超音波検査技術

A female patient in her 80s developed Stanford type A aortic dissection in 202X–10 and underwent ascending aortic replacement. She had been followed up at another hospital; however, because she was diagnosed with hemolytic anemia, she was observed for postoperative follow-up. On admission, continuous murmur was audible. Transthoracic echocardiography revealed a cavity at the central anastomosis of the ascending aortic graft in the parasternal left ventricular long-axis section, and a pseudoaneurysm was suspected. Color Doppler imaging revealed a continuous color signal flowing into the pseudoaneurysm from the central anastomosis of the ascending aortic graft during both systole and diastole. Continuous-wave Doppler imaging demonstrated that the blood flow into the pseudoaneurysm had a pulsatile continuous waveform. Furthermore, a color signal flowing from the pseudoaneurysm to the right ventricular outflow tract was detected, and continuous-wave Doppler imaging revealed a pulsatile continuous waveform of the blood flowing into the right ventricular outflow tract. The right ventricular outflow tract was also visualized in a section at the level of the short axis of the aortic valve, and the blood flow into the right ventricular outflow tract was confirmed by color Doppler imaging. Transthoracic echocardiography indicated perforation from the central anastomosis of the ascending aorta to the right ventricular outflow tract pseudoaneurysm. Autoimmunity and paroxysmal nocturnal hemoglobinuria were eliminated as the cause of hemolytic anemia, and no severe stenosis was detected in the lumen of the ascending aortic graft on contrast-enhanced CT. The cause of hemolytic anemia was mechanical hemolysis due to perforation of the right ventricular outflow tract pseudoaneurysm.