My T1 husband had a vitrectomy some time ago and it didn't go well. They damaged the retina, which they then had to stick back into place with oil. In the pre-op discussion they said the chances of something going wrong were slight. Since then I've found it's actually quite common. He now has limited vision in that eye and may well need further surgery. All I can suggest is you question the surgeon thoroughly about the risks and his own record of success and make sure you're talking to the one who will actually be doing the procedure.
If possible, go to a specialist eye hospital.
Hana