As the researchers on the new study put it, Due to the associations between diacetyl, bronchiolitis obliterans and other severe respiratory diseases among workers inhaling heated vapors containing diacetyl, urgent action is recommended to further evaluate the extent of this new exposure to diacetyl and related flavoring compounds in e-cigarettes. You can read all about the science of e-cigarettes here.
However, if your surgery is sooner, stopping any time before surgery is beneficial
Aiming to reduce the amount of nicotine you take in is a good idea and its made easier with vaping as you can slowly reduce the amount of nicotine in the e-liquids you choose either by buying lower-nicotine versions or by mixing your own and adding the nicotine yourself
Keep it in the fridge, and take it out about 30 minutes before using it to take off the chill
It may manifest as increased alertness, an increase in your heart rate, and increased muscle activity