Kota Imashimizu
Juntendo University
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Featured researches published by Kota Imashimizu.
Thoracic and Cardiovascular Surgeon | 2015
Takeshi Matsunaga; Kenji Suzuki; Kota Imashimizu; Takamitsu Banno; Kazuya Takamochi; Shiaki Oh
BACKGROUND In general, obesity is thought to be associated with increased surgical mortality and morbidity. On the other hand, low body mass index (BMI) has recently been reported as a poor prognostic factor for surgical candidates. This study investigated the effect of BMI on lung surgery. METHODS A retrospective study was conducted on 1,518 consecutive patients who had malignant pulmonary tumors resected between February 2008 and March 2013. BMI was used to classify patients according to the World Health Organization definition: BMI < 18.5: underweight (UW); BMI 18.5 to <25: normal weight (NW); BMI 25 to <30: overweight (OW); and BMI ≥ 30: obese (OB). We defined surgical resection-related mortality as any patient who died within 90 days after resection or while in the hospital. We analyzed morbidity and surgical resection-related mortality, and logistic regression analysis was used to identify predictors for surgical resection-related mortality. RESULTS Among the four groups, the incidence of cerebrovascular complications was 1.5% in UW, 0.4% in NW, 0% in OW, and 0% in OB, and that of pulmonary complications was 13.1% in UW, 8.4% in NW, 7.3% in OW, and 7.6% in OB. Surgical resection-related mortality was 2.9% in UW, 0.6% in NW, 1.7% in OW, and 0% in OB. Multivariate analysis revealed underweight, diffusing capacity of the lung for carbon monoxide, and male sex as the significant predictors. CONCLUSIONS In this study, low BMI was an independent risk factor for mortality, and the incidence of cerebrovascular and pulmonary complications tended to be higher in patients with low BMI than in obese patients. Underweight patients should be closely monitored following pulmonary resection.
European Journal of Cardio-Thoracic Surgery | 2017
Masaaki Sato; Taiji Kuwata; Keiji Yamanashi; Atsushi Kitamura; Kenji Misawa; Kota Imashimizu; Masashi Kobayashi; Masaki Ikeda; Terumoto Koike; Shinji Kosaka; Ryuta Fukai; Yasuo Sekine; Noritaka Isowa; S. Hirayama; Hiroaki Sakai; Fumiaki Watanabe; Kazuhiro Nagayama; Akihiro Aoyama; Hiroshi Date; Jun Nakajima
Abstract OBJECTIVES: Virtual-assisted lung mapping (VAL-MAP) is a preoperative bronchoscopic multispot dye-marking technique using virtual images. The purpose of this study was to evaluate the safety, efficacy and reproducibility of VAL-MAP among multiple centres. METHODS: Selection criteria included patients with pulmonary lesions anticipated to be difficult to identify at thoracoscopy and/or those undergoing sub-lobar lung resections requiring careful determination of resection margins. Data were collected prospectively and, if needed, compared between the centre that originally developed VAL-MAP and 16 other centres. RESULTS: Five hundred patients underwent VAL-MAP with 1781 markings (3.6 ± 1.2 marks/patient). Complications associated with VAL-MAP necessitating additional management occurred in four patients (0.8%) including pneumonia, fever and temporary exacerbation of pre-existing cerebral ischaemia. Minor complications included pneumothorax (3.6%), pneumomediastinum (1.2%) and alveolar haemorrhage (1.2%), with similar incidences between the original centre and other centres. Marks were identifiable during operation in approximately 90%, whereas the successful resection rate was approximately 99% in both groups, partly due to the mutually complementary marks. The contribution of VAL-MAP to surgical success was highly rated by surgeons resecting pure ground glass nodules (P < 0.0001), tumours ≤ 5 mm (P = 0.0016), and performing complex segmentectomy and wedge resection (P = 0.0072). CONCLUSIONS: VAL-MAP was found to be safe and reproducible among multiple centres with variable settings. Patients with pure ground glass nodules, small tumours and resections beyond conventional anatomical boundaries are considered the best candidates for VAL-MAP. Clinical Trial Registration Number: UMIN 000008031. University Hospital Medical Information Network Clinical Trial Registry (http://www.umin.ac.jp/ctr/).
