A 60-year-old woman was admitted to our hospital due to abnormal findings on an electrocardiogram. She was a diabetic patient and had been taking neutral protamine Hagedorn insulin previously. After admission, since a coronary angiography was performed and showed three-vessel disease we performed coronary artery bypass grafting. After the cardiopulmonary bypass, she was given protamine sulfate. Subsequently her systolic blood pressure decreased below 35mmHg. Immediately cardiopulmonary bypass was restarted as an assist device for circulation. We administered epinephrine, and her blood pressure increased. After the second cardiopulmonary bypass, protamine administration was not given. Her postoperative course was uneventful, and she was discharged on the 18th postoperative day. A skin test titration to protamine was done. She had positive reaction at a dilution of 1mg/ml. Neutral protamine Hagedorn insulin use may immunologically sensitize patients to protamine, leading to anaphylactic reaction upon subsequent exposure to protamine sulfate during cardiac surgery. It is important to avoid adverse reaction to protamine.

A 79-year-old man was admitted for thoracoabdominal aortic aneurysm repair. He had already twice undergone coronary artery bypass grafting, 19 and 2 years previously. The value of the ejection fraction of the left ventricle was 36%, measured by ventriculography; and transthoracic echocardiography revealed moderate aortic valve regurgitation. In the presence of aortic valve regurgitation or coronary artery disease, myocardial perfusion under hypothermic fibrillatory arrest may be significantly impaired. Therefore, to maintain a beating heart we used separate perfusions of the upper and lower body that enabled individual temperature control of each organ. The femoral and axillary arteries were cannulated, and a long cannula was inserted into the right common femoral vein and positioned in the right atrium. Cardiopulmonary bypass was established, and the upper body was mildly cooled until the pharyngeal temperature was 33°C, while the lower body was cooled until the bladder temperature reached 20°C. Mild hypothermia of the upper body maintained the beating heart, and deep hypothermia in the lower body provided adequate protection to the spinal cord. Furthermore, in a case of aortic valve regurgitation and low left ventricular function, left ventricular venting is essential for the heart. However, it was difficult to insert the venting tube through the apex of the left ventricle or through the left inferior pulmonary vein; therefore, we selected the left main pulmonary artery for left ventricular venting, and maintained a non-working beating heart. After cardiopulmonary bypass was discontinued, cardiac function was good although a bleeding tendency became apparent. Postoperatively, the maximum dose of dopamine we needed was only 3γ. There were no remarkable complications and the patient was discharged on postoperative day 30. This experience suggests that pulmonary artery venting and separate perfusion of the upper and lower body to individually control organ temperatures is a useful procedure for thoracoabdominal aortic aneurysm repair in patients with low left ventricular function.

A 43-year-old man was admitted for mitral valve repair. After quadrangular resection of the posterior leaflet, folding plasty was performed. Chordal reconstruction of the anterior leaflet was carried out and a 32-mm Cosgrove-Edwards ring was placed. Seven weeks after the operation, hemolytic anemia developed and serum lactate dehydrogenase elevated to 1,923IU/l. Doppler echocardiography showed only mild residual mitral regurgitation, but the regurgitation jet collided with the annuloplasty ring. The velocity of the regurgitation jet was 5.19m/s. After bisoprolol administration, the hemolytic anemia improved. However, the patient had been complaining of general fatigue; serum lactate dehydrogenase was found to be re-elevated after discharge despite the administration of bisoprolol. Therefore, re-operation was undertaken. The cause of the residual mitral regurgitation was mainly anterior leaflet prolapse. Chordal reconstruction and ring annuloplasty were re-performed. The hemolytic anemia was cured after re-operation. This case showed that a high-velocity regurgitation jet can cause hemolytic anemia, especially by colliding with an annuloplasty ring. It is important to accurately evaluate the severity, direction and velocity of the regurgitation jet by transesophageal echocardiography. It seems that the velocity of the regurgitation jet could become a parameter when deciding on the treatment plan.