I first got my veins treated 10 years ago. I had about 5 bulging veins on the back of my leg below the knee--they also only appear when I stand up. After my 2 sessions of sclerotherapy, it seemed to have worked but over a year or two they resurfaced and had more than before. I've been continuously attending the clinic since then and the veins never went away again after years of numerous sclerotherapy treatments. There seems to be more than ever like a cluster of small bulging veins.