PURPOSE: To evaluate the in vivo efficiency of 2 multiple-electrode radiofrequency (RF) systems to create confluent areas of coagulation in porcine liver, compared with consecutive overlapping ablation. MATERIALS AND METHODS: A total of 18 coagulations were created with 3 RF devices and 3 internally cooled electrodes at laparotomy in 6 female pigs. RF was applied to the porcine livers in a consecutive, monopolar mode (group A), in a switching monopolar mode (group B), or in a multipolar mode (group C). Energy efficiency values for the RF systems, shape and dimensions, and the coefficients of variation of the coagulation zones were compared in the 3 groups. RESULTS: The duration of the RF ablation procedures in groups A, B, and C were 36 minutes, 18 minutes, and 21.2 +/- 1.9 minutes. The average energy delivered to produce 1 cm(3) coagulation was greater in group A (5.6 +/- 2.3 kJ/cm(3)) than in group B (1.8 +/- 0.5 kJ/cm(3)) or in group C (2.0 +/- 0.8 kJ/cm(3)) (P < 0.05). The mean volumes of the coagulations in groups A, B, and C were 28.8 +/- 13.2 cm(3) in group A, 49.1 +/- 12.3 cm(3) in group B, and 40.6 +/- 16.3 cm(3) in group C, respectively (P = 0.07). Regarding the shape of the coagulations, the coagulations of groups B (isoperimetric ratio; 0.88) and C (0.84) were more spherical than those of group A (0.69) (P < 0.05). In addition, the coefficients of variation of the volumes of the ablation zones in groups A, B, and C were 0.46, 0.25, and 0.40, respectively. CONCLUSIONS: Multiple-electrode RF systems in switching monopolar and multipolar modes more efficiently created a larger, confluent, spherical-shaped coagulation than conventional consecutive RF ablation.
PURPOSE: To evaluate the in vivo efficiency of 2 multiple-electrode radiofrequency (RF) systems to create confluent areas of coagulation in porcine liver, compared with consecutive overlapping ablation. MATERIALS AND METHODS: A total of 18 coagulations were created with 3 RF devices and 3 internally cooled electrodes at laparotomy in 6 female pigs. RF was applied to the porcine livers in a consecutive, monopolar mode (group A), in a switching monopolar mode (group B), or in a multipolar mode (group C). Energy efficiency values for the RF systems, shape and dimensions, and the coefficients of variation of the coagulation zones were compared in the 3 groups. RESULTS: The duration of the RF ablation procedures in groups A, B, and C were 36 minutes, 18 minutes, and 21.2 +/- 1.9 minutes. The average energy delivered to produce 1 cm(3) coagulation was greater in group A (5.6 +/- 2.3 kJ/cm(3)) than in group B (1.8 +/- 0.5 kJ/cm(3)) or in group C (2.0 +/- 0.8 kJ/cm(3)) (P < 0.05). The mean volumes of the coagulations in groups A, B, and C were 28.8 +/- 13.2 cm(3) in group A, 49.1 +/- 12.3 cm(3) in group B, and 40.6 +/- 16.3 cm(3) in group C, respectively (P = 0.07). Regarding the shape of the coagulations, the coagulations of groups B (isoperimetric ratio; 0.88) and C (0.84) were more spherical than those of group A (0.69) (P < 0.05). In addition, the coefficients of variation of the volumes of the ablation zones in groups A, B, and C were 0.46, 0.25, and 0.40, respectively. CONCLUSIONS: Multiple-electrode RF systems in switching monopolar and multipolar modes more efficiently created a larger, confluent, spherical-shaped coagulation than conventional consecutive RF ablation.
Authors: E S Lee; J M Lee; W S Kim; S H Choi; I Joo; M Kim; D H Yoo; R-E Yoo; J K Han; B I Choi Journal: Br J Radiol Date: 2012-03-14 Impact factor: 3.039
Authors: Guilherme Lopes P Martins; Joao Paulo G Bernardes; Marcello S Rovella; Raphael G Andrade; Publio Cesar C Viana; Paulo Herman; Giovanni Guido Cerri; Marcos Roberto Menezes Journal: World J Gastroenterol Date: 2015-05-28 Impact factor: 5.742
Authors: Colin M Harari; Michelle Magagna; Mariajose Bedoya; Fred T Lee; Meghan G Lubner; J Louis Hinshaw; Timothy Ziemlewicz; Christopher L Brace Journal: Radiology Date: 2015-07-02 Impact factor: 11.105