The effect of microbial contamination on musculocutaneous and random flaps

Although musculocutaneous flaps have been shown to have the ability to withstand a greater inoculum of bacteria than random flaps, it has not been shown that the musculocutaneous flap has any greater ability to decrease the bacterial population in a contaminated wound. In this series of experiments, granulating wounds were developed containing 10(4), 10(5), or 10(6) bacteria per gram of tissue. These contaminated wounds were then covered either with musculocutaneous flaps, random flaps, or left uncovered as a control. In the heavily contaminated wounds containing 10(6) bacteria per gram of tissue, neither type of flap was able to prevent bacterial proliferation and all flaps dehisced. In the minimally contaminated wounds containing 10(4) bacteria per gram of tissue, both the musculocutaneous and random flaps achieved wound healing and decreased the bacterial level in the wound. However, in the intermediate group containing 10(5) bacteria per gram of tissue, musculocutaneous flaps lowered the bacterial count and allowed wound closure, whereas the random flaps did not control the bacterial growth and failed. Therefore, in the moderately contaminated wound, musculocutaneous flaps are advantageous and can decrease bacterial counts and obtain successful closure when random flaps cannot.