Kazumasa Orihashi

Kochi University, Kôti, Kōchi, Japan

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Publications (200)306.58 Total impact

  • The American surgeon 12/2014; 80(12). · 0.92 Impact Factor
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    ABSTRACT: When performing coronary artery bypass grafting, anastomotic insufficiency needs to be detected during surgery. We developed a novel indocyanine green angiography system, the HyperEye Medical System (HEMS), which enables color imaging of the bypass flow. This article described the accuracy of HEMS angiography for predicting graft patency.
    Surgery Today 08/2014; · 0.96 Impact Factor
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    ABSTRACT: We have developed a novel method of measuring spinal cord evoked potentials with stimulation and recording at the intercostal nerves (trans-intercostal evoked spinal cord potential: Tic-ESCP). The purpose of this study was to examine the feasibility and accuracy of Tic-ESCP during thoracic aortic surgery.
    Annals of Vascular Surgery 05/2014; · 0.99 Impact Factor
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    ABSTRACT: In the treatment for pacemaker infection, removal of infected devices and intensive antibiotics therapy are in principle and new devices should be implanted apart from the infected site. However, there are some problems in the case of children:it is not easy to remove infected devices because epicardial leads are often used for them. If endocardial leads are chosen as a new system, extension of the lead would be concerned with their growth. We report a pediatric case of infection of pacemaker using epicardial leads. It was difficult to cure infection by repeated local treatment leaving epicardial leads and antibiotics therapy was obliged to continue for 9 years to keep infection under control. After growing up, we implanted endocardial leads for her and removed infected devices to cure infection completely.
    Kyobu geka. The Japanese journal of thoracic surgery 02/2014; 67(2):157-60.
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    ABSTRACT: Real-time graft flow assessment in the operative field has been performed to ascertain the patency in coronary artery bypass grafting (CABG). This study aims to evaluate the efficacy of graft flow assessment by epigraftic ultrasonography. CABG was performed in 135 patients from January 2010 to December 2012. One hundred and ten patients (81.4%) underwent both real-time graft flow measurement using epigraftic ultrasonography and coronary angiography (CAG) with a total of 249 grafts. Parameters were obtained from flow velocity curves in all grafts. The grafts were divided into two groups: patent grafts (Group A) and failing grafts (Group B). All parameters were compared in these two groups. Logistic regression analysis was performed to detect the predictors of graft failure and receiver operating characteristic (ROC) curve analysis was used to calculate the optimal cut-off value of the predictors of graft failure. The overall patency as measured by CAG of the grafts was 97.2% (242/249). Logistic regression analysis revealed that the percentage of systolic and diastolic reverse flow (%sRF, %dRF) as well as the pulsatility index (PI) were predictors of early postoperative graft failure. ROC curve analysis revealed that mean velocity <12.5 cm/s, %sRF >9.3%, %dRF >4.1% and PI >4.4 were predictors of early graft failure. In this series, epigraftic ultrasonography depicted graft flow clearly. Epigraftic ultrasonography is a useful tool to predict graft failure during CABG. This technique is easily performed using a conventional linear ultrasound transducer.
    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: We report two cases of graft migration during open stent grafting, detected by transesophageal echocardiography (TEE). The incidence was 3.7% in our series. The length of landing zone was reduced from 45 mm to 25 mm in case 1 and from 50 mm to 22 mm in case 2 before chest closure. Aneurysmal protrusion on the greater curvature with thin mural thrombus were findings common in both cases. Although additional intervention was not done based on the TEE findings of no endoleak and thrombus formation in the aneurysm, and postoperative course was uneventful, meticulous imaging check-up was needed.
    Annals of Vascular Diseases 01/2014; 7(1):75-8.
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    ABSTRACT: Here we report the case of a 68-year-old woman who presented with shortness of breath. Respiratory function tests showed a slightly obstructive physiology. Computed tomography (CT) revealed an aberrant left subclavian artery and a Kommerell diverticulum arising from a right-sided aortic arch that was compressing the trachea and surrounding tissues. A median sternotomy was performed with the patient under circulatory arrest with moderate hypothermia, and a trans-aortic stent graft was inserted to exclude the Kommerell diverticulum. The aberrant left subclavian artery was ligated and an axillo-axillar bypass was constructed. Postoperative CT showed complete exclusion of the Kommerell diverticulum without an endoleak. The patient's breathing difficulty resolved and she was discharged uneventfully. This procedure should be considered as an alternative strategy for exclusion of Kommerell diverticulum.
