Comparison of the intracellular bacterial killing activity of leukocytes in musculocutaneous and Random-pattern flaps

The in vivo physiologic response to gram-negative bacterial inoculation within wound cylinder spaces enclosed by the deep surface of paired musculocutaneous and random-pattern flaps was studied in the canine model. Leukocyte function was assessed by calculating the following values: leukocyte counts, bacterial counts, phagocytic indices, and intracellular bacterial killing ratios. The following results were observed in the wound cylinder spaces after bacterial inoculation with 5 × 107 of Pseudomonas aeruginosa bacteria: (1) the numbers of mobilized leukocytes within each wound cylinder space flap were not statistically different, (2) the bacterial counts were significantly lower in the musculocutaneous flap wound cylinder space at both 24 and 48 hours, (3) the phagocytic activity of the leukocytes within musculocutaneous flap wound cylinder space was 1.5 times greater than the leukocytes in the random-pattern flap wound cylinder space, and (4) the intracellular bacterial killing ratio of the musculocutaneous flap leukocyte was 83 percent versus 26 percent in the random-pattern flap leukocyte, a significant difference.