Are suppressive antibiotics necessary for aortic rupture and repair with an aortic cuff?

Suppressive Antibiotics for Aortic Rupture and Repair with Aortic Cuff

Lifelong suppressive antibiotic therapy should be considered for patients who have undergone aortic rupture and repair with an aortic cuff, especially when the device is retained in a previously infected field.

Rationale and Evidence

The American Heart Association (AHA) provides clear guidance on this issue in their scientific statement on vascular graft infections. For patients with intrathoracic vascular graft infections or those with retained endovascular devices, lifelong suppressive antimicrobial therapy may be considered, particularly in high-risk patients who cannot tolerate extensive reconstructive surgery 1.

Duration of Antimicrobial Therapy

The recommended approach follows a two-phase treatment strategy:

1. Initial Phase:

   • Parenteral antimicrobial therapy for 4-6 weeks postoperatively 1, 2

2. Extended Phase:

   • Additional 3-6 months of oral antimicrobial therapy 2
   • Lifelong suppressive therapy should be considered in:
     • Patients with retained endovascular devices 1, 2
     • Cases with rifampin-bonded synthetic grafts 2
     • Infections with difficult organisms (MRSA, Pseudomonas, multidrug-resistant organisms) 1, 2
     • Extensive perigraft infection 2

Clinical Considerations

Risk Assessment

The decision for lifelong suppression should consider:

• Infection Risk: The aorta repaired with a cuff represents a foreign body in a potentially infected field
• Mortality Risk: Untreated infections can lead to catastrophic outcomes with mortality approaching 100% in some cases 1
• Recurrence Risk: The risk of recurrent infection and associated morbidity/mortality is high, particularly with retained devices 1

Monitoring

For patients on long-term suppressive therapy:

• Regular monitoring of inflammatory markers (ESR, CRP)
• Periodic imaging surveillance
• Clinical assessment for signs of recurrent infection

Antimicrobial Selection

The choice of suppressive antibiotic should be:

• Based on culture results and susceptibility testing
• Bactericidal when possible
• Well-tolerated for long-term use
• Orally bioavailable for outpatient management

Important Caution

Fluoroquinolones should generally be avoided in patients with aortic repair due to their association with increased risk of aortic aneurysm and dissection 3.

Evidence from Clinical Experience

Multiple case series support the efficacy of long-term suppressive therapy:

• A study of patients with infected abdominal aortic grafts showed good outcomes with indefinite antibiotic suppressive therapy, with patients surviving up to 6 years 4
• Another report demonstrated 83% early survival and 70% long-term survival in patients with infected ascending aorta and aortic arch treated with surgery and lifelong suppressive antibiotics 5
• A case report showed successful management of an infected thoracic aorta graft with triple antibiotic therapy for over 25 months, preventing recurrent septic episodes 6

Surgical Considerations

When surgical intervention is performed:

• In situ reconstruction with cryopreserved allograft can be effective, with good early and midterm outcomes 7
• Even with optimal surgical management, suppressive antibiotics are often necessary, though some studies report successful outcomes with limited use of long-term suppression (only 8 of 50 patients in one series) 7

In conclusion, while the optimal duration of antibiotic therapy remains somewhat controversial, the weight of evidence from guidelines and clinical experience supports the use of lifelong suppressive antibiotics for aortic rupture and repair with aortic cuff, particularly when the device is retained in a previously infected field or when other high-risk factors are present.