Sclerotherapy for hand veins - what are the risks and reasons why this is not performed?

I have large, dark, bulging veins in my hands. I had hoped to find a provider to perform sclerotherapy to address this issue but even places that say they do that online or on the phone eventually tell me that they do not do sclerotherapy for hands. I cannot find a provider or a solution (everyone says they can do filler instead) but I also can't find any data on risks or reasons why they won't do sclerotherapy for hand veins. Any insight would be appreciated.