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Saline-enhanced hepatic radiofrequency ablation using a perfused-cooled electrode: comparison of dual probe bipolar mode with monopolar and single probe bipolar modes.

Lee JM, Han JK, Kim SH, Lee JY, Kim DJ, Lee MW, Cho GG, Han CJ, Choi BI - Korean J Radiol (2004 Apr-Jun)

Bottom Line: RF was applied to excised bovine livers in both bipolar and monopolar modes using a 200 W generator (CC-3; Radionics) and the perfused-cooled electrodes for 10 mins.The dimensions of the ablation zones and changes in the impedance currents and liver temperature during RFA were then compared between the groups.However, there was no significant difference between the short-axis diameter of the coagulation necrosis in the three groups: 3.1+/-0.8 cm, 2.9+/-1.2 cm and 4.0+/-1.3 cm in groups A, B and C, respectively (p > 0.05).

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, and Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, Korea.

ABSTRACT

Objective: To determine whether saline-enhanced dual probe bipolar radiofrequency ablation (RFA) using perfused-cooled electrodes shows better in-vitro efficiency than monopolar or single probe bipolar RFA in creating larger coagulation necrosis.

Materials and methods: RF was applied to excised bovine livers in both bipolar and monopolar modes using a 200 W generator (CC-3; Radionics) and the perfused-cooled electrodes for 10 mins. After placing single or double perfused-cooled electrodes in the explanted liver, 30 ablation zones were created at three different regimens: group A; saline-enhanced monopolar RFA, group B; saline-enhanced single probe bipolar RFA, and group C; saline-enhanced dual probe bipolar RFA. During RFA, we measured the tissue temperature at 15 mm from the electrode. The dimensions of the ablation zones and changes in the impedance currents and liver temperature during RFA were then compared between the groups.

Results: The mean current values were higher for monopolar mode (group A) than for the bipolar modes (groups B and C): 1550+/-25 mA in group A, 764+/-189 mA in group B and 819+/-98 mA in group C (p < 0.05). The volume of RF-induced coagulation necrosis was greater in group C than in the other groups: 27.6+/-2.9 cm(3) in group A, 23.7+/-3.8 cm(3) in group B, and 34.2+/-5.1 cm(3) in group C (p < 0.05). However, there was no significant difference between the short-axis diameter of the coagulation necrosis in the three groups: 3.1+/-0.8 cm, 2.9+/-1.2 cm and 4.0+/-1.3 cm in groups A, B and C, respectively (p > 0.05). The temperature at 15 mm from the electrode was higher in group C than in the other groups: 70+/- 18 degrees C in group A, 59+/-23 degrees C in group B and 96+/-16 degrees C in group C (p > 0.05).

Conclusion: Saline-enhanced bipolar RFA using dual perfused-cooled electrodes increases the dimension of the ablation zone more efficiently than monopolar RFA or single probe bipolar RFA.

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Comparison of radiofrequency-induced coagulation in the three groups. Note that the mean long-axis coagulation diameters were larger in group C than in the other groupsA. Photograph of specimen from group A (hypertonic saline-enhanced monopolar RFA)B. Photograph of specimen from group B (hypertonic saline-enhanced single probe bipolar RFA)C. Photograph of specimen from group C (hypertonic saline-enhanced dual probe bipolar RFA)
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Figure 3: Comparison of radiofrequency-induced coagulation in the three groups. Note that the mean long-axis coagulation diameters were larger in group C than in the other groupsA. Photograph of specimen from group A (hypertonic saline-enhanced monopolar RFA)B. Photograph of specimen from group B (hypertonic saline-enhanced single probe bipolar RFA)C. Photograph of specimen from group C (hypertonic saline-enhanced dual probe bipolar RFA)

Mentions: After RFA, a well-defined area with a central white discoloration was observed in the ablated zone sections. The mean Dv values of the RF induced central white zone, measured in the gross specimens of the three groups, were as follows: 5.0±0.7 cm in group A, 5.2±1.2 cm in group B and 3.8±0.8 cm in group C. The differences in the Dv values between groups A and C, and between groups B and C were statistically significant (p < 0.05) (Table 1). The mean Dt values were 3.4±0.9 cm in group A, 3.0±1.1 cm in group B and 4.3±1.3 cm in group C (Fig. 3). There was a significant difference in the Dt value between groups B and C (p < 0.05). The mean Ds values of the ablated spheres were 3.1±0.8 cm, 2.9±1.2 cm and 4.0±1.3 cm in groups A, B and C, respectively. The differences between the groups were not significant (p > 0.05). However, saline-enhanced dual probe bipolar RFA (group C) created ablation zones with a significantly larger volume than either monopolar-(group A) or single probe bipolar RFA (group B): 27.6±2.9 cm3 in group A, 23.7±3.8 cm3 in group B and 34.2±5.1 cm3 in group C. The differences between the volume of group C and those of the other groups were statistically significant (p < 0.05).