    Annals of Vascular Surgery 12/2013; · 0.99 Impact Factor
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    ABSTRACT: A calcified amorphous tumor (CAT) is a rare intracardiac mass that carries a risk of embolism. We herein present the case of a club-shaped CAT that originated from the calcified mitral annulus. Echocardiography indicated a pendular motion of the mass and repeated entrapment by a stenotic aortic valve that was sustained for several beats, mimicking a chameleon's tongue. An emergency operation was performed because of the risk of embolism, as well as potential progression of cardiac failure due to worsening aortic valve stenosis. The histological findings were consistent with the diagnosis of a CAT. This report describes a case of an intracardiac tumor that showed unique motion like a chameleon's tongue.
    Surgery Today 08/2013; · 0.96 Impact Factor
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    ABSTRACT: This study tested to see if trehalose, a cytoprotective disaccharide, protects against spinal cord ischemia in a rabbit model. The infrarenal aorta was mobilized in four groups of 10 rabbits. In groups I, II, and III, it was clamped proximally and distally for 20 minutes. In group I, the clamped aorta was infused at 2.5 L/min for 2 hours with lactated Ringer's (LR) solution. In group II, the clamped aorta was infused with 5% trehalose in LR. LR was administered intravenously (2.0 mL/min) in groups I and II starting 30 minutes before clamping. In group III, 5% trehalose in LR was infused intravenously only. Group IV was a sham-operated control group without aortic clamping. At 8, 24, and 48 hours after reperfusion, hind limb function was scored using the Tarlov score (paralysis = 0, perceptible joint movement = 1, good joint movement but unable to stand = 2, able to walk = 3, normal = 4). Histologic analysis and electron microscopy were performed on anterior horn cells. The Tarlov scores in groups I, II, and III were, respectively, 1.1 ± 1.4, 3.5 ± 0.5, and 2.9 ± 0.9 at 8 hours; 0.8 ± 1.2, 3.9 ± 0.3, and 2.9 ± 0.9 at 24 hours; and 0.6 ± 0.7, 3.9 ± 0.3, and 2.7 ± 0.9 at 48 hours after reperfusion. Group IV scores were normal (4 ± 0) at all assessments. These scores were higher in groups II and III than in group I (P < .01) at all assessments. Scores at 24 and 48 hours were higher in group II than in group III (P < .05). In group III, delayed paraparesis developed in one rabbit at 24 hours and in two more at 48 hours. Histopathologic analysis showed the number of normal neurons was higher in groups II (P < .0001), III (P = .006), and IV (P < .0001) vs group I. Electron microscopy confirmed preserved neuronal cell ultrastructure in rabbits with normal limb function. Transaortic trehalose infusion was protective against paraplegia, whereas intravenous trehalose reduced spinal cord ischemia. This study was preliminary and further studies are needed.
    Journal of vascular surgery: official publication, the Society for Vascular Surgery [and] International Society for Cardiovascular Surgery, North American Chapter 08/2013; · 3.52 Impact Factor
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    ABSTRACT: The two most common types of coronary perfusion cannulae currently being used are the "balloon type", with a balloon at the tip, and the "fenestrated type", which has holes along the side near the tip. However, on occasion an unusually high perfusion pressure or a considerable amount of leakage is encountered during infusion of the cardioplegic solution. We have examined the properties of a newly developed Kochi Medical School (KMS)-type cannula and compared these to the properties of the balloon-type and fenestrated-type cannulae in an ex vivo experimental model that contains ostia of 4, 3, or 2 mm in diameter. Ejected flow velocity, circuit pressure, and the amount of leakage were measured at an infusion rate of 100 and 200 mL/min, with the latter two parameters measured under the counterpressure of 0 and 50 cmH2O to examine the influence of coronary vascular resistance. Without counterpressure, the balloon type presented with the highest flow velocity (263 cm/s at 200 mL/min) and perfusion pressure (64 mmHg at 200 mL/min) but without leakage. The fenestrated type yielded a considerable amount of leakage (40 % at an ostium size of 2 mm). The KMS type showed a lower flow velocity and circuit pressure with less leakage. Under 50 cmH2O counterpressure, however, only the KMS-type cannula could inject the water to any ostium size at both flow rates. These results suggest that the concept of the KMS-type cannula may be advantageous to achieving a secure infusion to a diseased coronary ostium.
