Long-Term Outpatient Parenteral Antimicrobial Therapy Effective Treatment for Aortic Graft Infection

Outpatient parenteral antimicrobial therapy (OPAT) was found to be a feasible long-term preventive therapy for aortic graft infection (AGI) following endovascular aortic aneurysm repair (EVAR). These findings were published in BMC Infectious Diseases.

Data from patients (N=11) who underwent EVAR at a tertiary referral hospital in Ireland between 2014 and 2018 were retrospectively reviewed in this study. Clinical outcomes of OPAT (n=20 episodes) through 2019 were assessed.

The patient population was 91% men with a median age of 76 (range, 65-85) years, and they had a median Charlson comorbidity index of 6.5. Most patients (n=8) met the criteria for definite AGI, and the other three met the criteria for suspected AGI.

The initial procedures were mainly due to noninfectious indications (n=10), and 3 were in emergency situations. OPAT was administered due to late AGI (n=5), early AGI (n=3), and mycotic aneurysm (n=1). Most patients were enrolled in OPAT after a treatment failure (n=8).

Patients with AGI presented a median of 7 (range, 0-81) months after EVAR with the symptoms of fever (55%), anorexia (55%), abdominal pain (45%), back pain (27%), and bleeding (18%).

The causative infections included staphylococci and streptococci species (n=6), anaerobes (n=4), enterococci (n=2), Pseudomonas aeruginosa (n=2), Candida albicans (n=2), and Salmonella species (n=1). A total of 4 patients had polymicrobial infections.

All but 1 patient received more than 1 intravenous antimicrobial agent and all received at least 6 months of oral antibiotics.

Readmission due to infection occurred among 4 patients. Adverse events were reported by 3 patients. All events were antimicrobial-related.

At a median follow-up of 36 (range, 25-64) months, 72% were alive, and OPAT outcomes were determined to be success (n=9), partial success (n=3), failure (n=5), and indeterminate (n=3).

Patients who died were older (median, 84 vs 76 years) and had a median Charlson comorbidity index score of 4.

At the time of publication, 7 patients were being maintained on antibiotic therapy, and 1 patient had discontinued OPAT after 12 weeks of empiric antimicrobials and 6 months of oral suppressive therapy.

In total, patients received intravenous antibiotics for 1560 days, were hospitalized for 696 days, and were on OPAT for 864 days. Patients on OPAT had a 55% decrease in length of hospitalization.

This study was limited by not including a cost analysis. It remains unclear whether these findings justify the efficacy of OPAT when considering cost.

The study authors concluded that OPAT was an effective long-term treatment option for patients who developed postoperative AGI following EVAR.

Reference

Allen N, Adam M, O’Regan G, et al. Outpatient parenteral antimicrobial therapy (OPAT) for aortic vascular graft infection; a five-year retrospective evaluation. BMC Infect Dis Published online July 9, 2021. doi:10.1186/s12879-021-06373-4