Ultrasound guided foam sclerotherapy is another important technique in the treatment of chronic venous insufficiency. Ultrasound-guided foam sclerotherapy involves treatment of veins that are too small to close with laser or radiofrequency. These refluxing, smaller varicose veins are located by ultrasound and, when visualized, they are injected with a medicine such as Sotradecol® or Polidocanol® to seal them shut. Ultrasound-guided foam sclerotherapy can also be performed at the same setting as the RF or ELT procedure. Many times however, this type of varicose veins treatment is performed a few weeks after the ELT or RF procedure.