Conservative management of type 2 endoleaks is not associated with increased risk of aneurysm rupture. 
Endovascular repair (EVAR) of abdominal aortic aneurysms (AAAs) has led to a reduction in the perioperative mortality when compared with open repair.  However, re-intervention for complications, such as endoleak, may be required in up to 20% of the cases.  Controversy exists over the management of type 2 endoleaks.  This study examined the outcomes of patients with type 2 endoleaks treated conservatively to inform the ongoing management debate.  All patients with a confirmed type 2 endoleak after EVAR for an infrarenal AAA were included in the study.  Data regarding device details, endoleak and time point, aneurysm sac growth, intervention and outcome were collected retrospectively from case notes and the vascular research database.  Forty-one type 2 endoleaks were seen in 369 EVARs performed for infrarenal AAA between March 1994 and June 2006.  Twenty-five were isolated type 2 endoleaks and 16 occurred in conjunction with other endoleaks.  Of the 25 isolated type 2 endoleaks, 18 (72%) patients demonstrated no increase in sac size, six (24%) patients showed an enlargement of the sac and one patient was lost to follow-up.  Only one patient underwent intervention for an isolated type 2 endoleak.  After a mean follow-up period of 4 years, approximately half of the patients (48%) remain under observation (with an enlarging or stable sac), whilst the others (48%) have spontaneously sealed.  Only five patients under surveillance (20%) have an enlarging sac.  There were no ruptured aneurysms or aneurysm-related deaths and no patients required conversion to open repair.  In this study, a policy of regular surveillance for type 2 endoleaks was not associated with any adverse events.  We therefore advocate the conservative approach for type 2 endoleaks.