Early and Late Outcomes of Endovascular Aneurysm Repair for Infected Abdominal Aortic and/or Iliac Aneurysms

Infected abdominal aortic and/or iliac aneurysm (AAIA) is a rare condition with a high mortality rate when treated with open surgery. In the past decade, the condition has increasingly been treated with endovascular aneurysm repair (EVAR). However, early and late outcomes, including the continued need for antibiotic treatments and predictors of persistent infection, are poorly understood.

We evaluated the outcomes of patients who underwent EVAR for infected AAIA from January 2010 to October 2017. We collected data including patient age, gender, clinical presentation, aneurysm location, culture results, intraoperative details, postoperative complications, 30-day mortality, in-hospital mortality, persistent infection, reintervention, and survival.

Among 792 patients diagnosed with AAIA, 64 were diagnosed with primary infected aneurysm, underwent EVAR, and were included in this study (81.3% male; median age, 72 years; range, 18-94 years). The most commonly isolated organisms were Salmonella species (34%), followed by Streptococcus (21%), and Staphylococcus species (21%). Aneurysms were intact in 48 patients (75%) and were ruptured in 16 (25%). The perioperative mortality was 4.7% (3 patients) of whom one was diagnosed with ruptured infected AAIA. Six (9.4%) patients died during hospitalization, 5 of severe sepsis with multiorgan failure and one of myocardial infarction. Among the 58 surviving patients, 34 (58.6%) had persistent infection, of whom 13 (22.4%) required early and late reintervention, including 2 with endograft infection, 8 with primary and secondary aortoenteric fistula, 2 with recurrent new aortic infection, and one with graft limb occlusion. The remaining 24 patients were able to discontinue antibiotics and had no recurrence or need for reintervention. Overall survival rates at 1, 3, and 5 years in the antibiotic-discontinuation group were 91.7%, 87.5%, and 68.0%, respectively, and 82.4%, 52.6%, and 32.9%, respectively, in the persistent-infection group (P = 0.009). In multivariable analysis, primary aortoenteric fistula (Adjusted OR [aOR], 20.469; 95% confidence interval (CI), 1.265-331.320; P = 0.034) and preoperative serum albumin level <3 g/dL (aOR, 7.399; 95% CI, 1.176-46.558; P = 0.033) were preoperative parameter that predicted persistent infection. A C-reactive protein level more than 5 mg/L (aOR, 34.378; 95% CI, 4.888-241.788; P < 0.001) was observed in patients with persistent infection.

EVAR is a feasible treatment with acceptable perioperative mortality for infected AAIA. Patients able to discontinue antibiotics have better survival and lower reintervention rates than those with persistent infection. A preoperative albumin level below 3 g/dL and primary aortoenteric fistula predicted persistent infection in this population.