Koichi Toda

Osaka University, Suika, Ōsaka, Japan

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Publications (95)230.37 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Severe donor shortage in Japan makes the waiting period for heart transplantation extremely long and the left ventricular assist devices (LVADs) are often used for bridge-to-transplant. We present three cases of infected and exposed DuraHeart(®) LVAD system treated with free flaps. Four free flaps (two latissimus flaps and two anterolateral thigh flaps) were transferred using the right internal thoracic vessels or left deep inferior epigastric vessels as recipients. The potential significance of the continuous low pressure blood flow generated by the LVAD system on microvascular patency has not been previously reported. All flaps survived and worked efficiently to control the infection and cover the devices. Heart transplantation was conducted in the two of three patients. Free flap transfer is an efficient treatment for the patients with infected and exposed implantable LVAD.
    Journal of Artificial Organs 12/2014; · 1.39 Impact Factor
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    ABSTRACT: Background:The aim of the present study was to assess the efficacy of a non-invasive method, transient elastography (FibroScan), in measuring liver stiffness (LS), and whether LS can be used as a marker of cardiac - and hence perioperative - status.Methods and Results:Perioperative LS was prospectively measured using a FibroScan in 30 patients (21 male; 42.2±13.3 years old) who underwent left ventricular assist device (LVAD) implantation. LS was checked pre- and postoperatively, then analyzed in regard to perioperative status. Preoperative LS was 13.3±13.0 kPa (normal, <5.5 kPa), and was abnormal in 77% of patients. Four required bilateral VAD. LS in patients with bilateral VAD tended to be higher than in LVAD patients (25.1±22.7 vs. 11.5±10.5 kPa, P=0.051). No patient with LS ≤7.0 kPa required a right VAD. The incidence of major adverse events was lower in patients with LS ≤12.5 kPa (25% vs. 80%, P<0.05). There were also no mortalities among patients with LS ≤12.5 kPa.Conclusions:LS was correlated with preoperative severity in patients with severe heart failure and reflected liver congestion, and may be useful to predict the requirement of right VAD, as well as postoperative complications in patients with LVAD implantation. This novel modality may be a useful non-invasive assessment method for management of severe heart failure.
    Circulation Journal 12/2014; · 3.69 Impact Factor
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    ABSTRACT: Cell-sheet transplantation induces angiogenesis for chronic myocardial infarction (MI), though insuf?cient capillary maturation and paucity of arteriogenesis may limit its therapeutic effects. Omentum has been used clinically to promote revascularization and healing of ischemic tissues. We hypothesized that cell-sheet transplantation covered with an omentum-flap would effectively establish mature blood vessels and improve coronary microcirculation physiology, enhancing the therapeutic effects of cell-sheet therapy. Rats were divided into 4 groups after coronary ligation; skeletal myoblast cell-sheet plus omentum-flap (combined), cell-sheet only, omentum-flap only, and sham operation. At 4 weeks after the treatment, the combined group showed attenuated cardiac hypertrophy and fibrosis, and a greater amount of functionally (CD31(+)/lectin(+)) and structurally (CD31(+)/α-SMA(+)) mature blood vessels, along with myocardial upregulation of relevant genes. Synchrotron-based microangiography revealed that the combined procedure increased vascularization in resistance arterial vessels with better dilatory responses to endothelium-dependent agents. Serial (13)N-ammonia PET showed better global coronary flow reserve in the combined group, mainly attributed by improvement in the basal left ventricle. Consequently, the combined group had sustained improvements in cardiac function parameters and better functional capacity. Cell-sheet transplantation with an omentum-flap better promoted arteriogenesis and improved coronary microcirculation physiology in ischemic myocardium, leading to potent functional recovery in failing heart.Molecular Therapy (2014); doi:10.1038/mt.2014.225.
