K Akiyama

Iwaki Kyoritsu General Hospital, Ивакуни, Yamaguchi, Japan

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Publications (44)35.13 Total impact

  • K Akiyama · J Hirota · Y Tsuda · H Ebishima · C Li ·

    The Journal of cardiovascular surgery 03/2006; 47(1):81-2. · 1.46 Impact Factor
  • Kazuya Akiyama · Jun Hirota · Yasutoshi Tsuda · Hironori Ebishima · Chun Li ·
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    ABSTRACT: Grafts with four presewn side branches have proven very useful for total aortic arch replacement worldwide. However, the four side branches often obscure the surgeon's view of the distal anastomotic site. Thus, we designed a holder for this graft, which sheaths and hides the graft body and branches, allowing the surgeon a better view of the distal anastomosis. By using this device, distal anastomosis can be achieved early and quickly without obstruction of the surgeon's view, resulting in reduced cardiac ischemic time in aortic arch surgery.
    Surgery Today 02/2005; 35(9):800-2. DOI:10.1007/s00595-004-2986-z · 1.53 Impact Factor
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    ABSTRACT: A 64-year-old female, admitted because of severe dyspnea on exertion and facial edema, showed echocardiographic findings of a large tumor in the right ventricle (RV). Echocardiography revealed a cardiac mass extending from the RV across the tricuspid valve into the right atrium, synchronized with the cardiac cycle, and severe tricuspid regurgitation was apparent. The mass was removed under cardiopulmonary bypass. It measured 7 x 5 x 5 cm with diffuse superficial calcification and arose from the posterior wall of the RV, just under the tricuspid valve ring, with a short pedicle. During the same procedure, after the successful excision of the tumor, small atrial and ventricular septal defects were found that had been caused by the tumor and these were closed directly. The tricuspid valve was repaired with valvuloplasty, chordoplasty and annuloplasty. The microscopic findings were of typical myxoma; however, a right ventricular myxoma protruding into the right atrium is exceedingly rare.
    Circulation Journal 09/2004; 68(8):799-801. DOI:10.1253/circj.68.799 · 3.94 Impact Factor
  • Y Kobayashi · K Akiyama · J Hirota · N Taniyasu · M Yui · M Nakayama ·
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    ABSTRACT: A 17-year-old woman with scimitar syndrome without an atrial septal defect was operated by intra-cardiac conduit repair. Computed tomography (CT) and magnetic resonance imaging (MRI) showed resolution images of anatomical findings of scimitar vein. Surgical procedures for the scimitar syndrome have varied according to the anatomic features presented in each case. The detection of precise anatomy of scimitar syndrome is important for determining the appropriate surgical procedure. Images of 3-dimensional (3-D) CT and MRI of scimitar syndrome were demonstrated.
    Kyobu geka. The Japanese journal of thoracic surgery 07/2004; 57(6):493-6.
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    ABSTRACT: Aortic valvular regurgitation has several mechanisms and the present study investigated its clinicopathological correlations with aortic valve fenestration. Six male patients with massive regurgitation and enlarged fenestrations or ruptured fenestrated fibrous cords underwent aortic valve replacement. The clinicopathological features showed many similarities. Four cases had family histories of aortic regurgitation. All six patients showed moderate to severe myxomatous degeneration of the aortic valve and enlargement of aortic annulus. Four patients had 1-2 ruptured fibrous cords, located at the right coronary cusp. Echocardiographic examinations showed an abnormal fibrous cord attached to the prolapsing cusp in 3 cases with ruptured fenestrated valve and detailed examination by transesophageal echocardiography showed an intact fenestrated fibrous cord at the commissure in 1 case. Extensively fenestrated cusps with an enlarged aortic annulus because of myxomatous degeneration can cause chronic regurgitation or sudden deterioration after rupture of the fibrous cord. There is an increasing incidence of fenestration-related aortic regurgitation in the Japanese population. An important pathogenetic factor in male patients is myxomatous degeneration of the aortic cusp and annulus.
    Circulation Journal 06/2004; 68(5):439-43. DOI:10.1253/circj.68.439 · 3.94 Impact Factor
