Masato Minami

Osaka City University, Ōsaka, Ōsaka, Japan

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Publications (102)200.72 Total impact

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    ABSTRACT: Intraoperative alveolar air leaks remain a significant problem in thoracoscopic surgery (TS) cases. We examined the usefulness of covering damaged lung tissue with a subcutaneous fat pad for preventing postoperative air leakage in patients with non-small cell lung cancer (NSCLC). Patients with NSCLC underwent a thoracoscopic lobectomy or segmentectomy. When alveolar air leakage from the superficial pulmonary parenchyma was found, fibrin glue in combination with an absorbable mesh sheet was applied (S group; n = 100). When leakage originated from deep within the pulmonary parenchyma, a subcutaneous fat pad about 2 × 2 cm in size was harvested from the utility incision and placed on the damaged lung tissue with fibrin glue and sutures (F group; n = 66). Patient characteristics, air leak duration, and chest-tube removal time were analyzed. The homogeneity of each group was consistent, with no statistical differences for age, respiratory function, surgical procedures, pathologic stage, and histological type. The air leak duration was significantly shorter (p = 0.015), and the chest tube was removed significantly earlier (p = 0.002) in patients in the F group. Use of a free subcutaneous fat pad during pulmonary resection for TS patients with NSCLC reduced the duration of air leakage and chest tube drainage. The present method is easy, safe, and effective for repairing an air leak from remaining lung tissues in such cases.
    Surgical Endoscopy 12/2014; · 3.31 Impact Factor
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    ABSTRACT: We previously introduced video-assisted thoracoscopic ET (VATS-ET) as a therapeutic option for MG with acceptable results. We have conducted further investigations to improve the procedure without deterioration of operative results, including myasthenia gravis (MG) remission rate and palliation rate. Here, we report the details of our current procedure, as well as surgical results and patient outcomes as compared with the original VATS-ET procedure. From January 2002 to September 2013, we performed a VATS-ET procedure with an anterior chest wall lifting method for 77 patients who had MG with or without a thymoma. During that period, we investigated the appropriate indications and improved the procedure. Our current indication for this procedure is MG with the anti-acetylcholine receptor antibody or sero-negative type, or MG with a thymoma <5 cm in diameter without invasion to adjacent organs. With our procedure, the thymus and surrounding tissue are sufficiently resected using a bilateral thoracoscopic surgical method without neck incision. Remission and palliation rates were found to be equivalent to those obtained with the original VATS-ET procedure. VATS-ET is suitable for select patients with MG with or without a thymoma. In addition, our current method has shown to be effective while also offering cosmetic advantages as compared with the original, neck incision needed, VATS-ET method.
    Surgical Endoscopy 12/2014; · 3.31 Impact Factor
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    ABSTRACT: We reviewed our institutional experience with cases of multimodality treatment for advanced thymic carcinoma to determine patient outcomes and prognostic indicators.
    General Thoracic and Cardiovascular Surgery 10/2014;
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    ABSTRACT: AimsTo pursue the histological evolution in the development of pleuroparenchymal fibroelastosis (PPFE).Methods and resultsWe examined four patients who had undergone surgical lung biopsy twice, or who had undergone surgical lung biopsy and had been autopsied, and in whom the histological diagnosis of the first biopsy was not PPFE, whereas the diagnosis of the second biopsy or of the autopsy was PPFE. The histological patterns of the first biopsy were cellular and fibrotic interstitial pneumonia, cellular interstitial pneumonia (CIP) with organizing pneumonia, CIP with granulomas, and acute lung injury in Cases 1, 2, 3 and 4, respectively. Septal elastosis was already present in the NSIP-like histology of Case 1, but a few additional years were necessary to reach consolidated subpleural fibroelastosis. In Case 3, subpleural fibroelastosis was already present in the first biopsy, but only to a small extent. Twelve years later, it was replaced by a long band of fibroelastosis. Septal inflammation and fibrosis and airspace organization observed in the first biopsies were replaced by less-cellular subpleural fibroelastosis within three to twelve years.Conclusions Interstitial inflammation or acute lung injury may be an initial step in the development of PPFE.This article is protected by copyright. All rights reserved.
