What veins are suitable for Radiofrequency Ablation (RFA)?
Like all catheter based thermoablation devices, radiofrequency ablation (RFA) is suitable for long straight veins which are deep to the skin through which a catheter can be passed under ultrasound control. As the vein is heated, it is also necessary to inject local anaesthetic around the vein not only to numb the vein and surrounding tissues, but also to make sure that the heat generated in the vein wall is dissipated in this fluid and does not damage surrounding tissues such as fat, nerves, arteries or skin. It is not suitable for the varicose veins that can be seen on the surface, very small diameter veins that will not allow the device to be passed into, or very torturous veins. As such, radiofrequency ablation (RFA) like endovenous laser ablation (EVLA) usually has to be performed in conjunction with other techniques such as foam sclerotherapy or ambulatory phlebectomy.
Radiofrequency ablation (RFA) can be used in treating incompetent truncal veins such as the Great Saphenous Vein (GSV), Small Saphenous Vein (SSV) and Anterior Accessory Saphenous Vein (AASV). As it relies upon good contact with the vein wall, if this contact might be lost for any reason, then another technique such as Endovenous Laser Ablation (EVLA) should be considered instead. This occurs in situations such as thrombus or clots in the vein wall, scar tissue in the vein wall or exceptionally large “blowouts” where the vein has dilated massively in isolated sections.
The bipolar radiofrequency devices such as RFiTT or VNUS RFS can also be used in small sections of other veins that are straight enough to allow the catheter to be inserted in and passed into them under ultrasound guidance. Examples of these sorts of veins are the incompetent perforating veins of the lower legs which might only be 0.5-1 cm long. Other examples of these can be recurrent varicose veins where inadequate previous surgery (either stripping which has allowed sections of the vein to grow back again or inadequate endovenous surgery using poor technique or incorrect settings) have left short sections of the main truncal veins patent and allowing recurrent venous reflux.
Unfortunately the VNUS ClosureFAST device, with its long 7 cm treatment end, cannot be used in many of these situations. Although it has little problems in the main venous trunks, once the section of vein to be treated is less than 7 cm long, it cannot be used. A fair number of Anterior Accessory Saphenous Veins (AASV) have treatable sections of less than 7 cm, no perforating veins are over 7 cm long and many recurrent varicose veins have sections that need treatment of less than 7 cm making it unusable in all of these situations. VNUS do produce an RFS device for vein short sections and have recently introduced a 3 cm device for short sections of veins (VENEFIT). However, each device is disposable and so if more than one is needed, costs escalate quickly.
Thus by using the RFiTT device which can be used for long truncal veins, short sections of veins and incompetent perforating veins, one device can be used for a large number of different veins – keeping prices down for the patient and allowing the professional to be able to treat a wide number of veins with one system.