Radiofrequency ablation
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]
Overview
Radiofrequency ablation (RFA) is use of radiofrequecy energy to destroy biological tissue for medical treatment.
Use in Cardiology
Radiofrequency energy is used to destroy abnormal electrical pathways in heart tissue. It is used in recurrent atrial fibrillation and other types of supraventricular tachycardia. The energy emitting probe (electrode) is placed into the heart through a catheter. The practitioner first "maps" an area of the heart to locate the abnormal electrical activity before the responsible tissue is eliminated. Ablation is a newer technique and has shown some promise for cases unresponsive to conventional treatments. New techniques include the use of cryoablation (tissue freezing using a coolant which flows through the catheter), and microwave ablation, where tissue is ablated by the microwave energy "cooking" the adjacent tissue. The abnormal electrophysiology can also be modified in a similar way surgically, and this procedure referred to as the "Cox maze procedure", is commonly performed concomitantly with cardiac surgery.
This procedure is usually performed by a subspecialty of cardiologists known as cardiac electrophysiologists.
Renal and Hepatic Tumor Ablation
Applications other than cardiology field include ablations of tumor masses, e.g. hepatocellular carcinoma, adrenal tumors and breast tumors.
The procedure is performed either under ultrasound or CT guidance. A radiofrequency probe is inserted into or next to a tumor mass. By exerting radio-energy with frequency around 460 kHz, the tumor mass is heated to a point where cell necrosis occurs. Coagulation necrosis can be shown microscopically. It is usually used to treat patients with solitary inoperable lesions, as opposed to multiple metastases.
The most extensively investigated field should be the treatment of hepatocellular carcinoma in gastroenterology. According to the Barcelona Consensus 2002, such technique had been ranked " curative " procedure and proved as effective as surgical resection and chemical injection provided the hepatic tumor mass is smaller than 3 cm and the total tumor number fewer than 3.
Treatment of Varicose Veins
Radiofrequency ablation is a minimally-invasive procedure used in the treatment of varicose veins. An alternative to the traditional stripping operation, it is usually used to treat the great or small saphenous veins. Branch varicose veins are then treated either with phlebectomy or sclerotherapy.
Under ultrasound guidance, a radiofrequency catheter is inserted into the abnormal vein and the vessel treated with radio-energy, resulting is closure of the involved vein. Early studies have shown a high success rate with low rates of complications.
Other Uses
RFA is also used in radiofrequency lesioning, somnoplasty, and for vein closure in areas where intrusive surgery is contraindicated by trauma. Radiofrequency energy is also used in liver resection to control bleeding (hemostasis) and facilitate the transection process.