Development of the Single Nodular VX-2 Carcinoma Model in Rabbit Liver: Tissue Chip Implantation under Ultrasonographic Guidance

Abstract

Purpose: To implant tissue chips in New Zealand rabbits, and thus redurce the frequency with which scat-tered VX2 carcinoma nodules and early metastasis develop in these animals.Materials and Methods: VX2-carcinoma tissue chips of two different sizes were implanted under ultrasono-graphic guidance. In each of 12 New Zealand rabbits (group 1), there 1-tissue chips were implanted in the liver using an 18-gauge needle, and in the same way, one 3- chip with an added gelfoam pellet was im-planted in the proximal lumen of the liver of each of ten other New Zealand rabbits (group 2). Three weeks after implantation, the animals underwent dval-phase CT scanning and were sacrificed, and the Number and size of tumor nodules, and metastasis were evaluated either macro-or microscopically.Results: In ten rabbits in group I, a total of 21 nodules (16 in the liver, 5 in the peritoneal wall) were observed, which in nine rabbits in group 2, a total of ten nodules-all in the liver-were present. CT scans depicted tumor nodules in 50% of group-I rabbits, and in 29% those in group 2. Mean tumor diameter was mm in group 1 and mm in group 2. Histologic examination indicated the presence of nodular VX2 carcinoma, with varying degrees of central necrosis, a feature more prominent in group 2.Conclusion: To provide a well-localized tumor nodule in rabbit liver, tissue chip implantation of VX2 carcino-ma, especially with added gelfoam, is a good alternative to intraparenchymal injection of tumor suspension.