INSURANCE INSURANCE INSURANCE HELP ME !!
It sounds like they need more information before they will approve it. If they don't receive the additional info they need, they will deny. So, does the letter state what information they are waiting on? Make sure your surgeon's office and your PCP etc are aware if they need to send anything else. It might also just be pending because they are still going through all your medical records...but the fact that they actually sent you a letter telling you that the decision is pending tells me that they are actually needing some kind of followup on your part...or the part of one of your doctors. You'll simply have to wait until tomorrow and call the surgeon's office. Hopefully they have the letter as well. They'll need to call Aetna and figure out what is needed.
You weren't denied though...which is good. It could just be that they need one more thing...
Good luck!!! Tomorrow will be here soon!