A comparative study of skin blood flow in musculocutaneous and random pattern flaps

The present study in dogs was performed to evaluate the development of blood flow in cranial-based, rectus abdominis musculocutaneous (MCF) and random pattern (RPF) flaps and in adjacent intact skin before and after operation. Prior to raising of the flaps the intact skin area had the same blood flow in all the test injections. Following flap elevation blood flow in the MCF increased and on the second postoperative day (POD) it was 2.6 times the preoperative value. From POD 2 through POD 15 only minor changes were found for blood flow in MCF. Blood flow in the RPF immediately after surgery was only 31% of the preoperative value and 24% of the MCF value. After POD 2-3 blood flow in RPF, however, increased and reached the preoperative level and continued to increase through POD 15. Intact adjacent skin showed changes similar to those of MCF through POD 6, however, by POD 15 blood flow had decreased and was lower than that in MCF and RPF. Blood flow rates at remote sites in the groin and shoulder were identical and showed only a slight increase during the first two postoperative days. It is concluded that MCF have an early and continuous increase in blood flow after raising, while RPF have an early decrease. RPF, however, develop a subsequent increase in flow lasting through POD 15. Intact adjacent skin also showed increased blood flow which could not be attributed to a generalized increase in skin blood flow.