    Histopathology 09/2014; · 3.30 Impact Factor
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    ABSTRACT: To evaluate the feasibility of aspirin continuation during the perioperative period for pulmonary resection in lung cancer patients. A retrospective study was conducted in 46 patients who were taking aspirin and underwent pulmonary resection. The indications for aspirin were generally a cardiovascular or cerebrovascular comorbidity. Whether to continue or discontinue aspirin was determined based on the severity of the cardiovascular or cerebrovascular comorbidity, along with the patient's overall condition. The intraoperative and postoperative outcomes were compared between patients continuing and those discontinuing aspirin. Twenty patients continued (group C) and 26 patients discontinued (group D) aspirin. The length of the operation (226 ± 97 min in group C vs. 189 ± 90 min in group D), intraoperative bleeding (234 ± 232 vs. 204 ± 367 g) and average pleural discharge on postoperative days 1, 2 and 3 (331, 230 and 215 vs. 304, 210 and 174 ml/day) showed no significant differences between the two groups. The postoperative complication rates were also not significantly different between the two groups [eight patients (40 %) in group C vs. nine patients (35 %) in group D]. Continuous administration of aspirin during the perioperative period for pulmonary resection in lung cancer patients appears to be clinically feasible in the Japanese population.
    Surgery Today 02/2014; · 1.21 Impact Factor
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    ABSTRACT: Because the donor shortage is extremely severe in Japan because of a strict organ transplantation law, special strategies have been established to maximize heart and lung transplantations (HTs and LTs, respectively). We reviewed 100 consecutive brain-dead donors to evaluate our strategies to identify and manage heart and lung donors. We retrospectively reviewed all 100 consecutive brain-dead donors procured since the law was issued in 1997. There were 56 mens and the overall mean donor age was 43.5 years. The causes of death were cerebrovascular disease (n = 62), head trauma (n = 20), and asphyxia (n = 16): Since November 2002, special transplant management doctors were sent to donor hospitals to assess cardiac and lung functions, seeking to identify transplant opportunities. They stabilized donor hemodynamics and lung function by administering antidiuretic hormone intravenously and performing bronchofibroscopy for pulmonary toilet. Seventy-nine HTs, 1 heart-lung transplantations, and 78 LTs (46 single and 32 bilateral) were performed. By applying these strategies organs per donor were increased from 4.5 to 6.8. Among heart donors, 61/80 were marginal: high inotrope requirement (n = 29), cardiopulmonary resuscitation (n = 28), and/or >55 years old (n = 20). None of the 80 HT recipients died of primary graft failure (PGF). Patient survival rate at 10 years after HT was 95.4%. Among lung donors, 48/65 were marginal: pneumonia (n = 41), chest trauma (n = 4), and >55 years old (n = 9). Only 2/78 LT recipients died of PGF. Patient survival rate at 3 years after LT was 72.2%. After inducing frequent pulmonary toilet, lung procurement and patient survival rates increased significantly after LT. Although the number of cases was still small, the availability of organs has been greater and the outcomes of HT/LT acceptable.
    Transplantation Proceedings 10/2013; 45(8):2871-4. · 0.95 Impact Factor
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    ABSTRACT: Lung transplantation (LTx) is an established therapy for end-stage lung failure. However, in Japan, the donor organ shortage is extremely severe compared with other developed countries, because of the strict Japanese Organ Transplantation Law. To maximize LTx opportunities in Japan, we have established a special donor evaluation and management system termed the medical consultant (MC) system. Data from 171 lung donor candidates registered in Japan from May 1998 to May 2012 were obtained and investigated in a retrospective manner. The candidates were separated into the non-MC-intervened and MC-intervened groups, and then data regarding the PaO2/FiO2 ratio, donation rate and organ survival rate were analyzed and compared between the groups. The PaO2/FiO2 ratio of the MC-intervened group was ameliorated from the time of first brain death diagnosis to organ harvest. Although the base condition of the MC-intervened group was significantly worse than that of the non-MC-intervened group, the donation rates showed no significant difference (0.64 and 0.66, respectively; p = 0.89). There was a difference in the organ survival rate between the non-MC and MC-intervened groups (5-year survival rates of 67.2 and 88.3 %, respectively; p = 0.16). The MC system used for organ donor evaluation and management in Japan has achieved acceptable interim results.
