Customizing foam sclerotherapy of the great saphenous vein: A proposed algorithm to enhance technical efficacy.

The catheter-directed foam sclerotherapy (FS) and the suggested perivenous tumescent application for great saphenous vein (GSV) diameter reduction are suggested to improve technical and clinical results; yet, their use is reported rather indiscriminately. Our aim is to introduce an algorithm categorising the use of technical modalities accompanying ultrasound-guided FS of the GSV and present the technical efficacy of FS through a 5 F × 11  cm sheath placed at the knee level. Representative cases of GSV insufficiency were chosen to describe our methodology. Sole sheath-directed FS can achieve complete GSV occlusion proximally at a level comparable to the catheter-directed technique. We apply perivenous 4°C cold tumescent to GSV >6 mm even in the standing position to ensure diameter reduction of the proximal GSV as close to the saphenofemoral junction. We use long catheters only to overcome large varicosities above the knee level that could otherwise compromise the adequate foam infusion from the sheath tip. When GSV insufficiency extends along the entire limb and severe skin lesions preclude the antegrade distal catheterisation, the sheath-directed FS in the thigh can be concomitantly combined with retrograde FS from catheterisation just below the knee. A topology-oriented methodology with sheath-directed FS is technically feasible and avoids indiscriminate use of more complex modalities.