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Dive into the research topics where Tomonori Yano is active.

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Featured researches published by Tomonori Yano.


Clinical Gastroenterology and Hepatology | 2004

Clinical outcomes of double-balloon endoscopy for the diagnosis and treatment of small-intestinal diseases.

Hironori Yamamoto; Hiroto Kita; Keijiro Sunada; Yoshikazu Hayashi; Hiroyuki Sato; Tomonori Yano; Michiko Iwamoto; Yutaka Sekine; Tomohiko Miyata; Akiko Kuno; Hironari Ajibe; Kenichi Ido; Kentaro Sugano

BACKGROUND & AIMS A specialized system for a new method for enteroscopy, the double-balloon method, was developed. The aim of this study was to evaluate the usefulness of this endoscopic system for small-intestinal disorders. METHODS The double-balloon endoscopy system was used to perform 178 enteroscopies (89 by the anterograde approach and 89 by the retrograde approach) in 123 patients. The system was assessed on the basis of the rates of success in jejunal and ileal insertion and the entire examination of the small intestine, diagnostic yields, ability to perform treatment, and complications. RESULTS Insertion of the endoscope beyond the ligament of Treitz or ileocecal valve was possible in all 178 procedures. It was possible to observe approximately one half to two thirds of the entire small intestine by each approach, and observation of the entire small intestine was possible in 24 (86%) of 28 trials. The source of bleeding was identified in 50 (76%) of 66 patients with GI bleeding, scrutiny of strictures was possible in 23 patients, and a tumor was examined endoscopically in 17 patients. Two complications (1.1%) occurred. Endoscopic therapies in the small intestine including hemostasis (12 cases), polypectomy (1 case), endoscopic mucosal resection (1 case), balloon dilation (6 cases), and stent placement (2 cases) were performed successfully. CONCLUSIONS Double-balloon endoscopy permits the exploration of the small intestine with a high success rate of total enteroscopy. The procedure is safe and useful, and it provides high diagnostic yields and therapeutic capabilities.


Journal of Clinical Oncology | 2010

Early Detection of Superficial Squamous Cell Carcinoma in the Head and Neck Region and Esophagus by Narrow Band Imaging: A Multicenter Randomized Controlled Trial

Manabu Muto; Keiko Minashi; Tomonori Yano; Yutaka Saito; Ichiro Oda; Satoru Nonaka; Tai Omori; Hitoshi Sugiura; Kenichi Goda; Mitsuru Kaise; Haruhiro Inoue; Hideki Ishikawa; Atsushi Ochiai; Tadakazu Shimoda; Hidenobu Watanabe; Hisao Tajiri; Daizo Saito

PURPOSE Most of the esophageal squamous cell carcinomas (ESCCs) and cancers of the head and neck (H&N) region are diagnosed at later stages. To achieve better survival, early detection is necessary. We compared the real-time diagnostic yield of superficial cancer in these regions between conventional white light imaging (WLI) and narrow band imaging (NBI) in high-risk patients. PATIENTS AND METHODS In a multicenter, prospective, randomized controlled trial, 320 patients with ESCC were randomly assigned to primary WLI followed by NBI (n = 162) or primary NBI followed by WLI (n = 158) in a back-to-back fashion. The primary aim was to compare the real-time detection rates of superficial cancer in the H&N region and the esophagus between WLI and NBI. The secondary aim was to evaluate the diagnostic accuracy of these techniques. RESULTS NBI detected superficial cancer more frequently than did WLI in both the H&N region and the esophagus (100% v 8%, P < .001; 97% v 55%, P < .001, respectively). The sensitivity of NBI for diagnosis of superficial cancer was 100% and 97.2% in the H&N region and the esophagus, respectively. The accuracy of NBI for diagnosis of superficial cancer was 86.7% and 88.9% in these regions, respectively. The sensitivity and accuracy were significantly higher using NBI than WLI in both regions (P < .001 and P = .02 for the H&N region; P < .001 for both measures for the esophagus, respectively). CONCLUSION NBI could be the standard examination for the early detection of superficial cancer in the H&N region and the esophagus.


