Percutaneous Radiofrequency Ablation of Liver Tumors Periprocedural Care

Updated: Oct 23, 2015
  • Author: Badar Bin Bilal Shafi, MBBS, MRCP, FRCR, CCT, EBIR; Chief Editor: Kurt E Roberts, MD  more...
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Periprocedural Care

Equipment

The imaging equipment needed for radiofrequency ablation (RFA) depends on the modality used. It can include the equipment necessary for ultrasonography, computed tomography (CT), or magnetic resonance imaging (MRI).

RFA equipment itself has three main components, as follows:

  • Needle electrodes
  • Electrical generator
  • Grounding pads

The needle electrodes are available in two forms. The first is a simple straight needle (see the first image below). The second is a straight needle containing multiple curved, retractable electrodes that are kept inside the needle until its tip is positioned within a tumor. Once this needle is properly positioned, a plunger on the hub of the needle is advanced so that the electrodes extend from the needle tip; when fully extended, the electrodes resemble an open umbrella (see the second image below).

Electrodes for radiofrequency ablation. Electrodes for radiofrequency ablation.
Umbrella-type electrodes for radiofrequency ablati Umbrella-type electrodes for radiofrequency ablation.

The radiofrequency (RF) generator is connected by insulated wires to the needle electrodes and to grounding pads that are placed on the patient's thighs. The generator produces alternating electrical current in the range of RF waves.

Currently, the following three RFA systems are commercially available for clinical application in the United States [34] :

  • Integra Radionics (Burlington, MA) manufactures a 200W generator with internally cooled electrodes; it is available as a cluster-array system or a single-needle system and includes optional automated pulsing of the current
  • RITA Medical Systems (Mountain View, CA) produces various models of umbrella-type electrodes [35] ; these systems do not allow for pulsing of the internal current and do not have internal cooling electrodes
  • RadioTherapeutics (Mountain View, CA) produces expandable, umbrella-type electrodes, including the LeVeen RFA system; this system does not allow for pulsing of the internal current and does not have internal cooling electrodes
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Patient Preparation

Anesthesia

Percutaneous RFA can be performed with local anesthesia and mild sedation. Deep sedation or general anesthesia can also be used. The modality of anesthesia depends on the patient's choice and the operator's preferences. For more information, see Local Anesthetic Agents, Infiltrative Administration and Procedural Sedation.

In a day-case setting, the local anesthetic is injected into the site where the skin incision is planned, and the patient is sedated by an intravenous injection. The patient is often able to go home the same day. If general anesthesia is not used, discomfort or pain may be felt while the area is being ablated. Day-case treatments for RFA are becoming more common.

Positioning

This procedure has no set patient positioning. Positioning depends upon the modality being used, the site of the lesion, the nature of the anesthesia, and the preferences of the operator and patient. The patient should be as comfortable as possible without compromise of the operator’s ability to adequately view and treat the lesion.

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