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Dive into the research topics where Yoshitaka Okamura is active.

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Featured researches published by Yoshitaka Okamura.


The Annals of Thoracic Surgery | 1990

Coronary revascularization in a child with kawasaki disease : use of right gastroepiploic artery

Takeuchi Y; Akihiko Gomi; Yoshitaka Okamura; Hideaki Mori; Mitsugi Nagashima

In coronary insufficiency produced by Kawasaki disease, myocardial revascularization using saphenous vein, internal mammary arteries, and a combination of both grafts has been performed with considerable success. Recently, we successfully used a right gastroepiploic artery as another conduit in coronary revascularization of a 6-year-old boy with Kawasaki disease. Use of the gastroepiploic artery was feasible even in a small child, and this technique is expected to contribute to long-term graft patency as an arterial graft adjunct to internal mammary arteries.


The Annals of Thoracic Surgery | 1998

Interleukin-6 and "complex" cardiac myxoma.

Yoshihiko Mochizuki; Yoshitaka Okamura; Hiroshi Iida; Hideaki Mori; Kouichiro Shimada

A rare case of complex cardiac myxoma is reported. Complex cardiac myxoma manifests with more constitutional signs than the sporadic type. These constitutional signs are known to be associated with the overproduction of interleukin-6 by cardiac myxomas. In our study, immunohistochemical staining of the myxoma for interleukin-6 was strongly positive. The serum interleukin-6 level decreased after surgical removal of the tumor and has remained undetectable for the past 2 years.


Diagnostic and interventional radiology | 2015

Risk factors associated with late aneurysmal sac expansion after endovascular abdominal aortic aneurysm repair

Motoki Nakai; Akira Ikoma; Hirotatsu Sato; Morio Sato; Yoshiharu Nishimura; Yoshitaka Okamura

PURPOSEnWe aimed to identify the risk factors associated with late aneurysmal sac expansion after endovascular abdominal aortic aneurysm repair (EVAR).nnnMETHODSnWe retrospectively reviewed contrast-enhanced computed tomography (CT) images of 143 patients who were followed for ≥6 months after EVAR. Sac expansion was defined as an increase in sac diameter of 5 mm relative to the preoperative diameter. Univariate and multivariate analyses were performed to identify associated risk factors for late sac expansion after EVAR from the following variables: age, gender, device, endoleak, antiplatelet therapy, internal iliac artery embolization, and preprocedural variables (aneurysm diameter, proximal neck diameter, proximal neck length, suprarenal neck angulation, and infrarenal neck angulation).nnnRESULTSnUnivariate analysis revealed female gender, endoleak, aneurysm diameter ≥60 mm, suprarenal neck angulation >45°, and infrarenal neck angulation >60° as factors associated with sac expansion. Multivariate analysis revealed endoleak, aneurysm diameter ≥60 mm, and infrarenal neck angulation >60° as independent predictors of sac expansion (P < 0.05, for all).nnnCONCLUSIONnOur results suggest that patients with small abdominal aortic aneurysms (<60 mm) and infrarenal neck angulation ≤60° are more favorable candidates for EVAR. Intraprocedural treatments, such as prophylactic embolization of aortic branches or intrasac embolization, may reduce the risk of sac expansion in patients with larger abdominal aortic aneurysms or greater infrarenal neck angulation.


Perfusion | 2005

Dextran sulfate as a leukocyte-endothelium adhesion molecule inhibitor of lung injury in pediatric open-heart surgery.

