It will depend on the size of your AAA. The DVLA states you need to contact them if you have an AAA of 6.5cms or larger. If you have a large AAA you may be advised not to drive until you have received treatment. If you are unsure, speak to your doctor or the hospital specialist team, who can advise you whether or not you should drive.
The Driver and Vehicle Licensing Agency (DVLA) decide whether people can drive on the basis of their health or any conditions they may have.
You can find more information on the GOV.UK website.