Akihiko Kawai

Tokyo Women's Medical University, Edo, Tōkyō, Japan

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Publications (71)161.48 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study was to examine the clinical results of current circulatory support with step-by evaluation of biventricular and pulmonary function. Six patients who had undergone cardiac surgery and two non-cardiotomy patients underwent current circulatory support with the step-by functional evaluation. Of six postcardiotomy patients, four patients with severe ischemic heart disease underwent coronary artery bypass giafting (CABG), and the remaining two patients with advanced aortic stenosis underwent aortic valve replacement (AVR). All six patients received intra-aortic balloon pump (IABP) support before or during operation. Two non-cardiotomy patients suffered from dilated cardiomyopathy, and both showed acute deterioration with cardiogenic shock or low cardiac output syndrome. Three of six postcardiotomy patients with circulatory support were weaned and discharged from the hospital. Two noncardiotomy patients in critical condition were successfully supported for more than 6 months by the Novacor left ventricular assist system (LVAS). We conclude that the ongoing current strategy of circulatory support with step-by functional evaluation might be applied for various types of severe heart failure with or without associated cardiac operations.
    Journal of Artificial Organs 04/2012; 3(2):158-161. · 1.39 Impact Factor
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    ABSTRACT: There has been a changing preference for bioprosthetic valves over mechanical valves in dialysis patients, but there is still much controversy. We reviewed our 17-year experience and assessed the influence of prosthesis choice. From 1990 to 2007, a total of 63 consecutive dialysis patients who underwent valvular surgery (64 operations including one reoperation) at our hospital were retrospectively reviewed. The mean age of the patients was 58.3 +/- 9.0 years. The reasons for dialysis were glomerulonephritis (n = 32) and diabetes (n = 10). The major preoperative diagnosis was aortic stenosis (n = 44). The surgical procedures included aortic valve replacement (n = 44), mitral valve replacement (n = 7), double valvular replacement (n = 7), and mitral valve repair (n = 5). Prostheses for valve replacement were mechanical valves (n = 37) or bioprosthetic valves (n = 22). Follow-up was accomplished in 95.2%, and the mean follow-up period was 49 months. Actuarial survivals at 1, 5, and 10 years were 85%, 64%, and 45% respectively. Freedom from cardiovascular events at 1 and 5 years was 61% and 41%, respectively. Mechanical valve patients had significantly higher early mortality than bioprosthetic valve patients (P = 0.03). However, both mechanical and bioprosthetic valve patients had similar survival and event-free rates (P = 0.87 and P = 0.27, respectively) in the midterm results. The mechanical group had a higher rate of bleeding events. There was no structural valve deterioration up to the 5-year follow-up. The choice of prosthesis did not influence the surgical outcome except for early mortality. Careful consideration of preventive measures against bleeding is important, and prosthesis selection should be based on the patient's profile as well as the criteria for nondialysis patients.
    General Thoracic and Cardiovascular Surgery 05/2009; 57(4):197-202.
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    ABSTRACT: A 33-year-old-man had severe secondary pulmonary hypertension due to perivalvular leakage at the aortic and mitral positions after aortic and mitral valve replacement. Preoperative cardiac catheterization revealed pulmonary artery pressure of 105/45 mmHg and pulmonary vascular resistance of 929 dynes.s.cm(-5) To save the patient, we performed aortic and mitral valve re-replacement, and tricuspid annuloplasty. After surgery, selective pulmonary vasodilators, beraprost sodium, inhaled nitric oxide, and intravenous prostaglandin (PG) I(2) were administered because of persistent severe pulmonary hypertension. Cardiac catheterization on postoperative day 58 showed that the pulmonary artery pressure and pulmonary vascular resistance had decreased to 40/20 mmHg and 87.7 dynes x s x cm(-5), respectively The simultaneous use of inhaled nitric oxide, intravenous PGI(2), and oral beraprost sodium might be useful for treating postoperative persistent pulmonary hypertension.
    General Thoracic and Cardiovascular Surgery 11/2008; 56(10):521-5.
