Complete left main coronary artery occlusion: angiographic evaluation of collateral vessel patterns and assessment of hemodynamic correlates. An angiographic study of eight patients with total occlusion of the left main coronary artery identified six patients with chronic occlusion and two with acute complete occlusion. In each of six patients, there were two to six different intercoronary collateral pathways. Altogether, a total of 13 specific collateral channels were recognized. One patient had evidence of unique homocollaterals represented by enlarged vasa vasorum, which created a vascular cuff that surrounded a totally obstructed left main artery. The ventricular function and hemodynamic parameters in these patients not only depend on the collateral vessels but may also be affected by the severity of coronary artery disease in the artery that supplies collaterals. 