One discussion last week included the risk of rupture with type II endoleaks.

Reference: Brown A, et al. Type II endoleaks: challenges and solutions. Vascular Health Risk Management. 2016;12:53-63.

Summary:  Although type II endoleak appears to be associated with sac expansion (volume changes), the significance of this expansion on risk of aneurysm rupture remains unclear.

Wyss et al found a significant association between sac expansion and rupture.Twenty-seven ruptures occurred in an EVAR population of 848 patients, with an average follow-up of 4.8 years. Sixty-three percent of these ruptures occurred more than 30 days post-repair and were associated with prior complications detected on follow-up imaging. Five of these 17 ruptures demonstrated evidence of type II endoleak with associated sac expansion (four were isolated type II endoleaks and one was associated with a concomitant type Ib endoleak).

Conversely, other authors have shown no correlation. Van Marrewijk et al demonstrated that sac expansion was significantly associated with type II endoleaks; however, there was no correlation with rupture or increase in aneurysm-associated mortality. A recent systematic review reported a low incidence of rupture in patients with isolated type II endoleaks (under 1%) of which 57% were associated with sac expansion.

Sac expansion may therefore be a poor marker of risk in this population of patients; however, we do not currently have a more sensitive way of monitoring risk of rupture. As such, some authors suggest that consideration should be given to prevention of/or treatment for type II endoleak.