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Radio frequency ablation in the rabbit lung using wet electrodes: comparison of monopolar and dual bipolar electrode mode.

Jin GY, Park SH, Han YM, Chung GH, Kwak HS, Jeon Sb, Lee YC - Korean J Radiol (2006 Apr-Jun)

Bottom Line: The dimensions of the ablation zones in the gross specimens from the groups were compared using one-way analysis of variance by means of the Scheffe test (post-hoc testing).There were significant differences in the largest and smallest dimension between the monopolar (group A) and dual electrode wet bipolar mode (groups B-E).Using a wet electrode, dual electrode bipolar RFA can create a larger ablation zone more efficiently than monopolar RFA.

View Article: PubMed Central - PubMed

Affiliation: Department of Diagnostic Radiology, Chonbuk National University Medical School, Research Institute of Clincal Medicine, Chonbuk, Korea. gyjin@chonbuk.ac.kr

ABSTRACT

Objective: To compare the effect of radio frequency ablation (RFA) on the dimensions of radio frequency coagulation necrosis in a rabbit lung using a wet electrode in monopolar mode with that in dual electrode bipolar mode at different infusion rates (15 mm/hr versus 30 ml/hr) and saline concentrations (0.9% normal versus 5.8% hypertonic saline).

Materials and methods: Fifty ablation zones (one ablation zone in each rabbit) were produced in 50 rabbits using one or two 16-gauge wet electrodes with a 1-cm active tip. The RFA system used in the monopolar and dual electrode wet bipolar RFA consisted of a 375-kHz generator (Elektrotom HiTT 106, Berchtold, Medizinelektronik, Germany). The power used was 30 watts and the exposure time was 5 minutes. The rabbits were assigned to one of five groups. Group A (n = 10) was infused with 0.9% NaCl used at a rate of 30 ml/hr in a monopolar mode. Groups B (n = 10) and C (n = 10) were infused with 0.9% NaCl at a rate of 15 and 30 ml/hr, respectively in dual electrode bipolar mode; groups D (n = 10) and E (n = 10) were infused with 5.8% NaCl at a rate of 15 and 30 ml/hr, respectively in a dual electrode bipolar mode. The dimensions of the ablation zones in the gross specimens from the groups were compared using one-way analysis of variance by means of the Scheffe test (post-hoc testing).

Results: The mean largest diameter of the ablation zones was larger in dual electrode bipolar mode (30.9+/-4.4 mm) than in monopolar mode (22.5+/-3.5 mm). The mean smallest diameter of the ablation zones was larger in dual electrode bipolar mode (22.3+/-2.5 mm) than in monopolar mode (19.5+/-3.5 mm). There were significant differences in the largest and smallest dimension between the monopolar (group A) and dual electrode wet bipolar mode (groups B-E). In dual electrode bipolar mode, the mean largest diameter of the ablation zones was larger at an infusion rate of 15 ml/hr (34.2+/-4.0 mm) than at 30 ml/hr (27.6+/-0.1 mm), and the mean smallest diameter of the ablation zones was larger at an infusion rate of 15 ml/hr (27.2+/-7.5 mm) than at an infusion rate of 30 ml/hr (24+/-2.9 mm).

Conclusion: Using a wet electrode, dual electrode bipolar RFA can create a larger ablation zone more efficiently than monopolar RFA.

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Measurement of the ablation zone. There was a significant difference in the Da and Dt between the monopolar and dual bipolar wet electrode mode.
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Figure 3: Measurement of the ablation zone. There was a significant difference in the Da and Dt between the monopolar and dual bipolar wet electrode mode.

Mentions: The mean Da values of the RF induced central white zone measured in the gross specimens of groups A, B, C, D, and E were 22.5±3.5 mm, 27.5±6.9 mm, 31.3±6.9 mm, 27.7±3.1 mm and 37±8.6 mm, respectively. The mean Dt values of groups A, B, C, D, and E were 19.5±3.5 mm, 22.3±2.5 mm, 23±7 mm, 25.7±2.7 mm and 31.3±6.3 mm, respectively. The mean Da diameter of the ablation zones was larger in dual electrode bipolar mode (30.9±4.4 mm) than in monopolar mode (22.5±3.5 mm). The mean Dt diameter of the ablation zones was larger in dual electrode bipolar mode (22.3±2.5 mm) than in the monopolar mode (19.5±3.5 mm). There were statistically significant differences in the Da and Dt values between the monopolar (group A) and dual electrode wet bipolar (groups B E) RFA procedures (Table 1) (Fig. 3).


