Nobuya Koyama

Clinical efficacy of heparin-bonded bypass circuits related to cytokine responses in children.

BACKGROUND Cardiopulmonary bypass (CPB) induces numerous systemic reactions. This study examined the efficacy of heparin-bonded CPB circuits on inflammatory responses and postoperative status in children. METHODS Thirty-four infants undergoing elective cardiac surgery were randomly divided into two groups: a heparin-bonded CPB group (n = 17) and a non-heparin-bonded group (n = 17). Plasma levels of the inflammatory cytokines were measured before, during, and after CPB, and postoperative status was determined by examining the respiratory index, blood loss, and the post- and preoperative body weight percent ratio. RESULTS Significant differences in tumor necrosis factor-alpha, interleukin-6, and interleukin-8 patterns were observed during and after CPB between the two groups (p < 0.01, p < 0.01, p < 0.05, respectively). All cytokines measured were significantly lower in the heparin-bonded group just after CPB (p < 0.05). There were no differences in duration of intubation, intensive care unit or hospital stay, or postoperative blood loss, but the respiratory index 3 hours after CPB and body weight percent ratio 24 and 48 hours after CPB were significantly reduced in the bonded group (p < 0.05, p < 0.01, p < 0.05, respectively). CONCLUSIONS Our findings suggest that heparin bonding of the bypass circuits affects early postoperative status and reduces cytokine responses in pediatric cardiac surgery.

Tissue-engineered grafts matured in the right ventricular outflow tract.

Autologous smooth muscle cell (SMC)-seeded biodegradable scaffolds could be a suitable material to repair some pediatric right ventricular outflow tract (RVOT) cardiac anomalies. Adult syngenic Lewis rat SMCs (2 × 106) were seeded onto a new biodegradable copolymer sponge made of ∊-caprolactone-co-L-lactide reinforced with poly-L-lactide fabric (PCLA). Two weeks after seeding, the patch was used to repair a surgically created RVOT defect in an adult rat. At 8 weeks after implantation the spongy copolymer component was biodegraded, and SM tissue and extracellular matrices containing elastin fibers were present in the scaffolds. By 22 weeks more fibroblasts and collagen were present (p < 0.05). The number of capillaries in the grafts also increased (p < 0.001) between 8 and 22 weeks. The fibrous poly-L-lactide component of the PCLA scaffold remained. The 22-week grafts maintained their thickness and surface area in the RVOT. The SMCs prior to implantation were in a synthetic phenotype and developed in vivo into a more contractile phenotype. By 8 weeks the patches were endothelialized on their endocardial surfaces. Future work to increase the SM tissue and elastin content in the patch will be necessary before implantation into a pediatric large-animal model is tested.

Perception in relation to a potential influenza pandemic among healthcare workers in Japan: implications for preparedness.

Perception in Relation to a Potential Influenza Pandemic among Healthcare Workers in Japan: Implications for Preparedness: Teppei Imai, et al. University of Occupational and Environmental Health, Japan—Due to the potential for an influenza pandemic, preparedness for infection control in healthcare settings is essential from the standpoint of occupational health for healthcare workers. We conducted questionnaire surveys among Japanese hospitals to assess preparedness at the individual and institutional levels and their inter‐relationship. Questionnaires were administered at 7 tertiary hospitals in Japan during the spring of 2006. We analyzed 7,378 individual responses of the 10,746 questionnaires administered and all seven institutional responses by hospital infection control committees. Healthcare workers assigned low importance to personal protective equipment and showed mixed attitudes (anxious but accepting) to the potential risk. Institutional gaps existed in preparedness across hospitals and most hospitals lacked the specificity to cope with a pandemic. A higher level of institutional preparedness, as determined by expertise as well as general and specific countermeasures, was an important predictor of individual recognition of preventive measures, perception of institutional measures, and attitude toward coping with risk. A higher level of institutional preparedness stood out to be an important predictor of individual preparedness. Considering the risk of a future influenza pandemic, hospitals should improve preparedness at all levels.

