Experimental And Clinical Studies On Radiofrequency Ablation Nearby Macrovascular

BackgroundHepatic cancer is the most commonly in malignant tumors of human race. It was only 20 – 30 percent that patients could receive surgical resection because of the size, site and numbers of tumors, extrahepatic involvement and poor liver function. Most patients had to accept other non-surgical candidates.Radiofrequency ablation (RFA), one of newest local therapeutic methods, has received much recent attention as a minimally invasive strategy for the treatment of focal malignant diseases in the liver. It works by converting radiofrequency waves into heat. The alternating current passing down from waves into heat. The alternating current passing down from an uninsulated electrode tip into the surrounding tissues generates changes in the direction of ions and creates ionic agitation and frictional heating, which results in the final destruction of the tissue as a result of coagulative necrosis. RFA was widely adopted in the treatment of liver cancer, and fairly good effects had been made in small HCC. But the tumor which near macrovascular is difficult to treatment because of worrying about serious complication. There has been no such report about the safety and efficacy of radiofrequency ablation(RFA)near macrovascular in our country.ObjectiveIn this study, based on the observation of a canine model treated with RFA near macrovascular, We discussed the feasibility, safety and effect of RFA near macrovascular, and to provide scientific data and clinical evidence for clinical performance. We also discussed combining RFA with acetic acid injection in order to Increase coagulation.Methods and Results1. A canine model was established by Image-guided radiofrequency liver ablation near Inferior vein cava(IVC), and the hemodynamics of IVC was monitored with color Doppler flow imaging (CDFI). Subsequently the radiologic and pathologic characteristics of RFA lesions, procedure-related complications and the outcomes were examined. The results showed that RFA were performed uneventfully and safety, vascular walls were not suffered , and the coagulation was decreased. There were hepatic cells resided in infarcted zone. 2. A model was established by ex vivo Swine liver which treated with combining RFA with acetic acid injection. RFA lesions and temperature were examined. The results showed that Significantly greater RF heating (at 20 mm) was observed when the livers were pretreated with 50% acetic acid in 10% NaCl, compared with RFA alone. RFA combined with acetic acid produced more coagulation than RFA.A canine model was established by Image-guided combining radiofrequency liver ablation with acetic acid injection near IVC, and the hemodynamics of IVC was monitored with color Doppler flow imaging CDFI. Subsequently the radiologic and pathologic characteristics of RFA lesions, procedure-related complications and the outcomes were examined. The results showed that no death was observed, and treatment were performed uneventfully. The combination of RF ablation with acetic acid resulted in greater coagulation than with RFA alone. The combining RFA with acetic acid injection lesions were necrosis completely. 3. Radiofrequency ablation was practiced clinically for patients with liver cancer which near macrovascular. Outcomes, complications were collected and analysed. The clinical results demonstrated that it was safe of RFA for patients with liver cancer which near macrovascular. But the long-term outcome should be observed.Conclusions It is safe and feasibile to perform radiofrequency ablation near the macrovascular, but the RFA lesions was decreased because of blood flow, and the long-term outcome should be observed. Addition of acetic acid injections to RF ablation substantially increases coagulation compared with RF or injection therapy alone. this is a successful attempt to combining indications of ablative technique.