Three- and four-dimensional computed tomography angiographic studies of commonly used abdominal flaps in breast reconstruction

BACKGROUND: The innovative technique of three- and four-dimensional computed tomographic angiography allows us to analyze the areas of perfusion in commonly used free abdominal flaps in breast reconstruction, such as pedicled transverse rectus abdominis musculocutaneous (TRAM) flaps, full TRAMs, muscle-sparing TRAMs, and deep inferior epigastric perforator (DIEP) flaps. The authors compared the vascular territories in these flaps. METHODS: A total of 11 lower abdominal flaps were obtained from nine cadavers and two abdominoplasty procedures. The authors simulated the perfusion of seven pedicled TRAMs, eight full TRAMs, eight muscle-sparing TRAMs, 14 DIEPs, and six superficial inferior epigastric artery flaps. For each simulated flap, the named artery/perforator was injected with Omnipaque contrast using a Harvard precision pump at 0.5 ml/minute, and the flap was subjected to dynamic computed tomographic scanning using a GE Lightspeed 16-slice scanner. Scans were repeated at 0.125-ml increments (every 15 seconds) for the first 1 ml, then at 0.5-ml increments (every 60 seconds) for the next 2 to 3 ml, thus giving progressive computed tomographic images over time. Images were viewed using both General Electrics and TeraRecon systems, allowing analysis of branching patterns and perfusion flow as well as measurements of vascular territory. CONCLUSIONS: This study shows that there are definitive differences in vascular territory based on flap type. The sequences of images also allow us to reappraise the classic Hartrampf zones of perfusion.