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Featured researches published by Keisuke Hori.


Gastrointestinal Endoscopy | 2008

Risk factors associated with local recurrence of early gastric cancers after endoscopic submucosal dissection

Ryuta Takenaka; Yoshiro Kawahara; Hiroyuki Okada; Keisuke Hori; Masafumi Inoue; Seiji Kawano; Daisuke Tanioka; Takao Tsuzuki; Satoru Yagi; Jun Kato; Masayuki Uemura; Nobuya Ohara; Tadashi Yoshino; Atsushi Imagawa; Shigeatsu Fujiki; Rie Takata; Kazuhide Yamamoto

BACKGROUND Although endoscopic submucosal dissection (ESD) is expected to reduce the local recurrence of gastric cancers, we still experience cases of recurrence after an ESD. OBJECTIVE To characterize clinical and pathologic features of cases with local recurrence of early gastric cancer after an ESD. DESIGN A prospective cohort study. SETTING AND PATIENTS A total of 306 patients with gastric cancers removed by ESD at Okayama University Hospital and Tsuyama Central Hospital between March 2001 and December 2005 were enrolled. INTERVENTION ESD. MAIN OUTCOME MEASUREMENT Local recurrence. RESULTS The incidence of a complete en bloc resection was 80.4% when pathologically evaluated. Within a median follow-up period of 26 months (12-64 months), a local recurrence was found in 7 cases, all of which had been declared incomplete resections. One patient underwent a second ESD, and the remaining 6 underwent a surgical resection. All removed lesions were mucosal cancers. No lymph-node metastases were found in patients with a surgical resection. There was a significant correlation between the incidence of an incomplete resection and that of a local recurrence (P < .0001). Among the clinical characteristics, tumor size (>30 mm vs <20 mm; odds ratio [OR] 16 mm [95% CI, 2.0-130 mm]) and tumor location (upper vs middle or lower; OR 7.6 [95% CI, 1.3-45]) were identified as factors that were significantly associated with the incidence of a local recurrence. LIMITATION Short follow-up duration. CONCLUSIONS The incidence of a local recurrence was strongly associated with that of an incomplete resection. The frequency of a local recurrence also showed significant correlations with the tumor size and location within the stomach.


The American Journal of Gastroenterology | 2009

Narrow-Band Imaging Provides Reliable Screening for Esophageal Malignancy in Patients With Head and Neck Cancers

Ryuta Takenaka; Yoshiro Kawahara; Hiroyuki Okada; Keisuke Hori; Masafumi Inoue; Seiji Kawano; Daisuke Tanioka; Takao Tsuzuki; Masayuki Uemura; Nobuya Ohara; Susumu Tominaga; Tomoo Onoda; Kazuhide Yamamoto

OBJECTIVES:The narrow-band imaging (NBI) system is a novel technology that enhances the visualization of microvasculature and mucosal patterns. The aim of this study was to assess the reliability of the NBI system for esophageal cancer screening in patients with head and neck cancers.METHODS:A total of 142 patients with head and neck squamous cell carcinoma (SCC) were examined by NBI endoscopy, followed by Lugol chromoendoscopy between April 2006 and June 2008 at the Okayama University Hospital, Okayama, Japan. Detection of SCC and high-grade intraepithelial neoplasia (HGIN) was conducted.RESULTS:The median age of the patients was 64 years (range: 29–86 years), and approximately three-fourths of all the patients were male. In total, 21 superficial lesions in 16 patients were detected by NBI endoscopy. Of these, 4 lesions were diagnosed histologically as SCC and 11 lesions as HGIN. An additional 22 Lugol-voiding lesions ≥5 mm were detected in 19 patients by Lugol chromoendoscopy. Although 1 of these lesions was diagnosed as HGIN, 21 lesions were diagnosed as low-grade intraepithelial neoplasia or lesions without atypical findings. The sensitivity of NBI endoscopy for detecting esophageal SCC and HGIN was 90.9% (95% confidence interval (CI), 58.7–99.8), specificity was 95.4% (95% CI, 90.3–98.3), and accuracy was 95.1% (95% CI, 90.1–98.0).CONCLUSIONS:NBI seems to be useful and reliable for screening for esophageal SCC in patients with head and neck cancers.


