Surgery for an atrioventricular septal defect (AVSD) is rare in septuagenarians. This is the case of a 75-year-old man with partial AVSD. He developed dyspnea on exertion. Detail examinations revealed partial AVSD, severe left atrioventricular valve (LAVV) regurgitation, severe right atrioventricular valve (RAVV) regurgitation, persistent atrial fibrillation, and coronary artery stenosis, which required surgical intervention. Subsequently, we performed ostium primum-type atrial septal defect closure using an autologous pericardium patch, LAVV replacement with a bioprosthetic valve, RAVV repair without annuloplasty, a modified Maze IV procedure, left atrial appendage closure, and coronary artery bypass grafting. Although LAVV repair for LAVV regurgitation was initially performed, it was converted to LAVV replacement because the repair could not control the regurgitation due to advanced degenerative changes with the thickening of the leaflets. The patient was discharged on the 15th postoperative day uneventfully. One and a half years after surgery, he had neither cardiovascular events nor arrhythmias.

A 76-year-old woman required aortic valve replacement due to severe aortic stenosis. She had a huge thyroid cancer, which invaded the innominate and left internal jugular veins. We planned a two-stage operation : the first involved aortic valve replacement ; and the second involved operation of the thyroid cancer. To avoid median sternotomy, we adopted the right parasternal approach. A 7-cm right parasternal skin incision was made. The third and fourth costal cartilages were cut and bent into the right thoracic cavity, without removal of the ribs. The postoperative course was uneventful, and second operation was performed via the median sternotomy approach on postoperative day 53. The right parasternal approach can be used as an alternative when sternotomy is unsuitable in cases of aortic valve replacement.

We report a rare case of primary cardiac lymphoma in the right atrium. An 85-year-old woman with severe heart failure was referred to our hospital. The echocardiography revealed a huge tumor occupying the right atrial cavity. We conducted an emergency operation to resect the tumor. However, as the tumor strongly adhered to the wall of the right atrium and tricuspid valve, we performed partial resection of the tumor to improve hemodynamics. The pathological examination of the tumor was consistent with malignant lymphoma of B-cell origin. Although the postoperative chemotherapy was effective to reduce a volume of the tumor, the patient died because of the adverse reaction to medication.

OBJECTIVESPrevious types of rock wool has been recently replaced with high-temperature wool (HT wool). HT wool is characterized by a chemical composition with a higher concentration of Al(2)O(3) and a lower concentration of SiO(2), lower biopersistence, and a higher melting point than previous types of rock wool. To evaluate the safety of HT wool, an asbestos substitute, we examined the biopersistence of HT wool in the lungs, based on changes in fiber count according to the length and fiber size (length and width), by performing a nose-only inhalation exposure study in rats.

METHODSMale Fischer 344 rats were exposed to fibers at the target exposure concentration of 30 mg/m(3) continuously for 3 hours daily for 5 consecutive days. Rats were sacrificed shortly after exposure, and 1, 2, and 4 weeks after exposure, and their lung tissues were incinerated at a low temperature. Then, fiber counts and sizes in the lungs were analyzed using a phase contrast microscope.

RESULTSThe fiber count in the lungs 4 weeks after exposure significantly decreased from the baseline value (shortly after exposure). The half-life of fibers calculated from the approximation curve was 34 days for all fibers and 11 days for fibers longer than 20 μm.

CONCLUSIONSBoth the length and width significantly decreased 4 weeks after exposure, probably because fibers were ingested by alveolar macrophages, discharged to outside of the body by mucociliary movement, or lysed by body fluid. In future studies, it is necessary to examine the long-term persistence of fibers in the lungs.

We report the in vitro establishment of a highly stable green fluorescent protein (GFP) -expressing transfectant of a highly-invasive human tongue squamous cell carcinoma (HTSCC) cell line, SAS-H1. The fluorescent cells permitted the visualization of tumor growth, local invasion, micrometastasis and cervical lymph node metastasis after submucosal injection into the tongues of nude mice. SAS-H1 cells were transfected with the pEGFP-N1 expression vector containing the GFP and neomycin resistance genes. Stable SAS-H1 clones expressing high levels of GFP were selected stepwise in vitro in levels of geneticin (G418) of up to 3,500 μg/ml. Subsequent early stages of local invasion and micrometastasis were visualized by GFP fluorescence in a primary tumor of the tongue. Furthermore, lymph node metastasis was confirmed for all of the orthotopic transplants in mice. However, no distant metastases, including those of lung and liver, were observed. Thus, this model should be useful for studying the metastatic process and for evaluating anti-metastasis agents in pre-clinical trials.