    Journal of Artificial Organs 08/2013; · 1.41 Impact Factor
  • Kazumasa Orihashi
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    ABSTRACT: BACKGROUND: Despite a reduced incidence of false lumen perfusion with preferential use of axillary arterial perfusion in acute type A aortic dissection, malperfusion remains a major cause of operative mortality and sequelae. The incidence of unpredictable malperfusion and its mechanism were examined. METHODS: We examined the 59 consecutive cases of type A aortic dissection treated surgically, including 17 cases (28.8%) with preoperative malperfusion. Whereas femoral arterial perfusion was used in 7 cases with profound shock, axillary arterial perfusion was employed in the remaining 52 cases. Organ perfusion was assessed with various modalities including transesophageal echocardiography, orbital Doppler, and near-infrared spectroscopy. RESULTS: Although false lumen perfusion was not encountered, persistent or new malperfusion was detected in 5 cases (8.5%) with unrestored true lumen. Malperfusion remained in 3 cases. Of these, bilateral axillary arterial perfusion in 1 case and selective perfusion through the femoral artery in 1 case were effective; however, additional ascending aortic cannulation in 1 case was unsuccessful. In the remaining 2 cases, unilateral axillary arterial perfusion led to reduced oxygen saturation in the contralateral frontal lobe, which was restored by bilateral axillary arterial perfusion probably due to augmented collateral circulation. Subclavian steal due to occluded innominate artery was detected in 1 of them. Immediate decision making based on real-time information was beneficial. CONCLUSIONS: Despite preferential axillary arterial perfusion, new or persistent malperfusion occurred in 5 cases (8.5%). There is no perfect perfusion route but real-time assessment and individualized navigation may be beneficial in further improving the outcomes.
    The Annals of thoracic surgery 04/2013; · 3.45 Impact Factor
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    ABSTRACT: A 63-year old man had dysphagia for 4 months and was admitted to our hospital with sudden haematemesis. Computed tomography revealed an aberrant right subclavian artery (ARSA) aneurysm and free air inside the aneurysm. Arterio-oesophageal fistula was diagnosed, and an emergency operation was performed. Before thoracotomy, a percutaneous transluminal angioplasty (PTA) balloon was inserted from the right brachial artery and placed at the orifice of the ARSA to control bleeding. Through a left thoracotomy, the aorta was excised and the orifice of the ARSA was exposed. There was no sign of infection in the operative field. Bleeding from the ARSA was controlled by balloon occlusion. The proximal portion of the right vertebral artery was ligated and blood backflow from the ARSA stopped. The ARSA was ligated proximal to the aneurysm, and the orifice of the ARSA to the aorta was closed. The infected aneurysm was not resected. The descending aorta was replaced by a rifampin-bonded artificial graft, and omentopexy was performed. Gastrostomy was performed for decompression of the oesophagus and enteric feeding. Three months after the operation, gastrointestinal endoscopy showed a healed oesophageal ulcer, and the patient was discharged uneventfully.
    Interactive Cardiovascular and Thoracic Surgery 03/2013; · 1.11 Impact Factor
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    ABSTRACT: Background:We searched for a viral aetiology for non-small cell lung cancer (NSCLC), focusing on Merkel cell polyomavirus (MCPyV).Methods:We analysed 112 Japanese cases of NSCLC for the presence of the MCPyV genome and the expressions of RNA transcripts and MCPyV-encoded antigen. We also conducted the first analysis of the molecular features of MCPyV in lung cancers.Results:PCR revealed that 9 out of 32 squamous cell carcinomas (SCCs), 9 out of 45 adenocarcinomas (ACs), 1 out of 32 large-cell carcinomas, and 1 out of 3 pleomorphic carcinomas were positive for MCPyV DNA. Some MCPyV DNA-positive cancers expressed large T antigen (LT) RNA transcripts. Immunohistochemistry showed that MCPyV LT antigen was expressed in the tumour cells. The viral integration sites were identified in one SCC and one AC. One had both episomal and integrated/truncated forms. The other carried an integrated MCPyV genome with frameshift mutations in the LT gene.Conclusion:We have demonstrated the expression of a viral oncoprotein, the presence of integrated MCPyV, and a truncated LT gene with a preserved retinoblastoma tumour-suppressor protein-binding domain in NSCLCs. Although the viral prevalence was low, the tumour-specific molecular signatures support the possibility that MCPyV is partly associated with the pathogenesis of NSCLC in a subset of patients.British Journal of Cancer advance online publication, 15 January 2013; doi:10.1038/bjc.2012.567 www.bjcancer.com.
    British Journal of Cancer 01/2013; · 5.08 Impact Factor
  • Yasunaga Okazaki, Kazumasa Orihashi
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    ABSTRACT: endovenous heat-induced thrombosis (EHIT) and great saphenous vein (GSV) recanalization. To eliminate these complications, we developed ultrasonographyguided high ligation (UGHL) using a puncture-sized incision as an adjunct treatment to EVLA. UGHL combined with EVLA was used in 20 patients. The GSV was encircled with 2-0 silk thread at 2 cm distal to the saphenofemoral junction through two incisions of 2-3 mm by using a Deschamps aneurysm needle under ultrasonographic guidance. UGHL was technically feasible in all cases, and no case presented with complications. UGHL may be used in addition to EVLA.
