Why haven't certain patches of my spider veins responded to Sclerotherapy?

When veins are resistant to treatment there is usually a reason.  The first thing that I would suggest would be to repeat the venous ultrasound to see if there is any feeding source for the spider veins such as valves that have not closed or other veins with leaking valves.  If there are no leaking valves, then I would next recommend looking for feeding veins to the spiders with special lights which we call Vein Lites.  Thirdly, I would then increase the concentration of the sclerosing solution or change the sclerosing solution. There are times when the treatment of spider veins could be challenging,but usually with persistence we can solve the problem.

Once the 'underlying problem' is fixed, namely venous insufficiency, the focus should be to treat the spider veins (telangiectasias), reticular veins and varicose veins (smaill and large). It should be remembered that one needs expertise to treat venous insufficiency, as most doctors just treat truncal venous insufficiency (at the groin - saphenofemoral junction) or at the level of the knee (saphenoopliteal junction) - they have no expertise in treating perforator venous insufficiency that is so often the reason why sclerotherapy fails or cosmetic laser work fails. It may be that you have perforator vein refux (sometimes called feeder veins) and these have to be treated with special laser devices such as perforator EVLT procedures or ultrasound guided sclerotherapy before cosmetic sclerotherapy or topical laser work is reattempted.