Mikizo Nakai

National Cerebral and Cardiovascular Center, Ōsaka, Ōsaka, Japan

Are you Mikizo Nakai?

Claim your profile

Publications (18)12.65 Total impact

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Unruptured sinus of Valsalva aneurysm is a rare anomaly which may be acquired or congenital. We describe a case of a 64 year old man with aneurysms (left : 31 mm, non : 21 mm) of the coronary sinus. The Bentall operation was successfully performed and his postoperative course was uneventful. The histopathology of the aortic wall showed Takayasu's arteritis. Bentall surgery is a good choice for multiple aneurysms of the Valsalva sinus with aortitis.
    01/2015; 44(2):117-120. DOI:10.4326/jjcvs.44.117
  • [Show abstract] [Hide abstract]
    ABSTRACT: In elderly patients, open surgery for patent ductus arteriosus (PDA) is more difficult than that in children and often requires a cardiopulmonary bypass. We report the case of a 67-year-old patient with a PDA that was successfully treated with thoracic endovascular aortic repair (TEVAR). The patient was diagnosed with congestive heart failure (ejection fraction, 36 %) and PDA (9.7 mm in diameter). TEVAR was successfully performed to exclude the PDA. After TEVAR, the patient's heart failure was well controlled by diuretics. TEVAR may be a good alternative to open surgery.
    General Thoracic and Cardiovascular Surgery 07/2014; DOI:10.1007/s11748-014-0457-z
  • Source
    Koji Nakanishi · Nobuhisa Tajiri · Mikizo Nakai · Shuji Shimizu ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Arterial aneurysm rupture is one of the most critical complications in patients with vascular-type Ehlers–Danlos syndrome (vEDS). Here, we report a case of recurrent aneurysm rupture successfully treated by endovascular embolization. A 38-year old woman who underwent brachial artery ligation for a ruptured aneurysm was diagnosed postoperatively with vEDS. Impending rupture of a collateral artery aneurysm was encountered 5 months after the initial open surgery. Endovascular embolization with a liquid embolic agent was successfully performed. Given that arterial rupture can occur repeatedly in patients with vEDS, careful life-long follow-up is necessary.
    Interactive Cardiovascular and Thoracic Surgery 07/2014; 19(4). DOI:10.1093/icvts/ivu208 · 1.16 Impact Factor
  • Koji Nakanishi · Ryoji Watanabe · Shuji Shimizu · Mikizo Nakai ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Non-anastomotic graft rupture is a rare but critical complication after abdominal aortic aneurysm (AAA) repair. Therefore, identifying the rupture sites is important to perform endovascular stent grafting. A 78-year old man who had undergone Y-grafting for infrarenal AAA before 17 years was referred to our hospital with the complaints of abdominal pain. Computed tomography revealed acute pancreatitis and an enlargement around the grafted abdominal aorta. Contrast-enhanced ultrasonography revealed an extravazation from the graft body 1.5 cm distal to the proximal anastomosis, and endovascular stent grafting was successfully performed. Contrast-enhanced ultrasonography might be useful in detecting the graft rupture.
    Interactive Cardiovascular and Thoracic Surgery 11/2013; 18(2). DOI:10.1093/icvts/ivt485 · 1.16 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Intravenous leiomyomatosis is a benign smooth muscle tumor that sometimes spreads to the right heart via the inferior vena cava. A complete surgical resection is necessary to ensure its successful treatment. Surgical removal has been performed safely in middle-aged patients. Here we report a case of successful surgical removal in an elderly woman (age 81 years). The woman was admitted with palpitation and diagnosed as having an intravenous leiomyomatosis with cardiac extension. She underwent a one-stage surgical removal with cardiopulmonary bypass and circulatory arrest. We therefore recommend a one-stage operation, if possible, even in elderly patients.
    General Thoracic and Cardiovascular Surgery 03/2012; 60(3):153-6. DOI:10.1007/s11748-011-0791-3
  • [Show abstract] [Hide abstract]
    ABSTRACT: In contrast to high mortality of open surgery for thoracic aortic catastrophes including ruptured thoracic aortic aneurysm (RTAA) and traumatic aortic injury (TAI), excellent short-term outcomes of thoracic endovascular aortic repair (TEVAR) have recently been reported. We report our single-center experiences with TEVAR for aortic catastrophes. Thirteen patients with thoracic aortic catastrophes (RTAA in 7 patients, TAI in 6 patients) have received TEVAR from February 2004 to June 2010. In cases of RTAA, 5 descending aortic aneurysm ruptures and 2 aortic arch aneurysm ruptures were included. In patients with arch aneurysm ruptures, fenestrated stent grafting (SG) and SG combined with arch debranching were performed. In all cases of TAI, aortic injuries occurred near the isthmus and 5 patients received fenestrated SG. The initial success rate was 100% and there was no perioperative death. Mean duration of observation was 24 months, which revealed 4 late deaths. The causes of late death were liver failure, cerebral contusion, senility and unknown. A patient with RTAA experienced a type III endoleak as an aorta-related event 24 months after operation. There was no enlargement of aneurysm in any patient. TEVAR for aortic catastrophes seems to be performed safely with acceptable outcomes. Although morphological incompatibility, unstable preoperative haemodynamics and longer time for preparation may become impediments to perform TEVAR, we believe that TEVAR should be the 1st choice for life-threatening aortic catastrophes. However, a careful follow-up is necessary because TEVAR has several unique late complications.
    Kyobu geka. The Japanese journal of thoracic surgery 01/2011; 64(1):69-73.
  • Source
    M. Nakai · S. Shimizu · G. Kato · H. Mitsui · S. Sano ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Abdominal aortic aneurysm (AAA) is a life-threatening complication in patients with Behçet’s disease. Recently, endovascular aneurysm repair (EVAR) has been reported with acceptable short-term outcomes. However, we report a case in which open surgery was required for a recurrent pseudo-aneurysm after EVAR. A 54-year-old man with Behçet’s disease was diagnosed with a pseudo-aneurysm at the proximal margin of a previously inserted stent graft for AAA. We performed open surgery for removal of the stent graft and reconstruction of the left accessory renal artery. Long-term outcomes of EVAR in patients with Behçet’s disease are not necessarily acceptable.
    EJVES Extra 08/2010; 20(1). DOI:10.1016/j.ejvsextra.2010.04.003

