I have braces too that I wear at night. They help.But carpal tunnel is not a lack of blood flow, it is a compression of the nerves going through the carpal tunnel, a structure in your wrist. (BTW, even "pins and needles" is not a lack of blood flow, it is also a nerve problem.)
too many years of quilting, knitting, crocheting, and mine was made worse by sleeping with my hands in weird positions.