    Molecular Therapy 11/2014; · 6.43 Impact Factor
  • Koichi Toda, Yoshiki Sawa
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    ABSTRACT: More than 250 continuous flow LVADs have been implanted in Japan during the last 3 years, with 1-year survival rates of 90 %. These excellent results cannot be achieved without VAD teams who know the detail of surgical techniques and perioperative management. Preoperative optimization of RV function is essential and intraoperative managements are focused on adequate balance between right and left ventricle to prevent right ventricular (RV) failure. For postoperative RV failure early institution of temporary RV mechanical support improves outcomes. Immediate CT scanning is crucial if LVAD patients complain of new neurological symptoms. When CT reveals cerebral hemorrhage, INR should be reduced as soon as possible. The driveline (DL) exit site remains a significant source of LVAD-related infections, and orientation and immobilization of the DL is important. Although vacuum assisted closure is useful to facilitate drainage and healing in pump pocket as well as DL infections, urgent heart transplantation, bridging to recovery, or pump exchange may become the only options to eradicate LVAD-related infections. Patients with continuous flow LVAD are more prone to developing de novo aortic insufficiency. Although majority of them can be managed medically, some require surgical intervention. The cause of pump thrombosis is multifactorial, including lowered INR and pump speed, and implantation techniques. It is important to exchange pumps in a timely manner either through a median sternotomy or subcostal incision in highly suspected patients indicated by elevated LDH and left-sided heart failure.
    General Thoracic and Cardiovascular Surgery 11/2014;
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    ABSTRACT: Myocardial recovery occurs in a small cohort of patients receiving left ventricular assist device (LVAD) support, but identification of candidates for device removal remains challenging. We hypothesized that hemodynamic evaluation using echocardiography and right heart catheter during temporary suspension of LVAD support (LVAD-off test) can assess cardiac recovery to predict successful device removal. To prove this hypothesis, we reviewed 44 patients who underwent LVAD-off test from January 2000 to March 2011 at Osaka University Hospital. Twenty-two of them underwent LVAD explant, 9 showed sustaining recovery (successful explant, SE-group); whereas 13 had a recurrent heart failure (failed explant, FE-group). The other 22 patients remained LVAD dependent (nonrecovery, NR-group). Echocardiography showed significant lower ejection fraction (LVEF) in NR-group than in SE- and FE-group after termination of LVAD support, but there was no difference between SE- and FE-group. On the other hand, elevation in pulmonary capillary wedge pressure (ΔPCWP) was significantly smaller in SE-group than in FE- and NR-groups. The degree of cardiac fibrosis significantly increased in FE- and NR-group during the LVAD support, while it did not increase in SE-group. The degree of cardiac fibrosis at the time of LVAD explantation correlated significantly with PCWP at LVAD halt and ΔPCWP, and it had significant impact on the outcome after LVAD weaning. In conclusion, the data obtained during LVAD-off test using echocardiography and right heart catheter significantly correlated with the degree of cardiac fibrosis at the time of LVAD explantation. LVAD-off test is a useful method to predict the successful LVAD explantation.
    Journal of Artificial Organs 11/2014; · 1.39 Impact Factor
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    ABSTRACT: Recent evidence suggests that transcatheter aortic valve replacement (TAVR) is feasible for treating severe aortic valve stenosis (AS) in patients who are considered high risk for elective surgery. However, it is still unclear whether TAVR is a better option than surgical aortic valve replacement for severe AS with acute decompensated heart failure. We report a case of severe AS with acute heart failure, which was treated successfully by urgent TAVR, with cardiopulmonary support.
