Chart 2. System for classification of extension of endovenous thermoablation to the saphenopopliteal junction described by Lawrence et al.⁹.

Class	Extension of thrombosis	Treatment
1	Below the level of the superficial epigastric vein	Watchful waiting
2	At the level of the superficial epigastric vein	Watchful waiting
3	At the level of the common femoral vein	Surgeon’s choice
4	Bulging into the common femoral vein	Low molecular weight heparin
5	Beyond the saphenopopliteal junction, adjacent to the wall of the common femoral vein	Low molecular weight heparin
6	In the common femoral vein, consistent with deep venous thrombosis	Low molecular weight heparin and vitamin k antagonist