Antibiotic prophylaxis in peripheral vascular and orthopaedic prosthetic surgery.

Peripheral vascular by-pass and orthopaedic joint replacement surgery have much in common. The consequences of infection are serious and occasionally fatal. The incidence of infection varies from 0.5% to 3% depending on the anatomical site; the infecting organisms and distribution of organisms are similar. In orthopaedics a clean theatre environment, high local concentrations of antibiotic in the cement and systemic antibiotic prophylaxis are well established methods of reducing infection rates and are supported by clinical trials. In contrast, scientific evidence supporting these three tenets is lacking for peripheral vascular surgery. There are wide variations in the choice of prophylaxis cover for peripheral vascular surgery and the first clinical cases of antibiotic containing graft material have only recently been described. The choice of an ideal antibiotic for the prophylaxis of infections associated with vascular surgery is debatable; wound and graft infections in those receiving antibiotic prophylaxis range from 0.9% to 5.8% and 0.0 to 0.9%, respectively. For both forms of surgery whether single dose, short course or longer periods of prophylaxis is preferred, it is agreed that the antibiotic must achieve adequate concentrations at the time of potential bacterial contamination. One of the limiting factors of single dose prophylaxis is the ability of the antibiotic to penetrate bone, soft tissue or haematoma. However, single dose prophylactic antibiotic cover in prosthetic surgery will attract increasing support whenever the criteria of spectrum and 'risk period' cover is fulfilled. This may help to contain the increase in multi-resistant bacteria, particularly staphylococci within the hospital ecosystem. Prolonged systemic administration can now be replaced by high local antibacterial activity at the site of prosthesis insertion via a bonded sealant or an impregnated cement. This permits high activity which can last for several weeks until all the lines are removed and tissue incorporation has become established.