Aortic graft infection

Diagnosis

MAGIC Case Definition

Category	Major Criteria	Minor Criteria
Clinical	Pus confirmed by microscopy around graft of in aneurysm sac at surgery Open wound with exposed graft or communicating sinus Fistua development e.g. aortoenteric or aortobronchial Graft insertion in an infected site, e.g. fistula, mycotic aneursym, or infected pseudoaneurysm	Localized clinical features of AGI e.g. erythema, warmth, swelling, purulent discharge, pain Fever ≥38 degrees Celsius with AGI as most likely cause
Radiology	Peri-graft fluid on CT scan ≥3 months after insertion Peri-graft gas on CT scan ≥7 weeks after insertion Increase in peri-graft gas volume demonstrated on serial imaging	Other e.g. suspicious per-graft gas/fluid/soft tissue inflammation; aneurysm expansion; pseudoaneurysm formation; focal bowel wall thickening; discitis/osteomyelitis; suspicious metabolic activity on FDG PET/CT; radiolabelled leukocyte uptake
Laboratory	Organisms recovered from an explanted graft Organisms recovered from an intraoperative specimen Organisms recovered from a percutaneous, radiologically-guided aspirate of peri-graft fluid	Blood culture(s) positive and no apparent source except AGI Abnormally elevated inflammatory markers with AGI as most likely cause e.g. ESR, CRP, white cell count

Interpretation

• Suspected AGI:
  • Any isolated major criterion, or
  • Minor criteria from two of the three categories
• Diagnosed AGI:
  • A single major criterion, plus any other criterion from another category
• Note that, for bacteria that may be contaminants, they must be isolated from at least two samples (any combination of blood cultures and intraoperative samples)

Further Reading

• Diagnosis of Aortic Graft Infection: A Case Definition by the Management of Aortic Graft Infection Collaboration (MAGIC). Eur J Vasc Endovasc Surg. 2016;52:758-763. doi: https://doi.org/10.1016/j.ejvs.2016.09.007