I have a pfo and due to have keyhole surgery on my gall bladder should i be worried about air embolisms?

Likely not: Many in our population can have a lifetime of small PFO's without any concerns or consequences. Since we do more imaging now a days, we pick more of these. Out of the many with positive screen, only a tiny handful ever are considered for closure or as a cause of any sort of embolism (usually people with stroke). Talk to your Doctor/Cardiologist, chances are you will be ok to undergo surgery.