This clinic is mentioned in the US Embassy web page on medical services for Americans in Kiev...
I have no knowledge of it personally.
Here is their address:
BORIS (http://www.boris.com.ua/)
Address: 55A, Velyka Vasylkivska Street, Kyiv
E-mail: Med_Boris@ukr.net
24-HOUR PHONE:
238-0000
Address: 55A, Velyka Vasylkivska Street, Kyiv
E-mail: Med_Boris@ukr.net
24-HOUR PHONE:
238-0000