Hiroyoshi Komai; Yasuaki Naito; Yoshitaka Okamura

Background: In spite of the progress in operative techniques and pre- and postoperative management for congenital heart disease, lung injury induced by the extracorporeal circulation is still a serious insult in pediatric open-heart operations. To prevent this injury, we used a leukocyte - endothelial cell adhesion molecule blocking agent, dextran sulfate, in a clinical setting. Methods: Sixty mg/kg of dextran sulfate (DS) was intravenously infused to the patients just before cardio-pulmonary bypass was started and 600 mg was added to the bypass circuit prime. Thirty patients (DS group, 14 patients with atrial septal defect, and 16 patients with ventricular septal defect) were compared with age and body-weight matched control patients (control group, 14 patients with atrial septal defect, 11 patients with ventricular septal defect). Postoperative respiratory index, white blood cell counts, complement C3 and plasma granulocyte elastase levels during and after the operation were measured. Results: Respiratory index just after the termination of cardiopulmonary bypass was better preserved in the DS group than in the control group (0.50±0.08 versus 0.81±0.12, p<0.01). The sum total amount of measured granulocyte elastase across whole study period was significantly lower in the DS group (p<0.05). Conclusions: The data suggested the possible effects of dextran sulfate in ameliorating post-perfusion lung damage by interfering with leukocyte-endothelial cell adhesion in pediatric open-heart operations. Future application to patients with more complex anomalies is anticipated.


The Japanese Journal of Thoracic and Cardiovascular Surgery | 2003

Intrapleural administration of a large amount of diluted fibrin glue for intractable pneumothorax. A clinical study based on 57 cases: including 2 unsuccessful cases.

Takahiro Kinoshita; Shinichiro Miyoshi; Takaomi Suzuma; Teruhisa Sakurai; Katsumi Enomoto; Tatsuya Yoshimasu; Shinzi Maebeya; Masanobu Juri; Yoshitaka Okamura

OBJECTIVEnPleurodesis using chemical agents has been applied to high-risk patients with pneumothorax. This treatment, however, is sometimes unsuccessful in patients with intractable pneumothorax. We have developed intrapleural administration of diluted fibrin glue as an effective treatment for such patients.nnnMETHODSnFibrin glue was diluted 4-fold with saline and/or contrast media. Pleurodesis with a large amount of the diluted fibrin glue was performed in 55 high risk patients (57 cases, bil.2 patients) with intractable pneumothorax.nnnRESULTSnThe air leaks were stopped by administration of the glue in all except 2 patients. During the follow-up period, a recurrence rate of 10.5% was observed. These recurrent pneumothoraces were successfully treated using the same procedure with no further recurrence. Pyrexia (12.3%) and chest discomfort (8.8%) were observed as side effects, and there was no occurrence of severe chest pain or thoracic empyema.nnnCONCLUSIONSnThese results suggested that intrapleural administration of a large amount of diluted fibrin glue was an effective treatment for intractable pneumothoraces in high-risk patients.


Case Reports in Oncology | 2013

Response of meningeal carcinomatosis from breast cancer to capecitabine monotherapy: a case report.

Yumi Tanaka; Shoji Oura; Tatsuya Yoshimasu; Fuminori Ohta; Koma Naito; Rie Nakamura; Yoshimitsu Hirai; Masako Ikeda; Yoshitaka Okamura

A 62-year-old woman with breast cancer received neoadjuvant chemotherapy followed by breast-conserving surgery and sentinel node biopsy. During adjuvant endocrine therapy with aromatase inhibitor, she developed multiple bone metastases. Thereafter, she received tamoxifen and zoledronate therapy. In May 2011, she developed a tongue deviation and was diagnosed as having meningeal carcinomatosis. The tongue deviation disappeared 3 weeks after taking capecitabine (2,400 mg/day). Magnetic resonance imaging of the brain showed regression of meningeal carcinomatosis. Levels of tumor markers CEA and CA15-3 changed from 96.0 IU/ml and 3.5 ng/ml to 47.0 IU/ml and 1.5 ng/ml, respectively. Progression-free survival with capecitabine monotherapy was 5 months.


Heart and Vessels | 2010

Surgical correction of isolated unilateral absence of right pulmonary artery

Takeshi Hiramatsu; Shigeru Komori; Yoshitaka Okamura; Hiroyuki Suzuki; Takashi Takeuchi; Syoichi Shibuta

A 2-year-old girl with isolated unilateral absence of right pulmonary artery is described. Catheterization at 5 months demonstrated hypoplastic right pulmonary artery by pulmonary venous wedge angiography, and the patient underwent right Blalock-Taussig shunt and angioplasty of right pulmonary artery with autologous pericardial roll as an initial step. At 2 years, she underwent anastomosis of right pulmonary artery to main pulmonary artery with an autologous pericardial tube. Postoperative computed tomography showed a patent reconstructed right pulmonary artery.


