Masato Kume

Mycotic Aneurysm of the Right Coronary Artery

Mycotic embolism in patients with infective endocarditis is not uncommon, however, mycotic aneurysm of a coronary artery is very rare. We report the case of a 62-year-old woman with mitral valve endocarditis complicated by mycotic aneurysm of the right coronary artery. Mitral valve replacement and resection of the mycotic aneurysm with coronary artery bypass were performed.

Nonocclusive mesenteric ischemia after cardiopulmonary bypass

Nonocclusive mesenteric ischemia (NOMI) is a rare abdominal pathology caused by mucosal hypoperfusion without actual obstruction to the mesenteric arteries. We present a case of NOMI after a cardiopulmonary bypass operation. The patient was a 79-year-old woman with a history of hypertension and diabetes mellitus. A coronary bypass operation was performed with stable hemodynamic conditions, and continuous venovenous hemodialysis was performed on the second postoperative day because of renal insufficiency. After 24 h of hemodialysis, the hematocrit level increased from 29.1% to 36.1%. The patient had some vague abdominal pain on the third postoperative day with abnormal laboratory values: leukocytes 17.10 × 103/µl, creatine kinase 1085 U/l, glutamic-oxyloacetic transaminase 6188 U/l, and lactate dehydrogenase 8695 U/l. Selective angiography showed diffuse stenosis of the superior mesenteric artery (SMA) without any occlusive findings on the major branches; the patient was therefore diagnosed with NOMI. An infusion of urokinase and prostaglandin E1 was started; however, disseminated intravascular coagulopathy had developed and the patient died on the 21st postoperative day as a result of multiple organ failure. The autopsy demonstrated extensive necrosis and hemorrhage in the small intestine without any occlusive findings on the major branches of the SMA.

Hemostatic effect of tranexamic acid (transamin) during coronary artery bypass grafting

The hemostatic effect of tranexamic acid (TA) was evaluated in patients undergoing coronary artery bypass grafting (CABG). The subjects were 33 serial patients who underwent elective CABG performed by the same team between January 1997 and April 2000. They were divided into a group that received TA (n=15) and a non-TA control group (n=18). The TA group received 50mg/kg of TA intravenously before starting cardiopulmonary bypass (CPB) and 25 mg/kg immediately after CPB. Blood loss from the end of CPB to completion of surgery (post-CPB), as well as during the first 6h (BL6), 6–12 h (BL6–12), 12–18h (BL12–18), and 18–24h after surgery (BL18–24), was compared between the two groups. The time of chest tube removal, the volume of blood transfused, and graft patency were also compared. The blood loss at BL6, BL6–12, BL12–18, and BL18–24, as well as the blood transfussion volume, were all significantly (P<0.05) lower in the TA group than in the control group. There was no significant difference in graft patency between the two groups. In CABG patients, TA reduced blood loss without affecting graft patency, suggesting that it is useful in this setting.

Congenital Bicuspid Aortic Stenosis in Siblings.

当施設では, これまで22例の先天性大動脈二尖弁の症例を経験しているが, 今回同胞に発生した大動脈二尖弁狭窄を経験し, 文献上検索したかぎり1例の報告も認められなかったので報告する. 症例は兄58歳, 妹56歳であり, 兄は51歳時, 妹は15歳時より心臓弁膜症を指摘されていた. 両者とも大動脈二尖弁狭窄の診断にて21mm Medtronic-Hall 弁にて大動脈弁置換術を施行し, さらに妹ではペースメーカー植込み術を追加した. 術後経過は両者とも良好である. 先天性大動脈二尖弁は遺伝的な関係が関与するため, 発見されたなら, 家族内および親族の精査が必要であろうと考えられる.

Pathophysiological Relevance of Oxygen to Reperfusion-Induced Arrhythmias.

Langendorff modeによるラット摘出心を用いて,再灌流後不整脈(reperfusion-induced arrhythmia)発生に及ぼす酸素の影響を検討した.10分間のglobal ischemiaの後,酸素化灌流液で再灌流したA群[n=12]では再灌流後,0.4～2.8秒(平均1.48±0.78秒)の間に心室頻拍が全例に発生し,6.9～19.0秒後(平均13.47±2.91秒後)にはすべて心室細動に移行した.無酸素化灌流液で再灌流したB群[n=12]でも1.0～3.5秒(平均1.98±0.96秒)の間に心室頻拍が全例に発生し,11.1～80.1秒後(平均27.01±18.52秒後)にはすべて心室細動に移行したが,A, B両群間には,再灌流から心室細動発生までの時間に有意差(p<0.05)を認めた.無酸素化灌流液による再灌流は心室細動の発生を遅らせたが,心室細動および心室頻拍は全例に発生した.再灌流時に酸素の存在下に発生するoxygen-derived free radical(活性酸素)は,再灌流後不整脈の発生に大きな影響を及ぼすが,発生のために必須の因子ではないと考えられた.