Early postoperative spasm in left internal mammary artery bypass grafts

Two patients with early postoperative spasm of a left internal mammary artery bypass graft are described. To our knowledge, this entity has not been reported previously. Both patients were characterized by vasomotor collapse secondary to intractable spasm responsive only to local application of vasodilator agents. Although the mechanism of graft spasm is not clear, prophylactic nifedipine therapy in appropriate dose may be of some value. The profound hemodynamic effect of internal mammary artery spasm in the immediate postoperative period may allow no time for anything other than emergency reoperation to assess the nature of the problem and treat it appropriately.