Pediatric Surgery International | 2017
Atsuyuki Yamataka; Hiroyuki Koga; Takanori Ochi; Kota Imashimizu; Kazuhiro Suzuki; Ryohei Kuwatsuru; Geoffrey J. Lane; Kinya Nishimura; Eiichi Inada; Kenji Suzuki
Thoracoscopic pulmonary lobectomy (TPL) techniques in infants and children are presented practically with concise descriptions and numerous illustrations. TPL is the treatment of choice for congenital pulmonary airway malformation and intralobar pulmonary sequestration, both now commonly diagnosed prenatally. Timing of surgery is somewhat controversial in asymptomatic cases with small isolated lesions. Incomplete fissures and history of chest infections are most problematic. Thorough understanding of anatomic relations preoperatively is vital for successful outcome and thin-slice computed tomography with 3D reconstruction of vessels is valuable. Judicious placement of trocars and switching instruments between trocars improves visualization and safety. Specific techniques for all commonly performed TPL are included.
PLOS ONE | 2017
Kazuya Takamochi; Kaoru Mogushi; Hideya Kawaji; Kota Imashimizu; Mariko Fukui; Shiaki Oh; Masayoshi Itoh; Yoshihide Hayashizaki; Weijey Ko; Masao Akeboshi; Kenji Suzuki
Background 18F-fluoro-2-deoxy-glucose (18F-FDG) positron emission tomography (PET) is a functional imaging modality based on glucose metabolism. The correlation between EGFR or KRAS mutation status and the standardized uptake value (SUV) of 18F-FDG PET scanning has not been fully elucidated. Methods Correlations between EGFR or KRAS mutation status and clinicopathological factors including SUVmax were statistically analyzed in 734 surgically resected lung adenocarcinoma patients. Molecular causal relationships between EGFR or KRAS mutation status and glucose metabolism were then elucidated in 62 lung adenocarcinomas using cap analysis of gene expression (CAGE), a method to determine and quantify the transcription initiation activities of mRNA across the genome. Results EGFR and KRAS mutations were detected in 334 (46%) and 83 (11%) of the 734 lung adenocarcinomas, respectively. The remaining 317 (43%) patients had wild-type tumors for both genes. EGFR mutations were more frequent in tumors with lower SUVmax. In contrast, no relationship was noted between KRAS mutation status and SUVmax. CAGE revealed that 4 genes associated with glucose metabolism (GPI, G6PD, PKM2, and GAPDH) and 5 associated with the cell cycle (ANLN, PTTG1, CIT, KPNA2, and CDC25A) were positively correlated with SUVmax, although expression levels were lower in EGFR-mutated than in wild-type tumors. No similar relationships were noted with KRAS mutations. Conclusions EGFR-mutated adenocarcinomas are biologically indolent with potentially lower levels of glucose metabolism than wild-type tumors. Several genes associated with glucose metabolism and the cell cycle were specifically down-regulated in EGFR-mutated adenocarcinomas.
The Journal of Thoracic and Cardiovascular Surgery | 2017
Kazuya Takamochi; Shuko Nojiri; Shiaki Oh; Takeshi Matsunaga; Kota Imashimizu; Mariko Fukui; Kenji Suzuki
Objective: The objective of this study was to evaluate whether a digital thoracic drainage system (group D) is clinically useful compared with a traditional thoracic drainage system (group T) in chest tube management following anatomic lung resection. Methods: Patients scheduled to undergo segmentectomy or lobectomy were prospectively randomized before surgery to group D or T. A stratification randomization was performed according to the following air leak risk factors: age, sex, smoking status, and presence of emphysema and/or chronic obstructive pulmonary disease. The primary end point was the duration of chest tube placement. Results: No statistically significant differences were found between groups D (n = 135) and T (n = 164) with regard to the duration of chest tube placement (median, 2.0 vs 3.0 days; P = .149), duration of hospitalization (median, 6.0 vs 7.0 days; P = .548), or frequency of postoperative adverse events (25.1% vs 20.7%; P = .361). In subgroup analyses of the 64 patients with postoperative air leak (20 in group D and 44 in group T), the duration of chest tube placement (median, 4.5 vs 4.0 days; P = .225) and duration of postoperative air leak (median, 3.0 vs 3.0 days; P = .226) were not significantly different between subgroups. Conclusions: The use of a digital thoracic drainage system did not shorten the duration of chest tube placement in comparison to a traditional thoracic drainage system after anatomic lung resection.
