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Muonic He (μ He) is a hydrogen-like atom composed of a helium atom with one of its electrons replaced by a negative muon. Measurements of the ground-state hyperfine structure (HFS) interval of the μ He atom is a sensitive tool to test the three-body atomic system, bound-state quantum electrodynamics (QED) theory, and determine fundamental constants of the negative muon magnetic moment and mass. It allows a test of the CPT theorem in muons by comparing these constants with positive muons. Precise measurements of the ground-state HFS interval using a microwave magnetic resonance technique are now in progress at J-PARC by the MuSEUM collaboration. Furthermore, a new experimental approach to recover the muon polarization lost during the muon cascade process is being investigated by repolarizing μ He atoms using a spin-exchange optical pumping (SEOP) technique. The first laser repolarization experiment was recently performed. An overview of the different features of these new μ He atom HFS measurements and the latest results are presented. [ABSTRACT FROM AUTHOR]

Measurements of circular polarization of γ -ray emitted from neutron capture reactions provide valuable information for nuclear physics studies. The spin and parity of excited states can be determined by measuring the circular polarization from polarized neutron capture reactions. Furthermore, the γ -ray circular polarization in a neutron capture resonance is crucial for studying the enhancement effect of parity nonconservation in compound nuclei. The γ -ray circular polarization can be measured using a polarimeter based on magnetic Compton scattering. A polarimeter was constructed, and its performance indicators were evaluated using a circularly polarized γ -ray beam. Finally, as a demonstration, the γ -ray circular polarization was measured in 32S(n , γ )33S reactions with polarized neutrons. [ABSTRACT FROM AUTHOR]

A previously healthy 77-year-old woman with a 4-week history of back pain and fever was admitted to our hospital for chronic type A aortic dissection. The aortic arch was enlarged to 7.5 cm in diameter, and the large dissecting aortic aneurysm involved all three branches of the aortic arch and compressed the trachea. Laboratory tests showed an increased C-reactive protein level (10.5 mg/dl). Blood cultures performed upon admission were negative. Progression of the symptoms suggested the possibility of impending aneurysm rupture. The patient underwent urgent total arch replacement, and cultures of samples obtained from the aortic wall during surgery were positive for Listeria monocytogenes. Two months after surgery, advanced rectal cancer was diagnosed. It is believed that the rectal cancer predisposed the patient to development of an arterial infection associated with L. monocytogenes. [ABSTRACT FROM AUTHOR]

A 59-year-old man with a long history of hypertension and diabetes was admitted to our hospital with acute type B aortic dissection 14 days after the sudden onset of back pain. The dissecting descending thoracic aorta was enlarged to 5.2 cm in diameter, and laboratory tests showed an elevated white blood cell count (15 530/mm3) and an increased C-reactive protein level (19.2 mg/dl). Computed tomography performed 2 days after admission revealed rapid growth of the aortic dissection. Blood cultures obtained upon admission were positive for Salmonella. Impending rupture of the aortic dissection complicated by Salmonella infection was strongly suspected, and the patient underwent emergency surgery consisting of debridement and prosthetic graft placement covered by an omental flap. In this case, it is believed that insidious Salmonella aortitis caused acute type B aortic dissection. [ABSTRACT FROM AUTHOR]

