I had CTA done (cricothyroid approximation) back in (I think) 1995 with Dr. Menard, when he was still working with Brassard in Montreal. Honestly most of the people I had seen get the surgery never succeeded or sounded like mini mouse or w/e but here are the following reasons WHY most of theirs didn't work...
#1 - Smoking. Especially shortly afterwards.. very foolish.
#2 - Not waiting for it to heal, and 'revising' it.
#3 - Straining too fast and not letting your voice heal. Its gonna be weeks to months for your voice to be fully operational.
#4 - Unrealistic Expectations. In my particular case I've never fully regained my singing voice... but I'm working it up by practicing.
#5 - Bad juju - Or easier said... bad luck, or bad roll of the surgical dice. Sometimes things just don't work out right.
In my case I avoided all 5, and my voice has never given me problems (well except really bad days) since. I get mammed on the phone all the time. I also suspect having just recently had the voice 'drop' and freaking out & getting the surgery to fix it back to female norm might've helped too.. My voice hadn't been changed all that long, and it was DEEP at the time, and causing tons of problems mentally for me (I think it was 3 years). So glad I ignored *EVERYONE* that was saying not to do it, it'll ruin me, etc.. the same dingbats that told me not to get GCS in Thailand with Kunaporn, and don't get FFS in mexico.
Guess what naysayers? It ALL turned out wonderfully. A pox on you and all your doubts lol.