Tomohiko Sumida

Role of mitochondrial KATP channels and protein kinase C in ischaemic preconditioning.

1. Activation of mitochondrial KATP (mitoKATP) channels and protein kinase C (PKC) has been implicated in cardioprotective mechanisms of ischaemic preconditioning (IPC). However, the exact role of these events in early IPC remains unclear.

Combined pharmacological preconditioning with a G‐protein‐coupled receptor agonist, a mitochondrial KATP channel opener and a nitric oxide donor mimics ischaemic preconditioning

1. Although pharmacological preconditioning (PPC) has emerged as an alternative to ischaemic preconditioning (IPC) in cardioprotection, the efficacy of PPC compared with IPC has not been investigated. Because IPC is mediated by complex signalling cascades arising from multiple triggers, we have hypothesized that combined PPC is necessary to mimic IPC.

Revascularization of left subclavian artery for coronary subclavian steal syndrome.

We have experienced 2 patients with coronary subclavian steal syndrome which progressed each to a different prognosis. Both cases received percutaneous transluminal angioplasty for subclavian artery stenosis after coronary artery bypass grafting. Although one case is doing well without any symptoms, the other case required a xilloaxillary artery bypass grafting for the subclavian artery restenosis.

Right ventricular myxoma in a 71-year-old female

Right ventricular myxoma in elderly is very rare and this is the 36th case report of right ventricular myxoma in Japan. A healthy 71-year-old female with no symptoms or constitutional signs except heart murmur was hospitalized. Findings of transthoracic echocardiogram, CT scan, MRI and angiocardiogram demonstrated a mobile tumor in the right ventricular outflow tract. Transesophageal echocardiogram clearly revealed that the stalk was arising from the right ventricular free wall. Under cardiac arrest, right atriotomy was made and a gelatinous tumor (4.5 x 2 x 2 cm in size, 7.3 g in weight) was excised with 5 mm of surrounding endocardium and a few millimeters of underlying myocardium through the tricuspid valve. Histopathologically, the tumor was diagnosed as a myxoma. Her postoperative course was uneventful.

Multiple papillary fibroelastoma with quadricuspid aortic valve.

had chronic rheumatoid arthritis; 9 patients (30%) had other underlying risk factors, such as congenital or degenerative heart valve disease or coagulation problem; and 3 patients (10%) had no risk factors. The majority of their patients underwent surgery for valve dysfunction. When patients can tolerate cardiac surgery with cardiopulmonary bypass, indications for surgery are valve dysfunction, recurrent embolic events, and mobile vegetation. Removal of vegetation and repair of the valve seem to be feasible if the vegetation is small and localized. Prognosis after valve replacement or repair for nonbacterial thrombotic endocarditis is unknown but depends on the underlying cause. Even if the previous femoropopliteal bypass was performed with the working diagnosis of Burger disease, it is unlikely because there was no arterial disease in the other leg. Because of the large size of the vegetation plus the possible delay of time between ischemic events, the patient’s limb ischemia was thought to be arterial embolization caused by the vegetation. His noncoronary aortic leaflet was atrophic, which may be a factor in causing nonbacterial thrombotic endocarditis. Despite the patient’s young age and good general condition, he should be monitored carefully for possible occult malignant disease.

Aortic valve replacement in a patient with idiopathic thrombocytopenic purpura

A patient with aortic regurgitation and idiopathic thrombocytopenic purpura underwent a successful valve replacement. Cardiac surgery requiring a cardiopulmonary bypass in idiopathic thrombocytopenic purpura can be safely carried out with the preoperative intravenous administration of high-dose gammaglobulin, which may thereby reduce the need for either perioperative transfusion or prophylactic splenectomy.

Autologous Adventitial Overlay Method Reinforces Anastomoses in Aortic Surgery

In this study, we present an inexpensive and effective method for providing a secure and hemostatic anastomosis using autologous adventitia obtained from a dissected or aneurysmal wall. The resected aortic wall is separated between the adventitia and media, and a soft, 2 × 10-cm adventitial strip is overlaid to cover the anastomotic margin. A graft is sutured to the aortic stump. This autologous adventitial overlay method can inexpensively and strongly reinforce the anastomosis during aortic surgery for dissection or aneurysm and will contribute to anastomotic hemostasis and long-term stability.

Repair of a recurrent pseudoaneurysm of the ascending aorta in an atomic bomb survivor with myelodysplastic syndrome.

Abstract  The occurrence of infective aortic pseudoaneurysms tends to be intractable and difficult to treat. We experienced a very rare case of a recurrent infective pseudoaneurysm in the ascending aorta that occurred after cardiac surgery in an atomic bomb survivor with myelodysplastic syndrome. The pseudoaneurysm was successfully repaired using a femoral artery autograft with an omentopexy and the patient recovered well without any recurrence.

Bypass graft material and myocardial protective procedure in combined coronary artery bypass grafting and valve surgery

OBJECTIVE The aortic cross clamping time is prone to be longer when coronary artery bypass grafting (CABG) is combined with valve surgery. Therefore, the myocardium that is revascularized by in-situ internal thoracic artery graft is at risk to ischemia, and, myocardial protection is especially important in such operation. In this study, the effect of myocardial preservation of combined antegrade, retrograde and terminal warm blood cardioplegia during combined valve surgery and CABG using the internal thoracic artery as a bypass conduit was evaluated. METHODS From November 1992 to August 1999, 15 patients received combined CABG and valve surgery. Among these 15 patients, 13 patients who did not need hemodialysis were divided into 2 groups, and a comparative study was done. In Group I (n = 5), only the saphenous vein graft was employed for combined CABG and valve surgery, and myocardial protection was done by combined antegrade and terminal warm blood cardioplegia. In Group II (n = 8), at least 1 in-situ internal thoracic artery graft was employed for CABG and valve surgery, and myocardial protection was done by combined antegrade, retrograde and terminal warm blood cardioplegia. RESULTS Despite longer aortic cross clamping time in Group II, the peak creatine kinase-MB of Group II was significantly lower. In addition, the postoperative administration of dopamine tended to be less in Group II. CONCLUSION Myocardial protection by combined antegrade, retrograde and terminal warm blood cardioplegia may be an effective adjunct to combined valve surgery and CABG employing the in-situ internal thoracic artery graft.