The Variations in the Immunologic Features and Interleukin-6 Levels for the Surgical Treatment of Cardiac Myxomas

PurposeIn this study, we propose the existence of a relationship between cardiac myxomas and the immunologic features or interleukin-6 (IL-6), while also considering the optimal treatment of cardiac myxoma, especially “familial myxoma.”MethodsIn a 19-year period at our hospital, 20 patients underwent 21 operations for cardiac myxomas. The immunologic features and the IL-6 levels were measured pre-operatively in 13 cases and post-operatively in 10 cases. A case of “familial myxoma” was diagnosed based on molecular genetic analyses.ResultsNo patients died in the hospital. The tumor size correlated with the preoperative IL-6 and/or α1-globulin values (P < 0.05). In addition, all of the immunologic features and IL-6 levels normalized by 4 weeks after surgery. “Familial myxoma” demonstrated recurrence without showing increases in either the immunologic features, inflammatory signs, or serum IL-6 levels.ConclusionsPatients with cardiac myxoma should therefore be operated on immediately because the possibility that the tumor size might be large when IL-6 and/or α1-globulin values are high. In addition, cases of “familial myxoma” require careful observation and periodic echocardiography after surgery to identify any possible recurrence. Recently, molecular genetic analyses are therefore considered to be an important diagnostic tool for cardiac myxoma, especially “familial myxoma.” Our “familial myxoma” case demonstrated a C769T PRKAR1a mutation, which has also been observed in other cases of “familial myxoma.”

Tuberculous abdominal aortic pseudoaneurysm penetrating the left psoas muscle after BCG therapy for bladder cancer

We describe a case of a 75-year-old man with abdominal aortic and right femoral tuberculous pseudoaneurysms 32 months after intravesical bacillus Calmette-Guerin therapy for bladder cancer. These aneurysms were probably brought on by systemic infection by Mycobacterium bovis. The infrarenal aorta and right common femoral artery were successfully replaced with an in situ expanded polytetrafluoroethylene graft. Tuberculous pseudoaneurysm after bacillus Calmette-Guerin therapy for malignancy is very rare, and we review the related literature.

Study of the efficacy of nicorandil in patients with ischaemic heart disease using Exercise-Tl-201 myocardial tomography

SummaryThe effect of nicorandil on myocardial perfusion in ischaemic heart disease has been studied using exercise-load Tl-201 myocardial SPECT (Ex-SPECT). Ex-SPECT was carried out in 12 patients with previous myocardial infarction (OMI) and 9 with angina pectoris (AP) before and after administration of nicorandil 15 mg/day, for three or more weeks; % Tl uptake and the washout rate in infarcted or ischaemic areas were calculated from short axial images using the Bulls eye method.In the OMI group, % Tl uptake and washout rates in the infarction areas improved significantly from 52.4% and 0.25 before nicorandil to 60.4% and 0.38 after it. In the AP group, too, % Tl uptake and washout rates showed a significant improvement from 56.9% and 0.10 before to 69.1% and 0.33 after administration. Six subjects who had not received the drug, and who showed negative washout rates, had high improvement rates when nicorandil was administered, suggesting that the drug could increase myocardial perfusion during exercise loading as well as suppressing coronary spasm.Ex-SPECT was done in 4 subjects before and after nicorandil and after subsequent surgical treatment (PTCA or CABG) and the effects of the two therapies were compared. The washout rate was improved from 0.01 to 0.34 by administration of nicorandil, and a notable increase in coronary artery blood flow was achieved compared to the level after surgical treatment, i.e. 0.50.It was concluded that, normal dosages of nicorandil have a powerful direct effect of dilating the coronary arteries without any influence on preload or afterload.

Defibrillation Effects of Intravenous Nifekalant in Patients with Out‐of‐Hospital Ventricular Fibrillation

Nifekalant (NF), a pure K+ channel blocker developed in Japan, has been reported to be effective in the treatment of life‐threatening ventricular arrhythmias. We studied its efficacy in 18 men and 4 women with out‐of‐hospital ventricular fibrillation (VF) admitted to our emergency department between August 2001 and March 2004. The number of DC shocks delivered for out‐of‐hospital VF, serum Na+ and K+, arterial blood pH, and base excess were compared in 8 patients treated with NF, 0.3 mg/kg i.v. followed by a continuous intravenous (group N) versus 14 patients treated with lidocaine, 2 mg/kg, i.v. (group C). The two groups were similar with respect to their baseline characteristics. Sinus rhythm returned in 5 of 8 patients in group N versus 2 of 14 patients in group C (P < 0.05). These seven patients were admitted to the intensive care unit, though all died within 1 month. The results of this study suggest that NF may be effective in defibrillation of out‐of‐hospital VF, though controlled studies are needed to confirm our observations.

