Korean J Pain.  2012 Jul;25(3):151-154. 10.3344/kjp.2012.25.3.151.

Morphologic Analysis of Water-Cooled Bipolar Radiofrequency lesions on Egg White in Vitro

• Kang SS
• Park JC
• Yoon YJ
• Shin KM

• KMID: 2278148
• DOI: http://doi.org/10.3344/kjp.2012.25.3.151

Abstract

BACKGROUND
The aim of this study was to document the optimal spacing of two cannulae to form continuous strip lesions and maximal surface area by using water-cooled bipolar radiofrequency technology.
METHODS
Two water-cooled needle probes (15 cm length, 18-gauge probe with 6 mm electrode tip) were placed in a parallel position 10, 20, 24, 26, and 28 mm apart and submerged in egg white. Temperatures of the probes were raised from 35degrees C to 90degrees C and the progress of lesion formation was photographed every 1 minute with the increase of the tip temperature. Approximately 30 photographs were taken. The resultant surface areas of the lesions were measured with the digital image program.
RESULTS
Continuous strip lesions were formed when the cannulae were spaced 24 mm or less apart; monopolar lesions around each cannula resulted if they were spaced more than 26 mm apart. Maximal surface areas through the formation of continuous strip lesion were 221 mm2, 375 mm2, and 476 mm2 in 10, 20, and 24 mm, respectively. Summations of maximal surface area of each monopolar lesions were 394 mm2 and 103 mm2 in 26 and 28 mm, respectively.
CONCLUSIONS
Water-cooled bipolar Radiofrequency technology creates continuous "strip" lesions proportional in size to the distance between the probes till the distance between cannulae is 24 mm or less. Spacing the cannulae 24 mm apart and treating about 80degrees C for 24 minutes maximizes the surface area of the lesion.

Keyword

bipolar; egg white; radiofrequency

MeSH Terms

Catheters
Egg White
Electrodes
Needles
Ovum

Figure

• 

  Fig. 1 Bipolar cooled radiofrequency lesions formed with cannulae spaced 10, 20, 24, 26, and 28 mm apart in egg white when maximal surface area achieved. A continuous "strip" lesion is formed when the cannulae are separated by 24 mm or less and discrete lesions are formed when the cannula are 26 mm or more apart.

• 

  Fig. 2 Lesion surface area (mm2) according to duration of bipolar cooled radiofrequency treatment (minutes) is shown. The spacing of the 2 cannulae is indicated to the right of each line. Continuous "strip" lesions were made when the cannulae were spaced 24 mm or less apart. This figure was created by spreadsheet program (Microsoft excel® 2007, California, USA).

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