The relation between ischemia and infection is well known, but the hazards of surgical retractors to wound healing is not well documented. We developed a experimental model to study the effects of ischemia induced by retractor in the surgical wounds. One hundred and four Wistar Male rats were studied. For the study of the ischemia induced by retractors, 40 rats were divided in 4 groups: T0, T1, T2 and T3, to study the relation between ischemia and infection, 64 animals were allocated in 8 groups: C0, C1, C2, C3: L0, L1, L2 and L3. All the animals had a paramedian incision on the upper part of the anterior abdominal wall. The wound was then retracted for one hour period. The force of traction employed was 0Kgf for the groups T0, L0, C0; 0,062Kgf for the groups T1, L1, C1; 0,125Kgf for the groups T2, L2 , C2 and 0,25Kgf for the groups T3, L3, C3. The Evans Blue die was injected in lhe animals of the TO,T1,T2 and T3 groups. One hour later, a sample of the abdominal wound was taken to the analyse the concentration of the die in tissues and consequently the degree of ischemia in the wound. In the C0, C1, C2 and C3 groups 1ml of a solution containing 10(5) Stafilococcus aureus was injected in the wound just before it. We concluded that in the groups T1, T2 and T3, the greater the traction of the retractors, the lesser was the concentration of Evans Blue die in tissues and the greater was the degree of ischemia. In the animals of L0, L1 and L2 groups the wounds were clean, but in 50% of the wounds of the L3 group we identified the growth of microorganisms. In the group CO, 37% of the wound cultures dcveloped Stafilococcus aureus while in the remaining groups 100% developed positive cultures for the same bactéria in the first 24 hours.
Infection; Ischemia; Surgical Retractors
