When Is it ok to take B3 (niacin) after Facial Fat Transfer surgery?

Is it true that about 60% of the fat will survive as 'permanent'? I also read that macrophages continue to eat the newly transferred fat -- will it all eventually dissolve, i.e. around eyes, cheeks and in lips? In the past I've taken B3 and am concerned that because of the 'flushing' it causes that it will dissolve the fat faster or disrupt the outcome, or even cause dislodging of the fat (blindness/heart attack, etc.) What if anything should I be concerned with?