Masanori Hirota

Showa University, Shinagawa, Tōkyō, Japan

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Publications (15)35.55 Total impact

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    ABSTRACT: Surgical treatment is effective to exclude all infected tissue in patients with infective endocarditis. Although various techniques have been reported, it has remained a great challenge for patients with extensive infected regions. A patient with extensive bivalvular endocarditis including the aortic and mitral valve and aorto-mitral continuity is described. A handmade aorto-mitral bioprosthetic valve was created to reconstruct the defect after extensive debridement. The patient was discharged on the 30th postoperative day without inflammatory signs.
    Interactive Cardiovascular and Thoracic Surgery 11/2012; · 1.11 Impact Factor
  • The Journal of cardiovascular surgery 04/2012; 53(2):272-4. · 1.51 Impact Factor
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    ABSTRACT: Open heart operations for patients with myelodysplastic syndrome (MDS) are associated with infective and bleeding complications. We report a 67-year-old woman with rheumatic, severe mitral regurgitation and mitral stenosis associated with MDS who underwent a mitral valve (MV) repair. Commissurotomy was performed in the anterior commissure. Autologous pericardial patch treated with glutaraldehyde solution was prepared. The anterior leaflet was completely detached from the posterior to the anterior commissure. The anterior leaflet was augmented by autologous pericardial patch treated with glutaraldehyde solution and three pairs of artificial chordae were implanted. Postoperative transesophageal echocardiography showed an increase in the MV orifice and less than trivial mitral regurgitation. Two years after the operation, the patient has normal sinus rhythm with no deterioration of the MV lesion by transthoracic echocardiography. Although the feasibility of MV repair is low in patients with restrictive pathology due to rheumatic disease, MV repair may be preferred in patients with MDS.
    Annals of thoracic and cardiovascular surgery : official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia. 07/2011; 17(6):614-7.
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    ABSTRACT: A case of a large primary cardiac sarcoma on the left ventricular free wall is reported. Although the definitive diagnosis of this tumor was not made preoperatively, total excision was planned for rapid diagnosis and optimal procedure. However, the operation was discontinued due to intraoperative diagnosis of malignancy. As a result, the patient suffered from the symptoms of cardiac tamponade caused by the large tumor. We discuss the surgical strategy to provide therapeutic benefit for possible patients in the future. In conclusion, an aggressive attempt at volume reduction such as cardiac autotransplantation may relieve the symptoms, even though such surgery would only be palliative.
    Interactive Cardiovascular and Thoracic Surgery 11/2010; 11(5):670-2. · 1.11 Impact Factor
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    ABSTRACT: Subepicardial aneurysm is a rare complication of acute myocardial infarction (AMI) and is associated with the risk of spontaneous rupture. We present two patients with subepicardial aneurysms detected after 1 day and 6 weeks after AMI. Both lesions were successfully treated by patch repair.
    Annals of thoracic and cardiovascular surgery : official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia. 08/2010; 16(4):291-3.
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    ABSTRACT: Intracoronary microthrombi may cause primary graft failure of hearts harvested from non-pre-treated non-heart-beating donors (NHBDs). We examined the extent of functional recovery to compare the protective effects of post-mortem tissue-type plasminogen activator (t-PA) and heparin pre-treatment. Heparin pre-treatment was systemically administered before hypoxic cardiac arrest in 6 mongrel dogs (Group A). No pre-treatments, including heparin, were administered in 8 dogs (Group B). After 60 minutes of ischemia, intracoronary microthrombi were flushed by retrograde blood cardioplegia with t-PA. After 120 minutes of controlled reperfusion, pre-load was increased for ejection against an after-load of 80 mm Hg. Pressure-volume loops were recorded to obtain the end-systolic pressure-volume relationship (ESPVR) and end-diastolic pressure-volume relationship (EDPVR). Stroke volume at a given pre-load was calculated from averaged ESPVR, EDPVR, and after-load identical to the averaged baseline value. The Frank-Starling relationship was obtained, and cardiac status was classified using the Forrester hemodynamic sub-set. There were no significant differences between Group A and Group B in post-resuscitated end-systolic elastance (3.1 +/- 0.7 vs 3.0 +/- 0.8 mm Hg/ml), time constant of isovolumic relaxation (40 +/- 7 vs 40 +/- 6 msec), LV max +dP/dt (1133 +/- 131 vs 1090 +/- 105 mm Hg/s), and LV max -dP/dt (732 +/- 131 vs 752 +/- 122 mm Hg/s). The post-resuscitated cardiac index was decreased to about 50%, and cardiac status was classified as Forrester III or IV sub-set. Post-mortem t-PA preserves graft function of hearts harvested from non-pre-treated NHBDs. This pharmaceutical intervention may be an alternative to heparin pre-treatment, which could increase the number of cardiac allografts harvested from potential non-pre-treated NHBDs.