Superior biocompatibility of heparin-bonded circuits in pediatric cardiopulmonary bypass.

BACKGROUND Heparin bonding of pediatric cardiopulmonary bypass circuits may decrease activation of blood compartments as inflammatory responses. We studied the biocompatibility of heparin-bonded circuits in infant cardiac surgery. METHODS Twenty-four infants undergoing elective cardiac surgery were randomly assigned to either a nonheparin-bonded control circuit (n = 12) or a fully heparin-bonded circuit (n = 12) including membrane oxygenator, reservoir, and all tubing. Blood samples were used to identify differences in complement activation and cytokine release between groups during and after cardiopulmonary bypass. The postbypass oxygenation index was also compared. RESULTS The C3 activation product in the heparin-bonded group was significantly lower during (p < 0.01) and just after (p < 0.05) cardiopulmonary bypass. No statistically significant difference in C4 activation products was observed. Lower interleukin-6 and tumor necrosis factor-alpha were found immediately after cardiopulmonary bypass (p < 0.05) and a higher mean postbypass oxygenation index was also seen (p < 0.05) in the heparin-bonded group. CONCLUSION We found that a heparin-bonded cardiopulmonary bypass circuit reduced inflammatory response and improved oxygenation in pediatric cardiac surgery. These results suggest that the superior biocompatibility of the bonded circuit may reduce pulmonary complications.

A case of pulmonary arteritis with stenosis of the main pulmonary arteries with positive myeloperoxidase-antineutrophil cytoplasmic autoantibodies

A 53‐year‐old woman was referred to our hospital with the main symptoms of productive cough, fever and exertional dyspnoea. Chest X‐ray revealed enlargement of the left hilar shadow and cavitary infiltration in the right upper lobe. 99mTechnetium‐macroaggregated albumin (99mTc‐MAA) perfusion scintigram showed complete hypoperfusion through the entire right lung. A pulmonary angiogram revealed stenotic lesions in the right and left main pulmonary arteries. Right cardiac catheterization showed an elevated right ventricular systolic pressure. There was no evidence of systemic arterial lesions nor vasculitis. The patient was positive for myeloperoxidase (MPO)antineutrophil cytoplasmic autoantibodies (ANCA) (168 EU). The Mycobacterium avium complex sputum culture was positive. The pulmonary stenotic lesions were surgically resected. The resected pulmonary arterial lesions were pathologically diagnosed as non‐specific vasculitis. The cavitary lesion disappeared 6 months after the surgery. Two years after the surgery, although the MPO‐ANCA level had decreased to 12 EU, stenosis of the pulmonary arteries reappeared. It is suggested that the patient became positive for MPO‐ANCA in association with the Mycobacterium avium complex infection, and that the presence of MPO‐ANCA may not be related to the development of pulmonary stenosis of the main pulmonary arteries.

Acute Type B Aortic Dissection With Communicating vs. Non-Communicating False Lumen

BACKGROUND In practice, patients with acute aortic dissection (AAD) are generally divided into 2 groups according to the status of the false lumen: non-communicating or communicating. The similarities and differences between the 2 groups, however, have not been fully determined in a large population. METHODS AND RESULTS: We studied 502 patients with Stanford type B AAD. Clinical background at symptom onset was compared, and similarities and differences characterized, for patients with non-communicating (NC group, n=288) vs. communicating (C group, n=214) false lumens. Time of day (00.00-06.00 hours, 06.00-12.00 hours, 12.00-18.00 hours, and 18.00-24.00 hours) and extent of physical activity (extreme exertion, slight exertion, at rest, and sleeping) at symptom onset were similar between groups. Patients in the NC group were older (mean age, 71±11 years vs. 64±14 years, P<0.01) and had lower prevalence of distally extended aortic dissection (26% vs. 8%, P<0.01) and deaths in hospital (2% vs. 7%, P=0.011) than those in the C group. CONCLUSIONS At symptom onset, clinical circumstances and physical activity were similar between the groups, and old age and a background of DeBakey IIIa aortic dissection may be associated with determination of false lumen status. The outcome in the NC group was better than in the C group.