Experimental modified orthotopic piggy-back liver autotransplantation.

UNLABELLED: The classical orthotopic liver autotransplantation is a very challenging and time wasting technique; it includes the division of major hepatic vessels and choledocus, and subsequent reconnection by end to end anastomoses. The caval end to end anastomoses are the most difficult to be performed and the interposition of a prosthesis can be required. We adopted the classical orthotopic liver autotransplantation technique in 2 patients affected with diffused liver metastases from colorectal cancer, for extracorporeal neutron capture therapy (BNCT). The procedure required very long operating times and the extracorporeal circulation (ECC) set up; furthermore the vena cava reconstruction was performed by the interposition of a goretex-prosthesis. We propose a "modified orthotopic piggy-back technique" to simplify liver reconnection and shorten the operating time. MATERIALS AND METHODS: The technique was developed in the swine (25 kg body weight), under general anaesthesia. We performed the resection of the retro-hepatic vena cava with preservation of the caval flow during the anhepatic phase, by interposing a goretex-prosthesis. The reconstruction of the vena cava was then performed by a side-to-side cava-prosthesis anastomosis with lateral clamping of the prosthesis. The procedure was then completed according to the classical technique of liver transplantation. RESULTS: The mean time for VC reconstruction was 56 (+/-10)min. and the mean time for side-to-side VC-prosthesis anastomosis was 13(+/-4)min. CONCLUSIONS: The "modified orthotopic piggy-back technique" can simplify the reimplant of the liver during autotransplantation and shorten the operating time. Furthermore also the time of total extracorporeal circulation is reduced, as during the anhepatic phase and during the side-to-side cava-prosthesis anastomosis the flow in the inferior vena cava is uninterrupted.

Feasibility study on the utilization of boron neutron capture therapy (BNCT) in a rat model of diffuse lung metastases.

In order for boron neutron capture therapy (BNCT) to be eligible for application in lung tumour disease, three fundamental criteria must be fulfilled: there must be selective uptake of boron in the tumour cells with respect to surrounding healthy tissue, biological effectiveness of the radiation therapy and minimal damage or collateral effects of the irradiation on the surrounding tissues. In this study, we evaluated the biological effectiveness of BNCT by in vitro irradiation of rat colon-carcinoma cells previously incubated in boron-enriched medium. One part of these cells was re-cultured in vitro while the other was inoculated via the inferior vena cava to induce pulmonary metastases in a rat model. We observed a post-irradiation in vitro cell viability of 0.05% after 8 days of cell culture. At 4 months follow-up, all animal subjects in the treatment group that received irradiated boron-containing cells were alive. No animal survived beyond 1 month in the control group that received non-treated cells (p<0.001 Kaplan-Meier). These preliminary findings strongly suggest that BNCT has a significant lethal effect on tumour cells and post irradiation surviving cells lose their malignant capabilities in vivo. This radio-therapeutic potential warrants the investigation of in vivo BNCT for lung tumour metastases.

Surface properties and implantation site affect the capsular fibrotic overgrowth.

Transplantation of encapsulated pancreatic islets is a promising approach for the treatment of type 1 diabetes. Large-scale application of this technique, however, is hampered by insufficient biocompatibility of the capsules. In this study, we have evaluated the biocompatibility of a new synthetic material with six different chemical groups on their surface (amino, carboxy-sulfate, carboxylate, hydroxylate, sulfate, and PMMA) used for the fabrication of the microcapsules. Eight Lewis rats were inoculated with a suspension of empty capsules made for each candidate material in the retroperitoneal ileopsoas muscle and renal subcapsular space. Four weeks later kidney and muscle containing the capsules were explanted, paraffin embedded, sectioned and stained with Sirius Red and Masson's Trichrome for histological analysis. The amount of fibrosis was also ultrastructurally evaluated with scanning electron microscopy. The samples were then subjected to digitalized quantitative analysis using specific software to determine the degree of fibrotic overgrowth. The quantification of collagen deposition, calculated in proximity of the microcapsules, was expressed as a percentage of the total area and can be considered a good index for the biocompatibility, an essential prerequisite for functional pancreatic islet transplantation. The results show that subcapsular renal space is the best implantation site and the positive surface charge induces a more intense collagen synthesis.