Some of the techniques, especially glottoplasty changes the timbre of the voice, so it has less masculine "undertones" to it, which also changes the way the voice resonates, because those low frequencies are not there anymore and otherwise they would resonate in the throat.
The only option so far that I know which deliberately changes resonance surgically in some way is the big surgery by Dr Thomas in Portland, who will actually take your larynx apart and make it smaller as well as place it higher. But its a rather big surgery and seems to have some possible complications - it also leaves a bit bigger scar on the throat , I believe.