Saline-enhanced hepatic radiofrequency ablation using a perfused-cooled electrode: comparison of dual probe bipolar mode with monopolar and single probe bipolar modes.

Lee JM, Han JK, Kim SH, Lee JY, Kim DJ, Lee MW, Cho GG, Han CJ, Choi BI - Korean J Radiol (2004 Apr-Jun)

Comparison of radiofrequency-induced coagulation in the three groups. Note that the mean long-axis coagulation diameters were larger in group C than in the other groupsA. Photograph of specimen from group A (hypertonic saline-enhanced monopolar RFA)B. Photograph of specimen from group B (hypertonic saline-enhanced single probe bipolar RFA)C. Photograph of specimen from group C (hypertonic saline-enhanced dual probe bipolar RFA)
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2698140&req=5

Figure 3: Comparison of radiofrequency-induced coagulation in the three groups. Note that the mean long-axis coagulation diameters were larger in group C than in the other groupsA. Photograph of specimen from group A (hypertonic saline-enhanced monopolar RFA)B. Photograph of specimen from group B (hypertonic saline-enhanced single probe bipolar RFA)C. Photograph of specimen from group C (hypertonic saline-enhanced dual probe bipolar RFA)
Mentions: After RFA, a well-defined area with a central white discoloration was observed in the ablated zone sections. The mean Dv values of the RF induced central white zone, measured in the gross specimens of the three groups, were as follows: 5.0±0.7 cm in group A, 5.2±1.2 cm in group B and 3.8±0.8 cm in group C. The differences in the Dv values between groups A and C, and between groups B and C were statistically significant (p < 0.05) (Table 1). The mean Dt values were 3.4±0.9 cm in group A, 3.0±1.1 cm in group B and 4.3±1.3 cm in group C (Fig. 3). There was a significant difference in the Dt value between groups B and C (p < 0.05). The mean Ds values of the ablated spheres were 3.1±0.8 cm, 2.9±1.2 cm and 4.0±1.3 cm in groups A, B and C, respectively. The differences between the groups were not significant (p > 0.05). However, saline-enhanced dual probe bipolar RFA (group C) created ablation zones with a significantly larger volume than either monopolar-(group A) or single probe bipolar RFA (group B): 27.6±2.9 cm3 in group A, 23.7±3.8 cm3 in group B and 34.2±5.1 cm3 in group C. The differences between the volume of group C and those of the other groups were statistically significant (p < 0.05).

Bottom Line: RF was applied to excised bovine livers in both bipolar and monopolar modes using a 200 W generator (CC-3; Radionics) and the perfused-cooled electrodes for 10 mins.The dimensions of the ablation zones and changes in the impedance currents and liver temperature during RFA were then compared between the groups.However, there was no significant difference between the short-axis diameter of the coagulation necrosis in the three groups: 3.1+/-0.8 cm, 2.9+/-1.2 cm and 4.0+/-1.3 cm in groups A, B and C, respectively (p > 0.05).

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, and Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, Korea.

ABSTRACT

Objective: To determine whether saline-enhanced dual probe bipolar radiofrequency ablation (RFA) using perfused-cooled electrodes shows better in-vitro efficiency than monopolar or single probe bipolar RFA in creating larger coagulation necrosis.

Materials and methods: RF was applied to excised bovine livers in both bipolar and monopolar modes using a 200 W generator (CC-3; Radionics) and the perfused-cooled electrodes for 10 mins. After placing single or double perfused-cooled electrodes in the explanted liver, 30 ablation zones were created at three different regimens: group A; saline-enhanced monopolar RFA, group B; saline-enhanced single probe bipolar RFA, and group C; saline-enhanced dual probe bipolar RFA. During RFA, we measured the tissue temperature at 15 mm from the electrode. The dimensions of the ablation zones and changes in the impedance currents and liver temperature during RFA were then compared between the groups.

Results: The mean current values were higher for monopolar mode (group A) than for the bipolar modes (groups B and C): 1550+/-25 mA in group A, 764+/-189 mA in group B and 819+/-98 mA in group C (p < 0.05). The volume of RF-induced coagulation necrosis was greater in group C than in the other groups: 27.6+/-2.9 cm(3) in group A, 23.7+/-3.8 cm(3) in group B, and 34.2+/-5.1 cm(3) in group C (p < 0.05). However, there was no significant difference between the short-axis diameter of the coagulation necrosis in the three groups: 3.1+/-0.8 cm, 2.9+/-1.2 cm and 4.0+/-1.3 cm in groups A, B and C, respectively (p > 0.05). The temperature at 15 mm from the electrode was higher in group C than in the other groups: 70+/- 18 degrees C in group A, 59+/-23 degrees C in group B and 96+/-16 degrees C in group C (p > 0.05).

Conclusion: Saline-enhanced bipolar RFA using dual perfused-cooled electrodes increases the dimension of the ablation zone more efficiently than monopolar RFA or single probe bipolar RFA.

Show MeSH
Related in: MedlinePlus