  • Hideki Sasaki, Akihiko Kawai, Hiromi Kurosawa
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    ABSTRACT: Acute fulminant myocarditis can cause left ventricular dysfunction that predisposes the patients to critical condition. Left ventricular assist device (LVAD) is a useful option for the patient whose condition is resistant to medical therapy. However, when right ventricular dysfunction with hypoxia is complicated with left ventricular dysfunction, it can be difficult to make a prompt decision in order to achieve better outcome. We present our case in which the support on LVAD and extracorporeal membrane oxygenation (ECMO) was effective to treat critically ill patients.
    Journal of Cardiac Surgery 06/2008; 23(5):526-7. · 1.35 Impact Factor
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    ABSTRACT: We report a case of a 13-year-old boy with congenitally corrected transposition of the great arteries after conventional repair who underwent an implantation of ventricular assist device (VAD) due to right (systemic) ventricular failure after tricuspid valve replacement. The anatomical right ventricle (systemic ventricle) was completely unloaded and the function improved over time under LVAD. He had an explantation of the VAD due to bacteremia 43 days after implantation, and his clinical condition improved significantly.
    Interactive Cardiovascular and Thoracic Surgery 01/2007; 5(6):792-3. · 1.11 Impact Factor
  • Journal of Cardiac Failure 10/2006; 12(8). · 3.07 Impact Factor
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    ABSTRACT: A 17-year-old male with tachycardia-induced cardiomyopathy presented with persistent, drug-resistant atrial tachycardia (AT). An electrophysiological study suggested focal abnormal automaticity, and localized the AT origin to the left atrial appendage. Radiofrequency catheter ablation at the site of the earliest endocardial activation during AT failed. A minimally invasive, video-assisted thoracoscopic (VAT) atrial appendectomy terminated the AT and restored left ventricular contractility. The patient remained free of AT and normal left ventricular function was maintained over a 24-month follow-up period. To our knowledge, we are the first to use VAT atrial appendectomy to treat focal AT.
    Journal of Cardiovascular Electrophysiology 09/2006; 17(8):895-8. · 2.88 Impact Factor
  • Circulation 04/2005; 111(8):e107. · 14.95 Impact Factor
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    ABSTRACT: Treatment for hypertrophic obstructive cardiomyopathy (HOCM) has been reported; however, there has been no report on the characteristics of medication-responsive and -refractory hypertrophic obstructive cardiomyopathy (HOCM). Using the classification of systolic anterior movement (SAM) which has been previously reported, we tried to identify the characteristics and use them to treat HOCM appropriately. The clinical, echocardiographic, catheterization, and surgical data of 29 hospitalized patients with HOCM during 1980 to 1999 were analyzed retrospectively. We classified SAM in all patients by echocardiography. Nineteen patients improved with medical treatment (medical group), and 10 patients underwent surgical treatment because of ineffectiveness of medication (surgical group). We studied the relation between types of SAM and medical/surgical groups, and examined the relation between types of SAM and the surgical methods. Type I SAM was significantly more frequent in the medical group, while type II SAM was more frequent in the surgical group (p = 0.047). Patients in the surgical group underwent mitral valve replacement (MVR), myectomy, or a combination of MVR and myectomy. Left ventricular outflow gradient (LVOG) of over 100 mmHg was recognized in almost all patients with type II SAM. It was suggested that patients with medication-responsive HOCM tended to have type I SAM and those with refractory HOCM tended to have type II SAM. We consider that in type I SAM, if the position of the papillary muscles changed with medication or myectomy, shift of the chordae and type I SAM were reduced or disappeared. However, in type II SAM, even if the position of the papillary muscles changed, SAM did not disappear because lifting of the mitral leaflets remained. It is therefore suggested that patients with type II SAM should undergo at least MVR.
    Journal of Cardiac Surgery 01/2005; 20(1):8-15. · 0.89 Impact Factor
  • ASAIO Journal 01/2005; 51(2). · 1.39 Impact Factor
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    ABSTRACT: A patient with infective endocarditis (IE) due to methicillin-resistant staphylococcus aureus (MRSA) was found to have conversion of the hypoechoic region of the posterior mitral valve ring apparatus into a clearly delineated echolucent space by repeating transthoracic echocardiography at an interval of 1 week. Color Doppler showed features of blood entry into this space. Abscess formation in IE due to MRSA may be quick and repeated echocardiography may help detect the complications of IE. Semiurgent mitral valve plasty was performed for the associated prolapse of the posterior mitral leaflet using a hand-made, rolled, twisted autologous pericardial ring.
