Background and Objective:Percutaneous ultrasound-guided thermal ablation is one of the major treatment methods for liver cancer.Tumor location close to the diaphragm or gastrointestinal tract was regarded as the treatment contraindication before due to poor visibility of the tumor or increased risk of thermal injury to the adjacent organs.This study used artificial pleural effusion or ascites to extend the indications of thermal ablation for liver cancer.Methods:Artificial pleural effusion (20 cases) or ascites (36 cases) was performed in 56 difficult cases of percutaneous thermal ablation for liver tumors.The technical success rates, the rate of approaching the procedure goal, complications, and local treatment response were assessed.Results:The technical success rates were 95%(19/20) for artificial pleural effusion and 100% (36/36) for artificial ascites, the achieve purpose rates were 100%(19/19) and 91.7% (33/36), the complete ablation rates were 84.2% (16/19) and 93.9% (31/33), respectively.Coughing, transient hematuria, and subcutaneous effusion were observed in 3 patients after the procedure of artificial pleural effusion, and hydrothorax in the right chest occurred in 1 patient during the artificial ascites process.Conclusions:Thermal ablation with the use of artificial pleural effusion or ascites is a safe and effective treatment for liver tumors, and the technique can widen the indications of thermal ablation for liver tumors. Background and Objective: Percutaneous ultrasound-guided thermal ablation is one of the major treatment methods for liver cancer. Tumor location close to the diaphragm or gastrointestinal tract was viewed as the treatment contraindication before due to poor visibility of the tumor or increased risk of thermal injury. to the adjacent organs. This study used artificial pleural effusion or ascites to extend the indications of thermal ablation for liver cancer. Methods: Artificial pleural effusion (20 cases) or ascites (36 cases) was performed in 56 difficult cases of percutaneous thermal ablation for Results: The technical success rates were 95% (19/20) for artificial pleural effusion and 100% (36/36 ) for artificial ascites, the achieve purpose rates were 100% (19/19) and 91.7% (33/36), the complete ablation rates were 84.2% (16/19) and 93.9% (31/33), re spectively. Coughing, transient hematuria, and subcutaneous effusion were observed in 3 patients after the procedure of artificial pleural effusion, and hydrothorax in the right chest occurred in 1 patient during the artificial ascites process. Conclusions: Thermal ablation with the use of artificial pleural effusion or ascites is a safe and effective treatment for liver tumors, and the technique can widen the indications of thermal ablation for liver tumors.