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

This retrospective cohort analysis focuses on the role of outpatient parenteral antimicrobial therapy in the management of aortic vascular graft infections after endovascular aortic aneurysm repair.

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