VIABILITY OF THE RECTUS-ABDOMINIS MUSCLE FOLLOWING INTERNAL MAMMARY ARTERY LIGATION

The purpose of this study was to determine if the rectus abdominis mus cle in the dog model could be used as a transposition flap based on it s proximal blood supply following ligation of the internal mammary art ery. In 11 dogs, the left internal mammary artery and vein were ligate d at the fifth intercostal space. Both the left and right rectus abdom inis muscles were elevated from their respective beds, dividing the in ferior epigastric and intercostal vascular pedicles. Each muscle was t hen wrapped in a thin silicone sheet and replaced. One week later the dogs were returned to surgery and the muscles inspected. The right rec tus abdominis muscle was completely viable in all the dogs. In 10 of t he 11 dogs, the left rectus abdominis muscle was completely viable. We conclude that a superiorly based rectus abdominis muscle in the dog c an maintain its viability following ligation of its proximal blood sup ply at the fifth intercostal space.