Coronary artery bypass grafting (CABG) in hemodialysis-dependent patients is associated with high mortality and morbidity rates. This retrospective study was undertaken to identify the risk factors for in-hospital mortality for hemodialysis-dependent patients. Methods: Subjects included 87 consecutive hemodialysis-dependent patients (81 men and 6 women), aged 47–82 years (mean age, 65 years), who underwent CABG. Operative procedures included CABG alone (n=77) and CABG with valve replacement, repair, or the Dor procedure (n=10). Thirty-one perioperative risk factors were subjected to univariate and multivariate analyses to identify the risk factors for hospital death. Results: The overall in-hospital mortality rate, including operative death, was 14.9% (13/87). Univariate analysis showed the following 7 risk factors to be statistically significant predictors of hospital death: age≧70 years, a concomitant cardiac procedure, left ventricular ejection fraction<30%, left ventricular end-systolic volume index>70 ml/m2, a left main lesion, emergency/urgent surgery, and anemia (hemoglobin<10 mg/dl) ( p<0.05 for each predictor). Multivariate logistic regression analysis confirmed that a concomitant cardiac procedure ( X 2=17.080, p=0.013) and age≧ 70 years ( X 2=9.112, p=0.019) are statistically significant independent risk factors for hospital death. Conclusion: A concomitant cardiac procedure and age ≧ 70 years were identified as significant independent risk factors for hospital mortality after CABG for hemodialysis-dependent patients. These preoperative risk factors may help in predicting operative risks and improving clinical outcomes in hemodialysis-dependent patients undergoing CABG. (Jpn J Thorac Cardiovasc Surg 2006; 54:142-148) [ABSTRACT FROM AUTHOR]

A 58-year-old man was admitted for an aortoesophageal fistula (AEF) resulting from a thoracic aortic aneurysm. He underwent immediate in-situ prosthetic graft replacement, primary esophageal repair and wrapping of the aneurysm. Postoperative upper gastrointestinal endoscopy and computerized tomography (CT) findings were unremarkable. He was discharged on postoperative day (POD) 25. Three months after surgery, he was readmitted with complaints of worsening cough and hemoptysis. CT showed a thrombosed aneurysm adjacent to the left bronchus. Aortobronchial fistula due to mycotic pseudoaneurysm was suspected. The patient underwent immediate resection of the infected graft and prosthetic graft replacement positioned to avoid the infected area. The graft was wrapped with omentum. On POD 7, pleural empyema developed, and esophagography revealed a residual leak. Staged reconstruction of the esophagus was performed successfully. We conclude that even if the fistulous opening is small, simultaneous esophageal resection should be performed during the initial treatment of AEF. [ABSTRACT FROM AUTHOR]

Percutaneous cardiopulmonary support (PCPS) is a powerful resuscitation tool for patients in cardiogenic shock. The femoral artery is generally used for arterial access; however, vascular complications, particularly in atherosclerotic arteries, can occur. Although such complications occur infrequently, they can be fatal. We describe the case of a 75-year-old woman who required extended PCPS for cardiogenic shock secondary to coronary spasm after on-pump beating coronary artery bypass grafting. Limb ischemia occurred because of an occlusive cannula, and distal perfusion with a 20G elastic intravenous catheter inserted into the dorsalis pedis artery resolved the ischemia. The catheter was connected to the side port of an oxygenator and provided distal limb perfusion during PCPS. This technique appears to be useful in treating limb ischemia and may have application in patients with arterial occlusive disease who are dependent on mechanical support. [ABSTRACT FROM AUTHOR]

A 55-year-old man was admitted for acute myocardial infarction. Cardiac catheterization revealed total occlusion of the left circumflex artery. During catheterization, he suffered cardiogenic shock. Percutaneous cardiopulmonary support was established, and the patient was transferred to the operating room. A blow-out left ventricular free wall rupture (LVFWR) with an epicardial tear, 1 mm in diameter, was found, and sutureless repair with a collagen hemostat (TachoComb™) was performed. However, on postoperative day 7, echocardiography revealed an echo-free space resembling a pseudoaneurysm. A second operation was performed immediately for impending re-rupture. An epicardial tear, 2×10 mm in diameter, was found at the previous bleeding point where hemostasis had been achieved with only one sheet of TachoComb™. The defect was closed with mattress sutures buttressed with Teflon? felt. We conclude that even if the risk of re-rupture is low, sutureless repair with a collagen hemostat alone should be avoided in treating blow-out LVFWR. [ABSTRACT FROM AUTHOR]

