Yasutoshi Kobayashi
Showa University
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Featured researches published by Yasutoshi Kobayashi.
Journal of The American College of Surgeons | 2015
Haruhiro Inoue; Hiroki Sato; Haruo Ikeda; Manabu Onimaru; Chiaki Sato; Hitomi Minami; Hiroshi Yokomichi; Yasutoshi Kobayashi; Kevin L. Grimes; Shin-ei Kudo
BACKGROUND After the first case of per-oral endoscopic myotomy (POEM) at our institution in 2008, the procedure was quickly accepted as an alternative to surgical myotomy and is now established as an excellent treatment option for achalasia. This study aimed to examine the safety and outcomes of POEM at our institution. STUDY DESIGN Per-oral endoscopic myotomy was performed on 500 consecutive achalasia patients at our institution between September 2008 and November 2013. A review of prospectively collected data was conducted, including procedure time, myotomy location and length, adverse events, and patient data with short- (2 months) and long-term (1 and 3 years) follow-up. RESULTS Per-oral endoscopic myotomy was successfully completed in all patients, with adverse events observed in 3.2%. Two months post-POEM, significant reductions in symptom scores (Eckardt score 6.0 ± 3.0 vs 1.0 ± 2.0, p < 0.0001) and lower esophageal sphincter (LES) pressures (25.4 ± 17.1 vs 13.4 ± 5.9 mmHg, p < 0.0001) were achieved, and this persisted at 3 years post-POEM. Gastroesophageal reflux was seen in 16.8% of patients at 2 months and 21.3% at 3-year follow-up. CONCLUSIONS Per-oral endoscopic myotomy was successfully completed in all cases, even when extended indications (extremes of age, previous interventions, or sigmoid esophagus) were used. Adverse events were rare (3.2%), and there were no mortalities. Significant improvements in Eckardt scores and LES pressures were seen at 2 months, 1 year, and 3 years post-POEM. Based on our large series, POEM is a safe and effective treatment for achalasia; there are relatively few contraindications, and the procedure may be used as either first- or second-line therapy.
Gastrointestinal Endoscopy | 2013
Hiroki Sato; Haruhiro Inoue; Yasutoshi Kobayashi; Roberta Maselli; Esperanza Grace Santi; Bu'Hussain Hayee; Kenta Igarashi; Akira Yoshida; Haruo Ikeda; Manabu Onimaru; Yutaka Aoyagi; Shin-ei Kudo
BACKGROUND Recent technological advances have allowed superficially spreading intramucosal carcinomas of the esophagus to be successfully resected by circumferential endoscopic submucosal dissection (cESD). After this procedure, esophageal strictures develop in most patients and are mainly treated by endoscopic balloon dilation (EBD). OBJECTIVE To compare oral steroids plus EBD with EBD alone for the management of benign esophageal strictures after cESD. DESIGN Retrospective cohort study. SETTING Tertiary-care referral center. PATIENTS We studied 23 consecutive patients who underwent complete cESD for superficial esophageal carcinoma (22 squamous cell carcinomas and 1 adenocarcinoma associated with Barretts esophagus). INTERVENTION After cESD, patients were managed with EBD alone (EBD, n = 13) or with EBD and oral prednisolone (steroid + EBD, n = 10), 30 mg daily, started 2 days after cESD and gradually tapered and discontinued after 8 weeks. MAIN OUTCOME MEASUREMENTS Total number of EBD sessions and total EBD period (months). RESULTS Steroid + EBD patients required fewer sessions (13.8 ± 6.9 vs 33.5 ± 22.9; P < .001) and a shorter management period (4.8 ± 2.3 vs 14.2 ± 17.5 months, P = .005) compared with the EBD group. An additional 3 patients received oral steroids a mean interval of 158 days after cESD. These patients required more EBD sessions (46.3 ± 30.0; P = .002), and the EBD period was significantly longer (17.5 ± 13.0 months; P = .005) than in the early steroid + EBD group. LIMITATIONS Nonrandomized study; retrospective analysis. CONCLUSION After cESD, oral steroid therapy dramatically reduced the need for EBD. We conclude that oral steroid therapy after EBD is an effective strategy for the management of esophageal strictures after complete cESD.
