A cooled needle electrode for radiofrequency tissue ablation: thermodynamic aspects of improved performance compared with conventional needle design.

RATIONALE AND OBJECTIVES I developed and tested a cooled needle electrode (CNE) for radiofrequency (RF) tissue ablation in vitro. METHODS A 2-mm needle electrode with two lumina for internal water perfusion and irrigation of the needle tip and a conventional needle electrode were tested in ex vivo calf liver during different levels of output power (wattage). RF lesions produced by the two needle types were further evaluated with a thermal camera. RESULTS When the CNE was used, a significant increase in the duration of ablation was observed, which caused a significant increase in delivered energy and lesion size when compared with the conventional needle electrode. The largest lesion produced with the CNE was almost spherical and measured 41 x 37 mm (longitudinal x transverse). The cooling effect was reflected in the image obtained with the thermal camera. CONCLUSION This technique produced very large lesions compared with conventional methods and may have a role in many different kinds of RF needle ablation.

[1]  H. Sittek,et al.  Previously treated, locally recurrent breast cancer: treatment with superselective intraarterial chemotherapy. , 1995, Radiology.

[2]  Percutaneous tissue ablation by radiofrequency thermal energy as a prelim to tumour ablation , 1993 .

[3]  D D Watson,et al.  Electrode radius predicts lesion radius during radiofrequency energy heating. Validation of a proposed thermodynamic model. , 1990, Circulation research.

[4]  D. Haines,et al.  Basic Aspects of Radiofrequency Catheter Ablation , 1994, Journal of cardiovascular electrophysiology.

[5]  J. McGahan,et al.  Percutaneous ultrasound-guided radiofrequency electrocautery ablation of prostate tissue in dogs. , 1995, Academic radiology.

[6]  D. Ohad,et al.  Transurethral needle ablation (TUNA) of the prostate using low-level radiofrequency energy: an animal experimental study. , 1993, European urology.

[7]  R N Hauer,et al.  Control of radiofrequency lesion size by power regulation. , 1989, Circulation.

[8]  S L Dawson,et al.  Tissue ablation with radiofrequency: effect of probe size, gauge, duration, and temperature on lesion volume. , 1995, Academic radiology.

[9]  S L Dawson,et al.  Tissue ablation with radiofrequency using multiprobe arrays. , 1995, Academic radiology.

[10]  G S Gazelle,et al.  Radiofrequency tissue ablation in the rabbit lung: efficacy and complications. , 1995, Academic radiology.

[11]  Sandro Rossi,et al.  Percutaneous ultrasound-guided radiofrequency electrocautery for the treatment of small hepatocellular carcinoma , 1993 .

[12]  Craig D. Miller,et al.  Management of Patients With Intramural Hematoma of the Thoracic Aorta , 1993, Circulation.

[13]  J. McGahan,et al.  Treatment of Liver Tumors by Percutaneous Radiofrequency Electrocautery , 1993 .

[14]  D. Haines,et al.  Biophysics and pathology of catheter energy delivery systems. , 1995, Progress in cardiovascular diseases.

[15]  H Calkins,et al.  Temperature monitoring during radiofrequency catheter ablation of accessory pathways. , 1992, Circulation.

[16]  L. Organ.  Electrophysiologic principles of radiofrequency lesion making. , 1976, Applied neurophysiology.