A secondary aortoenteric fistula (AEF) is an abnormal connection between the aorta and gastrointestinal tract inpatients with history of an aortic surgery, including open repair surgery or endovascular treatment. It has been suggested that AEF arises due to either continuous physical stimulation or prosthesis infection. Although AEFs are rare (incidence rate varies between 1.6 to 4%) they are life-threatening and have a high mortality rate (between 24 to 45.8%).

Here we present a case of secondary AEF recurrence with different treatment strategies.

Clinical Case A 64-year-old man with a history of an endovascular aneurysm repair (EVAR) was hospitalized after performing a control CTA at 6 months with evidence of diffuse densification of fat around the abdominal aorta but without organized fluid collections capable of drainage (Figure 1 A). He had also been submitted two months after the EVAR to thrombectomy of the left branch of EVAR and stent placement due to thrombosis with acute limb ischemia. He had no other relevant medical history. Endoscopy confirmed an AEF (Figure 1B) and the patient was submitted to open surgery with partial aneurysmectomy, aneurysmal sac lavage with rifampicin and segmental duodenal resection with direct closure and interposition omentoplasty. The patient was discharged asymptomatic with levofloxacin and clindamycin. One month and one year control CTAs revealed no sign of infection or AEF and antibiotics were mantained for 12 months. Two years and 5 months after the first diagnosis of AEF, the patient presented in the emergency department with fever and a history of recurrent urinary tract infections in the last year, practically monthly. He denied abdominal pain and visible blood loss. He underwent septic screening and an abdominopelvic CTA which showed an aorto-biliacal endoprosthesis permeable but with a diffuse densification of fat around the abdominal aorta and presence of periprosthetic gas and endoscopy revealed an aortoenteric fistula with exposure of aortic endograft (Figure 1 C, D). The patient underwent primary duodenal closure, partial endoprosthesis explantation (Figure 2) and in situ reconstruction with aorto-bi-iliac silver-impregnated Dacron interposition graft and interposition omentoplasty. The surgery duration was 7h, estimated blood loss of 2.5L and was transfused 4 units of red cells and 1g tranexamic acid. The length of stay was 42 days at intensive care unit, 21 days at vascular surgery ward and 51 days at musculoskeletal rehabilitation center, from where he was discharged home totally asymptomatic and autonomous for activities of daily living. One month CT control showed no complications.

As we saw in this case, although relapse of AEF is very rare, this possibility should not be excluded, and patients with clinical suspicion should be studied with CTA and endoscopy. An initial strategy of non-explantation of the prosthesis, although less aggressive, may not be enough to solve the underlying problem, particularly in patients in whom a prolonged survival is expected after correction of the fistula. Therefore, in young and fit patients endoprosthesis explantation may be considered as the primary treatment. Finally, it is necessary to follow up these patients throughout their lives due to the risk of relapse of infection and AEF.