What is the 5-year risk for rupture of an abdominal aortic aneurysm (AAA) measuring 4 cm in diameter?

The risk of rupture of an abdominal aortic aneurysm (AAA) is closely related to its size. Research shows that for an AAA measuring 4 cm in diameter, the estimated 5-year risk of rupture is generally considered to be less than 10%.

At this size, the aneurysm is often monitored rather than immediately subjected to surgical intervention, as the likelihood of rupture is still relatively low compared to larger aneurysms. As the size increases, so does the risk; thus, a 4 cm AAA is classified within a smaller risk range.

The other options represent higher estimated risks associated with larger aneurysm sizes, which do not apply to a 4 cm diameter AAA. Therefore, saying the risk is less than 10% aligns well with clinical guidelines and observational studies regarding AAA management.