Two to four treatments may be required to achieve your desired result.
Laser energy causes your spider veins to coagulate
and shrink. It is most effective for small
and medium size spider veins. Large spider veins respond poorly and are best treated with sclerotherapy. In sclerotherapy, a sclerosing solution is injected into the vein with a micro-needle and causes the vein to turn white, and then gradually disappear.
I hope this helps. Take care and regards.