    Surgery Today 09/2013; · 1.21 Impact Factor
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    ABSTRACT: Fibroblasts are key components of the tumor microenvironment. We clarified the role of transforming growth factor (TGF)-β and interleukin (IL)-6 in the interaction between fibroblasts and non-small-cell lung cancer (NSCLC) cells. We used NSCLC cells (A549, NCI-H358) and normal human lung fibroblast (NHLF) cells to evaluate phenotypic changes in the presence of human IL-6, TGF-β1, and conditioned media (CM) from these cells. Possible pathways were evaluated with SB431542, a TGF-β receptor inhibitor, or an anti-human IL-6 receptor neutralizing antibody (IL-6R-Ab). A549 and NCI-H358 cells incubated with IL-6 (50ng/mL) and TGF-β1 (2ng/mL) showed significantly increased epithelial-mesenchymal transition (EMT) signaling compared to those treated with TGF-β1 alone. Furthermore, NHLF cells were synergistically activated by IL-6 and TGF-β1. IL-6 increased the expression of TGF-β type I receptors on the surface of A549, NCI-H358 and NHLF cells and enhanced TGF-β signaling. TGF-β1 induced phenotypic changes were attenuated by IL-6R-Ab. NHLF cells were activated and A549 cells showed induction of EMT in response to CM from the other cell type. These activities were attenuated by SB431542 or IL-6R-Ab, suggesting that interplay between NSCLC cells and NHLF may lead to increased EMT signaling in NSCLC cells and activation of NHLF cells through TGF-β and IL-6 signaling. Subcutaneous co-injection of A549 and NHLF cells into mice resulted in a high rate of tumor formation compared with injection of A549 cells without NHLF cells. SB431542 or IL-6R-Ab also attenuated the tumor formation enhanced by co-injection of the two cell types. IL-6 enhanced epithelial cell EMT and stimulated tumor progression by enhancing TGF-β signaling. IL-6 and TGF-β may play a contributing role in maintenance of the paracrine loop between these two cytokines in the communication between fibroblasts and NSCLC cells for tumor progression.
    Lung cancer (Amsterdam, Netherlands) 08/2013; · 3.14 Impact Factor
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    ABSTRACT: A new pathological classification for pre- and minimally invasive adenocarcinoma has been established, with distinction prior to surgery crucial because of the extremely good prognosis. Of 412 patients who underwent surgery for lung cancer from 2008 to 2011, 110 classified as c-stage I had each of the following four parameters assessed for predictive power for PRE or MIN adenocarcinoma and relapse-free survival (RFS): (i) whole tumour size (WS) shown by computed tomography (CT) , (ii) size of the solid (SS) component in CT findings, (iii) maximum standard uptake value in fluorodeoxyglucose positron emission tomography (FDG-PET)/CT scan images (SUVmax) and (iv) serum level of carcinoembryonic antigen. For prediction of PRE or MIN adenocarcinoma, the area under the receiver-operating curve was >0.7 for all the four parameters, while only SS was found to be an independent factor in multivariate logistic regression analysis. In Cox proportional hazard model analysis, SS and SUVmax were statistically significant, and SS was exclusively independent in multivariate analysis. Differences in RFS between T1a and T1b were more pronounced when using SS compared with WS. In the sub-classification of T1a, we used a breakpoint of 1.0 cm in SS (T1a-α and T1a-β), which resulted in a 2-year RFS rate of 1.00 for T1a-α (n = 21), 0.89 for T1a-β (n = 27) and 0.68 for T1b (n = 26) (P = 0.002 between T1a-β and T1b). The SS parameter was useful to distinguish PRE and MIN adenocarcinoma from other types of lung cancer, and set a T1a sub-classification.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 07/2013; · 2.40 Impact Factor
  • Masato Minami, Meinoshin Okumura
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    ABSTRACT: Lung retransplantation accounts for only 2.6% of all lung transplantations performed worldwide. Overall survival after lung retransplantation is known to be worse than that of initial lung transplantation, but in cautiously selected lung recipients survival has been shown to be equally good. Decision about types of procedure is critical and meticulous patient care is also essential for success.
