NKNaohiro Kajiwara

Naohiro Kajiwara

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Previous Organizations / Institutes

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Naohiro Kajiwara has a total of 68 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Intrathoracic lipoma in the horizontal fissure of the right lung: a case report

    by Eiji Nakajima, Hidenobu Takahashi, Naohiro Kajiwara, Kinya Furukawa, Taichiro Ishizumi, Hiroaki Kataba, Mitsuru Okubo, Hiroshi Hirano, Norihiko Ikeda

    Lipomas are benign tumors that originate from mesenchymal tissue, such as subcutaneous tissue. Intrathoracic lipomas are rare, and they can occur in the chest wall, mediastinum and bronchi. In the present case, the patient had an intrathoracic lipoma that was located in the horizontal fissure of the right lung. Retrospective review of chest radiographs taken at a previous health checkup confirmed that the tumor was growing. The patient had no symptoms, and computed tomography and magnetic resonance imaging suggested that the tumor was a hamartoma. The tumor was resected by video-assisted thoracic surgery, and was diagnosed by pathological analysis as an intrathoracic lipoma consisting of no atypical fats.


  • The NPe6 fluorescence measurements by using a fluorescence sensing system for skin photosensitivity risk assessment after photodynamic therapy

    by Keishi Ohtani, Jitsu Usuda, Emiyu Ogawa, Sachio Maehara, Kentaro Imai, Tatsuya Inoue, Masaru Hagiwara, Masatoshi Kakihana, Naohiro Kajiwara, Tatsuo Ohira, et al.

    Background: Skin photosensitivity is a major side effect of photodynamic therapy (PDT). It is induced by the photosensitizer remaining in the skin. It is usually rapidly metabolized by the liver, but the pharmacokinetic profile varies widely among individuals. This makes it difficult to predict the incidence of skin photosensitivity. Therefore, we conducted a prospective study to investigate whether the NPe6 fluorescence intensity in skin after NPe6-PDT could be measured safely in human patients using a fluorescence sensing system for judging the risk of skin photosensitivity. Methods: The NPe6 fluorescence measurements using a constructed fluorescence sensing system at the inside of the arm were acquired prior to and 5 and 10 minutes after NPe6 administration as well as at the time of PDT (4-5 hours after administration), at discharge (2 or 3 days after PDT), and at 1 or 2 weeks after PDT. Participants were interviewed as to whether they had any complications at 2 weeks after PDT. Results: Nine male patients and one female patient entered this study. All of the measurements of NPe6 fluorescence in the skin could be obtained without any complications. The spectral peak was detected at the time of discharge (2-3 days after administration) in most cases and it decreased at 1 or 2 weeks after PDT. Conclusions: The fluorescence of NPe6 in the skin could be detected feasibly using the fluorescence sensing system in human patients. Measuring fluorescence intensity in the skin might be useful to predict the incidence of skin photosensitivity after PDT.

  • Clinical applications of virtual navigation bronchial intervention

    by Naohiro Kajiwara, Sachio Maehara, Junichi Maeda, Masaru Hagiwara, Tetsuya Okano, Masatoshi Kakihana, Tatsuo Ohira, Norihiko Kawate, Norihiko Ikeda

    Background: In patients with bronchial tumors, we frequently consider endoscopic treatment as the first treatment of choice. All computed tomography (CT) must satisfy several conditions necessary to analyze images by Synapse Vincent. To select safer and more precise approaches for patients with bronchial tumors, we determined the indications and efficacy of virtual navigation intervention for the treatment of bronchial tumors. Methods: We examined the efficacy of virtual navigation bronchial intervention for the treatment of bronchial tumors located at a variety of sites in the tracheobronchial tree using a high-speed 3-dimensional (3D) image analysis system, Synapse Vincent. Constructed images can be utilized to decide on the simulation and interventional strategy as well as for navigation during interventional manipulation in two cases. Results: Synapse Vincent was used to determine the optimal planning of virtual navigation bronchial intervention. Moreover, this system can detect tumor location and alsodepict surrounding tissues, quickly, accurately, and safely. The feasibility and safety of Synapse Vincent in performing useful preoperative simulation and navigation of surgical procedures can lead to safer, more precise, and less invasion for the patient, and makes it easy to construct an image, depending on the purpose, in 5–10 minutes using Synapse Vincent. Moreover, if the lesion is in the parenchyma or sub-bronchial lumen, it helps to perform simulation with virtual skeletal subtraction to estimate potential lesion movement. By using virtual navigation system for simulation, bronchial intervention was performed with no complications safely and precisely. Conclusions: Preoperative simulation using virtual navigation bronchial intervention reduces the surgeon’s stress levels, particularly when highly skilled techniques are needed to operate on lesions. This task, including both preoperative simulation and intraoperative navigation, leads to greater safety and precision. These technological instruments are helpful for bronchial intervention procedures, and are also excellent devices for educational training.


