RESUMEN
AIM: This study sets out to test the biocompatibility of titanium clips in liver, in the presence of radiofrequency. Biocompatibility is assessed at various distances from the RF electrode and different points in time. METHOD: It is an experimental study conducted on pigs and makes use of histological changes that occur at the liver-titanium interface in presence of RF to test hypotheses. The titanium clips were modified in high vacuum (10 -5 atm) by heating them at 1000 degrees C and 1150 degrees C. Titanium clips were placed in liver at 0.5, 1.5 and 2.5 cm from RF probe. At 7, 14 and 28 days the inflammation, necrosis and fibrosis were assessed. RESULTS: The histological alterations decrease with the distance of implantation of titanium clips. The inflammation and necrosis nearby the titanium clips decrease in time, but the fibrosis does not increased, as expected. The modified titanium at 1000 degrees C clips cause less necrosis than commercial titanium clips. The moderator role of clip type between distance and cell alteration is empirically supported only for fibrosis and necrosis. The moderator role between time and cell alteration is supported only for inflammation. CONCLUSIONS: Experimental data suggests there are no preferred surgical clips in all situations. The biocompatibility of the titanium clips depends on the distance from the RF probe. The commercial ones prove less damaging if they are placed close to the RF probe (less than 1 cm) and those that were treated at 1150 C have a better bio-compatibility if placed more than 1 cm from RF probe.
Asunto(s)
Ablación por Catéter , Hepatectomía/instrumentación , Hígado/patología , Ensayo de Materiales , Instrumentos Quirúrgicos , Titanio , Animales , Modelos Animales de Enfermedad , Hepatectomía/métodos , Ensayo de Materiales/métodos , Sus scrofa , Porcinos , Resultado del TratamientoRESUMEN
Colorectal cancer became one of the most frequent malignant conditions of the past two decades. Non-resecable liver metastases might be destroyed in situ by radiofrequency although the local recurrence is still very important. Laser-Doppler flowmetry has proved to be a simple technique for monitoring the microcirculation, hereby the tissue perfusion at the edge of the post radiofrequency necrosis. The aim of the study was to evaluate microcirculation using lasser-Doppler for hepatic tissue and peripheral tumour perfusion after radiofrequency and the influence of local temperature increasing at 42 degrees C on tissular perfusion. Colorectal adenocarcinoma (CC531s) was used for liver tumour inoculationin on 15 Wag/Rij rats. Twenty-one days after inoculation, perfusion in hepatic tissue, on the tumour before and after radiofrequency treatment was mesured. When hepatic tissue was heated at 42 degrees C there was an increase in tissular perfusion, on the other part, heating the tumoural tissue do not increase perfusion. After radiofrequency in the periphery of necrosis the perfusion was still present, despite a clear drop towards initial level. Assessing the local microcirculation and tissue temperature during RF ablation by Laser-Doppler might be useful not only for RF efficiency evaluation but also as an indication for associating adjuvant local chemotherapy.