    Annals of Vascular Diseases 01/2013; 6(2):221-5.
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    Journal of the American Geriatrics Society 01/2013; 61(1):169-70. · 4.22 Impact Factor
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    ABSTRACT: We report two cases of acute limb ischemia with threatened myonephropathic metabolic syndrome (MNMS) in which continuous hemodiafiltration (CHDF) was started before revascularization with selective drainage from the clamped femoral vein of ischemic limb and return of processed blood into the contralateral femoral vein. It was aimed to optimise the removal of metabolites which were produced by myolysis following reperfusion as well as to minimize the deviation of metabolites into the systemic circulation. Both cases had uneventful postoperative course without MNMS and the limbs were salvaged.
    Journal of Artificial Organs 11/2012; · 1.41 Impact Factor
  • Hideaki Nishimori, Kazumasa Orihashi
    Kyobu geka. The Japanese journal of thoracic surgery 10/2012; 65(11):985-8.
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    ABSTRACT: The operation of cardiopulmonary bypass procedure requires an advanced skill in both physiological and mechanical knowledge. We developed a virtual patient simulator system using a numerical cardiovascular regulation model to manage perfusion crisis. This article evaluates the ability of the new simulator to prevent perfusion crisis. It combined short-term baroreflex regulation of venous capacity, vascular resistance, heart rate, time-varying elastance of the heart, and plasma-refilling with a simple lumped parameter model of the cardiovascular system. The combination of parameters related to baroreflex regulation was calculated using clinical hemodynamic data. We examined the effect of differences in autonomous-nerve control parameter settings on changes in blood volume and hemodynamic parameters and determined the influence of the model on operation of the control arterial line flow and blood volume during the initiation and weaning from cardiopulmonary bypass. Typical blood pressure (BP) changes (hypertension, stable, and hypotension) were reproducible using a combination of four control parameters that can be estimated from changes in patient physiology, BP, and blood volume. This simulation model is a useful educational tool to learn the recognition and management skills of extracorporeal circulation. Identification method for control parameter can be applied for diagnosis of heart failure.
    Artificial Organs 09/2012; · 1.96 Impact Factor
  • Journal of Plastic Reconstructive & Aesthetic Surgery 02/2012; 65(7):e200-1. · 1.44 Impact Factor
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    ABSTRACT: We performed box pulmonary vein isolation and the modified Maze procedure using cryoablation (cryo-maze) to eliminate chronic atrial fibrillation (AF) associated with mitral valve disease from 1999 to 2004. This article compares the elimination rate of chronic AF and the postoperative occurrence of new atrial tachycardia after both procedures over a follow-up period of >5 years. A total of 75 patients were enrolled in the study. Among them, 40 patients underwent box pulmonary vein isolation for chronic AF concomitant with solitary mitral valve surgery. Another 35 patients underwent the cryo-maze procedure for chronic AF concomitantly with both mitral and tricuspid valve surgeries. We evaluated the postoperative AF elimination rate and the occurrence of atrial tachycardia. During a total of 622.5 patient-years of followup, AF disappeared in 26 of 40 (65%) patients after the box pulmonary vein isolation and in 26 of 35 (74%) patients after the cryo-maze procedure at 5 years. Common atrial flutter occurred in 2 of 40 (5.0%) patients after the pulmonary vein isolation procedure. Left atrial tachycardia occurred in 1 (2.9%) and right atrial tachycardia in 1 (2.9%) of 35 patients after the cryo-maze procedure. The cryo-maze procedure was rather effective for eliminating chronic AF associated with both mitral and tricuspid valve disease, but there were a few cases with new atrial tachycardia. The box pulmonary vein isolation was useful in solitary mitral valve cases.
    General Thoracic and Cardiovascular Surgery 02/2012; 60(2):82-9.

Publication Stats

1k Citations
306.58 Total Impact Points


  • 2011–2014
    • Kochi University
      • Division of Surgery II
      Kôti, Kōchi, Japan
    • Kashiwa Kousei General Hospital
      Kashiwa, Chiba, Japan
  • 2011–2013
    • Kochi Medical School
      Kôti, Kōchi, Japan
  • 1987–2013
    • Hiroshima University
      • • Department of Surgery
      • • Department of Cardiovascular Surgery
      • • School of Medicine
      Hiroshima-shi, Hiroshima-ken, Japan
  • 2007
    • Onomichi General Hospital
      Onomiti, Hiroshima, Japan
  • 2005
    • Showa General Hospital
      Edo, Tōkyō, Japan
  • 2000
    • Hiroshima International University
      • Department of Clinical Engineering
      Hiroshima-shi, Hiroshima-ken, Japan