Scandinavian Journal of Gastroenterology | 2008

Prevalence of non-steroidal anti-inflammatory drug-induced enteropathy determined by double-balloon endoscopy : A Japanese multicenter study

Takayuki Matsumoto; Tetsuji Kudo; Motohiro Esaki; Tomonori Yano; Hironori Yamamoto; Choitsu Sakamoto; Hidemi Goto; Hiroshi Nakase; Shinji Tanaka; Toshiyuki Matsui; Kentaro Sugano; Mitsuo Iida

Objective. Capsule endoscopy has shown that non-steroidal anti-inflammatory drugs (NSAIDs) can damage the small intestine. The aim of this study was to determine the prevalence of NSAIDs enteropathy in subjects indicated for double-balloon endoscopy (DBE). Material and methods. The Japanese Study Group for Double-Balloon Endoscopy (JSG-DBE) established a database for the practical use of DBE in the Japanese population during a 2-year period from 2004 to 2005. Using this database, we identified subjects who had been taking NSAIDs within a month prior to DBE (NSAIDs group) and those free from NSAIDs use (control group). The clinical background and DBE findings were compared between the two groups. Results. Among 1035 patients registered in the JSG-DBE database, 61 subjects were classified as the NSAIDs group and 600 served as the control group. Patients in the NSAIDs group were older (62±18 versus 51±19 years, p<0.0001) and gastrointestinal bleeding was a more frequent indication for DBE (79% versus 44%, p<0.001) compared with in the control group. Non-specific mucosal breaks were detected by DBE in 31 patients in the NSAIDs group (51%) and 29 patients in the control group (5%, p <0.0001). Aspirin was less frequently prescribed and cardiovascular disease was a less frequent indication for NSAIDs use in patients with mucosal breaks than in those without breaks. Conclusions. In the cases indicated for enteroscopy, NSAIDs enteropathy occurred in half of the patients taking NSAIDs. Aspirin seems to be less harmful to the small intestine than other NSAIDs.


Gastrointestinal Endoscopy | 2010

Magnifying narrow-band imaging versus magnifying white-light imaging for the differential diagnosis of gastric small depressive lesions: a prospective study

Yasumasa Ezoe; Manabu Muto; Takahiro Horimatsu; Keiko Minashi; Tomonori Yano; Yasushi Sano; Tsutomu Chiba; Atsushi Ohtsu

BACKGROUND The accurate diagnosis of gastric small depressive lesions (SDLs), including gastritis and cancerous lesions, is difficult with conventional endoscopy when using white-light imaging (WLI). Narrow-band imaging (NBI) is expected to make a more accurate diagnosis of gastric SDLs than WLI because it provides better visualization of the mucosal surface and microvascular architecture when combined with magnifying endoscopy. OBJECTIVE To compare the real-time diagnostic accuracy of magnifying WLI and magnifying NBI for gastric SDLs. DESIGN Prospective study. SETTING National Cancer Center Hospital East, Kashiwa, Japan. PATIENTS Fifty-seven lesions in 53 consecutive patients were analyzed: 30 cancers and 27 benign lesions. INTERVENTIONS If previously undiagnosed gastric SDLs smaller than 10 mm were identified during an endoscopic examination, magnifying observation with both WLI and NBI was performed for each SDL. Endoscopic diagnosis of SDLs was made by each method on site. MAIN OUTCOME MEASUREMENTS The diagnostic accuracy and the time required for diagnosis. RESULTS The diagnostic accuracy was significantly higher for NBI than for WLI (79% vs 44%; P = .0001), as was its sensitivity (70% vs 33%; P = .0005). The diagnostic specificity of NBI (89%) was higher than that of WLI (67%), but the difference was not statistically significant. The time required for the diagnosis was equivalent with both methods. LIMITATIONS Single-center study, small sample size. CONCLUSIONS Adding NBI to the WLI examination is essential for making an accurate diagnosis of gastric SDLs compared with magnifying WLI alone. (UMIN Clinical Trials Registry identification number C000000421).