    Echocardiography 09/2004; 21(6):531-6. · 1.25 Impact Factor
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    ABSTRACT: Mitral regurgitation (MR) due to only punched out lesion is extremely rare in infective endocarditis. A 31-year-old male was admitted to our hospital due to unusual cause of MR. Echocardiography showed MR due to punched out lesion of the mitral anterior leaflet, which is extremely rare. A round shape punched out lesion (about 16 mm in size) was found intraoperatively in the anterior leaflet of the mitral valve. The surface around the punched out lesion was smooth, and the leaflet displayed good movability. Neither vegetation nor calcification was found. Punched out lesion was successfully closed with autologous pericardial patch and annuloplasty was performed.
    Kyobu geka. The Japanese journal of thoracic surgery 04/2004; 57(3):223-5.
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    ABSTRACT: Accessory mitral valve (AMV) is a rare cause of left ventricular outflow tract (LVOT) obstruction and is extremely rare in adults. We report a case of an older adult with an AMV that caused severe LVOT obstruction. A parachute-like piece of tissue (the AMV) protruding into the LVOT during systole was first detected in a 45-year-old woman by echocardiography. Because the pressure gradient and dyspnea gradually progressed, she finally underwent a successful operation for removal when she was 48 years old.
    The Annals of Thoracic Surgery 03/2004; 77(2):713-5. · 3.63 Impact Factor
  • The Journal of Heart and Lung Transplantation 10/2003; 22(9):1065-6. · 5.61 Impact Factor
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    ABSTRACT: Pimobendan, an oral inotropic drug with phosphodiesterase III-inhibitory activity, induces cAMP-dependent relaxation of vascular smooth muscle in the pulmonary artery, as well as in the systemic cardiovascular system. We report here a patient with severe primary pulmonary hypertension (PPH), who had developed right heart failure (New York Heart Association functional class IV) despite uptitrated intravenous epoprostenol, and who was treated with extremely low-dose (0.625-1.25 mg daily) pimobendan as an adjunct to prostacyclin therapy. The combination therapy of low-dose pimobendan, prostacyclin, intravenous epoprostenol and oral beraprost has been continued for over 2 years without occurrence of fatal arrhythmia, and her six-minute walk test has exceeded 400 m. We suggest that low-dose pimobendan may enhance the hemodynamic effect of prostacyclin in severe PPH.
    Cardiovascular Drugs and Therapy 08/2003; 17(4):375-9. · 2.95 Impact Factor
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    ABSTRACT: It has been reported that the left ventricular mass index (LVMI) for the hypertrophic myocardium is reduced at an early stage following surgery. In this study, those factors affecting the changes in early postoperative LVMI were investigated in cases in which a St. Jude Medical 19A-HP (19HP) mechanical heart valve was used. We studied 16 consecutive patients with pure aortic stenosis undergoing isolated aortic valve replacement using a 19HP between January 1994 and July 2001. The patients were all female, aged 64 +/- 6 years, with a body surface area of 1.44 +/- 0.10 m2 and preoperative New York Heart Association (NYHA) classification of 2.2 +/- 0.5. All patients underwent transthoracic echocardiography at 4.2 +/- 3.3 days before and 16.3 +/- 10.2 days after operation, and cardiac catheterization within a mean period of one month before operation. The correlations between the decrease of LVMI at 16.3 +/- 10.2 days after operation and perioperative parameters were determined. There was significant LVMI regression postoperatively (15 +/- 12%, p = 0.01), and only a significant negative correlation between the decrease of LVMI and preoperative left ventricular pressure (LVp) [r = -0.74, p < 0.01]. There was no effective LVMI reduction in the high preoperative LVp group (> or = 210 mmHg). It is expected that in the high LVp group, huge wall stress was being applied to the left ventricular muscle immediately before surgery and in the early period after surgery. Preoperative LVp is an important index for determining the surgical timing and safe perioperative management. We recommend early surgical treatment before LVp becomes more than 210 mmHg.
    The Japanese Journal of Thoracic and Cardiovascular Surgery 08/2003; 51(8):361-7.