  • Journal of Echocardiography 06/2010; 8(2):62-64. DOI:10.1007/s12574-009-0032-2
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Our meticulous investigation of ePTFE graft breakage when a wire placed at the edge of an ePTFE graft was pulled, revealed that, depending on the breakage pattern, a break starts much earlier than the peak suture retention strength, which is the current international indicator for anastomotic-site break strength. Furthermore, the breakage patterns differ based on the thickness of the wire and the fiber direction of the ePTFE graft. Based on these findings, we advocate measuring the peak suture retention strength using 0.10-mm sutures and a standardized wire thickness in order to assess the anastomotic retention strength of ePTFE grafts.
    Acta medica Okayama 04/2010; 64(2):121-8. · 0.70 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Apicoaortic bypass for left ventricular outflow tract obstruction has been performed with acceptable mid-term mortality. However, sometimes it is difficult to anastomose the distal end of the conduit to the calcified descending aorta in patients with a porcelain aorta. We report an aortic non-touch modification of the apicoaortic bypass in an 80-year-old woman with valvular aortic stenosis and a porcelain aorta extending from the ascending to abdominal aorta. We performed apico-brachiocephalic artery bypass under circulatory arrest with deep hypothermia. This procedure may become a useful surgical option for patients with a severe porcelain aorta.
    The Annals of thoracic surgery 02/2010; 89(2):621-3. DOI:10.1016/j.athoracsur.2009.06.124 · 3.85 Impact Factor
  • M Nakai · S Shimizu · Y Ochi · G Kato · M Okada ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Paraplegia is one of the most tragic complications following endovascular aneurysm repair (EVAR) for descending thoracic aortic aneurysm (DTAA). Collateral circulation to the artery of Adamkiewicz (AA) is important to avoid spinal cord ischaemia. We report a case in which the thoracodorsal artery had become a collateral source to the AA. A 71-year-old man had undergone EVAR for DTAA. Three years after EVAR, an angiography demonstrated that the thoracodorsal artery had joined the 11th intercostal artery and had become a collateral source to the AA. The collateral circulation of thoracic wall arteries may play an important role in the postoperative spinal perfusion.
    European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery 04/2009; 37(5):566-8. DOI:10.1016/j.ejvs.2009.02.001 · 2.49 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Surgical treatment of aortic regurgitation due to Behçet's disease is difficult. A 57-year-old male with Behçet's disease underwent aortic valve replacement with a mechanical valve for aortic regurgitation in 1995. Due to prosthetic valve detachment, 5 months thereafter he underwent a Bentall type operation with a composite graft. Due to complication of the left ventricle to pulmonary arterial fistula, 6 months later a third operation was performed for closure of the fistula. He is doing well at present 5 years after the third operation. Left ventricle to pulmonary arterial fistula is an exceedingly rare complication and has not been reported in the literature.
    The Japanese Journal of Thoracic and Cardiovascular Surgery 04/2004; 52(3):135-8. DOI:10.1007/s11748-004-0129-5
  • Source
