I can't speak to current processing time for AETNA now but back in Early 2010 they approved my VSG within weeks of their publication of their new acceptance of the VSG procedure. The only process delays came from getting my PCP to generate he required Medical Necessity Letter. He wasn't a supporter of any Bariatric Surgery then but now he is taking credit for all my success over the past two years in lossing 180 lbs and keeping it off.
The key os to get your Surgeon's staff engaged to help you jump through all the hoops. Good Luck!