Journal of Thoracic Disease | 2018
Masaaki Sato; Taiji Kuwata; Atsushi Kitamura; Kenji Misawa; Kota Imashimizu; Keiji Yamanashi; Masaki Ikeda; Terumoto Koike; Masashi Kobayashi; Shinji Kosaka; Ryuta Fukai; Noritaka Isowa; Kazuhiro Nagayama; Akihiro Aoyama; Hiroshi Date; Jun Nakajima
Background Virtual-assisted lung mapping (VAL-MAP), a bronchoscopic multi-spot dye-marking technique, was tested for its ability to resect ground glass nodules (GGNs) in sublobar lung resections. Methods All patients were prospectively registered in the multi-institutional lung mapping (MIL-MAP) study using VAL-MAP. The data were retrospectively analyzed, focusing on GGNs. GGN characteristics, pathological findings, operation type, and the surgical contribution of VAL-MAP were evaluated. Results The 370 GGNs in 299 patients included 257 pure and 113 mixed GGNs. There were 146 wedge resections (43.6%), 99 simple segmentectomies (29.6%), and 60 complex segmentectomies (18.0%). The largest number of marks were used in complex segmentectomy (4.05±0.74), followed by simple segmentectomy (3.35±0.97) and wedge resection (2.96±0.80). The overall successful resection rate was 98.6%. Multiple [2-5] GGNs were concurrently targeted by VAL-MAP in 53 patients (17.7%) with 123 GGNs. Two concurrent resections were conducted in 36 patients (12.1%), most commonly wedge resection and segmentectomies (21 patients). Among 190 sub-centimeter GGNs, 24 out of 51 GGNs ≤5 mm in diameter (47.1%) and 113 of 139 GGNs >5 mm in diameter (81.3%) were primary lung cancer (P<0.0001). Regarding the contribution of VAL-MAP to successful resection, wedge resection and pure GGNs were graded higher than both other resection types and mixed GGNs. Conclusions VAL-MAP enabled thoracoscopic limited resection of GGNs. Its multiple marks facilitated resections of multi-centric GGNs. Resected suspicious GGNs >5 mm in diameter are likely to be lung cancer. VAL-MAP may impact decision-making regarding the indications and type of surgery for suspicious small GGNs.
Interactive Cardiovascular and Thoracic Surgery | 2007
Motoki Sakuraba; Hideaki Miyamoto; Shiaki Oh; Kazu Shiomi; Satoshi Sonobe; Nobumasa Takahashi; Kota Imashimizu; Yukinori Sakao
The Annals of Thoracic Surgery | 2017
Kazuya Takamochi; Kota Imashimizu; Mariko Fukui; Tatsuo Maeyashiki; Mikiko Suzuki; Takuya Ueda; Hironori Matsuzawa; Shunki Hirayama; Takeshi Matsunaga; Shiaki Oh; Kenji Suzuki
Journal of Bone and Joint Surgery, American Volume | 2017
Yoshiyuki Suehara; Kota Imashimizu; Nobukazu Miyamoto; Hirohisa Uehara; Yu Tanabe; Nobutaka Hattori; Kenji Suzuki; Tsuyoshi Saito; Kazuo Kaneko
Interactive Cardiovascular and Thoracic Surgery | 2014
Kenji Suzuki; Kazuya Takamochi; Shiaki Oh; Kota Imashimizu; Takamitsu Banno; Takeshi Matsunaga; Mariko Fukui