Will a higher volume of fat transfer be more likely to survive ?

I had gynocomastia surgery over a year ago and I was not happy with the results on one side. It looks kind of deflated and the nipple points down sometimes. My plastic surgeon (board certified), did two in office fat trasnfers to fix the issue. My chest looked a bit better at first, but most if notall of the fat died and was resorbed. My surgeon is now suggesting a transfer under twilight sedation at a surgery center. He says that he will be able to harvest and deposit more fat with mysedated, and that more fat will survive the procedure because he place a larger volume of fat. Is there any real reason to believe that this larger volume of fat has a better chance at surviving long term? I am unhappy with my result and would love to have it fixed. However, I do not want to proceed with the hassle and expense if there is little chance of success.