Vidn- means "notable", "prominent", or "outstanding" in Russian (probably other slavic languages, too). There is no "w" sound like that in the slavic languages, as far as I know. Certainly not in Russian.

Did that person write the name for you? If so, was he or she a speaker of a slavic language? Or did you or whoever wrote it down transliterate it based on what you heard someone say?

If it was distorted in some way by a non-native speaker of whatever language the name was originally, even if a speaker of a different slavic language than the original name, it would basically be near-impossible to find out what the name is.

It could, for example, be something like "iz Kieva", "from Kyiv (used to be spelled Kiev)" + "outstanding" or "famous". So it might not even be a name--could just originally have been someone's description of an excellent tomato from a place that is or sounds like "Kyiv". But there's no way of knowing for sure. As you point out, booberry, it could be based on a place name.

I think the only way you're going to know for sure is if you track down the person who gave you the seed. If you know their name IRL, maybe you can find them on some other garden forum or find their e-mail in your archives or something. Maybe someone like Carolyn or Craig might know that person and help you get in contact--if that person has at all been active in sharing seeds for little-known tomato varieties, especially if any of them have been listed at SSE, they would likely know something.