Internally cooled antenna for microwave ablation: results in ex vivo and in vivo porcine livers.
OBJECTIVE
To evaluate the performance of microwave ablation with an internally cooled antenna in ex vivo and in vivo porcine livers.


METHODS
Microwave ablations were performed in ex vivo and in vivo porcine livers with a 1.9 mm-diameter 2450 MHz microwave needle antenna. Four power settings (50, 60, 70 and 80 W) were used in this study, while application time was fixed at 10 min. Diameters of the coagulation zone were observed on gross specimens.


RESULTS
Excessive elongation of coagulation along the needle shaft was not encountered in all ablations. An arrow-shaped charring was observed. As the power increases, the long-axis coagulation diameter for in vivo liver increased significantly (P<.05). The short-axis coagulation diameter for in vivo liver was significantly smaller than that for ex vivo liver (P<.05) but not statistically different among the four power settings. After 10 min of ablation at 80 W, the short-axis and long-axis coagulation diameter for in vivo liver was 4.92+/-0.15 cm and 2.37+/-0.10 cm, respectively.


CONCLUSIONS
The internally cooled microwave antenna may be advantageous to minimize collateral damages.
Wang
Yang
Y
Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853 China.
Sun
Yuanyuan
Y
Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853 China.
Feng
Lei
L
Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853 China.
Gao
Yongyan
Y
Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853 China.
Ni
Xiaoxia
X
Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853 China.
Liang
Ping
P
Department of Ultrasound, Chinese PLA General Hospital, 28 Fuxing Road, Beijing 100853 China. Electronic address: liangping301@hotmail.com.
D000704:Analysis of Variance; D000818:Animals; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods*; D066298:In Vitro Techniques; D008099:Liver / Q000601:surgery*; D008872:Microwaves / Q000627:therapeutic use*; D013552:Swine