What antibiotics are recommended for treating an infected Arteriovenous (AV) graft?

From the Guidelines

For treating an infected arteriovenous (AV) graft, empiric antibiotic therapy should initially include vancomycin plus either ceftazidime, cefepime, or a carbapenem to cover both gram-positive and gram-negative organisms. This approach is based on the most recent and highest quality evidence available, which emphasizes the importance of broad-spectrum antibiotic coverage in the treatment of infected AV grafts 1.

Key Considerations

• Vancomycin is typically dosed at 15-20 mg/kg IV every 12 hours (adjusted for renal function), while cefepime is given at 1-2 g IV every 8-12 hours.
• Treatment duration is generally 4-6 weeks for bloodstream infections associated with infected grafts.
• Once culture results are available, therapy should be narrowed to target the specific pathogen.
• Staphylococcus aureus (particularly MRSA) and coagulase-negative staphylococci are common culprits, but gram-negative bacilli and polymicrobial infections can also occur.

Surgical Intervention

In addition to antibiotics, infected AV grafts typically require surgical intervention, including graft removal or revision, to achieve cure 1. This is because the graft material acts as a foreign body that can harbor infection, making surgical removal necessary for resolution.

Additional Recommendations

• Blood cultures should be obtained before starting antibiotics.
• Infectious disease consultation is recommended for complex cases.
• This approach is necessary because vascular access infections can lead to serious complications including sepsis, endocarditis, and metastatic infections if not properly treated 1.

From the Research

Infected AV Grafts and Antibiotics

• The treatment of infected Arteriovenous (AV) grafts typically involves surgical removal of the infected graft followed by prolonged antibiotic therapy 2.
• The choice of antibiotics is often empiric or based on Gram's stain findings, but the increasing virulence of bacteria causing these infections may render previous choices of antibiotics obsolete 3.
• A combination of vancomycin and either ticarcillin-clavulanic acid or ceftazidime is recommended for initial treatment of extracavitary arterial graft infections, as it provides excellent coverage against staphylococci, Pseudomonas, and other gram-negative bacteria 3.

Specific Antibiotics for Infected AV Grafts

• Vancomycin is a potent antibiotic against methicillin-resistant Staphylococcus aureus (MRSA) and has been shown to be effective in preventing MRSA graft infection when used as a local sustained release 4.
• Daptomycin and baneocin are also effective antibiotics that can be used to prevent vascular graft infection, particularly when combined with fibrin sealant 5.
• Staphylococcus aureus is the most frequent cause of AV graft infection, with 77.5% of cases being methicillin-resistant 6.

Treatment Strategies for Infected AV Grafts

• Total graft excision (TGE) is associated with a lower reinfection rate compared to partial graft excision (PGE) 6.
• Abandoned AV grafts (aAVG) are associated with a higher likelihood of reinfection, and TGE should be considered for patients with aAVG infections 6.
• The use of antibiotic therapy, such as vancomycin and ceftazidime, is crucial in the treatment of infected AV grafts, and the choice of antibiotics should be based on the results of culture and sensitivity tests 2, 3, 6.