Background & objective: Sonographically guided percutaneous microwave coagulation therapy has been widely used as an effective minimal invasive therapy for small liver cancer. However, high temperature of the shaft of the electrode blocks the advance of microwave coagulation in the treatment of liver cancer. The present study was conducted to investigate the prospect of the newly developed microwave coagulation equipment with "air-cooled" electrode in the treatment of liver cancer.
Methods: Six Pigs underwent hepatic coagulation at 60 W for 10 minutes, 60 W for 20 minutes, 80 W for 10 minutes, and 80 W for 20 minutes under US-guided percutaneous microwave coagulation using the "air-cooled" microwave coagulation equipment-ECO-100 Advanced Type.
Results: The experiment showed that the lesion size of microwave coagulation in single irradiation could be significantly enlarged when increasing the power output and exposure duration without the worry of high temperature of the shaft of the electrode. Microwave coagulation using the "air-cooled" electrode produced a necrosis volume of 4.0 cmx4.3 cm at 80 W for 10 minutes, 4.7 cmx5.2 cm at 80 W for 20 minutes. The "air-cooled" microwave coagulation did not leave a trail in the coagulation area.
Conclusion: The technique of "air-cooled" electrode can decrease the temperature of the shaft of the electrode. The effectiveness could be improved through increasing the power output and exposure duration