Journal of Clinical Gastroenterology | 2011

Efficacy of preventive endoscopic balloon dilation for esophageal stricture after endoscopic resection

Yasumasa Ezoe; Manabu Muto; Takahiro Horimatsu; Shuko Morita; Shinʼichi Miyamoto; Satoshi Mochizuki; Keiko Minashi; Tomonori Yano; Atsushi Ohtsu; Tsutomu Chiba

Background and Aim We earlier reported that mucosal defect involving over three-fourths of the circumference of the esophagus after endoscopic mucosal resection (EMR) is a risk factor for the development of the stricture. Although endoscopic balloon dilation (EBD) is a useful procedure to relieve the stricture, there is no standard strategy for preventing development of the stricture. The aim of this study was to evaluate the efficacy and the safety of preventive EBD. Methods From 1993 to 2008, 41 consecutive patients with extensive mucosal defect involving over three-fourths of the esophageal circumference after EMR or endoscopic submucosal dissection (ESD) were investigated. Preventive EBD was carried out for 29 cases within 1 week just after EMR/ESD and was repeated once a week until the mucosal defect was completely healed. The remaining 12 cases were not underwent preventive EBD and used as a historic control. If postEMR/ESD stricture developed regardless of preventive EBD, conventional EBD was given repeatedly until the stricture was completely relieved. Results Preventive EBD decreased the incidence of stricture (59% vs. 92%, P =0.04), reduced the severity of stricture [(⩽2 mm; >2 mm and ⩽5 mm; >5 mm)=(1; 2; 14) vs. (4; 4; 3), P = 0.01] and shortened the duration required for resolving the stricture (29 d vs. 78 d, P =0.04) even when stricture developed. There was no complication associated with preventive EBD procedure. Conclusions Preventive EBD is an effective procedure to prevent postEMR/ESD stricture. Preventive EBD should be considered when EMR/ESD results in a mucosal defect with a circumference greater than three-fourths of the esophageal lumen.


Clinical Gastroenterology and Hepatology | 2010

Long-term Outcome of Patients With Obscure Gastrointestinal Bleeding Investigated by Double-Balloon Endoscopy

Satoshi Shinozaki; Hironori Yamamoto; Tomonori Yano; Keijiro Sunada; Tomohiko Miyata; Yoshikazu Hayashi; Masayuki Arashiro; Kentaro Sugano

BACKGROUND & AIMS It is often difficult to determine the cause of obscure gastrointestinal bleeding (OGIB). We evaluated the diagnostic yield and long-term outcome of patients with OGIB by using double-balloon endoscopy (DBE). METHODS In this large, retrospective cohort study, DBE was performed in 200 consecutive patients with OGIB. Follow-up data were available from 151 patients for 29.7 months (range, 6-78 months), and clinical outcome was assessed. RESULTS DBE detected bleeding sources in 155 of 200 patients (77.5%). The most frequent source detected was small intestine ulcers/erosions (64 patients). Patients who underwent DBE within 1 month after the last episode of overt bleeding had a better yield of positive findings than those who did not (84%, 107/128 patients vs 57%, 24/42; P = .002). The overall rate of control of OGIB was 64% (97/151 patients). Patients with vascular lesions of the small intestine had a significantly lower rate of control of OGIB than those with other small intestine lesions (40%, 12/30 patients vs 74%, 52/70; P = .001). A requirement for a large transfusion before DBE (P = .012), multiple lesions (P = .010), and suspicious (not definite) lesions (P = .038) each significantly increased the likelihood of overt rebleeding in patients with vascular lesions of the small intestine. CONCLUSIONS DBE is useful for the diagnosis of patients with OGIB and should be performed as soon as possible after overt OGIB. Patients with vascular lesions of the small intestine should be followed with particular care.