Objective: Cardiac surgery with cardiopulmonary bypass (CPB) has been considered the main causative factors of postoperative inflammatory reactions. The aim of this study was to compare surrogate markers of the proinflammatory response in patients who underwent coronary artery bypass grafting (CABG) with or without CPB. Methods and Results: Twenty patients undergoing first-time CABG were enrolled in the study, 10 with and 10 without CPB. Blood samples were drawn at the following times: at the anesthetic induction, the end of surgery, and thereafter at 12 and 24 hours postoperatively. Neutrophil elastase, interleukin (IL)-6 , and serum soluble Fas were chosen to evaluate the extent of the systemic inflammatory response. The groups were similar in terms of age, gender ratio, number of grafts per patient. There were no operative mortality or serious postoperative complications. Two of each group received blood transfusion postoperatively. Neutrophil elastase showed a significantly higher value in the on-pump group compared with the off-pump group at the end of surgery. Soluble Fas level showed a higher value at the end of surgery compared with baseline, while it had no significant changes in the off-pump patients. IL-6 levels in the on-pump group were consistently higher compared to the off-pump group but showed no statistically significant differences between the groups. Conclusion: Compared with off-pump CABG, on pump CABG induced higher serum levels of proinflammatory markers including neutrophil elastase and soluble Fas. [ABSTRACT FROM AUTHOR]

Objectives: Mitral valve surgery for the correction of mitral regurgitation (MR) in patients with ischemic heart disease has been associated with poor prognosis. The criteria for selecting an appropriate surgical procedure are not clearly defined. The objectives of this study were to clarify the criteria for mitral valve manipulation and the outcome in patients with ischemic MR. Methods: Twenty patients with ischemic MR were proposed for surgery. Ten of them (group A) had grade II MR and underwent isolated coronary artery bypass grafting (CABG). The remaining 10 patients with grade III or more MR underwent both CABG and mitral valve repair (group B). Postoperative left ventricular function and outcome were compared. Results: Preoperative left ventricular end-systolic volume index (LVESVI) in group A was significantly smaller, while preoperative ejection fraction (EF) was almost equal between the groups. EF demonstrated a significant improvement in group A postoperatively, but no changes in group B. Two of group B died following surgery. The other patients were successfully treated with surgery which diminished MR. Congestive heart failure (CHF) developed in 2 patients of group B during follow-up and in none of group A. The 5-year freedom from CHF and the 5-year survival rate in group A were significantly greater than those in group B. Conclusions: Deterioration of mitral valve function, which necessitated mitral valve repair, was more frequent in the impaired and enlarged hearts. Although mitral repair was beneficial for diminishing MR and New York Heart Association, postoperative course in patients with ischemic MR depended on the preoperative LVESVI. [ABSTRACT FROM AUTHOR]

Objective: We studied disease and surgical outcomes in an 80-plus age group to determine the feasibility of cardiac surgery at this age. Methods: Between January 1991 and August 2000, we statistically analyzed 19 variables in 62 consecutive cases of cardiac surgery in the 80-plus age group to predict in-hospital and longterm mortality. Cases were classified by disease type (ischemic heart disease (IHD), n=39; valvular heart disease (VHD) n=19; and mechanical complications associated with acute myocardial infarction, n=4; and by surgical status (emergency, n=6; urgent, n=10; and elective, n=46). We compared these with 370 patients 70 to 79 years undergoing similar procedures during the same interval. Results: No significant difference was seen between groups in total in-hospital mortality—9.7% vs. 3.8%—or in-hospital mortality for IHD—2.6% vs.4.2%—or VHD—10.5% vs.2.8%. We found cardiopulmonary bypass time>150 min. and dialysis to be independent risk factors for hospital death. Actuarial survival at 7.5 years overall was 39% in the 80-plus age group vs. 53% in the 70–79 age group for VHD and 38% in the 80-plus age group vs. 62% in the 70–79 age group. No significant difference was seen in survival between groups for IHD. Stroke proved to be an independent prognostic factor. Conclusions: Cardiac surgery is conducted feasibly in selected octogenarians, providing acceptable mortality and results similar to those achieved in those 70 to 79 years old. [ABSTRACT FROM AUTHOR]