    K Nakanishi · T Shichijo · Y Shinkawa · S Takeuchi · M Nakai · G Kato · O Oba ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Open-heart surgery without homologous blood transfusion is still difficult in children because priming volume in cardiopulmonary bypass circuit results in extreme hemodilution. Vacuum-assisted cardiopulmonary bypass circuit has the benefit of improving venous return and results in lowering priming volume. We introduced vacuum-assisted cardiopulmonary bypass circuit in order to reduce priming volume for pediatric patients in March 1995. A retrospective study was made on the efficacy of vacuum-assisted circuit for pediatric open-heart surgery in reducing homologous blood transfusion. Patients weighing from 5 to 20 kg who underwent surgery between January 1991 and June 1996 were divided into two groups, group A comprised 128 patients before introduction of this circuit and group B comprised 49 patients after introduction, and their clinical course was compared. Vacuum-assisted circuit was used in 27 patients of group B. The percentage of transfusion-free operations was significantly higher in group B than in group A (33.6% in group A vs. 53.1% in group B, P = 0.014), and particularly this percentage in patients weighing less than 10 kg significantly increased (0% in group A vs. 42.9% in group B, P < 0.01). The amount of homologous blood transfusion was significantly lower in group B than in group A (374 +/- 362 ml in group A and 212 +/- 287 ml in group B, P < 0.01). The rate of complications and the duration of respiratory support did not differ between the two groups. The duration of hospital stay was lower in group B than in group A. The findings of this study indicate that vacuum-assisted circuit is useful for pediatric open-heart surgery in reducing homologous blood transfusion.
    European Journal of Cardio-Thoracic Surgery 09/2001; 20(2):233-8. DOI:10.1016/S1010-7940(01)00769-2 · 3.30 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Open heart surgery without homologous blood transfusion remains difficult in children. The introduction of vacuum-assisted cardiopulmonary bypass circuits to reduce priming volume for pediatric patients has improved the percentage of transfusion-free operations. We retrospectively analyzed blood transfusion risk factors to further reduce blood transfusion requirements after vacuum-assisted circuit introduction. From March 1995 to June 1996, 49 patients weighing between 5 and 20 kg underwent cardiac surgery with cardiopulmonary bypass at our institution, excluding hospital deaths. We retrospectively analyzed risk factors influencing blood use in 37 patients with no blood priming in cardiopulmonary bypass after introducing a vacuum-assisted system. Factors selected for univariate analysis were age, body weight, cyanosis, preoperative Hb, operation time, cardiopulmonary bypass time, aortic cross-clamping time, and intraoperative and postoperative bleeding volume. Correlation between total bleeding volume/body weight and cardiopulmonary bypass time was studied by regression analysis. As risk factors, univariate analysis identified cyanotic disease, longer operation time (> 210 minutes), longer cardiopulmonary bypass time (> 90 minutes), longer aortic cross-clamping time (> 45 minutes), greater intraoperative bleeding volume/body weight (> 4 ml/kg), and greater postoperative bleeding volume/body weight (> 15 ml/kg). Regression analysis showed a significant positive correlation between total bleeding volume/body weight and cardiopulmonary bypass time. Cyanotic disease and long bypass time are risk factors in reducing blood transfusion requirements in pediatric open heart surgery after introduction of vacuum-assisted circuits. Further efforts are needed, however, to reduce blood transfusion requirements, particularly in these children.
    The Japanese Journal of Thoracic and Cardiovascular Surgery 09/2001; 49(9):564-9. DOI:10.1007/BF02913533

