Arterial occlusion using a microguidewire as a radiofrequency electrode.

Purpose: To illustrate the use of superselective radiofrequency (RF) energy delivery for arterial occlusion in vessels requiring embolization.

Technique: A 3.0-F microcatheter and a 0.016-inch stainless steel microguidewire coated with polytetrafluoroethylene except for the floppy platinum-coiled tip are inserted into the diseased arteries. After positioning the microcatheter at the target site, the floppy tip of the microguidewire is advanced 1 to 2 cm beyond the microcatheter to act as an electrode. RF ablation is performed at a power of 20 watts until there was a rise in uncontrolled impedance. If occlusion is incomplete, embolic agents can be applied. The use of the technique is illustrated in 4 cases, 3 involving renal branch arteries and a large arteriovenous malformation in the buttock. RF energy was successful in occluding the target vessels in 3 cases; the other required additional embolization. There were no complications, and the patients had sustained occlusion of the lesions.

Conclusion: Diseased arteries can be endovascularly occluded using a microguidewire to deliver radiofrequency energy. However, further development of the technique is needed to circumvent wire adhesion to the arterial wall and optimize RF delivery to avoid damage to adjacent structures.