Antibiotics-why so many and when should we use them?

Antibiotic prophylaxis in vascular surgery has been proven beneficial to reduce surgical site infections after reconstruction of the aorta, procedures on the leg that involve a groin incision, any procedure that implants a vascular prosthesis or endoluminal stent, and lower extremity amputation for ischemia. Bactericidal antibiotics administered before induction-cefazolin or cefuroxime for 1 to 2 days alone or in combination with vancomycin if a hospital wound surveillance program indicates a high incidence of methicillin-resistant Staphylococcus aureus infection-is recommended. If a patient is felt to be at increased risk for infection and require prosthetic grafting, the use of a rifampin-soaked (1 mg/mL) gelatin- or collagen-impregnated graft may decrease the incidence of wound and graft infection. Antibiotic treatment of established vascular graft infections should begin with broad-spectrum coverage for expected pathogens (S aureus, Staphylococcus epidermidis, Gram-negative bacteria) followed by culture-specific therapy based on antibiotic susceptibility testing. Specific antibiotic usage involves a decision regarding efficacy to expected or isolated pathogens versus its potential side effects and the drug costs. New applications for antibiotics in vascular surgery include the use of specific tetracyclines (doxycycline, azithromycin) as an inhibitor of matrix metalloproteinases to retard aortic aneurysm growth or for their antiinflammatory properties to retard atherogenesis related to Chylamydia pneumoniae.