    The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 08/2010; 29(8):888-93. · 3.54 Impact Factor
  • M. Hirota, I. Kozo, T. Tedoriya, S. Sano
    Journal of Heart and Lung Transplantation - J HEART LUNG TRANSPLANT. 01/2010; 29(2).
  • European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 08/2009; · 2.40 Impact Factor
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    ABSTRACT: A successful apico-aortic bypass for a patient with a porcelain aorta suffering from aortic stenosis is reported. A sewing cuff with an outflow graft to the apex and a hand-made composite graft were used instead of a rigid apical connector.
    Interactive Cardiovascular and Thoracic Surgery 08/2009; 9(4):703-5. · 1.11 Impact Factor
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    ABSTRACT: We report an adult case of right aortic arch coarctation with a left descending aorta. Associated anomalies included dextrocardia, situs inversus, polysplenia, bilateral superior vena cava, and absent inferior vena cava with azygos connection. Extensive mobilization of the azygos vein was needed to obtain a good surgical field, including the left descending aorta via a right thoracotomy, and the lesion was anatomically repaired by resection and end-to-end anastomosis.
    Asian cardiovascular & thoracic annals 02/2009; 17(1):76-8.
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    ABSTRACT: We report a rare case of unguarded tricuspid orifice with pulmonary atresia, which is devoid of any guarding valvular tissue at tricuspid annulus. A left Blalock-Taussig shunt was constructed on the 17th day of life. At 4 years of age, a bidirectional Glenn's operation was performed for the further growth of the pulmonary bed and the volume reduction of the left ventricle. Finally, an extracardiac cavo-pulmonary connection was created using a ringed Gore-Tex graft at 6 years of age. Staged Fontan's strategy may contribute to a good surgical outcome for this highly lethal anomaly.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 09/2008; 34(5):1111-2. · 2.40 Impact Factor
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    ABSTRACT: A case of anomalous left coronary artery originating from the non-facing pulmonary sinus, located at the most distal position from the aorta, is described. An intrapulmonary tunnel was created without causing undue stenosis or kinking. The Takeuchi procedure is considered to be a useful surgical technique when the origin of the anomalous left coronary artery is far from the aorta.
    Asian cardiovascular & thoracic annals 09/2008; 16(4):324-6.
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    ABSTRACT: Pulmonary hypertension (PH) causes right ventricular (RV) hypertrophy and, according to the extent of pressure overload, eventual heart failure. We tested the hypothesis that the mechanical stress in PH-RV impairs the vasoreactivity of the RV coronary microvessels of different sizes with increased superoxide levels. Five-week-old male Sprague-Dawley rats were injected with monocrotaline (n=126) to induce PH or with saline as controls (n=114). After 3 wk, coronary arterioles (diameter = 30-100 microm) and small arteries (diameter = 100-200 microm) in the RV were visualized using intravital videomicroscopy. We evaluated ACh-induced vasodilation alone, in the presence of N(omega)-nitro-L-arginine methyl ester (L-NAME), in the presence of tetraethylammonium (TEA) or catalase with or without L-NAME, and in the presence of SOD. The degree of suppression in vasodilation by L-NAME and TEA was used as indexes of the contributions of endothelial nitric oxide (NO) and endothelium-derived hyperpolarizing factor (EDHF), respectively. In PH rats, ACh-induced vasodilation was significantly attenuated in both arterioles and small arteries, especially in arterioles. This decreased vasodilation was largely attributable to reduced NO-mediated vasoreactivity, whereas the EDHF-mediated vasodilation was relatively robust. The suppressive effect on arteriolar vasodilation by catalase was similar to TEA in both groups. Superoxide, as measured by lucigenin chemiluminescence, was significantly elevated in the RV tissues in PH. SOD significantly ameliorated the impairment of ACh-induced vasodilation in PH. Robust EDHF function will play a protective role in preserving coronary microvascular homeostasis in the event of NO dysfunction with increased superoxide levels.