Gastrointestinal Endoscopy | 2009

Role of double-balloon endoscopy in the diagnosis of small-bowel tumors: the first Japanese multicenter study

Keigo Mitsui; Shu Tanaka; Hironori Yamamoto; Tsuyoshi Kobayashi; Akihito Ehara; Tomonori Yano; Hidemi Goto; Hiroshi Nakase; Shinji Tanaka; Toshiyuki Matsui; Mitsuo Iida; Kentaro Sugano; Choitsu Sakamoto

BACKGROUND The early diagnosis of small-bowel tumors (SBT) was a difficult task until the advent of capsule endoscopy (CE) and double-balloon endoscopy (DBE) allowed access to the disease site. However, although CE and DBE have greatly simplified the task, DBE studies have yet to provide sufficient data on the diagnosis and outcome of patients with SBTs. OBJECTIVE To determine the efficacy of DBE examination in the detection and diagnosis of SBT. DESIGN A retrospective analysis of cross-sectional case series. SETTING Seven major medical centers in Japan. PATIENTS The first 1035 consecutive DBE cases at these major Japanese centers since the introduction of DBE. MAIN OUTCOME MEASUREMENTS The percentage of subjects with SBT and a diagnosis of SBT, their indications for DBE, and diagnostic and therapeutic DBE procedures carried out for SBT. RESULTS SBTs were identified in 144 of 1035 subjects (13.9%) who underwent DBE between September 2000 and December 2005. For subjects with SBT, the most common indication for DBE was the suspected presence of a SBT (61/144 [42.4%]). For subjects without SBT, the most common indication was obscure GI bleeding (OGIB) (419/891 [47.0%]). Malignant lymphoma and GI stromal tumor (GIST) were the most frequent (31/144 [21.5%]) and the second-most frequent SBTs (27/144 [18.8%]), respectively, in this database. We also performed 85 biopsies and 45 therapeutic procedures for the evaluation and treatment of SBTs in 144 patients. Although complications were encountered in 5.3% of cases (14/266 sessions), none of these were life threatening in the present study. CONCLUSION DBE proved a valuable tool for the detection and diagnosis of SBTs, especially when tumors were suspected. Biopsies and therapeutic procedures were also possible in most of these patients, which directed our management of the disease.


Radiotherapy and Oncology | 2009

Elective nodal irradiation (ENI) in definitive chemoradiotherapy (CRT) for squamous cell carcinoma of the thoracic esophagus

Masakatsu Onozawa; Keiji Nihei; Satoshi Ishikura; Keiko Minashi; Tomonori Yano; Manabu Muto; Atsushi Ohtsu; Takashi Ogino

BACKGROUND AND PURPOSE There are some reports indicating that prophylactic three-field lymph node dissection for esophageal cancer can lead to improved survival. But the benefit of ENI in CRT for thoracic esophageal cancer remains controversial. The purpose of the present study is to retrospectively evaluate the efficacy of elective nodal irradiation (ENI) in definitive chemoradiotherapy (CRT) for thoracic esophageal cancer. MATERIALS AND METHODS Patients with squamous cell carcinoma (SCC) of the thoracic esophagus newly diagnosed between February 1999 and April 2001 in our institution was recruited from our database. Definitive chemoradiotherapy consisted of two cycles of cisplatin/5FU repeated every 5 weeks, with concurrent radiation therapy of 60 Gy in 30 fractions. Up to 40 Gy radiation therapy was delivered to the cervical, periesophageal, mediastinal and perigastric lymph nodes as ENI. RESULTS One hundred two patients were included in this analysis, and their characteristics were as follows: median age, 65 years; male/female, 85/17; T1/T2/T3/T4, 16/11/61/14; N0/N1, 48/54; M0/M1, 84/18. The median follow-up period for the surviving patients was 41 months. Sixty patients achieved complete response (CR). After achieving CR, only one (1.0%; 95% CI, 0-5.3%) patient experienced elective nodal failure without any other site of recurrence. CONCLUSION In CRT for esophageal SCC, ENI is effective for preventing regional nodal failure. Further evaluation of whether ENI leads to an improved overall survival is needed.


