Shin-ichi Ohki

Jichi Medical University, Totigi, Tochigi, Japan

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Publications (19)8.43 Total impact

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    ABSTRACT: The purpose of this study was to evaluate retrospectively the clinical performance of the Bicarbon valve (Sorin Biomedica Cardio, Saluggia, Italy) implanted at our center in Japan. Between January 1997 and December 2011, 415 patients in our institution were implanted with the Bicarbon valve. Nine of these recipients were excluded from the study because they had already undergone valve implantation and received a Bicarbon valve in a different position. The remaining patients were analyzed for evaluation of the postoperative clinical outcomes. Of the 406 patients (mean age 60.2 ± 11.7 years), 179 underwent aortic valve replacement (AVR), 149 mitral valve replacement (MVR), and 78 both aortic and mitral valve replacement (DVR). There were 10 early deaths (2.5 %: 4 in the AVR group and 6 in the MVR group). Three hundred eighty-nine patients were followed up (95.8 % completeness of follow-up) with a mean follow-up of 6.6 ± 4.2 years overall (AVR 6.8 ± 4.2, MVR, 6.7 ± 4.4, and DVR 5.7 ± 3.4 years) and a cumulative follow-up of 2661 patient-years (1214, 1001, and 446 patient-years for AVR, MVR, and DVR, respectively). Ninety-nine patients died (3.7 % per patient-year: 22 valve-related and 77 valve-unrelated deaths). Survival at 10 years was 74.1 ± 4.0 % in the AVR group, 73.7 ± 4.2 % in the MVR group, and 61.0 ± 7.9 % in the DVR group. The linearized incidence of thromboembolic complications, bleeding complications, prosthetic valve endocarditis, paravalvular leaks, and sudden death in all patients was 0.5 %, 0.5 %, 0.2 %, 0.2 %, and 0.4 % per patient-year, respectively. The incidence of valve-related complications and reoperation was 1.6 % and 0.4 %, respectively. No other valve-related complications were observed. The Bicarbon prosthetic heart valve has shown excellent clinical results and is associated with a low incidence of valve-related complications.
    Journal of Cardiothoracic Surgery 01/2015; 10(1):89. DOI:10.1186/s13019-015-0294-x · 3.05 Impact Factor
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    Asian cardiovascular & thoracic annals 06/2012; 20(3):351. DOI:10.1177/0218492311419767
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    ABSTRACT: A 59-year-old man with a history of ascending aorta replacement for an aortic dissection using gelatin-resorcin-formalin glue at age of 50 years presented with paroxysmal nocturnal dyspnea. An echocardiogram showed severe aortic regurgitation associated with aortic root enlargement. Chest computed tomography showed that the ascending aorta was dilated and a pseudoaneurysm was observed around the implanted prosthetic graft. Upon opening the ascending aorta, we found that the posterior wall of the proximal anastomotic portion of the implanted graft was ruptured. After replacement of the aortic root with a composite graft and reconstruction of the orifices of the right and left coronary arteries, total arch replacement by the separated graft technique was performed. The postoperative course was uneventful.
