Can one change their size in silicone implants right on the day of surgery?

Thank you for sharing your excellent question.  Assuming your surgeon has additional implant sizes available for your case, or on consignment through a hospital or ambulatory surgery center, you can choose to change your implant size prior to surgery.  I would continue to try and reach your physician to let them know of your intentions, however. 

Firstly, you should make sure you are not sedated before you see your doctor. Changing sizes at this late date will be a decision between you and your doctor. Often, we won't have the right size at our disposal and surgery may need to be put off.