Sclerotherapy: Sclerotherapy involves injecting a chemical Answer (called a sclerosant) into your defective veins by means of a needle or catheter to result in their closure. It's not as efficient for veins bigger than 5mm in diameter and is predominantly used to take care of the scaled-down additional tortuous veins https://www.sgvascularctr.com/what-are-some-common-vein-treatments/