    General Thoracic and Cardiovascular Surgery 04/2012; 60(7):443-5. DOI:10.1007/s11748-012-0022-6
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    ABSTRACT: Purpose: This study aimed to determine the procedure-related morbidity and mortality of infrarenal abdominal aortic aneurysm (AAA) repair, to investigate the changes in perioperative laboratory val-ues, and to clarify the specific independent predictive factors for mortality and morbidity. We retro-spectively evaluated patients who were treated in Jichi Medical University Hospital. Methods: Consecutive patients with AAA between April 2007 and August 2010 were studied. The possible predictive values of various patient-and operation-related variables on outcomes (mortality, duration of stay in hospital (>7 days), and major morbidity) were assessed by multivariate analysis. Results: Overall in-hospital mortality was 3.3%. Statistically significant differences, all in favor of endovascular aneurysm repair (EVAR), were observed in the intraoperative and post-operative data. In multivariate logistic analysis, potassium, serum creatinine and C-reactive protein levels were sig-nificantly related to outcomes. Conclusions: Open repair and EVAR can both be safely performed in patients treated for elective and emergency infrarenal AAA. EVAR has perioperative advantages of reduced blood loss and blood transfusion, as well as decreased mortality and duration of post-operative hospital stay. In particular, we identified specific independent predictive factors of serum chemistry values for mortality and renal insufficiency. Introduction An abdominal aortic aneurysm (AAA) is defined as an enlargement of the aortic diameter with at least 150% of the diam-eter at the orifice of the renal arteries [1]. Elective treatment is recommended when the AAA size reaches 55 mm in diameter because of higher rates of rupture. Open
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    ABSTRACT: Purpose: This study aimed to determine the procedure-related morbidity and mortality of infrarenal abdominal aortic aneurysm (AAA) repair, to investigate the changes in perioperative laboratory val-ues, and to clarify the specific independent predictive factors for mortality and morbidity. We retro-spectively evaluated patients who were treated in Jichi Medical University Hospital. Methods: Consecutive patients with AAA between April 2007 and August 2010 were studied. The possible predictive values of various patient-and operation-related variables on outcomes (mortality, duration of stay in hospital (>7 days), and major morbidity) were assessed by multivariate analysis. Results: Overall in-hospital mortality was 3.3%. Statistically significant differences, all in favor of endovascular aneurysm repair (EVAR), were observed in the intraoperative and post-operative data. In multivariate logistic analysis, potassium, serum creatinine and C-reactive protein levels were sig-nificantly related to outcomes. Conclusions: Open repair and EVAR can both be safely performed in patients treated for elective and emergency infrarenal AAA. EVAR has perioperative advantages of reduced blood loss and blood transfusion, as well as decreased mortality and duration of post-operative hospital stay. In particular, we identified specific independent predictive factors of serum chemistry values for mortality and renal insufficiency. Introduction An abdominal aortic aneurysm (AAA) is defined as an enlargement of the aortic diameter with at least 150% of the diam-eter at the orifice of the renal arteries [1]. Elective treatment is recommended when the AAA size reaches 55 mm in diameter because of higher rates of rupture. Open
    04/2012; DOI:10.5455/aces.20120402072208
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    ABSTRACT: Purpose: This study aimed to determine the morbidity and mortality of infrarenal ruptured abdominal aortic aneurysm (rAAA) repair, and to investigate the changes in perioperative laboratory values, as well as clarify the specific independent predictive factors for mortality and morbidity. We retrospectively evaluated patients who were treated in Jichi Medical University Hospital. Methods: A consecutive fifty-six patients with rAAA between April 2007 and August 2010 were studied. The possible predictive values of various patient-related variables on outcomes (mortality, major morbidity and renal insufficiency) were assessed by univariate and multivariate analysis. Results: The overall in-hospital mortality was 16.1%. In univariate logistic analyses, lactate dehydrogenase, alanine aminotransferase, as well as pre-operative and post-operative serum creatinine levels were significantly related to mortality. Blood transfusion volume, white blood cells and C-reactive protein levels were significantly related to major morbidity. Intraoperative blood loss, white blood cells, C-reactive protein levels, lactate dehydrogenase and pre-operative serum creatinine levels were significantly related to renal insufficiency. Conclusions: Emergency open repair can be safely performed in patients for infrarenal rAAA. In particular, we identified specific independent predictive factors of clinical examination and laboratory studies for mortality, major morbidity and renal insufficiency.