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    ABSTRACT: A 57-year-old man suspected of having angina pectoris underwent coronary angiography and comprehensive examination, which revealed a right-side aortic arch accompanying Kommerell diverticulum and a aberrant left subclavian artery. Esophagography indicated that the esophagus was compressed on its right posterior side and the computed tomography (CT) revealed that the posterior side of the tracheal was compressed, however, the patient experienced no difficulty in breathing, hoarseness of voice or dysphasia. The size of the aortic diverticulum was less than 5 cm and the patient showed no symptom, however, if it was left untreated, there was a risk of rupture in the future. Also the esophagus and tracheal may develop complications due to prolonged compression. Therefore, we decided that the case required surgical operation. Total arch replacement was performed through mediastinotomy and right posterolateral in the 4th intercostal. The postoperative condition was good, and the patient was discharged without any complications.
    Kyobu geka. The Japanese journal of thoracic surgery 06/2003; 56(5):403-5.
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    ABSTRACT: From March 1996 to May 2000, 41 patients [age 39-78 (mean 63.5 +/- 8.8) years, 90.2% male] underwent all arterial multiple coronary artery bypass grafting (CABG) using bilateral internal thoracic (BiITA) and radial (RA) arterial conduits. The reason for using RA was that the right gastroepiploic artery (RGEA) was small or occluded on preoperative angiography, a history of upper abdominal surgery or disease, or the right coronary arterial lesion was proximal and mild. The BiITA were used as in situ grafts and the proximal anastomosis of RA was to the ascending aorta in all cases. All patients underwent conventional elective CABG with median sternotomy using cardiopulmonary bypass. The mean number of anastomoses was 3.3 +/- 0.5 branches and complete revascularization rate was 80.5%. Postoperative follow-up averaged 20 months and the longest was 50 months. There was no early death, and overall graft patency 2-3 weeks after surgery was 96.2% (LITA 94.0%, RITA 97.6%, RA 97.6%). Four-year actuarial survival rate was 96.4 +/- 3.5% (1 patient: 9 months, no cardiac death), and cardiac event-free rate after surgery was 89.7 +/- 4.9% [4 patients: percutaneous transluminal coronary angioplasty (PTCA)]. However, once patients were discharged from hospital, cardiac event-free rate was 100%. These excellent results suggest that all arterial graft CABG was satisfactory, and RA can be used as a third suitable arterial bypass conduit, if RGEA cannot be used or is unsuitable for use.
    Kyobu geka. The Japanese journal of thoracic surgery 12/2002; 55(12):1006-10.
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    ABSTRACT: We developed "EVAHEART": a compact centrifugal blood pump system as an implantable left ventricular assist device for long-term circulatory support. The 55 x 64 mm pump is made from pure titanium, and weighs 370 g. The entire blood-contacting surface is covered with an anti-thrombogenic coating of diamond like carbon (DLC) or 2-methacryloyloxyethyl phosphorylcholine (MPC) to improve blood compatibility. Flows exceeding 12 L/min against 100 mmHg pressure at 2600 rpm was measured. A low-temperature mechanical seal with recirculating cooling system is used to seal the shaft. EVAHEART demonstrated an acceptably low hemolysis rate with normalized index of hemolysis of 0.005 +/- 0.002 g/100L. We evaluated the pump in long-term in-vivo experiments with seven calves. Via left thoracotomy, we conducted left ventricular apex-descending aorta bypass, placing the pump in the left thoracic cavity. Pump flow rates was maintained at 5-9 L/min, pump power consumption remained stable at 9-10 W in all cases, plasma free Hb levels were less than 15 mg/dl, and the seal system showed good seal capability throughout the experiments. The calves were sacrificed on schedule on postoperative day 200, 222, 142, 90, 151, 155, and 133. No thrombi formed on the blood contacting surface with either the DLC or MPC coating, and no major organ thromboembolisms occurred except for a few small renal infarcts. EVAHEART centrifugal blood pump demonstrated excellent performance in long-term in-vivo experiments.
    The Japanese Journal of Thoracic and Cardiovascular Surgery 12/2002; 50(11):461-5.
  • Nihon Naika Gakkai Zasshi 08/2002; 91(7):2186-8.

Publication Stats

757 Citations
161.48 Total Impact Points


  • 1999–2009
    • Tokyo Women's Medical University
      • Department of Cardiovascular Surgery
      Edo, Tōkyō, Japan
  • 1992–2000
    • University of Pittsburgh
      • • School of Medicine
      • • Division of Cardiothoracic Surgery
      • • Department of Surgery
      Pittsburgh, PA, United States