  • 01/2001; 30(1):29-32. DOI:10.4326/jjcvs.30.29
  • K Nakanishi · O Oba · T Shichijo · M Nakai · T Sudo · K Kimura ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Study was made on the operative results, risk factors, and late results of coronary artery bypass grafting (CABG) for acute myocardial infarction (AMI) conducted at our hospital. The subjects of the present study were 70 cases of AMI who underwent CABG during a period of five years from January 1991 to December 1995. They were composed of 61 males and 9 females whose mean age was 61.9 years. LMT disease was observed in 13 cases and preoperative shock in 18 cases. The mean aortic cross-clamp time was 64 minutes with the mean extracorporeal circulation time being 134 minutes and the mean number of grafts being 2.5. The mean preoperative-postoperative peak creatine kinase was 4479 IU/L. The number of operative deaths was 14 with a mortality rate of 20%. When compared with elective cases of CABG conducted during the same period with a mortality rate of 2.7%, the operative result of AMI was poor. The mortality rate by risk factor was 40% for age of 70 years or more, 46.2% for complication of LMT disease, 52.9% for preoperative shock, 58.3% for preoperative C.I. of less than 2.0, 80% for postoperative C.I. of less than 2.0, 28.2% for conduct of postoperative circulatory support, and 42.1% for peak creatine kinase of 5000 IU/L or more. Aortic cross-clamp time and reperfusion time (interval from onset of AMI to aortic declamp) were found not to be risk factors. Late death accounted for 5 cases including one case of cardiac death due to suspected AMI. Survival rate excluding operative deaths and hospital deaths was 98% in one year and 83.9% in five years. When compared to non cardiacevent cases, the survival rate of positive cardiac event cases was significantly poor. The operative results of severe myocardial ischemia cases represented by cases of complication of LMT disease were poor and it is considered that improvement of intraoperative myocardial protection and aggressive use of postoperative circulatory support are necessary in the future. The survival cases of those who could endure surgery was comparatively satisfactory, but when cardiac event developed, prognosis was poor and thus more rigid follow-up is considered to be necessary.
    [Zasshi] [Journal]. Nihon Kyōbu Geka Gakkai 08/1997; 45(7):950-7.
  • T Shichijo · O Oba · K Nakanishi · M Nakai · T Sudo · K Kimura ·
    [Show abstract] [Hide abstract]
    ABSTRACT: A total of 121 patients aged 75 years or older underwent cardiac operation or thoracic aortic operation at our hospital between 1988 and February 1997. They were composed of 74 cases of ischemic heart disease, 22 cases of valvular disease, 1 case of myxoma, and 24 cases of thoracic aortic disease. Operative mortality rate was 13.5% in ischemic heart disease, 4.2% in valvular disease and myxoma, and 25% in thoracic aortic disease. In ischemic heart disease, the operative mortality rate was especially high in emergency operation for acute myocardial infarction. In thoracic aortic operation, further improvement should be made with regard to preoperative and intraoperative management.
    Kyobu geka. The Japanese journal of thoracic surgery 08/1997; 50(8 Suppl):714-7.

  • 01/1997; 26(5):279-284. DOI:10.4326/jjcvs.26.279

Publication Stats

65 Citations
12.65 Total Impact Points


  • 2012
    • National Cerebral and Cardiovascular Center
      Ōsaka, Ōsaka, Japan
  • 2010-2011
    • Minami Okayama Medical Center
      Okayama, Okayama, Japan
  • 2001-2004
    • Hiroshima City Hospital
      Hirosima, Hiroshima, Japan
    • Okayama University
      • Department of Cardiovascular Surgery
      Okayama, Okayama, Japan