  • N Taniyasu · K Akiyama · J Hirota · Y Iba ·
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    ABSTRACT: Percutaneous transluminal coronary stenting is a proven nonoperative method of direct myocardial revascularization. We encountered a case of iatrogenic significant subacute left main coronary artery stenosis in a patient who had undergone prior percutaneous transluminal coronary artery stenting of the left anterior descending (LAD) artery. Coronary artery bypass grafting was performed. To our knowledge, this is the first report of a surgical case of left main coronary artery stenosis worsened by changes secondary to earlier coronary stenting in the mid portion of left descending coronary artery in Japan.
    The Journal of cardiovascular surgery 03/2002; 43(1):55-8. · 1.46 Impact Factor
  • J Hirota · K Akiyama · N Taniyasu · Y Iba ·
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    ABSTRACT: A 66-year-old woman who received maintenance hemodialysis for the last 14 years was referred to our hospital due to the sudden onset of ischemic stroke and systemic emboli. Transthoracic echocardiography before surgery showed large protruding masses measuring 2 cm which projected into the lumen of the aortic root. The plaque originated on a wide base of the posterior aspect of the ascending aorta at its junction with the sinus of Valsalva. The mobile plaque was surgically removed by endarterectomy from the posterior wall of sino-tubular junction under cardiopulmonary bypass. Pathologic examination of the masses removed at the time of surgery showed that they were atherosclerotic plaque with superimposed thrombi. During operation, transesophageal echocardiography appears to be useful for the rapid detection of a protruding aortic atheroma especially in the initial period of cardiopulmonary bypass until aortic cross clamp.
    Kyobu geka. The Japanese journal of thoracic surgery 12/2001; 54(12):1059-61.
  • K Akiyama · N Taniyasu · J Hirota · Y Iba · K Maisawa ·
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    ABSTRACT: Gemella morbillorum (G. morbillorum) is part of the commensal flora of the oropharynx and intestinal tract, and on rare occasions causes infective endocarditis. A 55-year-old man with massive aortic regurgitation caused by recurrent infective endocarditis with G. morbillorum had a history of prior endocarditis caused by alpha-hemolytic streptococcus and multiple antibiotic allergies 5 years prior, and was successfully treated by aortic valve replacement. Almost all the reported cases of endocarditis caused by G. morbillorum have been bacteriologically cured with antibiotics and this is the first reported case of recurrent endocarditis caused by G. morbillorum in which the initial infection was bacteriologically cured by antibiotics and the secondary infection treated with valve replacement. This organism can be one of the causes of infective endocarditis and prompt surgical repair is mandatory if the infection is refractory or there is progression of congestive heart failure under antibiotic cover.
    Japanese Circulation Journal 12/2001; 65(11):997-1000.
  • N Taniyasu · K Akiyama · Y Iba · J Hirota ·
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    ABSTRACT: Graft replacement for arch aneurysms and concomitant coronary artery bypass grafting (CABG) were performed in four consecutive patients over a three-year period between March 1995 and October 1998. The etiology of the aneurysms was atherosclerosis in all the patients. One early death as a result of a cerebellar infarction occurred on the 74th postoperative day. In all cases, respiratory failure frequently occurred after surgery. In a recent case, the internal mammary artery was used as a graft conduit to the left anterior descending artery (LAD). Both artery and vein grafts were anastomosed to coronary arteries during the initial core cooling. Selective cerebral perfusion was carried out during the reconstruction of the transverse aortic arch and its branches. The left subclavian artery was anastomosed first to secure perfusion to the LAD. To achieve sufficient myocardial protection and obtain good postoperative hemodynamics, CABG was simultaneously performed at the time of aortic aneurysm repair in cases complicated with coronary artery disease.
    Kyobu geka. The Japanese journal of thoracic surgery 06/2001; 54(5):408-10.
  • K Akiyama · T Maeda · N Taniyasu · J Hirota ·

