inserted into, or immediately adjacent to, an hepatic vein. An electrolytic 'dose' of 100 C was then administered and the evolution of the lesion was monitored using ultrasound. Venous blood was collected before and during the electrolysis to evaluate potential acid/base disturbances and animals were closely monitored during electrolysis and during their recovery until a full autopsy was performed 4-7 days after treatment. RESULTS: Gas bubbles were seen to enter the hepatic veins or interior vena cava during treatment in five of the six animals. There were no major complications as a consequence and all animals recovered and remained in a healthy state until they were killed. At autopsy one animal had complete thrombotic occlusion of the left hepatic vein. Otherwise, findings were normal. CONCLUSION: In the clinical setting, due to the use of ultrasound to guide electrode placement into the centre of a tumour, the electrodes should rarely juxtapose an hepatic vein. Nevertheless, in this extreme situation, electrolysis is surprisingly safe with only one major vascular occlusion and no morbidity or mortality.

A new treatment for unresectable liver tumours: long-term studies of electrolytic lesions in the pig liver.

The majority of liver tumours are inoperable and an alternative treatment to surgical resection is urgently needed. Electrolysis has been investigated in a rat model and the procedure is safe, with accurate and predictable effects. The necrosis produced has also been shown to cause destruction of tumour deposits in the rat liver. A similar evaluation in a large animal model was necessary before clinical trials could commence. Using platinum electrodes connected to a d.c. generator, areas of hepatic necrosis were created in the pig liver. Animals were killed at various time points after treatment to assess the extent of healing. Treatment was uneventful and all animals made a full recovery. No animal died from the treatment or had to be killed prematurely. After 2 days of treatment, healing was minimal but at successive time points there was progressive evidence of healing, such that after 4 months, the original electrolytic lesion was greatly reduced in size and the large area of necrosis seen at the early time points was largely replaced by a fibrous scar with only small islands of necrotic tissue. In a large animal model, electrolysis is a safe method for creating areas of hepatic necrosis. The lesions heal with time and are associated with minimal morbidity. The results support a trial of electrolysis in patients with unresectable liver tumours.