What dimension indicates the necessity for surgical repair of an abdominal aortic aneurysm (AAA)?

The indication for surgical repair of an abdominal aortic aneurysm (AAA) is primarily based on its size, with a threshold typically set at greater than 5.5 cm in diameter. This guideline stems from extensive clinical studies that have shown a significant increase in the risk of rupture for aneurysms of this size. Aneurysms that exceed 5.5 cm demonstrate a rupture risk of 5-10% per year, which justifies the need for surgical intervention to prevent life-threatening complications.

In contrast, smaller aneurysms, while still monitored closely, are often managed with conservative strategies such as regular imaging and blood pressure control, as the associated risk of rupture is considerably lower. Therefore, the size of 5.5 cm serves as a critical benchmark in determining when the risks of surgery become outweighed by the potential dangers posed by the aneurysm itself.