    The Journal of cardiovascular surgery 05/2001; 42(2):281-4. · 1.46 Impact Factor
  • N Taniyasu · K Akiyama · A Takazawa · J Hirota ·
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    ABSTRACT: Medical therapy for chronic pulmonary thromboembolism is limited, and surgical treatment has become more frequent recently. We have performed pulmonary thromboendarterectomy on a patient with chronic pulmonary thromboembolism accompanied by protein C deficiency. The patient was a woman aged 68 years who had protein C deficiency. The preoperative condition was New York Heart Association functional class IV. Hypoxemia, marked pulmonary hypertension, and low cardiac output were observed. After a median sternotomy, moderate hypothermia was induced using a cardiopulmonary bypass, and thromboendarterectomy in the pulmonary artery was performed. The arterial blood oxygen concentration improved, and the mean pulmonary pressure decreased. The cardiac output also increased, and New York Heart Association functional class improved to I. Pulmonary thromboendarterectomy under cardiopulmonary bypass was effective for chronic pulmonary thromboembolism accompanied by protein C deficiency.
    Kyobu geka. The Japanese journal of thoracic surgery 04/2001; 54(3):237-40.
  • Kazuya Akiyama · Naohito Taniyasu · Jun Hirota · Yutaka Iba · Kazuma Maisawa ·

    Japanese Circulation Journal 01/2001; 65(11):997-1000. DOI:10.1253/jcj.65.997
  • Naohito Taniyasu · Kazuya Akiyama · Yutaka Iba · Jun Hirota ·
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    ABSTRACT: A patient with a thrombosed mechanical valve underwent valve re-replacement during which a tumor of the left ventricular outflow tract with the typical macroscopic and microscopic characteristics of a papillary fibroelastoma was successfully removed surgically. The 60-year-old woman had undergone isolated mitral valve replacement with a St Jude Medical 29-mm valve for mitral regurgitation 15 years ago. The present admission was for investigation of dyspnea on exertion. Two-dimensional transthoracic echocardiography demonstrated a posteroseptal, pedunculated mass, measuring 1.3x1.0 cm, in the outflow tract of the left ventricle, mild mitral regurgitation and slight aortic stenosis.
    Japanese Circulation Journal 11/2000; 64(10):797-9. DOI:10.1253/jcj.64.797
  • Kazuya Akiyama · Naohito Taniyasu · Yutaka Iba · Jun Hirota · Shigeyuki Asano ·
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    ABSTRACT: A 57-year-old man was admitted to hospital for acute myocardial infarction associated with mild aortic regurgitation, which was successfully treated by intracoronary thrombolysis. Twenty-four days later, he suffered from another chest pain attack without any electrocardiographic ST-T changes. The coronary angiogram did not show any significant lesions, but the aortic root angiogram showed massive aortic regurgitation. Surgery revealed a bicuspid aortic valve with a conjoined cusp that had a fenestrated raphe torn away from the aortic wall and prolapsing into the left ventricle. The aortic valve was successfully replaced with a St Jude Medical mechanical valve prosthesis. The pathological significance of the intact raphal cord and the rupture remains an unsolved problem. This is the first reported case in which an increase of aortic regurgitation due to a ruptured raphal cord supporting the conjoined cusp was confirmed by a serial root angiogram.
    Japanese Circulation Journal 07/2000; 64(6):477-80. DOI:10.1253/jcj.64.477
  • K Akiyama · A Takazawa · N Taniyasu · H Sato ·
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    ABSTRACT: A patient with Werner's syndrome suffering from a chronic ulcer on the right ankle joint underwent femoropopliteal bypass and patch angioplasty combined with endarterectomy of the distal popliteal artery. Postoperative angiography showed satisfactory graft patency and distal run-off, and the ulcer improved. Femoropopliteal occlusive disease in Werner's syndrome tends to have poor run-off and the internal diameter of the popliteal artery with diffuse arteriosclerotic lesion is often too small to facilitate distal anastomosis. Therefore, a conventional bypass procedure is not always effective and an aggressive attitude is essential to obtain sufficient ankle blood pressure and improve the leg ulcer in Werner' syndrome.
    The Journal of cardiovascular surgery 05/2000; 41(2):303-6. · 1.46 Impact Factor
  • K. Akiyama · A. Takazawa · N. Taniyasu · H. Sato ·

