Atsushi Nakahira

Supplementation of α-tocopherol improves cardiovascular risk factors via the insulin signalling pathway and reduction of mitochondrial reactive oxygen species in type II diabetic rats

This study determined the effects of α- and γ-tocopherol supplementation on metabolic control and oxidative stress in type 2 diabetic Otsuka Long–Evans Tokushima Fatty (OLETF) rats. Blood glucose, haemoglobin A1c (HbA1c), urinary protein, plasma free fatty acid, triacylglycerol and plasminogen activator inhibitor-1 (PAI-1) levels in OLETF rats were significantly higher than in non-diabetic control Long–Evans Tokushima Otsuka (LETO) rats. α-Tocopherol inhibited the increase in urinary protein, blood glucose, HbA1c and PAI-1 levels, but γ-tocopherol did not. Plasma and hepatic lipid peroxidation and hepatic steatosis were increased in OLETF rats. α-Tocopherol decreased lipid peroxidation. Mitochondrial reactive oxygen species production and uncoupling protein 2 (UCP2) expression were significantly increased in the heart and aorta of OLETF rats compared with LETO rats. Endothelial NO synthase and aortic nitrotyrosine were increased in OLETF rats. In contrast, the expression of phosphorylated vasodilator-stimulated phosphoprotein and glucose transporter 4 in the aorta was significantly decreased in OLETF rats. These abnormalities were reversed by α-tocopherol. These findings suggest that α-tocopherol may prevent cardiovascular tissues from oxidative stress and insulin signalling disorder resulting from diabetes mellitus.

Evaluation of risk factors for hospital mortality and current treatment for poststernotomy mediastinitis.

PurposePoststernotomy mediastinitis (PSM) following cardiovascular surgery remains an intractable complication associated with considerable mortality. It is therefore necessary to assess the risk factors associated with hospital mortality and evaluate the surgical treatment options for PSM.MethodsWe identified 59 (2.2%) patients who developed PSM after cardiovascular surgery between January 1991 and January 2010. PSM was defined as deep sternal wound infection requiring surgical treatment. In all, 31 patients were infected with methicillin-resistant Staphylococcus aureus (MRSA); and 14 patients died in hospital from PSM. A total of 51 patients were treated by simple closure or tissue flap reconstruction after débridement (traditional treatment), and 8 underwent closure or reconstruction after negative-pressure wound therapy (NPWT). The risk factors for in-hospital mortality due to PSM were analyzed by comparing the characteristics of survivors and nonsurvivors. The available surgical treatments for mediastinitis were also assessed.ResultsUnivariate analysis identified age, sex, pulmonary disease, MRSA infection, prolonged mechanical ventilation and prolonged intensive care unit stay as risk factors for in-hospital mortality (P < 0.05). Multiple logistic regression analysis identified MRSA infection (odds ratio 20.263, 95% confidence interval 1.580–259.814; P = 0.0208) as an independent risk factor for hospital mortality. NPWT was associated with significantly less surgical failure than traditional treatment (P = 0.0204). There were no deaths as a result of PSM in patients who underwent NPWT irrespective of the presence of MRSA infection.ConclusionMRSA infection was an independent risk factor for PSM-related in-hospital mortality. NPWT may improve the prognosis for patients with MRSA mediastinitis.

Platypnea-orthodeoxia diagnosed by sitting transesophageal echocardiography.

Platypnea-orthodeoxia is a rare syndrome presenting with dyspnea and cyanosis induced by an upright position and relieved by recumbency. We report a patient with an excessively enlarged aortic root who had critical hypoxia due to a paradoxical shunt through the patent foramen ovale only when seated. The postural changes of the shunt, caused by changes in posture, were dynamically detected by transesophageal Doppler echocardiography. We believe that this syndrome should be considered when patients with aortic root dilatation present with inexplicable hypoxia, and that transesophageal Doppler echocardiography in the sitting position can be useful for detecting platypnea-orthodeoxia syndrome.

