I have abductor dysphonia. Treated about 4 monthly wit botox injections which work. My prof. Does it under g.A always & microlarynoscopy. Is this unusual?

Different strokes . Different surgeons have their unique techniques to achieve efficacious treatment results. If you are worried about the repeated ga, ask your laryngologist about awake or sedated options. Ultimately you have to do what you think is best for you.
Somewhat. Although i personally do not perform this procedure I do refer to professors who do. All of them perform the procedure under local in their office. Your doctor may have a different philosophy or technique that obviously works for him. You always can get another opinion.