Biomedical subjects

Osamu Namura

Publications and source records attributed to Osamu Namura.

9 recordsLinked to original sources

PubMed2006

Vasoconstrictor administration during cardiopulmonary bypass affects acid-base balance in infants and children.

BACKGROUND: In experimental reports, blood flow redistribution occurred during cardiopulmonary bypass (CPB) and perfusion pressure was restored by vasoconstrictor administration without improving splanchnic perfusion. The influence of vasoconstrictor administration during CPB was clinically examined. MATERIALS AND METHODS: Twenty-two consecutive pediatric CPB cases of ventricular septal defect without blood transfusion were divided into two groups, depending upon whether a vasoconstrictor was administered during CPB or not (n = 7 vs. 15). Bypass flow and systemic perfusion pressure during CPB were maintained at 2.5 L/m(2)/min and not lower than 30 mm Hg by vasoconstrictor administration, respectively. RESULTS: Although preoperative state and CPB conditions were comparable between the two groups, more sodium bicarbonate was administered (P < 0.05); duration from the operation to extubation was longer (P < 0.05); and bowel movement occurred later in the vasoconstrictor-administered group than in the control group. CONCLUSIONS: Vasoconstrictor administration during CPB may deteriorate the acid-base balance and the postoperative state in infants and children.

Acid-Base Equilibrium↗

PubMed2006

A reduced priming system.

Cardiopulmonary bypass (CPB), an integral part of valve surgery, is known to cause hemodilution, which can lead to a need for blood transfusion as well as a systemic inflammatory reaction. Our aim was to evaluate a reduced priming (RP) system for CPB with regard to clinical outcomes in patients undergoing valve surgery. Eleven patients were assigned to the new system with an RP volume. The RP system allowed for reduced hemodilution and a possible reduction in the necessity for blood transfusions.

Adult↗

PubMed2005

A single-stage operation for abdominal aortic aneurysm with concomitant colorectal carcinoma.

The coexistence of abdominal aortic aneurysm (AAA) and colorectal carcinoma needs special operative consideration. A single-stage operation for concomitant AAA and colorectal carcinoma has been thought to increase the risk of vascular prosthetic graft infection. We report two patients who received a single-stage operation for AAA and colorectal carcinoma. The first patient had a fusiform aneurysm of the infrarenal aorta. The second patient had a saccular aneurysm of the infrarenal aorta and a fusiform aneurysm of the left internal iliac artery. Both patients had left-sided colorectal carcinoma classified as Dukes' stage B. The two patients underwent a single-stage operation with Hartmann's procedure to avoid graft infection caused by anastomotic leakage. They tolerated the operation and had no postoperative complications including graft infection. A single-stage operation for concomitant AAA and left-sided colorectal carcinoma could be safely performed with Hartmann's procedure in two cases.

Adenocarcinoma↗

PubMed2004

Clinical application of bone marrow implantation in patients with arteriosclerosis obliterans, and the association between efficacy and the number of implanted bone marrow cells.

BACKGROUND: There have been a number of recent reports on the use of autologous bone marrow implantation (BMI) in the treatment of peripheral arterial disease, with a clinical response rate of approximately 70%. However, the factors that influence efficacy have not yet been clarified. We have analyzed the relationship between the number of implanted bone marrow cells and the clinical efficacy of BMI. METHODS AND RESULTS: Eight patients with arteriosclerosis obliterans were treated with BMI. Bone marrow was aspirated from the ilium (500-1,000 ml), the mononuclear cells were separated and then were implanted. The clinical effectiveness of BMI was evaluated by assessing changes in the ankle-brachial pressure index (ABI) and the transcutaneous oxygen pressure (TcO2) between the pre-treatment baseline, with follow-up testing at 4 weeks. These changes were defined as DeltaABI and DeltaTcO2. The mean number of CD34-positive cells was 1.04+/-0.60 x10(6) /kg body weight. There was a strong correlation between the number of CD34-positive cells and DeltaABI (r=0.754, p=0.028). CONCLUSIONS: It is likely that the number of implanted CD34-positive cells is one of the primary factors that influence the clinical efficacy of BMI.

Aged↗

PubMed2003

Therapeutic role of pericardiocentesis for acute necrotizing eosinophilic myocarditis with cardiac tamponade.

We describe a patient with acute necrotizing eosinophilic myocarditis who recovered rapidly after pericardial drainage and without corticosteroid therapy. The 25-year- old man was referred to our hospital with suspected acute myocardial infarction on the basis of severe epigastralgia, abnormal Q waves and ST elevation on electrocardiography, and an increase in cardiac enzymes. Echocardiography disclosed pericardial effusion that compressed the right ventricle, left ventricular dysfunction in conjunction with posterolateral hypokinesis, and a thickened ventricular wall but no mural thrombus. The eosinophil count in the peripheral blood was slightly increased. Coronary angiography showed normal arteries and thus prompted an endomyocardial biopsy. The patient was transferred to the intensive care unit with a clinical diagnosis of myocarditis associated with cardiac tamponade. Emergency pericardiocentesis relieved symptoms immediately. The cells in the pericardial effusion were mainly eosinophils; interleukin 5 and interleukin 13 levels were predominantly elevated, and the effusion was drained for 5 days. The biopsy specimen revealed necrotizing eosinophilic myocarditis. Left ventricular function recovered within a week without corticosteroid therapy. No relapse was observed as of 8 months after diagnosis.