American Journal of Roentgenology | 2015

Utility of 99mTc–Human Serum Albumin Diethylenetriamine Pentaacetic Acid SPECT for Evaluating Endoleak After Endovascular Abdominal Aortic Aneurysm Repair

Motoki Nakai; Hirotatsu Sato; Morio Sato; Akira Ikoma; Tetsuo Sonomura; Yoshiharu Nishimura; Yoshitaka Okamura

OBJECTIVEnThe purpose of this study was to assess the utility of (99m)Tc-human serum albumin diethylenetriamine pentaacetic acid ((99m)Tc-HSAD) SPECT in the detection of endoleaks after endovascular abdominal aortic aneurysm repair.nnnSUBJECTS AND METHODSnFifteen patients (11 men, four women) with aneurysm sac expansion of 5 mm or greater after endovascular abdominal aortic aneurysm repair underwent three-phase CT, (99m)Tc-HSAD SPECT, and CT during aortography. Sensitivity calculations for three-phase CT and (99m)Tc-HSAD SPECT were performed with CT during aortography as the reference standard. The volume of each endoleak was measured with CT during aortography. Seven subjects underwent embolization with N-butyl cyanoacrylate (NBCA)-Lipiodol (ethiodized oil, Guerbet and metallic coils. Three-phase CT and (99m)Tc-HSAD SPECT were repeated after embolization to assess their efficacy.nnnRESULTSnEndoleaks were interpreted as perigraft radioisotope accumulation in 12 patients (80.0%) on (99m)Tc-HSAD SPECT images, in 13 patients (86.7%) on three-phase CT images, and in 15 patients (100%) on CT during aortography. The mean endoleak volume visualized with (99m)Tc-HSAD SPECT was 8.37 cm(3) (range, 5.2-15.1 cm(3)), and the volume not visualized was 3.47 cm(3) (2.5-4.6 cm(3)), a statistically significant difference (p = 0.019). In two patients, (99m)Tc-HSAD SPECT depicted endoleaks evident at delayed phase CT during aortography but not at three-phase CT, suggesting they were slow-filling endoleaks. Accumulation of (99m)Tc-HSAD corresponding to endoleaks disappeared after embolization, but CT evaluation of embolization was impeded by artifacts of NBCA-Lipiodol and metallic coils.nnnCONCLUSIONnTechnetium-99m-labeled HSAD SPECT proved less sensitive than three-phase CT but depicted endoleaks with volumes 5.2 cm(3) or greater as perigraft radioisotope accumulation. Slow-filling endoleaks can be visualized with (99m)Tc-HSAD SPECT, which can be used to evaluate the efficacy of embolization.


Case Reports in Oncology | 2014

Primary Clear-Cell Sarcoma in the Mediastinum

Yumi Tanaka; Tatsuya Yoshimasu; Shoji Oura; Yoshimitsu Hirai; Mitsumasa Kawago; Yoshitaka Okamura

We report a case of primary clear-cell sarcoma (CCS) in the mediastinum. In October 2011, a 63-year-old man was admitted to our hospital for surgical resection. The tumor was completely excised by video-assisted thoracoscopic surgery. The tumor was well encapsulated and did not invade the pleura. Histological examination led to a final diagnosis of primary CCS in the mediastinum. The patient remains alive without evidence of recurrence at 15 months after surgery.


The Annals of Thoracic Surgery | 1999

Healing of the intimal dissection of the internal thoracic artery graft

Yoshihiko Mochizuki; Yoshitaka Okamura; Hiroshi Iida; Hideaki Mori; Koichiro Shimada

We report healing of the intimal dissection of an internal thoracic artery graft. Triple coronary artery bypass grafting was performed using left internal thoracic artery and saphenous vein grafts. One month after operation, the intimal dissection of the internal thoracic artery graft was clearly visible by coronary angiography; however, after 1 year of only medical treatment consisting of warfarin, ticlopidine, and nitrate, the intimal dissection was undetectable by coronary angiography.

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Tatsuya Yoshimasu

Wakayama Medical University

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Shoji Oura

Wakayama Medical University

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Issei Hirai

Wakayama Medical University

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Yoshimitsu Hirai

Wakayama Medical University

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Yozo Kokawa

Wakayama Medical University

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