We studied 73 patients, 70 years of age or older, who underwent aortic valve replacement for aortic stenosis between October, 1990 and October, 2004. There were 31 men and 42 women with a mean age of 75.7±3.6 years. Mechanical valves were implanted in 37 patients, and bioprostheses in 36 patients. Operative mortality was 1 of 73 (1.4%) and the New York Heart Association functional class improved to class I or class II in all of the hospital survivors. Follow-up (100%) extended from 0.3 to 11.6 years (mean 3.7 years). There were 16 late deaths (5.9% per patient-year), including valve-related deaths in 6 patients. The overall survival rates at 5 and 10 years was 74.2% and 44.3%, respectively. The freedom from valve-related events at 5 and 10 years was 78.8% and 78.8%, respectively. The 10-year survival rates and freedom from valve-related events were not different between the patients with mechanical valves and those with bioprostheses. The size of the implanted valve did not influence the late survival or freedom from valve-related events. The outcome after aortic valve replacement in the elderly (70 years and older) was excellent with low operative mortality, and acceptable late mortality and morbidity. Thus, aortic valve replacement for elderly patients should have the same indications as for younger patients. Bioprostheses showed good long-term results with no structural valve deterioration, thromboembolism, or bleeding events. Mechanical valves, which required the maintenance of an anticoagulant therapy, were also useful with acceptable late morbidity. The long-term results with small valves (≤19mm) were comparable to the results with large valves (>19mm) in the elderly. Thus, the use of these small valves in this particular age group seems to be acceptable.

A 64-year-old man was transferred to our hospital because of acute heart failure associated with myocardial infarction. Echocardiography revealed severe mitral regurgitation due to total rupture of the posterior papillary muscle. Following the diagnosis of papillary muscle rupture, intraaortic balloon pumping support was started, and surgery was performed without coronary angiography because of cardiogenic shock and renal dysfunction. The posterior papillary muscle was completely ruptured, and the anterior leaflet of the mitral valve was severely prolapsed. Without resecting the posterior leaflet, mitral valve replacement was successfully performed using a St. Jude Medical^® prosthetic valve. The postoperative course was uneventful except for ventricular tachyarrhythmia which occurred during the acute phase postoperatively. Postoperative coronary angiography demonstrated no significant coronary arterial stenosis. In a patient with cardiogenic shock due to papillary muscle rupture, immediate surgical intervention is recommended as soon as the diagnosis has been established by echocardiography.

We report a 25-year-old man with ventricular septal perforation due to blunt chest trauma. He was transferred by ambulance to our hospital following a traffic accident. On admission, he had no cardiac murmur. Two days later, a pansystolic murmur appeared over the left lower sternal border. Doppler echocardiogram revealed a large left-to-right shunt through a ventricular septal perforation. We postponed surgical treatment as long as possible because he also exhibited bronchial bleeding due to a lung contusion. Surgical repair of the ruptured ventricular septum was performed 8 days after the chest trauma, because the pulmonary to systemic flow ratio was elevated to 4.6 and cardiac function had deteriorated. During the operation, the site of the septal perforation was easily detected by epicardial echocardiography. A 4-cm tear in the muscular septum was closed through a right ventriculotomy using a pericardial patch reinforced with a Dacron patch. Postoperative recovery was uneventful with the exception of transient right ventricular failure. There was no residual shunt.

A 61-year-old man, who had previously undergone quadruple coronary artery bypass graft surgery, was successfully treated for proximal descending aortic aneurysm using hypothermic circulatory arrest via a left thoracotomy. Preoperative angiograms revealed that the left internal thoracic artery bypass graft to the LAD was patent, and that the aneurysm was located at the descending aorta just distal to the left subclavian artery. Operative procedures were as follows. A left thoracotomy incision was made through the 4th intercostal space. The common femoral artery and vein were cannulated, and the venous cannula was positioned in the right atrium. The patient was cooled by partial cardiopulmonary bypass until the EEG was isoelectric (24°C rectal temperature), and then circulation was arrested. Left ventricular decompression was not performed. After opening of the aneurysm, proximal anastomosis was performed first at the aorta just distal to the left subclavian artery. Another arterial cannula, connected to the Y-shaped arterial line, was inserted into the graft, and perfusion to the brain was restored through this cannula. Distal anastomosis was then completed, and routine cardiopulmonary bypass was reestablished. After the heart was defibrillated, the patient was rewarmed to 34°C before discontinuing the bypass. Circulatory arrest time and total cardiopulmonary bypass time were 17 minutes and 139 minutes, respectively. Postoperative recovery was uneventful.