Radiofrequency ablation
Radiofrequency ablation (RFA), also called fulguration,[1] is a medical procedure in which part of the electrical conduction system of the heart, tumor or other dysfunctional tissue is ablated using the heat generated from medium frequency alternating current (in the range of 350–500 kHz).[2] RFA is generally conducted in the outpatient setting, using either local anesthetics or twilight anesthesia. When it is delivered via catheter, it is called radiofrequency catheter ablation.
Two important advantages of radio frequency current (over previously used low frequency AC or pulses of DC) are that it does not directly stimulate nerves or heart muscle and therefore can often be used without the need for general anesthesia, and that it is very specific for treating the desired tissue without significant collateral damage; due to this, it is gaining in popularity as an alternative for eligible patients who do not want to undergo surgery.[3]
Documented benefits have led to RFA becoming widely used during the 21st century.[4][5][6] RFA procedures are performed under image guidance (such as X-ray screening, CT scan or ultrasound) by an interventional pain specialist (such as an anesthesiologist), interventional radiologist, otolaryngologists, a gastrointestinal or surgical endoscopist, or a cardiac electrophysiologist, a subspecialty of cardiologists.
Aesthetics dermatology[edit]
Radiofrequency ablation[21] is a dermatosurgical procedure by using various forms of alternating current. Types of radiofrequency are electrosection, electrocoagulation, electrodessication and fulguration. The use of radiofrequency ablation has obtained importance as it can be used to treat most of the skin lesions with minimal side effects and complications.
Varicose veins[edit]
Radiofrequency ablation is a minimally invasive procedure used in the treatment of varicose veins. It is an alternative to the traditional stripping operation. Under ultrasound guidance, a radiofrequency catheter is inserted into the abnormal vein and the vessel treated with radio-energy, resulting in closure of the involved vein. Radiofrequency ablation is used to treat the great saphenous vein, the small saphenous vein, and the perforator veins. The latter are connecting veins that transport blood from the superficial veins to the deep veins. Branch varicose veins are then usually treated with other minimally invasive procedures, such as ambulatory phlebectomy, sclerotherapy, or foam sclerotherapy. Currently, the VNUS ClosureRFS stylet is the only device specifically cleared by FDA for endovenous ablation of perforator veins.[22]
The possibility of skin burn during the procedure is very small, because the large volumes (500 cc) of dilute Lidocaine (0.1%) tumescent anesthesia injected along the entire vein prior to the application of radiofrequency provide a heat sink that absorbs the heat created by the device. Early studies have shown a high success rate with low rates of complications.[23]
Pain management[edit]
Back[edit]
RFA, or rhizotomy, was developed by Nikolai Bogduk to treat chronic pain arising from the facet joints in the lower (lumbar) back. Radiofrequency waves are used to produce heat on specifically identified nerves surrounding the facet joints called the lumbar medial branches of the dorsal ramus of the spinal nerves.[28] By generating heat around the nerve, the nerve is ablated, thus destroying its ability to transmit signals to the brain.
The nerves to be ablated are identified through injections of local anesthesia (such as lidocaine) around the medial branches prior to the RFA procedure to first confirm the diagnosis. If the local anesthesia injections provide temporary pain relief, the injection is repeated a second time to confirm the diagnosis. Then RFA is performed on the nerve(s) that responded well to the injections.
RFA is a minimally invasive procedure which can usually be done in day-surgery clinics, going home shortly after completion of the procedure. The person is awake during the procedure, so risks associated with general anesthesia are avoided. Whether for back or knee pain, a drawback for this procedure is that nerves recover function over time, so the pain relief achieved lasts only temporarily (3–15 months) in most people.[6]
Knees[edit]
In April 2017, the US Food and Drug Administration approved a commercial device using cooled radiofrequency ablation, with effects lasting for up to a year of pain relief from knee arthritis.[6][29] Reviews of preliminary clinical research and clinical outcomes indicated that better efficacy of ablation for knee pain was achieved by targeting the genicular nerve (one of the articular branches of the tibial nerve), targeting larger nerves including the femoral nerve, or by using an intra-articular procedure.[30][31][32]
Barrett's esophagus[edit]
Radiofrequency ablation has been shown to be a safe and effective treatment for Barrett's esophagus. The balloon-based radiofrequency procedure was invented by Robert A. Ganz, Roger Stern and Brian Zelickson in 1999 (System and Method for Treating Abnormal Tissue in the Human Esophagus). While the person is sedated, a catheter is inserted into the esophagus and radiofrequency energy is delivered to the diseased tissue. This outpatient procedure typically lasts from fifteen to thirty minutes. Two months after the procedure, the physician performs an upper endoscopic examination to assess the esophagus for residual Barrett's esophagus. If any Barrett's esophagus is found, the disease can be treated with a focal RFA device. Between 80 and 90% or greater of people in numerous clinical trials have shown complete eradication of Barrett's esophagus in approximately two to three treatments with a favorable safety profile. The treatment of Barrett's esophagus by RFA is durable for up to 5 years.[33][34][35][36][37]
Other uses[edit]
RFA is also used in radiofrequency lesioning for vein closure in areas where intrusive surgery is contraindicated by trauma, and in liver resection to control bleeding (hemostasis) and facilitate the transection process.
This process has also been used to treat TRAP sequence in multiple gestation pregnancies. This has an acceptable success rate for saving the 'pump' twin in recent studies compared to previous methods including laser photocoagulation.
RFA is used to treat uterine fibroids using the heat energy of radio frequency waves to ablate the fibroid tissue. The Acessa device[38] obtained FDA approval in 2012.[39] The device is inserted via a laparoscopic probe and guided inside the fibroid tissue using an ultrasound probe. The heat shrinks the fibroids. Clinical data on the procedure show an average of 45% shrinkage.
RFA is also used in the treatment of Morton's neuroma[40] where the outcome appears to be more reliable than alcohol injections.[41]