www.nice.org.uk/guidance/ng156
It may be helpful to read this through with your mother Its the NICE guidlines and then go back to the consultant with a list of questions to be answered
Discussing the benefits and risks of repair or conservative management
1.5.2
When discussing aneurysm repair with people who have an unruptured AAA, explain the overall balance of benefits and risks with repair and with conservative management, based on their current health and their expected future health. The decision on whether repair is preferred over conservative management should be made jointly by the person and their clinician after assessment of a number of factors, including:
aneurysm size and morphology
the person's age, life expectancy, fitness for surgery, and any other conditions they have
the risk of AAA rupture if they do not have repair
the short- and long-term benefits and risks, and the other disadvantages of repair such as having to stay in hospital, the risks of the operation, the recovery period, the potential need for further procedures and the need for surveillance imaging appointments
the uncertainties around estimates of risk for AAAs larger than 5.5 cm (measured inner-to-inner maximum anterior-posterior aortic diameter on ultrasound).