    Surgery Today 10/2014; · 1.21 Impact Factor
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    ABSTRACT: Cell surface glycans vary widely, depending on cell properties. We hypothesized that glycan expression on induced pluripotent stem cells (iPSCs) might change during cardiomyogenic differentiation toward the myocardial phenotype. N-glycans were isolated from iPSCs, iPSC-derived cardiomyocytes (iPSC-CM), and original C57BL/6 mouse myocardium (Heart). Their structures were analyzed by a mapping technique based on HPLC elution times and MALDI-TOF/MS spectra. Sixty-eight different N-glycans were isolated; the structures of 60 of these N-glycans were identified. The quantity of high-mannose type (immature) N-glycans on the iPSCs decreased with cardiomyogenic differentiation, but did not reach the low levels observed in the heart. We observed a similar reduction in neutral N-glycans and an increase in fucosylated or sialyl N-glycans. Some structural differences were detected between iPSC-CM and Heart. No N-glycolyl neuraminic acid (NeuGc) structures were detected in iPSC-CM, whereas the heart contained numerous NeuGc structures, corresponding to the expression of cytidine monophosphate-N-acetylneuraminic acid hydroxylase. Furthermore, several glycans containing Galα1-6 Gal, rarely identified in the other cells, were detected in the iPSC-CM. The expression of N-glycan on murine iPSCs changed toward the myocardial phenotype during cardiomyogenic differentiation, leaving the structural differences of NeuGc content or Galα1-6 Gal structures. Further studies will be warranted to reveal the meaning of the difference of N-glycans between the iPSC-CM and the myocardium.
    PLoS ONE 10/2014; 9(10):e111064. · 3.53 Impact Factor
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    ABSTRACT: We performed successful off-pump coronary artery bypass grafting (OPCAB) in a patient with unstable angina caused by triple-vessel disease, who had undergone esophagectomy with substernal gastric tube reconstruction for esophageal cancer 40 years earlier. Preoperative multidetector-row computed tomography was done to evaluate the course of the gastric tube and also that of the gastroepiploic artery, which feeds the gastric tube. Following careful sternal re-entry and adequate dissection, OPCAB was performed safely via a median sternotomy without injuring the gastric tube or causing hemodynamic instability. The patient had an uneventful early postoperative course.
    Surgery Today 10/2014; · 1.21 Impact Factor
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    ABSTRACT: Right ventricular failure after left ventricular assist device (LVAD) implantation is associated with high mortality. This study was designed to evaluate the effectiveness of an atrial septostomy with a membrane oxygenator incorporated in an LVAD as a novel approach for right ventricular failure after LVAD implantation.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 10/2014; · 2.40 Impact Factor
  • Journal of Cardiac Failure 10/2014; 20(10):S146. · 3.07 Impact Factor
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    ABSTRACT: Moyamoya disease (MMD) is a rare disease characterized by occlusive intracranial arteriopathy with formation of abnormal cerebrovascular collateral networks. Conventional cardiovascular surgical procedures using cardiopulmonary bypass for patients with MMD is challenging because low cerebral perfusion pressure and nonpulsatile (continuous) flow during cardiopulmonary bypass can cause severe cerebral ischemia. We successfully performed transcatheter aortic valve replacement in 3 women with severe aortic valve stenosis complicated with MMD. Transcatheter aortic valve replacement may be useful for patients with severe aortic valve stenosis complicated with severe cerebral ischemia, including MMD.
    The Annals of Thoracic Surgery 10/2014; 98(4):1443-1445. · 3.63 Impact Factor
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    ABSTRACT: We report the successful longest biventricular support using dual Jarvik 2000 biventricular assist device (BVAD; Jarvik Heart, Inc., New York, NY, USA) as a bridge to transplant. A 27-year old woman with arrhythmogenic right ventricular cardiomyopathy underwent implantation of two Jarvik 2000s as a left ventricular assist device and right ventricular assist device. Although several BVAD-related complications including haemolysis, hepatic dysfunction, heart failure and pulmonary valve insufficiency developed at a very late stage, she was successfully bridged to heart transplantation after 1245 days of biventricular support, which is the longest in the literature. Despite advances in continuous-flow ventricular assist devices, their long-term use for biventricular support remains limited. We report a successful case of 1245 days of biventricular support with dual Jarvik 2000 axial flow pumps in a patient with a small body surface area.
