Secondary aortoenteric fistula after endovascular aortic aneurysm repair – a narrative review

Abstract

INTRODUCTION: Endovascular aortic repair (EVAR) has become the technique of choice in most vascular centres for abdominal aortic aneurysms (AAA). However, due to its low incidence, literature regarding secondary aortoenteric fistula (AEF) as an EVAR complication is still scarce. We aim to summarise the latest evidence on the topic through a narrative review. METHODS: We conducted a MEDLINE literature search and included studies on secondary aortoenteric fistula, abdominal aortic aneurysms and endovascular aneurysm repair. Relevant studies were selected by reading of the titles and abstracts. Only English literature was considered. RESULTS: Despite secondary AEF after EVAR first being reported in 1998, its incidence is hard to calculate, but is recognized to be lower (<0.5%) when compared to open aortic repairs (up to 1.6%). Aetiology may be categorised into local infection factors (pre-existent or associated with the procedure), mechanical factors associated with the aneurysm (such as anatomical shape and size) or mechanical factors associated with the stent graft (such as kinking, endoleak or endotension). Most common symptoms include abdominal or back pain, nausea, fever and gastrointestinal bleeding. Haemodynamic instability and shock at presentation is only present in less than a fifth of patients. Patients should be thoroughly submitted to a laboratory work-up, cultures and imaging tests, particularly CT scan and upper endoscopy. There are no guidelines regarding management, but it should include total graft excision along with arterial reconstruction (either in-situ or extra-anatomical), bowel repair and prolonged antibiotic therapy. Nonetheless, AEF is associated with a high mortality rate, even if adequate treatment is performed. CONCLUSION: Secondary AEF is an uncommon life-threatening complication after EVAR. Clinical presentation is non-specific, so a high level of suspicion is necessary to rapidly reach diagnosis. Treatment requires infection source control and prolonged antibiotic therapy. Considering the increasing use of endovascular devices, there is a need for future studies providing more insight on the most adequate treatment for this complication.

Keywords

• Secondary aortoenteric fistula
• endovascular aneurysm repair
• abdominal aorta aneurysm
• aortic endograft infection