Angiographic assessment of communication between coronary arteries and pedicle omentum. Communication between the coronary arteries and branches of the gastroepiploic artery was evaluated using three different methods with a different series of OM-only and combined group animals. A postmortem angiography examination from the aortic root in the combined (a) and OM-only (b) groups (n = 4 for each group). In the combined group, aortography revealed that the gastroepiploic artery branches feeding the OM expanded into the heart, and established several tight junctions between the native coronary arteries and OM (a). In contrast, in the OM-only group, the gastroepiploic artery branches failed to penetrate the heart, accompanied by immature leaky collateral vessel formation between the coronary artery and OM, evidenced by considerable leakage of contrast agent (red dotted circle) (b). Black dotted line indicates heart surface. Green triangles indicate the branches of the gastroepiploic artery. Selective India ink injection into the celiac artery to visually and histologically confirm vessel communication between the pedicle OM and native coronary artery (n = 4 for each group). Numerous collaterals filled with India ink were clearly identified between the gastroepiploic artery and native coronary arteries in the combined group (c–e), while that was not seen in the OM-only group (data not shown). Histological analysis confirmed vessel communication between those in the combined group (f: 40×, scale bar = 500 μm, g: 200×, scale bar = 100 μm). A selective perfusion via aortic root and celiac artery using two different MICROFIL colors (n = 4 for each group). In the combined group, MICROFIL solution injected in a retrograde manner into the aortic root (MV-117 Orange) was easily shown expanded into the OM to communicate with the gastroepiploic artery (h, 7.5×, scale bar = 2 mm). That solution injected into the celiac artery (MV-120 Blue) was also found to expand into the myocardium and communicated with native coronary arteries (i, 7.5×, scale bar = 2 mm). Those findings were not seen in the OM-only group (data not shown). Green triangles show visible vessel communication in the OM-flap (h) and host myocardium (i).