    03/2012; DOI:10.5455/aces.20120314112444
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    Modern Pacemakers - Present and Future, 02/2011; , ISBN: 978-953-307-214-2
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    ABSTRACT: We present a patient with a nine-year history of Behçet's disease (BD), who developed a rapidly expanding aneurysm of the aortic arch. Three-dimensional computed tomography demonstrated a saccular aortic arch aneurysm with a maximal diameter of 5 cm. No bacteria were detected by serial blood cultures. The aneurysm, however, showed a multi-lobular cavity, mimicking an infectious aneurysm. Therefore, we prescribed antibacterial agents for one week. The patient still had a high-fever and an elevated C-reactive protein level thereafter. Aortic arch replacement was performed emergently. Because we were unable to determine whether the aneurysm was caused by infection or BD, the implanted prosthetic graft and the anastomotic sites were covered with a pedicle graft of the greater omentum, and we continued to administer antibacterial agents for four weeks postoperatively. The pathological examination showed neither bacteria nor cystic medial necrosis in the resected aortic wall. Inflammatory changes with eosinophilic infiltration were recognized mainly around the adventitia near the aneurysm. The patient had a favorable postoperative course without any complications.
    Interactive Cardiovascular and Thoracic Surgery 12/2010; 12(3):502-4. DOI:10.1510/icvts.2010.260976 · 1.11 Impact Factor
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    ABSTRACT: A 57-year-old man, who was a chronic axillary crutch user as a result of childhood poliomyelitis, was referred to our hospital because of a sudden onset of right forearm ischemia. The right forearm had no pulse, and three-dimensional computed tomography (3DCT) showed an aneurysm of the right brachial artery associated with arterial occlusion. The thrombosed aneurysm of the brachial artery was resected and the brachial artery was successfully revascularized by interposing a saphenous vein graft. Postoperative 3DCT revealed an asymptomatic left brachial artery aneurysm. His postoperative course was uneventful under warfarin anticoagulation therapy.
    Interactive Cardiovascular and Thoracic Surgery 09/2009; 9(6):1038-9. DOI:10.1510/icvts.2009.219832 · 1.11 Impact Factor
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    ABSTRACT: A 59-year-old man was transferred to our hospital because of mural thrombus in the ascending aorta. He had suffered some neurological dysfunctions such as transient dysorientation. Electrocardiogram showed normal sinus rhythm without premature beats. Trans-thoracic echocardiogram and three-dimensional CT showed a mobile mural mass sticking to the ascending aortic wall. No coagulopathy was detected in the patient. The mural masses were thought to be a possible cause of the repeated cerebro-vascular symptoms. Under cardiopulmonary bypass and cardiac arrest, the masses were removed including the mass sticking to the aortic wall. Postoperative pathological findings showed the masses were organizing thrombi that had originated from the atherosclerotic aortic wall. Postoperative course was uneventful, and the patient was doing well one year after the operation without neurological dysfunction.
    Interactive Cardiovascular and Thoracic Surgery 09/2009; 9(5):899-900. DOI:10.1510/icvts.2009.212241 · 1.11 Impact Factor
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    ABSTRACT: A 42-year-old man, who 25 years previously underwent grafting of the descending aorta because of traumatic rupture after a traffic accident, was admitted to our hospital complaining of fever and hemoptysis. Computed tomography (CT) scans showed a low density area around the prosthetic graft. We diagnosed a graft infection. We undertook extraanatomical ascending-abdominal aorta bypass with stump closure of the descending aorta, with omentopexy around the stump. Postoperative course was uneventful and he has been free from infection for one year. Extraanatomical bypass was an effective strategy for treatment of a graft infection.
    Interactive Cardiovascular and Thoracic Surgery 06/2008; 7(4):646-7. DOI:10.1510/icvts.2008.178699 · 1.11 Impact Factor
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    ABSTRACT: This study reports on a 57-year-old woman who underwent a 3rd mitral valve replacement and presented with complaints of fatigue. Laboratory examination revealed severe hemolytic anemia, and trans-esophageal echocardiography revealed a paravalvular leak (PVL) around the prosthetic valve at the posterior trigone in the mitral position. PVL was regarded as the cause of hemolytic anemia. At surgery, a small tissue defect was detected around the calcified posterior trigone of the mitral annulus with no evidence of infective endocarditis. The mitral PVL was successfully repaired with suture closure of the annular defect. The postoperative course was uneventful: postoperative echocardiography revealed no evidence of PVL, and the hemolytic anemia subsided.
    Kyobu geka. The Japanese journal of thoracic surgery 10/2007; 60(10):903-5.