Cardiotomy suction, but not open venous reservoirs, activates coagulofibrinolysis in coronary artery surgery

OBJECTIVES Closed and miniaturized cardiopulmonary bypass circuits, which eliminate cardiotomy suction and open venous reservoirs with a reduced priming volume, have been reported to be advantageous. We comparatively examined the respective contribution of cardiotomy suction and open venous reservoirs to perioperative activation in coagulofibrinolysis and inflammation systems, with identical conditions of priming volume and anticoagulation. METHODS A total of 75 consecutive coronary artery bypass grafting procedures were performed using 1 of the following 3 cardiopulmonary bypass circuits under identical conditions of priming volumes, heparin coating, and protocols of anticoagulation and transfusion, as follows: a circuit with an open venous reservoir and cardiotomy suction (open group, n = 25), a circuit with an open venous reservoir without cardiotomy suction (nonsuction group, n = 25), or a circuit without either (closed group, n = 25). Blood samples were collected at 8 points up to the first postoperative morning. RESULTS The thrombin-antithrombin III complex, fibrinogen degeneration products, D-dimer, plasmin-α2 plasmin inhibitor complex, and plasminogen activator inhibitor-1 levels were significantly greater in the open group than those in the other 2 groups (P < .0001, for all markers). The C3a and interleukin-6 levels were similar among all the groups. The incidences of perioperative transfusion and postoperative bleeding were increased and the early graft patency rate of saphenous veins was lower in the open group than those in the other 2 groups. CONCLUSIONS Cardiotomy suction, but not open venous reservoirs, causes perioperative coagulofibrinolysis activation, although neither affects the inflammation system. The use of cardiotomy suction needs to be examined further in association with postoperative PAI-1 elevation and early vein graft occlusion.

Outcome After the Modified Bentall Technique With a Long Interposed Graft to the Left Coronary Artery

BACKGROUND The modified Bentall technique, which was reported by Svensson in 1992, is an aortic root composite valve graft replacement involving reimplantation of the left coronary ostium with a long interposed graft wrapping behind the composite graft. The technique is technically advantageous, particularly for complicated or redo aortic roots. To justify the technique, the midterm outcome needs to be evaluated. METHODS Since 1992, 40 patients (4 with Marfan syndrome) underwent the modified Bentall technique (Svenssons modification). The mean age was 54.7 +/- 13.6 years, and 32 patients (80.0%) were male. All hospital survivors have been consecutively followed with annual echocardiographic evaluations. Furthermore, in 2007, multislice computed tomography was performed at 4.7 +/- 3.5 years (maximum, 14.9 years) postoperatively in 30 patients who had preserved renal function. RESULTS No patients have experienced any complications regarding the technique at the follow-up of 5.7 +/- 4.0 years (maximum, 14.9 years), although there were 2 hospital deaths of emergency cases and 5 late deaths owing to noncardiac causes. In 35 patients (92.1% of hospital survivors), no structural complications were detected by multislice computed tomographies of the 30 patients or coronary angiograms of the remaining 5 patients. The consecutive echocardiographic follow-ups showed well-preserved left ventricular function with the most recent ejection fraction being 0.581 +/- 0.078. CONCLUSIONS This Svenssons modification technique was associated with favorable midterm outcomes by multislice computed tomography and consecutive echocardiographic evaluations, indicating long-lasting advantages as well as technical benefits. Thus, the technique can be considered as a helpful and justifiable alternative method.

A Surgical Case of Expanding Bilateral Coronary Aneurysms Regarded as Immunoglobulin G4-Related Disease

A 69-year–old man was referred to our department for surgical treatment of bilateral giant coronary artery aneurysms. He had no apparent clinical factors associated with atherosclerosis, such as diabetes mellitus, hyperlipidemia, or hypertension. Physical examination revealed no abnormalities. His medical history included malignant lymphoma that had been treated with chemotherapy and radiation therapy at the age of 60 years. He was also diagnosed with a plasma cell tumor in his tonsils at the age of 68 years. Just before treatment for this tumor, he developed sudden-onset myocardial infarction. Coronary angiography revealed 2 giant coronary aneurysms; one presented as a broad aneurysmal change of the right coronary artery (Figure 1A and Movie I in the online-only Data Supplement), and the other was located from the left main coronary artery to the left anterior descending artery (Figure 1B and Movie II in the online-only Data Supplement). On the basis of subsequent computed tomography, the maximum diameters of the right and left coronary aneurysms were 40 and 25 mm, respectively (Figure 2). Laboratory examination showed that the serum immunoglobulin …