    Asian cardiovascular & thoracic annals 12/1999; 7(4):331-332. DOI:10.1177/021849239900700421
  • N Taniyasu · K Akiyama · A Takazawa · J Hirata ·
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    ABSTRACT: We report the presence of a post aortic left innominate vein (PALIV) in a patient with a surgically corrected double outlet right ventricle. A 30-year-old male was admitted to our hospital with exertional dyspnea. The patient had undergone right ventricular outflow tract reconstruction and closure of ventricular septal defect at the age of 14. Echocardiography and cardiac catheterization showed severe pulmonary regurgitation and a residual ventricular septal shunt. After resternotomy, right ventricular outflow tract reconstruction and residual shunt closure were performed. During the operation, the left innominate vein was not found in front of the aorta. Postoperative cardiac catheterization and computed tomography showed that the left innominate vein was positioned behind the ascending aorta draining to the superior caval vein.
    Kyobu geka. The Japanese journal of thoracic surgery 12/1999; 52(12):1033-5.
  • Kazuya Akiyama · Jun Hirota · Naohito Taniyasu · Shigeyuki Asano ·
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    ABSTRACT: An unusual case of an inflammatory abdominal aortic aneurysm (IAAA) associated with coronary aneurysms and pathological fracture of the adjacent lumbar vertebrae. The associated coronary lesions in cases of IAAA are usually occlusions. In the present case, it was concluded that a possible cause of the coronary aneurysm was coronary arteritis and the etiology of the pathological fracture of the lumbar vertebrae was occlusion of the lumbar penetrating arteries due to vasculitis resulting in aseptic necrosis. Inflammatory AAA can be associated with aneurysms in addition to occlusive disease in systemic arteries. The preoperative evaluation of systemic arterial lesions and the function of systemic organs is essential.
    Japanese Circulation Journal 12/1999; 63(11):914-6. DOI:10.1253/jcj.63.914
  • N Taniyasu · K Akiyama · A Takazawa · H Satoh ·
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    ABSTRACT: We present two cases of thoracic aortic aneurysms with anomalous origin of the aortic arch branches. One was a 72-year-old female with a ruptured descending thoracic aneurysm and aberrant origin of the right subclavian artery. The other was a 64-year-old male with a saccular distal arch aneurysm and aberrant origin of the left vertebral artery. Preoperative examinations included angiography, computed tomography (CT), three dimensional enhanced CT (3DCT), digital subtraction angiography (DSA), and magnetic resonance imaging (MRI). Understanding the structure of neck vessels is important in deciding where to clamp or to reconstruct in surgical repair of the aortic arch. 3DCT was the most useful examination for this understanding.
    Kyobu geka. The Japanese journal of thoracic surgery 07/1999; 52(6):445-50.
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    ABSTRACT: The dual-stage venous cannula is widely used but can obstruct the surgeon's view and interfere with operative procedures in the aortic root. We designed a new stainless steel sheath for a dual-stage venous cannula that enables the cannula to bend and maintain the appropriate angle for the surgical procedures. We suggest that operative procedures in the aortic root can be performed faster during safety cardiopulmonary bypass by use of a dual-stage venous cannula bent by application of this new sheath.
    The Annals of Thoracic Surgery 04/1999; 67(3):862-3. DOI:10.1016/S0003-4975(99)00007-7 · 3.85 Impact Factor