[Coronary bypass surgery using arterial conduit and its pitfall].

Three patients with spasm of internal mammary arteries and gastroepiploic artery immediately after coronary bypass surgery were reported. On completion of the revascularization, all patients could not be weaned from cardiopulmonary bypass. The flow velocity waveforms of the arterial grafts measured by pulsed Doppler velocimeter showed only small systolic component without diastolic flow and the palpation revealed profound spasm partially in the arterial conduits. Although all patients could be weaned from cardiopulmonary bypass only after insertion of a saphenous vein graft, two of them died on the next day. In all patients, free flow measured prior bypass was considered to be sufficient and a technically satisfactory anastomosis was felt to be performed. If a profound hemodynamic instability as a result of intractable spasm of arterial conduit occurred after completion of coronary bypass surgery, an additional saphenous vein graft should be placed before discontinuation of cardiopulmonary bypass.