Resection of hepatocellular carcinoma arising from primary biliary cirrhosis

To the Editor: Except for liver transplantation, surgery is rarely performed for hepatocellular carcinoma (HCC) arising from primary biliary cirrhosis (PBC). However, the number of patients with HCC arising from PBC has been increasing recently as a result of progress in the diagnostic imaging and medical treatment of PBC. A 45-year-old Japanese woman with PBC with a hepatic tumor was admitted to our hospital. PBC with severe liver fibrosis had been initially diagnosed by laboratory examination and a biopsy at age 26 years. Steroid therapy had been started at the time, and her hepatic function remained good (Child-Pugh’s class, A; Mayo Risk Score, 0). In June 2001, serum concentrations of alphafetoprotein and protein induced by vitamin K absence or antagonist II was increased (Table 1). Ultrasonography showed a

Closed cardiopulmonary bypass circuits suppress thrombin generation during coronary artery bypass grafting

Thrombin generation is considered unavoidable during cardiac surgery using cardiopulmonary bypass (CPB). We compared the effects of open and closed circuits on coagulation and fibrinolysis under identical conditions of priming volume, heparin-coating, and anticoagulation and transfusion protocols. Thirty coronary surgery patients were randomized to surgery using open circuits with open reservoirs and cardiotomy suction (open group, n=15) or closed circuits without either (closed group, n=15). In the closed group, a cell-saving device was used instead of cardiotomy suction. Blood samples were collected at eight time points from before the operation to the first postoperative morning. Thrombin-antithrombin III (TAT), fibrinogen degradation products, and D-dimer were not elevated during CPB in the closed group, but were significantly increased in the open group (P<0.0001 for all markers). The peak TAT value at the termination of CPB in the open group was significantly correlated with CPB time (r(2)=0.879, P=0.037) and the simultaneous peak D-dimer value (r(2)=0.640, P=0.040). In conclusion, the use of closed circuits maximally suppressed thrombin generation and coagulofibrinolytic activation during coronary artery bypass grafting. The respective contribution of open reservoirs and cardiotomy suction to the perioperative thrombin generation remains to be elucidated.

Impact of non-di-(2-ethylhexyl)phthalate cardiopulmonary bypass tubes on inflammatory cytokines and coagulation-fibrinolysis systems during cardiopulmonary bypass

Di-(2-ethylhexyl)phthalate (DEHP), an excellent plasticizer for poly(vinyl chloride) (PVC), is a known endocrine-disrupting chemical. This study was designed to investigate whether a new non-DEHP bilayer tube reduced the release of DEHP, suppressed inflammatory cytokines, and altered coagulation-fibrinolysis systems. Sixteen patients undergoing coronary artery bypass grafting (CABG) were randomly assigned to the non-DEHP bilayer group (group B, n = 8), or the noncoated PVC group (group N, n = 8). The level of DEHP in the blood was measured before and after cardiopulmonary bypass (CPB). The levels of interleukin-6 (IL-6), D-dimer, and thrombin-antithrombin complex (TAT) were also measured at six points during and after CPB. DEHP was significantly lower in group B (472 ± 141 ng/ml) after CPB compared with group N (2094 ± 1046 ng/ml). The IL-6 level was significantly lower in group B (151 ± 131 pg/ml) than group N (206 ± 224 pg/ml) 180 min after protamine administration. The D-dimer level was significantly lower in group B 60 min after protamine administration (6.2 ± 2.4 μg/ml in group B vs 10.4 ± 4.5 μg/ml in group N) and 180 min after protamine administration (4.4 ± 0.7 μg/ml in group B vs 7.3 ± 2.7 μg/ml in group N). Group B had a tendency toward reduced postoperative bleeding compared with group N at any time. The bilayer tube was superior to the noncoated tube in terms of the inhibition of DEHP release, inflammatory cytokines, and the fibrinolysis system.

Successful surgical treatment of traumatic transection of the innominate artery: a case report.

Blunt traumatic injury to the innominate artery is relatively rare. We present the case of a 40-year-old woman who fell from a fourth-floor window and was transferred to our hospital with multiple injuries, hemodynamic shock, and disturbance of consciousness. Computed tomography with image reconstruction revealed transection of the innominate artery near its origin. Emergent surgery required establishment of cardiopulmonary bypass before sternotomy in preparation for uncontrollable hemorrhage. Proximal aortic arch replacement with a branch to the right axillary artery was successfully performed using circulatory arrest and selective cerebral perfusion.