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    ABSTRACT: A 60-year-old woman had previously undergone aortic valve replacement for aortic regurgitation. As the aortic wall was elastic hard, inflammatory change was suspected; therefore, we undertook a partial biopsy of the ascending aortic wall and the intraoperative pathological specimens were compatible with aortitis syndrome. As there was no active inflammatory change, she was diagnosed as inactive aortitis syndrome and steroid therapy was not applied. Seven years later, a follow-up computed tomography (CT) showed an ascending aortic aneurysm of 65 mm in diameter. Aortic root replacement was planned based on a clinical diagnosis of an aneurysm of the ascending aorta. The patient was discharged without complication 21 days after surgery. It is possible that an inactive stage of aortitis may lead to late dilatation of the ascending aorta; therefore, careful postoperative follow-up is necessary in such cases.
    Kyobu geka. The Japanese journal of thoracic surgery 12/2006; 59(12):1103-5.
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    ABSTRACT: We report 2 cases of cardiac papillary fibroelastomas in adults. Case 1: A 61-year-old man was admitted because echocardiography showed a 1 cm pedunculated papillary tumor in the left atrium. In an operation, it was located in the left atrium near the mitral valve and was resected along with a 5 mm margin of endocardium. Case 2: A 60-year-old woman had a 1 cm mobile tumor in the right ventricle near the tricuspid valve located by echocardiography in a preoperative examination of a ventricular septal defect. In an operation, a pedunculated tumor located in the right ventricle was resected. In these 2 cases, histopathology showed the tumor to be a papillary fibroelastoma. Almost all cardiac papillary fibroelastoma are closely related to the cardiac valve, but in these cases, the tumors were located in the left atrium, and the right ventricle, respectively, which is quite rare.
    Kyobu geka. The Japanese journal of thoracic surgery 01/2006; 58(13):1163-5.
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    ABSTRACT: Recently, there has been an increase in case of repeated open-heart valve surgery and the clinical results of the second surgery are only slightly worse than those of the first surgery. However, clinical results of the third open-heart valve surgery at the same position are rarely reported. Clinical features of third open-heart valve surgery at the same position are discussed in this study. Between 1995 and 2004, 16 patients underwent third open-heart valve surgery at the same valve position under cardiopulmonary bypass. The average age of the 16 patients, 12 females and 4 males, was 56 +/- 15 years. Clinical features of the 16 cases were retrospectively analyzed. Mechanical valve nonstructural dysfunction was the most common valve malady, followed by bioprosthetic valve dysfunction. The duration of surgery from skin incision to establishment of the cardiopulmonary bypass was 94 +/- 42 minutes. Myocardial ischemia time was 137 +/- 38 minutes and extracorporeal circulation time was 212 +/- 82 minutes. Early mortality was seen in 1 patient (6.25%) and late mortality was seen in 1 patient. Mechanical valve nonstructural valve dysfunction leads to repeated valve surgery. The clinical results of the third open-heart valve surgery at the same valve position are acceptable, and the mid-term survival is excellent.
    The Japanese Journal of Thoracic and Cardiovascular Surgery 01/2006; 53(12):627-31. DOI:10.1007/BF02665072
  • Yoshio Misawa, Shin-ichi Ohki, Yasuhito Sakano
    Journal of Thoracic and Cardiovascular Surgery 02/2005; 129(1):236-7; author reply 237. DOI:10.1016/j.jtcvs.2004.09.018 · 3.99 Impact Factor
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    ABSTRACT: A 62-years old man had plural aneurysms from the aortic arch to the descending aorta. Y-grafting had been performed twice for an abdominal aortic aneurysm. We performed the first operation which involved aortic valve and arch replacement under deep hypothermia with selective cerebral perfusion. During the operation, hemodynamics was stable, but after the operation he developed paraplegia due to ischemic change in the spinal cord. It was considered that the cause of the ischemia might have been the changing of the blood supply to the spinal cord. In patients with severe atherosclerosis, the blood supply for the spinal cord needs to be very strictly determined.