    AJP Heart and Circulatory Physiology 07/2007; 292(6):H2737-44. · 3.63 Impact Factor
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    ABSTRACT: Cardiac function of non-heart-beating donors (NHBDs) is uncertain due to severe myocardial damage. We developed an isolated myocardial perfusion system to resuscitate NHBD hearts and attempted to predict functional recovery of 60-minute warm ischemic hearts by analyzing systolic and diastolic functions. Hypoxic cardiac arrest was induced in 8 mongrel dogs without any pre-treatments. After 60-minute ischemia, intracoronary microthrombi were flushed out by retrograde blood cardiopledia with tissue-type plasminogen activator. Coronary arteries were initially perfused from the aortic root with tepid hyperkalemic blood (20 mmol/liter) at low pressure (20 mm Hg) for the first 60 minutes and then with normothermic blood for the next 60 minutes. After 120 minutes of reperfusion, pre-load was increased for ejection against an after-load of 80 mm Hg. Pressure-volume loops were recorded to obtain the end-systolic pressure-volume relationship (ESPVR) and end-diastolic pressure-volume relationship (EDPVR). Stroke volume at a given pre-load was calculated from averaged ESPVR, EDPVR and after-load identical to an averaged baseline value. The Frank-Starling relationship was obtained and cardiac status was classified according to Forrester's hemodynamic sub-set. End-systolic elastance decreased significantly to about 60% of baseline and the time constant of isovolumic relaxation was prolonged significantly by about 20%. Cardiac index was decreased to about 50% and cardiac status was classified in the Forrester III or IV sub-set. The extent of functional recovery of NHBD hearts is predictable by cardiac output. Although 120 minutes of recovery time may be short for 60-minute ischemic damage, this system may be feasible to predict post-transplant cardiac function before transplantation.
    The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 04/2006; 25(3):339-44. · 3.54 Impact Factor
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    ABSTRACT: We developed a total right ventricular (RV) exclusion procedure for the treatment of isolated congestive RV failure. The objective of the present study was to elucidate the effects of a complete removal of RV volume overload (RVVO) on the surgically created single left ventricle (LV). Three adults (2 arrhythmogenic RV dysplasia, 1 Ebstein) and 5 children (all Ebstein) in NYHA class IV underwent the procedure. The RV free wall was resected from the heart, and the tricuspid orifice was closed. Pulmonary blood supply was obtained by a cavopulmonary connection in 6 patients and a systemic-pulmonary shunt in 2. The LV function was evaluated by 2-dimensional echocardiography 1 month after the surgery. All patients are alive. The paradoxical movement of the interventricular septum and geometry of the LV expressed by its eccentricity (2.1 to 1.2, P<0.01) were normalized after the operation in all 8 patients. LV end-diastolic volumes (59% to 109% of normal value, P<0.01), indexed maximal left atrial area (6.5 to 10.5 cm2/m2, P<0.01), LV ejection fraction (27% to 62%, P<0.01), and cardiac index (2.1 to 3.3 L/min/m2, P<0.05) all significantly increased. Removal of the RVVO by means of the total RV exclusion procedure provides effective volume loading, restores a cylindrical shape, and improves contractile function of the LV, thus leading to increased systemic output.
    Circulation 09/2003; 108 Suppl 1:II226-9. · 15.20 Impact Factor