Keiichi Kikuchi
National Defense Medical College
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Featured researches published by Keiichi Kikuchi.
The Annals of Thoracic Surgery | 1989
Hideo Masuda; Ogata T; Keiichi Kikuchi
To evaluate the physiological changes that occur after temporary occlusion of the superior vena cava, we clamped the vena cava for one hour in 6 cynomolgus monkeys, monkeys with a venous system most resembling that of humans. The data from arterial blood gas analysis, ie, pH, arterial oxygen tension, arterial carbon dioxide tension, and HCO3-, were within normal limits during and after occlusion of the superior vena cava. Intracranial pressure was 8.6 +/- 0.8 mm Hg (mean +/- standard error) before occlusion and rose to 22.1 +/- 2.2 mm Hg during clamping. It decreased significantly to 17.7 +/- 1.9 mm Hg just before removal of the clamp and recovered to 8.6 +/- 0.9 mm Hg after the clamp was removed. Regional cerebral blood flow was 45 +/- 9 mL/min/100 g before clamping and decreased to 37 +/- 3 mL/min/100 g during clamping. It recovered to 47 +/- 5 mL/min/100 g after removal of the clamp. Cerebral perfusion pressure was within the margin of safety during clamping. Histological findings in the brain showed the effect of congestion in 1 monkey, but the change was slight. The electroencephalogram and electrocardiogram showed no abnormalities in this experiment. In conclusion, one-hour clamping of the superior vena cava with the azygos vein ligated was safe in 6 cynomolgus monkeys. We believe that in the clinical setting, one-hour occlusion of the superior vena cava would result in findings similar to those in this study, unless particular complications, such as arteriosclerosis or a cerebrovascular disorder, exist.
The Annals of Thoracic Surgery | 1989
Hideo Masuda; Ogata T; Keiichi Kikuchi; Susumu Tanaka
We previously reported that the expanded polytetrafluoroethylene (ePTFE) graft for superior vena cava (SVC) substitution presents the problems of flexion and kinking when the graft is long. We therefore replaced the SVC of dogs with two types of prosthetic substitutes, ePTFE (Gore-Tex) and spiral-supported ePTFE (Im/praflex), and evaluated the long-term patency of the prosthetic substitutes. Total replacement of the SVC was performed in 9 adult mongrel dogs. The substitutes were ePTFE and spiral-supported ePTFE in 5 and 4 dogs, respectively. The animals were killed about 3 years after replacement of the SVC, and the harvested specimens were histologically examined by light microscopy and scanning electron microscopy. Evaluation of ePTFE revealed late occlusion in 1 of 5 dogs. The spiral-supported ePTFE showed patency in all dogs. In the group with ePTFE grafts, light microscopic examination revealed abnormalities of endothelial cells, granulation, and necrosis. There was no hyperplasia of the subendothelial connective tissue near the center. In the animals with spiral-supported ePTFE grafts, the subendothelial connective tissue showed favorable growth even in the center of the reconstructed site. There was no granulation in the spiral-supported ePTFE group. Scanning electron microscopic examination in the ePTFE group showed that endothelial cells were spindle-shaped and had an irregular surface. The spiral-supported ePTFE group showed an almost regular form of endothelial cells and no abnormalities except for the slightly spindled shape in the center. Therefore, we recommend that spiral-supported ePTFE should be used as an SVC substitute in clinical situations.
Laser Surgery: Advanced Characterization, Therapeutics, and Systems III | 1992
Koji Sensaki; Tsunenori Arai; Keiichi Kikuchi; Keigo Takagi; Susumu Tanaka; Makoto Kikuchi
Spontaneous pneumothorax is a common disease in young people. Operative intervention has been done in most of the recurrent cases. Recently thoracoscopic treatment has been tested as a less invasive treatment modarity. We adopted carbon monoxide (CO) laser for thoracoscopic treatment of recurrent spontaneous pneumothorax. CO laser (wavelength; 5.4 micrometers ) could be delivered by chalcogenide glass (As - S) covered with a teflon sheath and ZnSe fiber tip. The sterilized flexible bronchoscope was inserted through the thoracoscopic outer sheath under local anesthesia. Shrinkage of blebs was obtained by non-contact method of CO laser irradiation. Laser power at the tip was 2.5 - 5 W and irradiation duration was 0.5 s each. Excellent shrinkage of bleb and bulla could be obtained by CO laser without perforation complication. Advantages of CO laser as a thoracoscopic treatment were: (1) capability of fiber delivery (flexible thoracoscopy was easy to operate and clear to visualize the blebs which were frequently found at the apical portion of the lung, and (2) shallow extinction length (good shrinkage of blebs, low risk of perforation, and thin layer of carbonization). In conclusion, our new technique of thoracoscopic CO laser irradiation was found to be a safe and effective treatment of spontaneous pneumothorax.
Haigan | 1986
Hideo Masuda; Toshiro Ogata; Keiichi Kikuchi; Keigo Takagi; Toshiaki Kawai; Kuniaki Nakanishi
縦隔の絨毛上皮癌は性腺原発を否定された症例がacceptable caseとされ, 若年男子に多く発症し大変予後の悪い疾患である.29才男性の急激に増大する縦隔腫瘍に対して手術を行い, 術後化学療法及放射線治療を併用したが全経過9か月で死亡した.剖検では睾丸に原発巣は認められず, 肺・肝・脳・腎に転移を認め, 肺腫瘍組織中のβ-hCGが1100ng/miであり縦隔原発絨毛上皮癌と診断した.
Haigan | 1988
Hideo Masuda; Toshiro Ogata; Keiichi Kikuchi; Keigo Takagi; Ken Shimizu; Kuniaki Nakanishi; Seiichi Tamai
Haigan | 1993
Koji Sensaki; Hideo Masuda; Keiichi Kikuchi; Keigo Takagi; Katsuichi Kase; Yoshiyuki Abe; Yuichi Ozeki; Toshiro Ogata; Susumu Tanaka
Surgical Laparoscopy Endoscopy & Percutaneous Techniques | 1992
Koji Sensaki; Tsunenori Arai; Katsuichi Kase; Keigo Takagi; Keiichi Kikuchi; Toshiro Ogata; Susumu Tanaka; Makoto Kikichi
Surgical Laparoscopy Endoscopy & Percutaneous Techniques | 1992
Koji Sensaki; Tsunenori Arai; Katsuichi Kase; Keigo Takagi; Keiichi Kikuchi; Toshiro Ogata; Susumu Tanaka; Makoto Kikichi
The Japanese journal of thoracic diseases | 1991
Yoko Nemoto; Yasuyuki Katayama; Keisaku Sugiyama; Kazuhiko Kudo; Takeshi Matsuoka; Naokazu Nagata; Osamu Takatani; Keiichi Kikuchi; Shinsuke Aida
Surgical Laparoscopy Endoscopy & Percutaneous Techniques | 1991
Koji Sensaki; Tsunenori Aral; Hiroto Takahashi; Hiroshi Tamaki; Katsuichi Kase; Keigo Takagi; Keiichi Kikuchi; Toshiro Ogata; Susumu Tanaka; Makoto Kikuchi; Susumu Matsukuma