Szilagyi et al classified surgical site infections associated with a synthetic vascular graft based on the depth of infection. The authors are from Henry Ford Hospital in Detroit, Michigan.

Depth of Infection


superficial (epidermis and dermis)


subcutaneous tissue but not reaching vascular implant


infection involving the vascular graft



Grade I and II infections tend to heal properly without sequelae.


A Grade III infection can be extremely difficult to treat. Success requires aggressive surgical management and antibiotic administration with the goals to control the infection and to prevent ischemia in the limb.


Subcategories of Grade III infection:

(1) infection limited to the bed of the graft (suture lines free of infection and pseudointima not involved)

(2) low grade infection of the vascular graft (involving pseudointima and/or suture line)

(3) significant infection of the vascular graft with the ability to place a second graft

(4) significant infection of the vascular graft but unable to place a second graft


The one type of graft infection that has a high rate of failure is one involving an entire aorto-bifemoral bypass in a patient without an uninfected segment in the upper femoral artery suitable for a second graft.

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