Development of a multimodal tumor model for porcine liver.

In our efforts to develop a guidance system for laparoscopic liver surgery, we are working towards a live animal tumor model. The objective of this study was to establish the tumor model for live porcine liver, visible on both computed tomography (CT) and ultrasound images. The tumor model was created by injecting a mixture of agarose, sephadex, and glycerol. Together with water, the mixture was heated to bring its components into solution. Once heating was complete, methylthionine chloride and CT contrast were added. Using laparoscopic ultrasound guidance, the tumor model mixture was injected into in vivo porcine liver. The resulting model tumors were radiolucent, visible on both CT and conventional X-ray. They appeared as hyperechoic lesions on ultrasound images. Compared to the CT images, the model tumors in the ultrasound images showed good correspondence in size. We conclude that our tumor model, due to its clearly identifiable nature on multiple imaging modalities, is a valuable tool for further studies on laparoscopic ultrasound (2D and 3D) and navigated ultrasound in laparoscopic surgery of the liver and other organs in a pre-clinical set-up.