Adult↗

PubMed2003

Preoperative respiratory physiotherapy for a patient with severe respiratory dysfunction and annuloaortic ectasia.

A 23-year-old man with Marfan syndrome, who had undergone surgery for pectus excavatum and scoliosis and who had severe respiratory dysfunction, was referred for surgical repair of annuloaortic ectasia. The preoperative pulmonary function test revealed severe obstructive and restrictive respiratory dysfunction, with forced expiratory volume in one second of 650 ml and vital capacity of 1,220 ml. These parameters improved after 4 months respiratory physiotherapy. A modified Bentall's procedure was performed after respiratory physiotherapy. A tracheostomy made on the 7th postoperative day (POD) appeared to improve respiratory condition and he was weaned off mechanical ventilation on the 14th POD. The lower limits of pulmonary function for open heart surgery have not been established clearly; however, our case will help elucidate these limits of respiratory function for open heart surgery. Preoperative respiratory physiotherapy improved parameters of pulmonary function test and may decrease the morbidity of postoperative pulmonary complications in a patient with severe respiratory dysfunction.

Adult↗

PubMed2002

Intensive imaging assessment for successful minimally invasive cardiac surgery.

To clarify special imaging assessment that is useful for minimally invasive cardiac surgery (MICS), we examined 141 cases of MICS operations with ministernotomy or minithoracotomy. In the 141 patients, 62 valve, 42 coronary, 37 congenital heart, and 2 other procedures were successfully completed without conversion to full sternotomy. Preoperative chest x-ray, computed tomography, and/or magnetic resonance imaging were necessary for determining the level of ministernotomy, especially in aortic valve operations. Transthoracic echocardiography was useful for selecting procedures of mitral valve or intracardiac repair through the MICS approach. Intraoperative transesophageal echocardiography was essential for continuous monitoring of cardiac function, intracardiac flow, air bubbles, and so forth. The above results suggest that intensive imaging assessment might be very important for successful MICS operations with ministernotomy or minithoracotomy and that extensive indications for this technique exist for various cardiovascular diseases.

Adolescent↗

PubMedDate not supplied

Deterioration of body oxygen metabolism by vasodilator and/or vasoconstrictor administration during cardiopulmonary bypass.

During cardiopulmonary bypass (CPB), tissue perfusion injury occurs even if perfusion pressure is maintained. Although a vasodilator and a vasoconstrictor are clinically administered if bypass flow is maintained, they may restore perfusion pressure without improving tissue perfusion. We evaluated the influence of vasodilators and vasoconstrictors on the whole body during CPB. Fifty-six patients with valvular disease who received moderately hypothermic CPB without blood transfusion were divided into four groups, depending upon whether a vasodilator and/or a vasoconstrictor was administered, and postoperative data were compared. Bypass flow and aortic pressure were maintained at 2.4 l/min/m and 5090 mm Hg. Body weight, dilution, hematocrit level, CPB, and aortic clamp duration, blood temperature, bypass flow, perfusion pressure, base excess levels during CPB, cardiac index, arterial and mixed venous oxygen pressure, and alveolar-arterial oxygen distribution after CPB were comparable among the four groups. However, the time to extubation was significantly longer. Blood lactate levels, measured for patients returned to the ward, were significantly higher in the agent-administered groups than in the no-agent group, whereas blood lactate levels on extubation and blood creatinine levels on postoperative day 1 were comparable among the groups. Vasodilator and/or vasoconstrictor administration during CPB may deteriorate the body oxygen metabolism, which might imply tissue perfusion and worsen the complications induced by hypoperfusion during CPB.

Aged↗

PubMedDate not supplied

Marked decrease of plasma VEGF after implantation of autologous bone marrow mononuclear cells in a patient with critical limb ischemia--a case report.

The authors performed autologous bone marrow mononuclear cells implantation (BMI) in a 79-year-old man with critical limb ischemia. After BMI, the resting pain of the ischemic leg improved gradually. They measured the plasma concentrations of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and serum hepatocyte growth factor (HGF) in the blood from bilateral femoral veins. Before BMI, the plasma VEGF and bFGF concentrations were much greater in the ischemic leg than in the other lower limb, but decreased to the same concentrations as those in the contralateral lower extremity after BMI. The large concentrations of the angiogenic factors VEGF and bFGF in plasma indicate the severity and extent of the leg ischemia. BMI resulted in lower levels of VEGF and bFGF, and this fall is the hallmark of the effectiveness of BMI in the treatment of peripheral artery disease.

Aged↗