    Interactive Cardiovascular and Thoracic Surgery 09/2014; · 1.11 Impact Factor
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    ABSTRACT: Purpose : To assess the significance of aortic remodeling in the prevention of the late aortic events after thoracic endovascular aortic repair (TEVAR) for aortic dissection. Methods : The study involved 52 patients (41 men; mean age was 59.7±13.3 years) with type B aortic dissections and patent false lumens treated with TEVAR between 2004 and 2011. Of the 52 patients, 18 were treated in the acute phase for rupture (n=1), malperfusion (n=10), aortic diameter over 40 mm at onset (n=3), and rapid enlargement of the false lumen (n=4). In the chronic setting, the indications for TEVAR were rupture (n=1), malperfusion (n=2), aortic diameter >50 mm (n=18), and rapid enlargement of the false lumen (n=13). Aortic remodeling was evaluated at 6 months postoperatively, and risk factors for late aortic events were evaluated in multivariate analysis using aortic remodeling and other pre-, peri-, and postoperative factors. Results : Over a mean 36.0±18.9 months, 19 aortic events were documented: enlargement of the false lumen (n=4), type I endoleak (n=2), and erosion at the stent-graft edges (n=13). Multivariate analysis revealed that failure to achieve aortic remodeling at 6 months postoperatively was the only significant risk factor for late aortic events (hazard ratio 0.20, p=0.037). Patients with aortic remodeling had a higher rate of freedom from aortic events compared with those without aortic remodeling (100% vs. 81.5% at 1 year and 79.3% vs. 48.4% at 3 years, respectively). Conclusion : Aortic remodeling after TEVAR is a significant prognostic factor for better long-term results for type B aortic dissection.
    Journal of endovascular therapy : an official journal of the International Society of Endovascular Specialists. 08/2014; 21(4):517-525.
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    ABSTRACT: In contrast to a pulsatile-flow left ventricular assist device (LVAD), an LVAD off test for evaluation of cardiac recovery with a continuous-flow device is difficult because of intra-circuit backflow from the outflow graft when a device is stopped. We report a case of reliable evaluation of cardiac recovery using balloon occlusion of the outflow graft, followed by successful removal of a continuous-flow EVAHEART LVAD using a minimally invasive approach.
    Journal of Artificial Organs 07/2014; · 1.39 Impact Factor
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    ABSTRACT: The aim of this study was to evaluate our clinical experience with the Jarvik 2000 axial flow pump (Jarvik Heart, Inc, New York, NY, USA), a miniature axial flow left ventricular assist device (LVAD). The clinical results of eight patients, who underwent LVAD implantation with the Jarvik 2000 (median age 55.0 years; six men) between 2005 and 2010, including two who participated in a multicenter clinical trial in Japan, were reviewed. Two patients underwent LVAD implantation as destination therapy. Four patients underwent Jarvik 2000 implantation via median sternotomy, while the other four underwent implantation via left thoracotomy. There were no major complications during surgery. Four patients were supported for more than 2 years. The longest support duration was 1,618 days. Six patients successfully bridged to heart transplantation after a median 725 days of support. One patient on destination therapy died of a cerebral infarction. The other patient on destination therapy had had the LVAD for 1,618 days. The overall survival rates at 1, 2, and 3 years were 100, 86, and 86 %, respectively. The median postoperative serum lactate dehydrogenase level was 860.5 U/L at 1 month, 735 U/L at 6 months, and 692 U/L at 1 year. There were no fatal device-related infections. We found that the Jarvik 2000 with pin bearing could support patients with end-stage heart failure with acceptable mortality and morbidity rates. Further evaluations of the prevalence of thromboembolic and hemolytic events in patients with the new conical-bearing Jarvik 2000 are required.