The American Journal of Gastroenterology | 2011

Lugol-Voiding Lesions Are an Important Risk Factor for a Second Primary Squamous Cell Carcinoma in Patients With Esosphageal Cancer or Head and Neck Cancer

Keisuke Hori; Hiroyuki Okada; Yoshiro Kawahara; Ryuta Takenaka; Sachiko Shimizu; Yuko Ohno; Tomoo Onoda; Yasuhiro Sirakawa; Yoshio Naomoto; Kazuhide Yamamoto

OBJECTIVES:Lugol-voiding lesions (LVLs), detected by chromoendoscopy using iodine dye in patients with esophageal squamous cell carcinoma (EC) or head and neck squamous cell carcinoma (HNC), are associated with a second primary carcinoma in the other organ. We undertook a cross-sectional and retrospective cohort study to assess the risk for second primary carcinomas according to the severity of LVLs, on the basis of their number and size.METHODS:A total of 1,060 patients with only EC, only HNC, or both EC and HNC (EC+HNC) underwent esophageal endoscopic examination between January 1994 and January 2010. The patients were classified according to the number of LVLs in an endoscopic visual field and the size of the largest LVLs. Factors associated with the second primary EC or HNC were analyzed.RESULTS:Univariate analysis showed that a larger number and size of LVLs increased the risk for synchronous and early metachronous second primary cancer (P value for trend <0.0001). Multivariate analysis showed that a number of LVLs ≥20 (EC+HNC vs. only HNC, odds ratio (OR)=15.7; EC+HNC vs. only EC, 3.5) and a size ≥10 mm (EC+HNC vs. only HNC, OR=3.1; EC+HNC vs. only EC, 3.2) were independent risk factors for synchronous and early metachronous second primary cancer. A larger number of LVLs was a risk factor for metachronous EC and HNC, and a size ≥10 mm was a risk factor for late metachronous EC.CONCLUSIONS:The severity of LVLs in patients with HNC or EC closely correlated with a second primary carcinoma in the other organ. Patients with LVLs must be followed closely for development of a second primary carcinoma.


Digestive Endoscopy | 2009

Novel chromoendoscopic method using an acetic acid-indigocarmine mixture for diagnostic accuracy in delineating the margin of early gastric cancers

Yoshiro Kawahara; Ryuta Takenaka; Hiroyuki Okada; Seiji Kawano; Masafumi Inoue; Takao Tsuzuki; Daisuke Tanioka; Keisuke Hori; Kazuhide Yamamoto

Background and Aim:  Recent endoscopic imaging techniques for recognition of unclear lesions in the stomach (e.g. narrow band imaging, magnifying endoscopy) require special equipment and therefore are not commonly used. The aim of the present study was to estimate the accuracy of a new chromoendoscopic method using an acetic acid–indigo carmine mixture (AIM) in diagnosing early gastric cancers (EGC).


Endoscopy | 2014

Predictive factors for technically difficult endoscopic submucosal dissection in the colorectum

Keisuke Hori; Toshio Uraoka; Keita Harada; Reiji Higashi; Yoshiro Kawahara; Hiroyuki Okada; Hemchand Ramberan; Naohisa Yahagi; Kazuhide Yamamoto

