Laser Ablation Versus Mechanochemical Ablation Trial

1% Lidocaine with 1:200,000 epinephrine will be used for skin infiltration. The EVLA fibre is introduced into the vein using the Seldinger technique and its tip will be positioned under duplex ultrasound (DUS). Then tumescent anaesthetic, made of a solution of 100ml of 1% Lidocaine with 1:200,000 epinephrine in 900ml of 0.9% Sodium Chloride and buffered to pH 7.4 with 10ml of 8.4% Sodium Bicarbonate, will be infiltrated around the target axial vein under DUS using a spinal needle and a peristaltic pump. Following deployment of appropriate laser safety precautions, the laser energy will be delivered via the fibre. The wavelength used is 1470nm, with NeverTouch Gold-Tip fibre, at 10W power. This laser light energy is converted into heat inducing a permanent, non-thrombotic occlusion.

1% Lidocaine with 1:200,000 epinephrine will be used for skin infiltration. MOCA is performed by a device called ClariVein® (Vascular Insights, UK) which is a long thin catheter that is passed up inside the vein, with a rotating wire that protrudes at an angle from the end when deployed. This is motorised via an electric motor in the handle and rotates at approximately 3500 revolutions per minute. In addition, liquid sclerotherapy is injected at the handle end by a syringe. This sclerotherapy liquid emerges from the end of the catheter and is present in the area of the rotating tip. The sclerosant will be Sodium Tetradecyl Sulphate (STS), marketed as Fibrovein. Concentration of 1.5% Fibrovein will be used, and maximum of 12ml.

It is used as local anaesthetic given via subcutaneous injection, so that the skin is numb prior to the introduction of either endovenous laser ablation or mechenochemical ablation catheter. Typically 1-2ml is required.

100ml of 1% lidocaine with 1:200,000 epinephrine is diluted into 900ml of 0.9% Sodium Chloride to make the tumescent anaesthetic solution, which is required when using endovenous laser ablation.

10ml of 8.4% Sodium Bicarbonate is added into the tumescent anaesthetic solution, to buffer the pH to 7.4. Tumescent anaesthetic solution is required when using endovenous laser ablation.

1.5% of Sodium Tetradecyl Sulphate, marketed as Fibrovein, will be used with the mechanochemical ablation device (ClariVein®). This is a sclerosing agent with Manufacturer Authorisation, and it will be used unmodified. Intravenous injection causes intima inflammation and thrombus formation. This usually occludes the injected vein.