Radio frequency ablation in the rabbit lung using wet electrodes: comparison of monopolar and dual bipolar electrode mode.

Jin GY, Park SH, Han YM, Chung GH, Kwak HS, Jeon Sb, Lee YC - Korean J Radiol (2006 Apr-Jun)

Measurement of the ablation zone. There was a significant difference in the Da and Dt between the monopolar and dual bipolar wet electrode mode.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2667594&req=5

Figure 3: Measurement of the ablation zone. There was a significant difference in the Da and Dt between the monopolar and dual bipolar wet electrode mode.
Mentions: The mean Da values of the RF induced central white zone measured in the gross specimens of groups A, B, C, D, and E were 22.5±3.5 mm, 27.5±6.9 mm, 31.3±6.9 mm, 27.7±3.1 mm and 37±8.6 mm, respectively. The mean Dt values of groups A, B, C, D, and E were 19.5±3.5 mm, 22.3±2.5 mm, 23±7 mm, 25.7±2.7 mm and 31.3±6.3 mm, respectively. The mean Da diameter of the ablation zones was larger in dual electrode bipolar mode (30.9±4.4 mm) than in monopolar mode (22.5±3.5 mm). The mean Dt diameter of the ablation zones was larger in dual electrode bipolar mode (22.3±2.5 mm) than in the monopolar mode (19.5±3.5 mm). There were statistically significant differences in the Da and Dt values between the monopolar (group A) and dual electrode wet bipolar (groups B E) RFA procedures (Table 1) (Fig. 3).

Bottom Line: The dimensions of the ablation zones in the gross specimens from the groups were compared using one-way analysis of variance by means of the Scheffe test (post-hoc testing).There were significant differences in the largest and smallest dimension between the monopolar (group A) and dual electrode wet bipolar mode (groups B-E).Using a wet electrode, dual electrode bipolar RFA can create a larger ablation zone more efficiently than monopolar RFA.

View Article: PubMed Central - PubMed

Affiliation: Department of Diagnostic Radiology, Chonbuk National University Medical School, Research Institute of Clincal Medicine, Chonbuk, Korea. gyjin@chonbuk.ac.kr

ABSTRACT

Objective: To compare the effect of radio frequency ablation (RFA) on the dimensions of radio frequency coagulation necrosis in a rabbit lung using a wet electrode in monopolar mode with that in dual electrode bipolar mode at different infusion rates (15 mm/hr versus 30 ml/hr) and saline concentrations (0.9% normal versus 5.8% hypertonic saline).

Materials and methods: Fifty ablation zones (one ablation zone in each rabbit) were produced in 50 rabbits using one or two 16-gauge wet electrodes with a 1-cm active tip. The RFA system used in the monopolar and dual electrode wet bipolar RFA consisted of a 375-kHz generator (Elektrotom HiTT 106, Berchtold, Medizinelektronik, Germany). The power used was 30 watts and the exposure time was 5 minutes. The rabbits were assigned to one of five groups. Group A (n = 10) was infused with 0.9% NaCl used at a rate of 30 ml/hr in a monopolar mode. Groups B (n = 10) and C (n = 10) were infused with 0.9% NaCl at a rate of 15 and 30 ml/hr, respectively in dual electrode bipolar mode; groups D (n = 10) and E (n = 10) were infused with 5.8% NaCl at a rate of 15 and 30 ml/hr, respectively in a dual electrode bipolar mode. The dimensions of the ablation zones in the gross specimens from the groups were compared using one-way analysis of variance by means of the Scheffe test (post-hoc testing).

Results: The mean largest diameter of the ablation zones was larger in dual electrode bipolar mode (30.9+/-4.4 mm) than in monopolar mode (22.5+/-3.5 mm). The mean smallest diameter of the ablation zones was larger in dual electrode bipolar mode (22.3+/-2.5 mm) than in monopolar mode (19.5+/-3.5 mm). There were significant differences in the largest and smallest dimension between the monopolar (group A) and dual electrode wet bipolar mode (groups B-E). In dual electrode bipolar mode, the mean largest diameter of the ablation zones was larger at an infusion rate of 15 ml/hr (34.2+/-4.0 mm) than at 30 ml/hr (27.6+/-0.1 mm), and the mean smallest diameter of the ablation zones was larger at an infusion rate of 15 ml/hr (27.2+/-7.5 mm) than at an infusion rate of 30 ml/hr (24+/-2.9 mm).

Conclusion: Using a wet electrode, dual electrode bipolar RFA can create a larger ablation zone more efficiently than monopolar RFA.

Show MeSH
Related in: MedlinePlus