Breakdown of atheromatous plaque due to shear force from arterial perfusion cannula.

Breakdown of an atheromatous plaque in the aorta due to jet from the arterial cannula is reported. The patient underwent mitral valve replacement under ventricular fibrillation because of severe atheromatous change in the ascending aorta, transverse aortic arch, and descending aorta. A dispersive arterial perfusion cannula was inserted into the middle portion of the ascending aorta where the atheromatous change was minimal. Postoperative epiaortic ultrasonography revealed a breakdown of the atheromatous plaque in the lesser curvature. In view of this complication, further study of the effects of shear stress to the diseased aorta should be done by clinical and flow dynamics investigation.