1 Week Post Op and Belly Button is Dark Red/black?

Thank you for this challenging question.  Blood in and around the belly button after an abdominoplasty can lead to significant redness and sometimes even a black belly button.  As long as the blood supply (one artery and two veins from the liver) remain in tact, more than likely it's just subcutaneous bleeding, and when the top layer falls off, you'll find good healthy skin covering your belly button (umbillicus).  This does not eliminate the potential for total necrosis (failure to survive) of the belly button; however, this is a much rarer case.  In my experience, situations where the surgeon knows that the tissue to the belly button no longer is truly viable, if given time the resultant scar mimics the normal belly button. Therefore, I wouldn't worry much.

That being said, to improve your chances of survival of the belly button (umbillicus), I would use DMSO, alternatively every two hours with nitroglycerin paste.  These two modalities will increase the chance of revival of the blood supply to the umbillicus.

Your description is very consistent with vascular compromise of the belly button. Following a full tummy tuck the belly button receives all its blood supply through the stalk which has remained attached to the abdominal wall. When the blood supply is interrupted / compromised, the color of the belly button will become dark reddish, bluish, or black. It sounds as if you have experienced partial loss.

How much skin and tissue loss will occur remains to be seen; so a watch-and-wait course of action is appropriate.  Sometimes the belly button may look quite injured, but will recover just fine with almost no visible evidence that there was ever a problem. You will need to be patient because it may take 8 weeks or so to heal.

Cleansing the belly button twice daily, gently drying it, and applying a thin layer of Polysporin (double) antibiotic ointment is appropriate. You should cover the area with a light gauze dressing that is not occlusive. But it would be best to be evaluated by your surgeon, not just your PA; I personally would want to care for this problem if you were one of my patients. If you develop increasing redness, swelling, or drainage you should consult with your surgeon immediately.

Best wishes.

The blood supply to your belly button is compromised.  This sometimes happens after tummy tucks, even in experienced hands.  Your surgeon is correct in having you simply keep it clean and apply antibiotic ointment.  You will likely lose belly button skin ("necrosis"), but the wound is likely to heal spontaneously and the result can actually be just fine.  There is nothing to do surgically right now.  Let the body heal and then you and your surgeon can decide later whether anything more is necessary.