Accurate depiction of cutaneous vascular microanatomy is of relevance to plastic surgical flap research, and to descriptive anatomy. Yet current techniques have not permitted full visualization of the subdermal plexus, or potential angiosomal connections. Nor has endothelial visualization been facilitated. Vascular corrosion casting techniques are promising in that regard, and were applied in an extended lateral thoracoabdominal suprafascial adipocutaneous flap in the rat (based on the superficial epigastric bundle). Technical refinements for application to further study of human cadaveric flap models are presented. The intraflap vascular branching pattern of the superficial epigastric artery is described, with filling of the lateral thoracic, intercostals, and iliolumbar angiosomes found when coagulation of vessels at the periphery was delayed until after clearance. The vascular casting protocol presented is an effective and promising tool for the study of macro- and microvascular anatomy.