    Journal of Artificial Organs 07/2014; · 1.39 Impact Factor
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    ABSTRACT: Background The EVAHEART left ventricular assist device was approved in 2010 by the Japanese Pharmaceuticals and Medical Devices Agency (PMDA) for bridge to heart transplantation (BTT). However, its effectiveness has not been evaluated since approval. This study evaluated the EVAHEART device in a commercial setting in Japan. Methods Ninety-six consecutive patients enrolled in the Japanese Registry for Mechanically Assisted Circulatory Support (J-MACS) who were listed for transplant or likely to be listed and who received an EVAHEART, were enrolled from 2011 to 2013 at 14 Japanese centres. Patients’ survival rates, adverse events, and quality of life data were obtained from the J-MACS registry. Results Patients’ median age was 43 years (male, 85). The Interagency Registry for Mechanically Assisted Circulatory Support profiles revealed 12 patients in level 1, 45 in level 2, 37 in level 3, and 1 patient in level 4. The mean support duration was 384.7 days, with a cumulative duration of 101.2 years. The Kaplan-Meier survival rate during support was 93.4% at 6 months, 87.4% at 1 year, and 87.4% at 2 years. Seventy-seven patients (80.2%) currently remain on support, 7 received a transplant, and 10 died during support. Major adverse events included driveline infection (14.6%) and neurological events such as ischemic stroke (17.7%), haemorrhage (13.5%), transient ischemic attack (3.1%), pump thrombosis (1%), and haemolysis (1%). There was no gastrointestinal bleeding, right heart failure requiring RVAD, or incidences of pump exchange due to mechanical failure. Conclusions The EVAHEART device provides safe and reliable long-term circulatory support, with an improved survival in commercial settings of BTT in Japan, where the transplant-waiting period is extremely longer. Incidences of GI bleeding, haemolysis, RV failure, device thrombosis, and mechanical failure were extremely rare in patients on EVAHEART devices.
    The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 06/2014; · 5.61 Impact Factor
  • International journal of cardiology 03/2014; · 6.18 Impact Factor
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    ABSTRACT: We describe the first clinical experiences in Japan with the HeartWare ventricular assist device (HVAD: HeartWare Inc., Miami Lakes, FL, USA) in patients awaiting heart transplantation. Nine patients (6 males, 3 females; mean 33.5 ± 7.8 years; New York Heart Association class III or IV) received the HVAD as a bridge to transplantation between 2011 and 2012. Six had dilated cardiomyopathy, 2 secondary cardiomyopathy, and 1 dilated phase hypertrophic cardiomyopathy. All operations were uneventful, with a mean operation time of 269 ± 77 min and cardiopulmonary bypass time of 121 ± 40 min. One required a temporary right ventricular assist device and was weaned on postoperative day 20, while another required pump exchange due to foreign tissue in the inflow. Mean support duration was 245 ± 162 days (range: 50-535 days) and mean pump blood flow at 1 month postoperatively was 4.8 ± 0.8 l/min. There was no mortality after 30 days, though 1 patient died during support due to cerebral hemorrhage. Presently, the others are waiting for heart transplantation without problems, except 1 who suffered from an active infection. There was no pump mechanical failure in any case. The HeartWare pump enables quick implantation with acceptable morbidity and mortality. Our preliminary results indicate that this left ventricular assist device is safe for circulatory assistance for heart transplant candidates in Japan.
