Radiofrequency Ablation: In Vivo Comparison of Four Commercially Available Devices in Pig Livers

Abstract

Larger coagulation volumes were obtained with the perfusion and internally cooled cluster devices. More spherical volumes of ablation were achieved with the 12-tine and cluster electrodes. The former proved superior with regard to the short axis perpendicular to the needle shaft. The cluster and nine-tine electrode produced better reproducibility, which is suggestive of improved predictability of the extent of coagulation with these systems.

Automatic temperature control for MR-guided interstitial ultrasound ablation in liver using a percutaneous applicator: Ex vivo and in vivo initial studies

“…described in previous reports (36,37), exhibiting a typical central ''white zone'' surrounded by a peripheral ''red zone''. Accurate correlation was found between the prescribed angles (relative to the first shot) for the US beam direction and the angular orientation of the flamelike elementary lesions, based on MR temperature maps, postoperative Gd-enhanced MR images, and macroscopic analysis (less than or equal to 68 trigonometric).…”

Distant Infusion of Saline May Enlarge Coagulation Volume During Radiofrequency Ablation of Liver Tissue Using Cool-tip Electrodes Without Impairing Predictability

“…The sphericity ratio is defined as the ratio of the largest diameter to the average of the two remaining diameters in each ablation [7]. A sphericity ratio close to 1 is associated with a spherical coagulation zone.…”

“…sue around the electrode and helps to prevent tissue charring [7]. However, the treatment of tumors larger than 2.5 cm in diameter has shown a high local recurrence rate; therefore, multiple overlapping ablations are required to encompass the tumor and the surrounding rim of liver tissue [8].…”

“…A hybrid applicator consisting of a cooled electrode combined with a tube to perfuse hypertonic saline (20% NaCl) at a distance of 2 mm and a flow rate of 1.7 mL/min created larger coagulation volumes than did the Cooltip [11,12]. However, high perfusion rates (> 1 mL/min) have recently been linked to irregular coagulation volumes [7] and also to higher complication rates, as a result of hot saline reflux along the applicator path [13,14]. On the other hand, low perfusion rates (< 0.1 mL/ min) are credited with avoiding such complications and providing similar ablation predictability [14].…”

Standards of Practice: Guidelines for Thermal Ablation of Primary and Secondary Lung Tumors

“…RFA destroys targeted tissue by heating cells to over 60°C to obtain an irreversible protein denaturation. The targeted tissue is therefore heated through ionic agitation [52,53]. Radiofrequency applicators have different designs: straight needle, expandable needle, and internally cooled single or cluster monopolar and bipolar needles.…”