What is the management for an infected Arteriovenous (AV) graft?

From the Guidelines

Management of an infected arteriovenous (AV) graft requires prompt antibiotic therapy and surgical intervention, with the specific approach based on the extent of infection and patient's individual circumstances, as recommended by the most recent guidelines 1. The initial treatment includes broad-spectrum antibiotics, such as vancomycin and piperacillin-tazobactam or cefepime, later narrowed based on culture results, as suggested by previous guidelines 1. Key considerations in the management of infected AV grafts include:

• Obtaining cultures and sensitivities of the blood and any available infected AV access vessel/material, surrounding tissue, or drainage prior to initiating antibiotic therapy 1
• Rapid initiation of empiric broad-spectrum antibiotics and timely referral to a surgeon knowledgeable in the management of vascular access complications 1
• Strict follow-up of culture results with the appropriate change in antibiotics based on organism sensitivities, with antibiotic duration according to extent of vascular access infection and surgical intervention 1
• Surgical treatment for AV access infections should be based on the patient’s individual circumstances considering the extent of infection, offending organism, and future vascular access options 1 Complete graft removal is typically necessary for extensive infections, while localized infections may be managed with partial excision and bypass, as indicated by the most recent and highest quality study 1. Temporary hemodialysis access via a central venous catheter is needed during treatment, and surgical debridement of infected tissue is essential, as antibiotics alone are insufficient due to biofilm formation on the graft material and poor penetration into the infected site. Prevention strategies include strict aseptic technique during dialysis, regular monitoring for infection signs, and prompt intervention for any concerning symptoms such as erythema, pain, or drainage at the graft site. The total antibiotic duration is usually 4-6 weeks, and blood cultures should be obtained before starting antibiotics. In general, the management of infected AV grafts should prioritize a multidisciplinary approach, including infectious disease specialists, surgeons, and nephrologists, to ensure optimal patient outcomes.

From the Research

Management of Infected Arteriovenous (AV) Graft

• The management of an infected AV graft typically involves urgent surgical removal of the infected graft followed by prolonged antibiotherapy 2.
• The choice of antibiotic therapy is often empiric or based on Gram's stain findings, but the increasing virulence of bacteria causing extracavitary arterial graft 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.

Prevention of Graft Infection

• Linezolid has been shown to be as effective as vancomycin in suppressing colony counts in MRSA- or MRSE-infected vascular Dacron grafts in rats 4.
• Local sustained release of vancomycin has been found to be a highly effective and less-invasive method for preventing methicillin-resistant Staphylococcus aureus graft infection 5.
• The use of rifampin-soaked synthetic prosthetic grafts has been widely used for prevention or treatment of vascular graft infections, but its high concentrations may be cytotoxic to vascular cells 6.
• Alternative prophylactic strategies, such as the use of recombinant phage endolysins, may be considered in the future, but further investigations are necessary 6.

Antibiotic Therapy

• Vancomycin and linezolid have been shown to be effective against MRSA and MRSE infections in vascular grafts 4, 5.
• Daptomycin and vancomycin have been found to be cytotoxic to vascular cells at high concentrations, while endolysin HY-133 did not display any cytotoxicity towards vascular cells 6.
• The choice of antibiotic therapy should be based on the specific bacteria causing the infection and the susceptibility of the bacteria to different antibiotics 2, 3.