Endoscopy | 2008

Long-term results of salvage endoscopic mucosal resection in patients with local failure after definitive chemoradiotherapy for esophageal squamous cell carcinoma

Tomonori Yano; Manabu Muto; S. Hattori; Keiko Minashi; M. Onozawa; K. Nihei; S. Ishikura; Atsushi Ohtsu; Shigeaki Yoshida

BACKGROUND AND STUDY AIMS Local failure after definitive chemoradiotherapy (CRT) in patients with esophageal cancer remains one of the major problems in finding a cure. Endoscopic mucosal resection (EMR) is one treatment option when failure lesions are superficial. However, there are no relevant long-term survival data. The aim of this study was to clarify the long-term survival of salvage EMR. PATIENTS AND METHODS Between January 1998 and March 2004, 289 patients with esophageal squamous cell carcinoma were treated with definitive CRT at the National Cancer Center Hospital East, Japan. Of these 289 patients, 21 patients with local failure without lymph-node or distant metastases were treated with salvage EMR. The technique of salvage EMR involved a strip biopsy method. We retrospectively analyzed the long-term survival data for the patients who underwent salvage EMR. RESULTS At a median follow-up period of 54 months (range, 16-108 months), eight of 21 patients (38%) were alive with no recurrence and two patients had died from another disease but with no recurrence of esophageal cancer. Local recurrence after EMR was detected in four patients, with local and lymph-node recurrence in two patients, and lymph-node and/or distant metastases in five patients. The 5-year survival rate from the initiation of salvage EMR was 49.1%. There were no severe complications associated with EMR. CONCLUSION EMR is one of the curative salvage treatment options for local failure after definitive CRT, if the failure lesion is superficial and there are no lymph-node or distant metastases.


Gastrointestinal Endoscopy | 2010

Safety and efficacy of double-balloon enteroscopy in pediatric patients

Naoyuki Nishimura; Hironori Yamamoto; Tomonori Yano; Yoshikazu Hayashi; Masayuki Arashiro; Tomohiko Miyata; Keijiro Sunada; Kentaro Sugano

BACKGROUND Although double-balloon enteroscopy (DBE) is performed increasingly often in adults, few findings are available on the use of DBE in pediatric patients in the published literature. OBJECTIVES The aim of our study was to evaluate the safety and efficacy of DBE in pediatric patients. DESIGN A retrospective database review. SETTING AND PATIENTS A database analysis was performed on all pediatric patients (18 years old or younger) who underwent DBE at the Jichi Medical University Hospital between September 2000 and October 2008 selected from a total of 825 patients. MAIN OUTCOME MEASUREMENTS Clinical utility and safety of DBE in pediatric patients. RESULTS A total of 92 procedures were performed in 48 patients (27 male, 21 female) with a median age (range) of 12.2 (4-18) years. DBE was performed with the patients under general anesthesia in 43 procedures and under moderate sedation in 49 procedures. The most common indication for DBE was treatment of a stricture of a biliary anastomosis after living-donor liver transplantation with establishment of Roux-en-Y hepaticojejunostomy (23 patients). Endoscopic retrograde cholangiography using DBE was performed, and endoscopic therapy could be performed successfully in 13 (56%) patients. The second most common indication was obscure GI bleeding (10 patients); the lesions responsible for the bleeding were found in 7 (70%) patients. Other indications included surveillance and treatment of hereditary polyposis syndromes (5 patients), abdominal pain (4 patients), and inflammatory bowel disease (2 patients). The overall diagnostic yield was 65% (31 of the 48 patients). Postpolypectomy bleeding occurred in 1 case, but no other complications such as perforation and pancreatitis were observed. LIMITATIONS Small number of patients, participation bias, and single centers experience. CONCLUSIONS DBE is a safe and clinically useful endoscopic procedure in pediatric patients.

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Keijiro Sunada

Jichi Medical University

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Kentaro Sugano

Jichi Medical University

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Hiroaki Ikematsu

Shiga University of Medical Science

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