  • Open Access

    Cost-Benefit Performance Simulation of Robot-Assisted Thoracic Surgery As Required for Financial Viability under the 2016 Revised Reimbursement Paradigm of the Japanese National Health Insurance System

    by Naohiro Kajiwara, Yasufumi Kato, Masaru Hagiwara, Masatoshi Kakihana, Tatsuo Ohira, Norihiko Kawate, Norihiko Ikeda

    Purpose: To discuss the cost–benefit performance (CBP) and establish a medical fee system for robotic-assisted thoracic surgery (RATS) under the Japanese National Health Insurance System (JNHIS), which is a system not yet firmly established.Methods: All management steps for RATS are identical, such as preoperative and postoperative management. This study examines the CBP based on medical fees of RATS under the JNHIS introduced in 2016.Results: Robotic-assisted laparoscopic prostatectomy (RALP) and robotic-assisted partial nephrectomy (RAPN) now receive insurance reimbursement under the category of use of support devices for endoscopic surgery ($5420 and $3485, respectively). If the same standard amount were to be applied to RATS, institutions would need to perform at least 150 or 300 procedures thoracic operation per year to show a positive CBP ($317 per procedure as same of RALP and $130 per procedure as same of RAPN, respectively).Conclusion: Robotic surgery in some areas receives insurance reimbursement for its “supportive” use for endoscopic surgery as for RALP and RAPN. However, at present, it is necessary to perform da Vinci Surgical System Si (dVSi) surgery at least 150–300 times in a year in a given institution to prevent a deficit in income.


  • Successful adjustment for self-expanding metallic stent migration using a flexible bronchoscope with two biopsy forceps technique

    by Remi Yoneyama, Hisashi Saji, Yojiro Makino, Yasufumi Kato, Naohiro Kajiwara, Tatsuo Ohira, Norihiko Ikeda

    Although tracheobronchial stents are widely used for tracheal obstruction due to malignant or benign stenosis, stent migration has been reported as a major postoperative complication. A self-expandable metallic stent (SEMS) is more easily introduced compared with silicone stents. However, it is also difficult to remove or replace without complications. We report a new technique for successful SEMS adjustment using a flexible bronchoscope with two biopsy forceps.


  • A Case of Pulmonary Artery Intimal Sarcoma Mimicking Pulmonary Thromboembolism

    by Yohei Kawaguchi, Tetsuya Okano, Masatoshi Kakihana, Naohiro Kajiwara, Tatsuo Ohira, Keidai Maruno, Nobusato Koizumi, Hitoshi Ogino, Hideaki Hirai, Hiyo Obikane, et al.

    肺動脈内膜肉腫は稀な疾患であり,外科的切除を行わない場合の予後は1.5か月程度と極めて不良である.臨床症状や画像所見からは肺塞栓症との鑑別に苦慮することが多い.今回我々は慢性血栓塞栓性肺高血圧症が疑われた肺動脈内膜肉腫の1例を経験したため報告する.

  • Maximizing Use of Robot-Arm No. 3 in Da Vinci–Assisted Thoracic Surgery

    by Naohiro Kajiwara, Junichi Maeda, Koichi Yoshida, Yasufumi Kato, Masaru Hagiwara, Masatoshi Kakihana, Tatsuo Ohira, Norihiko Kawate, Norihiko Ikeda

    We have previously reported on the importance of appropriate robot-arm settings and replacement of instrument ports in robot-assisted thoracic surgery, because the thoracic cavity requires a large space to access all lesions in various areas of the thoracic cavity from the apex to the diaphragm and mediastinum and the chest wall.1–3 Moreover, it can be difficult to manipulate the da Vinci Surgical System using only arms No. 1 and No. 2 depending on the tumor location. However, arm No. 3 is usually positioned on the same side as arm No. 2, and sometimes it is only used as an assisting-arm to avoid conflict with other arms (Fig. 1). In this report, we show how robot-arm No. 3 can be used with maximum effectiveness in da Vinci-assisted thoracic surgery. Fig. 1 Usual positioning of arms No. 1, No. 2, and No. 3. Fig. 1. Usual positioning of arms No. 1, No. 2, and No. 3.


  • Cost-Benefit Performance of Robotic Surgery Compared with Video-Assisted Thoracoscopic Surgery under the Japanese National Health Insurance System

    by Naohiro Kajiwara, James Patrick Barron, Yasufumi Kato, Masatoshi Kakihana, Tatsuo Ohira, Norihiko Kawate, Norihiko Ikeda

    Medical economics have significant impact on the entire country. The explosion in surgical techniques has been accompanied by questions regarding actual improvements in outcome and cost-effectiveness, such as the da Vinci(®) Surgical System (dVS) compared with conventional video-assisted thoracic surgery (VATS). To establish a medical fee system for robot-assisted thoracic surgery (RATS), which is a system not yet firmly established in Japan. This study examines the cost benefit performance (CBP) based on medical fees compared with VATS and RATS under the Japanese National Health Insurance System (JNHIS) introduced in 2012. The projected (but as yet undecided) price in the JNHIS would be insufficient if institutions have less than even 200 dVS cases per year. Only institutions which perform more than 300 dVS operations per year would obtain a positive CBP with the projected JNHIS reimbursement. Thus, under the present conditions, it is necessary to perform at least 300 dVS operations per year in each institution with a dVS system to avoid financial deficit with current robotic surgical management. This may hopefully encourage a downward price revision of the dVS equipment by the manufacture which would result in a decrease in the cost per procedure.


  • Cine MRI enables better therapeutic planning than CT in cases of possible lung cancer chest wall invasion

    by Naohiro Kajiwara, Soichi Akata, Osamu Uchida, Jitsuo Usuda, Tatsuo Ohira, Norihiko Kawate, Norihiko Ikeda


  • Glomus tumor of the left main bronchus

    by Soichi Akata, Mana Yoshimura, Jinho Park, Shinya Okada, Sachio Maehara, Jitsuo Usuda, Naohiro Kajiwara, Masahiro Tsuboi, Harubumi Kato, Dai Kakizaki