    Kyobu geka. The Japanese journal of thoracic surgery 07/2013; 66(8):727-31.
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    ABSTRACT: BACKGROUND: Fibroblasts are key components of the tumor microenvironment. The purpose of this study was to clarify the role of fibroblasts in tumor progression in non-small cell lung cancer (NSCLC). METHODS: Fibroblasts isolated from surgical exploration were co-cultured with human lung adenocarcinoma cell lines. We defined fibroblasts obtained from tumors as cancer associated fibroblasts (CAFs) and those from normal lung tissue as lung normal fibroblasts (LNFs). RESULTS: Expression levels of myofibroblast markers were higher in CAFs than LNFs within 5 passages in the absence of continuing interaction with carcinoma cells. Thus, we used at least 2 pairs of these CAFs and LNFs in the following experiments; conditioned medium (CM) from fibroblast-induced epithelial mesenchymal transition and acquisition of cancer stem cell-like qualities in lung cancer cells (A549 and NCI-H358), indicating that CM from fibroblasts was biologically active. Furthermore, the concentration of the transforming growth factor (TGF)-β1 was higher in CM from CAFs as compared with that from LNFs, and phenotypic changes of cancer cells by CM from CAFs were greater than those induced by CM from LNFs. These CAF-induced changes were inhibited by addition of the TGF-β inhibitor SB431542. Subcutaneous co-injection of lung cancer cells and CAFs in mice enhanced tumor growth when compared with cancer cells alone, which was attenuated by administration of SB431542. CONCLUSIONS: Fibroblasts were associated with increased malignant potential and the acquisition of stemness in NSCLC tumors. Targeting CAFs as a therapeutic strategy against cancer is an intriguing concept that would benefit from further study.
    The Annals of thoracic surgery 06/2013; · 3.45 Impact Factor
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    ABSTRACT: OBJECTIVES: Although video-assisted thoracoscopic thymectomy (VATS-Tx) for thymoma has been introduced, its oncological outcome remains unclear. Our institutional experience with early-stage thymoma was retrospectively reviewed to evaluate the oncological feasibility of thoracoscopic thymectomy. METHODS: A retrospective review consisting of 74 patients with Masaoka Stage I and II thymomas who had undergone thymectomy was performed. Forty-five patients underwent thoracoscopic thymectomy, while 29 underwent thymectomy through the open sternotomy approach. The clinical factors associated with the surgical outcome, including tumour recurrence, were investigated. RESULTS: Neither operative death nor major postoperative complications were observed. The median intraoperative blood loss and operative time of thoracoscopic thymectomy were 50 ml and 180 min, respectively. Among the patients with thymomas >5 cm, the number of patients with operative time >4 h was 9 of 26 (34.6%) in the thoracoscopic thymectomy and 1 of 21 (4.8%) in the open sternotomy groups. Pleural recurrence was observed in 3 (6.7%) patients with thymoma >5 cm only in the thoracoscopic thymectomy group. Tumour capsule injury by manipulation during the operation was recorded in 2 of these 3 patients. In 2 of the 3 cases who had tumours with cystic portions on computed tomography, a tumour capsule injury occurred due to manipulation during thoracoscopic thymectomy. CONCLUSIONS: VATS-Tx for early-stage thymomas is feasible, while the indications should be carefully considered in patients with large or cystic tumours. The conventional open sternotomy approach could be recommended in patients with thymomas >5 cm to avoid capsule injury.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 06/2013; · 2.40 Impact Factor
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    ABSTRACT: PURPOSE: As the donor shortage is extremely severe in Japan because of a strict Organ Transplantation Act, special strategies must be established to maximize organ transplant opportunities. The purpose of this study was to evaluate our strategies to identify and manage 200 consecutive brain-dead organ donors. METHODS AND MATERIALS: We retrospectively reviewed the 200 donors procured since the Organ Transplantation Act was issued in 1997, including 118 males, a mean overall age of 45.1 years and cause of death being cerebrovascular disease (n = 119), head trauma (n = 37), and asphyxia (n = 44). DONOR EVALUATION AND MANAGEMENT SYSTEM: Since November in 2002, special transplant management doctors ("medical consultants") were sent to donor hospitals to assess organ function and identify transplantable organs. They also provided intensive care to stabilize hemodynamics and improve cardiac and lung functions by administering antidiuretic hormone intravenously and providing bronchofiberscopic pulmonary toilet. RESULTS: We obtained 146 heart, 1 heart-lung, and 154 lung (87 single and 67 bilateral), 175 liver (28 splitted liver), 142 pancreas (114 pancreas-kidney), 253 kidney and 12 small bowel grafts. Organs procured from 1 donor increased from 4.5 to 6.8 after applying these strategies. CONCLUSIONS: Although the number of cases was still small, the availability of organs and outcomes of transplantation have been acceptable.