For safer and easier management of the cardiop-ulmonary bypass (CPB) system, we have developed a new CPB operating system with which a surgeon in the operation field can also control CPB flow by manipulating venous line. With the insertion of a pressure-sensitive flow pump regulator into the conventional closed-circuit CPB system, a surgeon in the operation field can precisely control CPB flow by clamping a venous line to various degrees. In this regulator, two pressure sensors are attached both in front of and behind the flow control roller pump, which allows regulation of bypass flow in case of inadvertent total clamping of an arterial line. Additionally, by attaching a level sensed on-off switch of a volume control pump to a blood reservoir chamber, semiautomated regulation of blood reservoir volume is feasible. A clinical trial of five cases with this system revealed that our control system provided safe and effective flow control in both the initiating and the discontinuing phases of CPB with the surgeon's manipulation. Moreover, throughout CBP, the blood reservoir volume was easily controlled only by changing the position of the level sensor, which reduced the perfusionist's task of operating the volume and suction control roller pump. In conclusion, our system can provide not only a fail-safe system against abrupt kinking of the bloodstream line, but also reduction of the perfusionists' burden during CPB management. [ABSTRACT FROM AUTHOR]

The long-term outcome of sutureless intraluminal graft insertion remains unclarified. Therefore, we reviewed the late surgical outcomes of patients who underwent this procedure for acute type A dissection. Between March 1990 and May 2000, 80 patients aged from 36 to 92 years underwent isolated replacement of the ascending aorta for type A acute aortic dissection. The surgical procedures performed were replacement with an intraluminal sutureless graft in 18 patients (group 1) and suturing of the aorta with a conventional Dacron prosthesis in 62 patients (group 2). The cross-clamp, extracorporeal circulation, circulatory arrest, and operation times were significantly shorter in group 1 than in group 2, and the amount of total blood transfusion was also significantly less in group 1 than in group 2. The hospital mortality rates were 11.1% (2/18) in group 1 and 9.7% (6/62) in group 2 ( P > 0.999). The 5-year actuarial survival rates (including operative mortality) were 71% ± 11% in group 1 and 77% ± 9% in group 2 ( P = 0.268). The event-free survival rates at 5 years were 80% ± 10% in group 1, and 67% ± 13% in group 2 ( P = 0.780). Regarding graft-related complications, long-term follow-up revealed one graft-related death and one reoperation in group 1 (12.5%), and no graft-related complications in group 2 (0%) ( P = 0.047). In conclusion, intraluminal sutureless grafts required less blood transfusion, and shorter cross-clamp, extracorporeal circulation, circulatory arrest, and surgery times. However, the procedure did not improve the hospital mortality or long-term outcome. In fact, the rate of graft-related complications was significantly higher in the intraluminal sutureless group than in the sutured group. Therefore, the intraluminal graft insertion technique should be used only under exceptional circumstances. [ABSTRACT FROM AUTHOR]

A 76-year-old woman was referred to our hospital because of postinfarction ventricular septal perforation (VSP). VSP occurred twelve days after acute myocardial infarction and resulted in interventricular shunt with Qp/Qs of 4.8. Because she suffered from pulmonary edema and oligouria, she underwent emergent surgical treatment after application of the intraaortic balloon pump. The infarction involved whole of right ventricle and the inferoposterior wall of left ventricle, and the location of the perforation was infero-septum with the size of 10 × 6 mm. A bovine pericardial patch was tailored in a triangular shape of approximately 7 × 7 × 5 cm. The base of the patch was sutured to the fibrous annulus of the mitral valve and medial margin of the patch was sewn to healthy septal endocardium. And the lateral side of the patch was sutured to the posterior wall of the left ventricle. Because of difficulty in weaning of the cardiopulmonary bypass, a percutaneous cardiopulmonary support system (PCPS) was inserted via femoral artery and vein with a flow support of 2.0 L/min. After 4 days support of PCPS, improvement of right ventricular function was detected by echocardiogram and PCPS was removed. While PCPS support, low dose heparin to maintain ACT level around 150 seconds was continuously administered. Any complication including bleeding and thrombosis was not remarkable. The patient was discharged on the 53th postoperative day, and is now doing well. [ABSTRACT FROM AUTHOR]

