Acute Aortic Disease.. - Index of

Long-Term Suppressive Therapy 319
initiation of screening programs in high-risk patients, more patients will be put
on the “watchful waiting” list, with a potential catastrophic outcome. The management
of patients with small, asymptomatic aneurysms is challenging. The size
of an aneurysm is used to determine whether repair is indicated. Intervention is
usually recommended for AAAs of at least 5.5 cm in anterior–posterior diameter
or greater than twice the diameter of nonaneurysmal aorta. In the U.K. small
aneurysm trial, open repair of AAAs smaller than 5.5 cm conferred no survival
advantage (127). With the advent of endovascular procedures, however, smaller
aneurysms are being repaired. Despite being minimally invasive, endovascular
repair of AAAs is not without risks; mortality can be up to 9%, and 35% of patients
have complications (128). Suppressive therapy might delay intervention permanently
for many patients because their life expectancy is often shorter than the
time necessary for the benefits of surgery to outweigh the risks (123). Even a 50%
effective therapy could delay intervention for nearly a decade (Fig. 2) (123).
Patients Who Are Poor Surgical Candidates
Some patients face the diagnosis of aneurysm without the option for surgery
because of comorbid illnesses. Open repairs require considerable physiologic
reserve. Although endovascular repairs can be performed in many patients who
are not candidates for open surgery, anatomical issues may preclude stent graft
placement. The possibility of pharmacologic suppression of aneurysm expansion
may be a lifesaving option in which patients may delay or avoid operations that
carry the risk of significant morbidity and death.
Figure 2 Diagram illustrating how even moderate suppression of aneurysm growth can
substantially forestall the need for surgical intervention. Source: From Ref. 123.