When the aorta measures __ cm, _____ will rupture in 5 years.

• A. 5 cm, 25%
• B. 6 cm, 50%
• C. 8 cm, 90%
• D. 7 cm, 75%

Answer: (D)

Rupture risk rises as an aortic aneurysm grows because wall tension increases with the vessel’s radius. As the aneurysm enlarges, the same blood pressure exerts greater stress on the wall, making rupture more likely over time. At a diameter around 7 cm, natural history data show a very high chance of rupture within five years—about 75%. That high likelihood fits the idea that larger size markedly increases danger in a relatively short time frame. Smaller sizes correspond to lower five-year rupture risk, so the 7 cm size paired with a 75% rupture risk in five years best matches the underlying relationship between diameter and rupture risk.