Intraoperative assessment of coronary bypass graft to posterior descending artery by means of transesophageal echocardiography.

Intraoperative transesophageal echocardiography (TEE) assessment of coronary artery graft anastomosed to posterior descending artery (PDA) was evaluated. Twenty-one patients with a saphenous vein (SV) graft (n=17) or right gastroepiploic artery (RGEA) graft (n=4) anastomosed to the PDA were examined. In the transgastric mid short-axis view, the graft was depicted as an echo-free zone between the right ventricle and diaphragm. The depth, diameter, angle for Doppler measurement, and angle-corrected blood flow velocity were determined. The graft was visualized in 20 cases (95.2%). The diameter of the SV graft was 3.0-6.5 mm (mean 4.0 mm), while that of RGEA graft was 2.2-2.9 mm (mean 2.5 mm), at the depth of 1.2-4.4 cm (mean 2.4 mm) with incident angle of 14-57 degrees (mean 38.6 degrees ). Blood flow was detected in 17 cases but was difficult to detect in three cases (velocity <10 cm/s). Postoperative coronary angiography showed patent graft in 16 of former cases (one case of operative death excluded) but occluded graft in all of latter cases. Intraoperative TEE assessment was feasible nearly consistently. Diastolic blood flow velocity <10 cm/s suggests an early occlusion of the graft.