BACKGROUND AND STUDY AIMS Because of technical difficulty, colorectal endoscopic submucosal dissection (CR-ESD) is not widely performed. We aimed to determine risk factors for such technical difficulty as defined by long procedure duration (≥  150 min), perforation, and piecemeal resection. PATIENTS AND METHODS Patients with consecutive colorectal tumors treated with ESD between April 2006 and December 2010 were enrolled in a prospective cohort study. For prediction of technical difficulty, three types of factor were investigated: tumor location, tumor type, and colonoscopy-related. Cases were subsequently categorized into earlier and later periods (April 2006 - August 2008, 123 lesions; September 2008 - December 2010, 124 lesions). Variables were analyzed using multiple logistic regression, with subgroup analyses for each period. RESULTS 247 lesions were analyzed. Flexure location was an independent risk factor for technical difficulty as measured by longer procedure duration (odds ratio [OR] 4.1, 95 % confidence interval [95 %CI] 1.1 - 14.9), piecemeal resection (4.7, 1.1 - 17.2), or perforation (8.8, 1.1 - 56.8). Tumor with scarring or locally recurrent was a risk factor for longer procedure duration (4.7, 1.7 - 13.7), and for piecemeal resection (7.8, 2.4 - 25.0). Tumor of size  ≥  50 mm or spreading across ≥  2 folds was the strongest independent risk factor for longer duration (6.3, 2.8 - 15.4), and was an independent risk factor for longer duration in both time periods (earlier, 3.3, 1.1 - 10.4; later, 27.4, 7.4 - 138.0). Flexure location was an independent risk factor for perforation (13.9, 1.5 - 129.1) and for piecemeal resection (5.1, 0.9 - 25.2) in the earlier but not the later period. CONCLUSIONS Factors predicting technical difficulty of CR-ESDs were clarified. Their importance was influenced by the increasing experience of the endoscopist.


Digestive Endoscopy | 2010

ADVANTAGES OF USING THIN ENDOSCOPE‐ASSISTED ENDOSCOPIC SUBMUCOSAL DISSECTION TECHNIQUE FOR LARGE COLORECTAL TUMORS

Toshio Uraoka; Shin Ishikawa; Jun Kato; Reiji Higashi; Hideyuki Suzuki; Eisuke Kaji; Motoaki Kuriyama; Shunsuke Saito; Mitsuhiro Akita; Keisuke Hori; Keita Harada; Shuhei Ishiyama; Junji Shiode; Yoshiro Kawahara; Kazuhide Yamamoto

Background:  Our purpose was to evaluate the effectiveness of a newly developed non‐invasive traction technique known as thin endoscope‐assisted endoscopic submucosal dissection (TEA‐ESD) procedure for the removal of colorectal laterally spreading tumors (LST).


World Journal of Gastroenterology | 2014

Prognosis of ulcerative colitis differs between patients with complete and partial mucosal healing, which can be predicted from the platelet count.

Asuka Nakarai; Jun Kato; Sakiko Hiraoka; Toshihiro Inokuchi; Daisuke Takei; Yuki Moritou; Mitsuhiro Akita; Sakuma Takahashi; Keisuke Hori; Keita Harada; Hiroyuki Okada; Kazuhide Yamamoto

AIM To determine the difference in clinical outcome between ulcerative colitis (UC) patients with Mayo endoscopic subscore (MES) 0 and those with MES 1. METHODS UC patients with sustained clinical remission of 6 mo or more at the time of colonoscopy were examined for clinical outcomes and the hazard ratios of clinical relapse according to MES. Parameters, including blood tests, to identify predictive factors for MES 0 and slight endoscopic recurrence in clinically stable patients were assessed. Moreover, a receiver operating characteristic curve was generated, and the area under the curve was calculated to indicate the utility of the parameters for the division between complete and partial mucosal healing. All P values were two-sided and considered significant when less than 0.05. RESULTS A total of 183 patients with clinical remission were examined. Patients with MES 0 (complete mucosal healing: n = 80, 44%) were much less likely to relapse than those with MES 1 (partial mucosal healing: n = 89, 48%) (P < 0.0001, log-rank test), and the hazard ratio of risk of relapse in patients with MES 1 vs MES 0 was 8.17 (95%CI: 4.19-17.96, P < 0.0001). The platelet count (PLT) < 26 × 10(4)/μL was an independent predictive factor for complete mucosal healing (OR = 4.1, 95%CI: 2.15-7.99). Among patients with MES 0 at the initial colonoscopy, patients of whom colonoscopy findings shifted to MES 1 showed significant increases in PLT compared to those who maintained MES 0 (3.8 × 10(4)/μL vs -0.6 × 10(4)/μL, P < 0.0001). CONCLUSION The relapse rate differed greatly between patients with complete and partial mucosal healing. A shift from complete to partial healing in clinically stable UC patients can be predicted by monitoring PLT.