    Transplantation Proceedings 05/2013; 45(4):1327-1330. · 0.95 Impact Factor
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    ABSTRACT: PURPOSE: To examine the perioperative and long-term outcomes of surgery for malignancies of the lungs in patients with a history of head and neck squamous cell carcinoma (HNSCC) and to evaluate the risk factors associated with postoperative complications. METHODS: The data of 39 patients with a history of HNSCC who underwent pulmonary resection were reviewed. The perioperative and long-term outcomes were analyzed. RESULTS: Eight patients (21 %) had difficult airways, and nine patients (23 %) developed postoperative complications. A low body mass index (<18.5), a history of malignancy besides HNSCC and chronic obstructive pulmonary disease were each found to be significantly associated with the development of postoperative complications. The 5-year survival rate of all patients was 80 %. CONCLUSIONS: The airway management of patients with a history of HNSCC should be carefully undertaken. Preoperative assessment of their nutritional status and careful prevention of air leakage during surgery are important. Because favorable outcomes can be achieved, aggressive surgical management should be considered for the treatment of pulmonary malignancies in patients with a history of HNSCC.
    Surgery Today 04/2013; · 1.21 Impact Factor
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    ABSTRACT: The Japanese Organ Transplant Law was amended, and the revised law took effect in July 2010 to overcome extreme donor shortage and to increase the availability of donor organs from brain-dead donors. It is now possible to procure organs from children. The year 2011 was the first year that it was possible to examine the results of this first extensive revision of the Japanese Organ Transplant Law, which took effect in 1997. Currently, seven transplant centers, including Tohoku, Dokkyo, Kyoto, Osaka, Okayama, Fukuoka and Nagasaki Universities, are authorized to perform lung transplantation in Japan, and by the end of 2011, a total of 239 lung transplants had been performed. The number of transplants per year and the ratio of brain-dead donor transplants increased dramatically after the revision of the Japanese Organ Transplant Law. The survival rates for lung transplant recipients registered with the Japanese Society for Lung and Heart-lung Transplantation were 93.3 % at 1 month, 91.5 % at 3 months, 86.3 % at 1 year, 79.0 % at 3 years, and 73.1 % at 5 years. The survival curves for brain-dead donor and living-donor lung transplantation were similar. The survival outcomes for both brain-dead and living-donor lung transplants were better than those reported by the International Society for Heart and Lung Transplantation. However, donor shortage remains a limitation of lung transplantation in Japan. The lung transplant centers in Japan should continue to make a special effort to save critically ill patients waiting for lung transplantation.
    General Thoracic and Cardiovascular Surgery 02/2013;
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    ABSTRACT: Although legislation regarding organ transplantation from brain-dead donors in Japan was approved in 1997, no heart-lung transplantation procedures were performed for some time. Herein, we report the first case of successful heart-lung transplantation in Japan. The recipient was a 35-year-old man with Eisenmenger syndrome, caused by a double outlet right ventricle, who had been suffering hemoptysis and continued NYHA class 3-4 symptoms for 66 months since being registered on the waiting list. He underwent heart-lung transplantation from a 30-year-old donor. The organ ischemic time was 247 min, the postoperative course was uneventful, and the patient was discharged 66 days after the transplant surgery.