    Kyobu geka. The Japanese journal of thoracic surgery 05/2004; 57(4):325-8.
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    ABSTRACT: A 52-year-old woman, height, 149 cm; weight, 40 kg, was admitted because of anterior chest discomfort and palpitations. There was no family history of Marfan syndrome. She had undergone replacement of the ascending aorta and aortic valve 10 years prior for DeBakey II aortic dissection. Postoperative pathological examination of the resected aortic wall revealed cystic medionecrosis. Computed tomography(CT) 4 years after the surgery showed moderate enlargement of the preserved sinuses of Valsalva, and CT 10 years after the surgery showed enlargement of the sinus. She consented to a reoperation. The prostheses were explanted, and the aortic root was replaced with a composite graft. The right coronary artery ostium was completely closed, and no graftable portions of the distal right coronary artery were detected. Thus, the left coronary artery alone was reimplanted. The patient required extracorporeal membrane oxygenation for 10 days postoperatively, after which she recovered fully without complications. This case may indicate that the complete aortic root should be replaced during initial surgery of the ascending aorta or aortic valve in patients with potential risk of sinus of Valsalva dilatation.
    Kyobu geka. The Japanese journal of thoracic surgery 09/2003; 56(9):786-9.
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    ABSTRACT: Between June, 1993 and January, 1995 a gelatin-sealed knitted Dacron (Gelseal) (g-G0, n = 7) and a collagen-sealed knitted Dacron graft (Hemashield) (g-H0, n = 8) were randomly implanted to 15 patients (pts) for replacement of thoracic aorta. We evaluated postoperative inflammatory responses and levels of Toxicolor and Endospecy which are the measurements of endotoxin. Five pts in g-G0 and 3 pts in g-H0 showed that a body temperature (BT) were above 37.5 degrees C on the 7th postoperative day (POD). In three of them (2 in g-G0 and 1 in g-H0), BT above 37.5 degrees C continued until POD 14 due to the bacterial infection. The other causes of elevation of BT were pleural effusion (2), pericardial effusion (1) and unknown origin (2). Patients without evidence of infection (n = 12) were divided into 2 groups (g-G: pts with Gelseal, n = 5, g-H: pts with Hemashield, n = 7). On POD3, postoperative BT in g-H was significantly higher than in g-G. And, on POD7, BT in g-G rose up more than in g-H. However, on POD14, BT decreased to the normal range in both groups. The values of WBC in g-G were slightly higher than in g-H and they became normal after POD7 in both groups. The levels of CRP in g-H were higher than in g-G after POD3 and in both groups they were still high on POD14. In terms of endotoxin., Toxicolor was already above the normal range from POD1 and decreased to the normal range after POD14. However, the level of Endospecy kept within normal range. In conclusion, Toxicolor-reactive substance elevates by using Gelseal and Hemashield. Its substance is not endotoxin. It would not be appropriate to consider that endotoxin is an origin of fever between POD7 and 14.
    [Zasshi] [Journal]. Nihon Kyōbu Geka Gakkai 05/1997; 45(4):531-5.
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    ABSTRACT: Thoracic graft infection is a serious complication with high mortality. We report a case of successful treatment of mediastinitis and graft infection after aortic arch and thoracoabdominal aortic reconstruction. A 56-year-old woman underwent surgery for thoracoabdominal aortic aneurysm. The aneurysm was replaced with prosthetic grafts. She had a high fever on the 12th postoperative day (POD). A Chest X-ray and CT scan demonstrated fluid collection around the grafts. On the 17th POD, mediastinal drainage was performed and Staphylococcus epidermidis was detected. Because of the difficulty to replace the infected grafts, a continuous drainage from the mediastinal cavity around the grafts was induced for 17 days and sensitive antibiotics to the pathogen was administered systemically for 40 days. Inflammatory reactions were improved and her general condition was stabilized. On the 64th POD, she was discharged.
    [Zasshi] [Journal]. Nihon Kyōbu Geka Gakkai 03/1997; 45(2):220-4.