Digestion | 2011

Proton pump inhibitor dose-related healing rate of artificial ulcers after endoscopic submucosal dissection: A prospective randomized controlled trial

Seiji Kawano; Hiroyuki Okada; Yoshiro Kawahara; Keisuke Hori; Daisuke Tanioka; Takao Tsuzuki; Masafumi Inoue; Satoru Yagi; Ryuta Takenaka; Kazuhide Yamamoto

Background/Aims: Two studies have reported on the superiority of a proton pump inhibitor (PPI) compared with a histamine-2-receptor antagonist for the treatment of artificial ulcers after endoscopic submucosal dissection (ESD), but the optimal dose of PPI remains to be defined. The aim of this study was to evaluate the possibility of reducing the dose of PPI. The authors thus compared 30 mg (standard-dose) and 15 mg (half-dose) lansoprazole in terms of ulcer healing, prevention of bleeding and quality of life. Methods: 91 patients with gastric mucosal neoplasm were enrolled. All patients who underwent ESD were administered lansoprazole 30 mg daily during the first week, after which they were randomly assigned to either the standard-dose or half-dose group. Results: One patient in each group developed hematemesis. The stage of ulcers, ulcer reduction ratios and scores on the Gastrointestinal Symptom Rating Scale did not differ at 28 and 56 days. The costs of PPI for the half-dose group and standard-dose group were 7,326.5 and 11,698.4 JPY, respectively, i.e. a difference of 471.9 JPY. Conclusions: A reduced dose of PPI after 1 week of ESD was equivalent in treatment performance to the standard dose and cheaper.


Digestive Endoscopy | 2011

CARBON DIOXIDE SUBMUCOSAL INJECTION CUSHION : AN INNOVATIVE TECHNIQUE IN ENDOSCOPIC SUBMUCOSAL DISSECTION

Toshio Uraoka; Yoshiro Kawahara; Nobuya Ohara; Jun Kato; Keisuke Hori; Hiroyuki Okada; Kazuhide Yamamoto

Aim:  Endoscopic submucosal dissection (ESD) can successfully resect large lesions en bloc, but it requires a satisfactory submucosal (sm) injection agent for proper safety and efficacy. The aim of the present study was to evaluate the effectiveness of carbon dioxide (CO2) as an ESD sm injection agent.


Endoscopy | 2013

Endoscopic submucosal dissection of esophageal cancer using the Mucosectom2 device: a feasibility study

Yoshiro Kawahara; Keisuke Hori; Ryuta Takenaka; Junichiro Nasu; Seiji Kawano; Masahide Kita; Takao Tsuzuki; Minoru Matsubara; Sayo Kobayashi; Hiroyuki Okada; Kazuhide Yamamoto

BACKGROUND AND STUDY AIMS Endoscopic submucosal dissection (ESD) is being increasingly used for superficial esophageal cancers. However, esophageal ESD is technically difficult, time consuming, and less safe compared with endoscopic mucosal resection (EMR). To perform ESD safely and more efficiently, various types of knives have been developed. This study compared the efficacy of our newly developed device, Mucosectom2, with that of conventional devices for esophageal ESD. PATIENTS AND METHODS Between May 2007 and February 2011, ESD was performed for 172 esophageal lesions. Of these, 120 lesions were treated by conventional devices only, whereas 52 lesions were treated by conventional devices and the Mucosectom2. Procedure time, en bloc and R0 resection rates, and adverse events were retrospectively compared between the conventional and Mucosectom2 groups. RESULTS The median procedure time was 48.0 minutes in the conventional group and 21.5 minutes in the Mucosectom2 group; the procedure time was significantly shorter in the Mucosectom2 group than in the conventional group (P < 0.0001). The en bloc and R0 resection rates were lower in the conventional group than those in the Mucosectom2 group, although these differences were not significant. The rate of exposure of the muscle layer in the Mucosectom2 group was significantly lower than in the conventional group (P = 0.04). The rates of perforation and postoperative bleeding were not significantly different between the two groups. CONCLUSIONS This feasibility study suggests that, compared with conventional ESD devices, the Mucosectom2 may decrease the time required for esophageal ESD. Although our groups appeared comparable, they were studied at different times. Endoscopic expertise and endoscope quality may have differed during these periods, thereby affecting the results of our study. A prospective trial is therefore required to confirm our results.

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