Radiofrequency Ablation-- How Does it Work?
Radiofrequency is a type of electrical energy that has been used in medical procedures for decades. At the most basic level, this electrical energy is used to create heat. The heat is created in a specific location, at a specific temperature, for a specific period of time, and ultimately results in the death of unwanted tissue.
During a radiofrequency procedure, an ablation probe is placed directly into the target tissue. An array of several small, curved electrodes are deployed from the end of the probe into the tissue. The generator is turned on and target temperatures are input. The radiofrequency energy flows through the electrodes, causing ionic agitation, and therefore friction, in the nearby tissue. This friction creates heat, and once sufficient temperatures have been reached, the heat kills the target tissue within a few minutes. Thermocouples (tiny thermometers) incorporated into the tips of the electrodes allow continuous monitoring of tissue temperatures, and power is automatically adjusted so that the target temperatures remain constant. Ultrasound is typically used to monitor the treatment process.
Heat is a very effective means of killing tissue. As tissue temperature rises above 113° F (50° C), protein is permanently damaged and cell membranes fuse. The process is rapid, typically requiring less than 10-15 minutes exposure time for a 3 cm ablation.
Depending on the power applied and the resistance of the tissues, heat decreases rapidly at a specific distance from the electrode tip, limiting the ablation size. The size of the ablated area is determined largely by the size of the probe, the temperature of the tissue, and the duration of time the energy is applied. There is a sharp boundary between dead tissue and unaffected surrounding tissue. Thus unwanted tissue can be ablated without much sacrifice of surrounding normal tissue.
What is an RF Procedure Like?
Your physician can tell you what to expect before and after the procedure. There are several different ways that a RF procedure may be performed, and each has different benefits, limitations, and applicability. Your physician can determine which is most suitable for you.
One option is a percutaneous approach, in which the electrode is inserted through the skin to the desired location. The physician usually uses ultrasound to guide the needle to the right location. This is the least invasive way that RF is performed. General anesthesia is usually not necessary, but typically the patient is sedated. Often the patient is able to go home the same day.
If general anesthesia is not used, some discomfort or pain may be felt while the area is being ablated.
Another option is a laparoscopic approach. With this approach, the surgeon makes a few small incisions in the abdomen, through which the necessary instruments are passed in order to treat the target tissue. This is also a minimally invasive approach, although general anesthesia is necessary. Patients typically go home the next day. One advantage of this approach is that intraoperative ultrasound can be used, which may result in more accurate location and visualization of the target tissue.
A third option is the open approach. This is what most people probably think of when they think of an operation. An incision is made in the area to be treated, and the surgeon can directly visualize the procedure. General anesthesia is necessary, and the recovery period is a bit longer.
Patients may experience a slight fever for two or three days after the procedure. Physicians often allow the fever to resolve without intervention.
RF ablation procedures have a relatively low rate of complications (~ 3.6%). Most of the complications are considered minor. The following are the complications associated with this procedure: infection (abscess), bleeding, collapse of the lung, abnormal heart rhythms, and skin burn.