Aortic aneurysms are ranked among the top 20 causes of death globally. Yet, aneurysms involving the ascending thoracic aorta (ATAA) are known as “silent killers”, as they are completely asymptomatic until they rupture or dissect, resulting in upto 50% chance of death. However, elective aneurysm replacement can prevent rupture, but the procedure is invasive and carries risks (1–2%) of mortality and stroke. Since both surgery and surveillance carry different risks, the management of ATAA relies on determining the point at which the dangers of surveillance outweigh those of surgery.

For aneurysms with a diameter between 5.0 and 5.4 cm, this threshold has not been firmly established. TITAN SvS is the first randomized control trial to determine whether a strategy of surgery or surveillance results in improved survival for patients with ATAA between 5.0 and 5.4 cm.