    Journal of Artificial Organs 01/2014; · 1.39 Impact Factor
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    ABSTRACT: The risk of neurological deterioration during valve surgery using cardiopulmonary bypass under systemic heparinization in infective endocarditis (IE) patients with intracranial haemorrhage (ICH) is unknown. The objective of this retrospective study was to investigate the stratified risk related to the timing of valve surgery on neurological outcomes in patients with active IE and preoperative ICH. From 2004 to 2012, 246 patients underwent valve surgery for IE in hospitals enrolled in the Osaka Cardiovascular Research Group. Of these, a group of 30 patients had preoperative ICH, and they included 18 patients with cerebral haemorrhage, 8 with subarachnoid haemorrhage and 4 with haemorrhagic infarction. The preoperative characteristics, neurological statuses and postoperative results of these patients were retrospectively explored to analyse the effects of the timing of surgery on neurological outcomes. Twenty-one patients had symptomatic ICH, and the median modified Rankin score was 1.5 (95% confidence interval [CI] 1.2-2.8). Eight patients were diagnosed with mycotic aneurysms, and 7 of these patients underwent aneurysm resection or clipping before valve surgery. All 30 patients underwent valve surgery, and the median interval between ICH onset and surgery was 22.5 (95% CI 15.5-39.4) days. Four patients died of multiple organ dysfunction or heart failure. The interval between ICH onset and valve surgery was within 7 days for 5 cases, between 8 and 14 days for 6, between 15 and 28 days for 9 and >29 days for 10. Postoperative neuroimaging showed that neither neurological deterioration nor exacerbation of haemorrhagic lesions had occurred among the 30 patients, regardless of the timing of surgery. However, 2 cases who underwent valve surgery 8 and 81 days after the onset of ICH developed new ectopic asymptomatic haemorrhages postoperatively. The risk of postoperative neurological deterioration resulting from the exacerbation of haemorrhagic lesions seemed relatively low, even in IE patients who underwent valve surgery within 2 weeks of ICH onset. However, further evaluation of the sizes and aetiologies of haemorrhagic lesions is vital to establish a safe interval between the ICH onset and surgery.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 01/2014; · 2.40 Impact Factor
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    ABSTRACT: Conventional coronary artery bypass grafting (CABG) using cardiopulmonary bypass and cardiac arrest is associated with higher mortality and morbidity rates in acute coronary syndrome (ACS) patients undergoing surgery. Although off-pump CABG (OPCAB) is beneficial for high-risk patients, its efficacy for ACS is unknown, with on-pump beating CABG an adjunctive method. We investigated the effects of OPCAB and on-pump beating CABG for ACS. We evaluated 121 consecutive patients with ACS (91 males, 30 females; mean age 69.5 ± 10.3 years) who underwent CABG since 2000. Seventy-five had unstable angina (UA) and 46 acute myocardial infarction (AMI) [non-ST elevation (NSTEMI): 22, ST elevation (STEMI): 24]. We assessed CABG for acute coronary syndrome under our primary OPCAB strategy, and compared perioperative status between UA and AMI patients. (1) Sixty-five (87 %) with UA underwent OPCAB, 8 on-pump beating CABG, and 2 conventional CABG. Conversion from OPCAB was seen in 4 patients. In-hospital mortality was 1.3 %. (2) All UA patients who had intra-aortic balloon pumping (IABP) underwent OPCAB. No patients with preoperative IABP experienced conversion from OPCAB. (3) In AMI patients, hospital mortality was higher (8.9 %) and the ratios for OPCAB, on-pump beating CABG, and conventional CABG were 39, 57, and 4 %, respectively. Mortality was exclusively seen in patients with STEMI who underwent conventional CABG. OPCAB might have beneficial effects for ACS patients with UA, while IABP was found essential for completing OPCAB. In AMI patients, on-pump beating CABG might be reasonable for avoiding conversion from OPCAB and ischemic perfusion injury.
    General Thoracic and Cardiovascular Surgery 12/2013;

Publication Stats

300 Citations
230.37 Total Impact Points

Institutions

  • 2013–2014
    • Osaka University
      • Division of Cardiovascular Surgery
      Suika, Ōsaka, Japan
  • 2006–2014
    • Osaka City University
      • Department of Cardiovascular Surgery
      Ōsaka, Ōsaka, Japan
  • 2009–2013
    • National Cerebral and Cardiovascular Center
      • Department of Cardiovascular Medicine
      Ōsaka-shi, Osaka-fu, Japan
  • 2008–2011
    • Osaka Rosai Hospital
      Ōsaka, Ōsaka, Japan
  • 2005–2007
    • Kure Medical Centre
      • Department of Cardiovascular Surgery
      Hirosima, Hiroshima, Japan