In order to determine the incidence and risk of central nervous system damage (CNSD) which accompanies cardiovascular surgery, a retrospective analysis was carried out on 1386 patients who received surgery utilizing cardiopulmonary bypass. CNSD occurred in 32 of the 1386 patients, the total incidence being 2.3 per cent. The major risk factors which led to a high incidence of CNSD were found to be reoperation, thrombus in the left atrium (TLA) and calcification of the ascending aorta (Cal aAo). In the primary surgical series, CNSD was found in only 29 of 1350 patients (2.2 per cent), however, of a total 36 patients who underwent reoperation, 3 (8.3 per cent) patients developed CNSD (p<0.05). In a surgical series done on 562 patients with mitral valve disease, the prevalence of CNSD was much higher in patients who suffered TLA than in those who did not, being 4/85 cases (4.7 per cent) vs 11/477 cases (2.3 per cent), respectively. Moreover, a significantly higher incidence of CNSD was noted in patients with Cal aAo, occurring in 6/10 cases (60 per cent) with Cal aAo vs 4/333 cases (1.2 per cent) without Cal aAo (p<0.001). The results of this study showed that patients with CNSD, who had received coronary artery bypass surgery and aortic arch replacement tended to follow a poor clinical course, suggesting that atheromatous plaque embolization may be the leading cause of the poor prognosis following CNSD in patients having undergone cardiopulmonary bypass. [ABSTRACT FROM AUTHOR]

A previously healthy 33-year-old man presented to our hospital with fever, left hemiparalysis, motor aphasia, and clouding of consciousness. Echocardiography revealed vegetation attached to the bicuspid aortic valve as well as an aneurysm originating below the annulus. Head computed tomography showed multiple infarctions. Under the diagnosis of infective endocarditis and perivalvular aneurysm, operation was performed because of the risk of further embolization. Operative findings showed an extracardiac aneurysm of the interleaflet triangle above the aortic-mitral curtain. Because there was no sign of active inflammation, the orifice was closed with an autologous pericardial patch, and the aortic valve was replaced with a mechanical valve. We should be aware of extracardiac aneurysm of the interleaflet triangle when dealing with infective endocarditis, which should be operated as soon as it is found because of the risk for extracardiac aneurysmal rupture. [ABSTRACT FROM AUTHOR]

Takayasu's disease affects the aorta and its major branches including coronary arteries, some of which may require coronary artery bypass grafting (CABG). However, calcification of the aorta affected by Takayasu's disease often makes proximal anastomosis of a vein graft very difficult. In addition, since the major branches of the aortic arch are also frequently affected by it, the internal mammary arteries are unsuitable for use in CABG. We report a 60-year-old woman with stenosis of the left main coronary artery and heavy aortic calcification caused by Takayasu's disease whose severe angina was successfully relieved by off-pump CABG using mechanical aortic connectors for proximal vein graft anastomoses. [ABSTRACT FROM AUTHOR]

We report the elective use of a laryngeal mask airway during cardiac surgery for congenital tracheal stenosis. A 53-year-old woman with severe aortic valve stenosis was scheduled for aortic valve replacement. During anesthesia induction, the anesthesiologists attempted conventional intubation but failed. Fiberoptic tracheal examination and computed tomography showed a tracheal stenosis with 5 mm minimal diameter. A laryngeal mask airway was used at the patient's rescheduled surgery. The laryngeal mask airway use did not lead any surgical complication. We concluded that the laryngeal mask airway may be considered as an alternative to conventional intubation in patients with tracheal stenosis. [ABSTRACT FROM AUTHOR]

We report a rare case of infected left atrial myxoma associated with mitral valve endocarditis. The tumor and a small amount of vegetative growth on the anterior mitral leaflet were surgically excised. Subsequent antibiotic therapy may have prevented the infection from recurring. Histological findings showed myxoma cells embedded in mucinous stroma at the tumor base and an organized thrombus with bacterial colonization at the tumor tip. [ABSTRACT FROM AUTHOR]

This report describes the unusual case of an acute occlusion of the descending thoracic aorta in a 52-year-old woman. The patient underwent successful extraanatomical bypass with intraoperative hemodialysis. [ABSTRACT FROM AUTHOR]