    Surgery Today 02/2013; · 1.21 Impact Factor
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    ABSTRACT: PURPOSE: A new diagnosis of chronic obstructive pulmonary disease is often made during the evaluation of patients requiring lung cancer surgery. The objective of the present study was to evaluate the clinical effects of inhaled tiotropium on the postoperative cardiopulmonary complications in patients with untreated chronic obstructive pulmonary disease requiring lung cancer surgery. METHODS: A retrospective study involving 104 consecutive patients with moderate to severe chronic obstructive pulmonary disease who underwent a lobectomy for lung cancer at two specialized thoracic centers between April 2008 and October 2011 was performed. The results were compared between patients who did and did not receive inhaled tiotropium during the perioperative period. The primary endpoint was the incidence of postoperative cardiopulmonary complications. The postoperative white blood cell counts and C-reactive protein levels as biomarkers of inflammation were also examined. RESULTS: The incidence of postoperative cardiopulmonary complications was significantly lower in the tiotropium group than in the control group (18 vs. 48 %, P = 0.001). Patients in the tiotropium group also showed significantly lower white blood cell counts and C-reactive protein levels postoperatively. CONCLUSIONS: Inhaled tiotropium treatment during the perioperative period had a prophylactic effect on postoperative cardiopulmonary complications in patients with newly diagnosed chronic obstructive pulmonary disease requiring lung cancer surgery.
    Surgery Today 01/2013; · 1.21 Impact Factor
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    ABSTRACT: OBJECTIVES Although video-assisted thoracoscopic surgery (VATS) is widely used for the resection of a mediastinal mass, it is converted to an open resection in some patients with a mature teratoma because of dense adhesions. We reviewed cases with a mature teratoma removed by VATS and investigated the indications for that procedure for this tumour.METHODS We retrospectively investigated 15 patients with a benign mediastinal mature teratoma who underwent a thoracoscopic procedure.RESULTSThe mean tumour diameter was 5.3 cm (range 3.2-8.5). The mean operative time was 188 min (78-430), and intraoperative blood loss was 138 ml (10-450). Thoracoscopic resection was completed in all except 3 patients with larger tumours, which presented the most difficult problems with dissection. Each of those 3 had severe preoperative chest pain and a tumour larger than 5.5 cm. No mortality or postoperative complications were recorded, except for postoperative chylothorax. Tumour recurrence did not develop in any patient during the mean follow-up period of 4.6 years.CONCLUSIONS For selected patients with a mediastinal teratoma, VATS may be considered standard care, as most are benign. In contrast, an open approach may be more appropriate for patients with a large tumour or preoperative symptoms.
    Interactive Cardiovascular and Thoracic Surgery 01/2013; · 1.11 Impact Factor
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    European Respiratory Journal 01/2013; 41(1):243-5. · 7.13 Impact Factor
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    ABSTRACT: Blunt chest trauma frequently leads to various complications such as pneumothorax, hemothorax, and lung contusion. Since neighboring organ injury caused by a rib fracture with chest trauma could be fatal when a great vessel is involved, immediate diagnosis and treatment including surgery are important. Here, we present a case of chest trauma, in which we performed video-assisted thoracoscopic rib resection to prevent injury to the descending aorta by the fractured rib tip.
    Annals of thoracic and cardiovascular surgery : official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia. 12/2012;

Publication Stats

917 Citations
200.72 Total Impact Points


  • 2001–2014
    • Osaka City University
      • Graduate School of Medicine
      Ōsaka, Ōsaka, Japan
  • 1997–2013
    • Osaka University
      • • Department of Therapeutics for End-Stage Organ Dysfunction
      • • Division of General Thoracic Surgery
      • • Center for Medical Research and Education
      • • Department of Integrated Medicine
      • • Division of Cellular and Molecular Biology
      Suika, Ōsaka, Japan
  • 2003–2005
    • Toneyama National Hospital - Toyonaka
      Toyonaka, Ōsaka, Japan