Endoscopy | 2015
Hiroki Sato; Haruhiro Inoue; Haruo Ikeda; Chiaki Sato; Manabu Onimaru; Bu Hayee; Chainarong Phlanusi; Esperanza Grace Santi; Yasutoshi Kobayashi; Shin-ei Kudo
BACKGROUND AND STUDY AIMS Intrapapillary capillary loops (IPCLs) have been used to estimate histopathological atypia and the invasion depth of squamous cell carcinoma (SCC). The aim of this study was to evaluate the clinical significance of IPCLs. PATIENTS AND METHODS A total of 358 consecutive patients with esophageal neoplasia on magnifying narrow-band imaging (M-NBI) were studied. The lesions were categorized according to the IPCL classification of Inoue et al. and were subsequently resected. Resected specimens were histopathologically analyzed to determine the invasion depth. The inter- and intraobserver agreements in the interpretation of IPCL images were also investigated. RESULTS A total of 446 lesions were diagnosed on M-NBI as IPCL type V lesions, which were further classified as 185 IPCL type V1, 109 type V2, 104 type V3, and 48 type Vn. Sensitivity and specificity of IPCL type V1-2 for invasion confined to the epithelium or lamina propria mucosa (m1-2) were 89.5 % (95 % confidence interval [CI] 85.4 % - 92.7 %) and 79.6 % (95 %CI 72.3 % - 85.7 %), respectively. Sensitivity and specificity of IPCL type V3 for invasion confined to the muscularis mucosa or slight submucosal invasion (m3-sm1) were 58.7 % and 83.8 %, respectively. Sensitivity and specificity of IPCL type Vn for deeper invasion (sm2-3) were 55.8 % and 98.6 %, respectively. Interobserver agreement was substantial (κ = 0.609, 0.641, and 0.705), as was intraobserver agreement (κ = 0.705 and κ = 0.819). CONCLUSION Changes in the morphology of IPCLs on M-NBI correlated with the depth of SCC invasion, and results were reproducible and reliable among observers. Identification of IPCL type V1-2 proved useful for the intraprocedural identification of m1-2 lesions, which are considered an absolute indication for endoscopic resection.
PLOS ONE | 2015
Hitomi Minami; Hajime Isomoto; Satoshi Miuma; Yasutoshi Kobayashi; Naoyuki Yamaguchi; Shigetoshi Urabe; Kayoko Matsushima; Yuko Akazawa; Ken Ohnita; Fuminao Takeshima; Haruhiro Inoue; Kazuhiko Nakao
Background and Study Aims Endoscopic diagnosis of esophageal achalasia lacking typical endoscopic features can be extremely difficult. The aim of this study was to identify simple and reliable early indicator of esophageal achalasia. Patients and Methods This single-center retrospective study included 56 cases of esophageal achalasia without previous treatment. As a control, 60 non-achalasia subjects including reflux esophagitis and superficial esophageal cancer were also included in this study. Endoscopic findings were evaluated according to Descriptive Rules for Achalasia of the Esophagus as follows: (1) esophageal dilatation, (2) abnormal retention of liquid and/or food, (3) whitish change of the mucosal surface, (4) functional stenosis of the esophago-gastric junction, and (5) abnormal contraction. Additionally, the presence of the longitudinal superficial wrinkles of esophageal mucosa, “pinstripe pattern (PSP)” was evaluated endoscopically. Then, inter-observer diagnostic agreement was assessed for each finding. Results The prevalence rates of the above-mentioned findings (1–5) were 41.1%, 41.1%, 16.1%, 94.6%, and 43.9%, respectively. PSP was observed in 60.7% of achalasia, while none of the control showed positivity for PSP. PSP was observed in 26 (62.5%) of 35 cases with shorter history < 10 years, which usually lacks typical findings such as severe esophageal dilation and tortuosity. Inter-observer agreement level was substantial for food/liquid remnant (k = 0.6861) and PSP (k = 0.6098), and was fair for abnormal contraction and white change. The accuracy, sensitivity, and specificity for achalasia were 83.8%, 64.7%, and 100%, respectively. Conclusion “Pinstripe pattern” could be a reliable indicator for early discrimination of primary esophageal achalasia.
World Journal of Gastroenterology | 2015
Hiroki Sato; Haruhiro Inoue; Haruo Ikeda; Chiaki Sato; Chainarong Phlanusittepha; Bu Hayee; Esperanza Grace Santi; Yasutoshi Kobayashi; Shin-ei Kudo
AIM To study the ability of endocytoscopy to identify normal gastric mucosa and to exclude Helicobacter pylori (H. pylori) infection. METHODS Endocytoscopic examination of the gastric corpus and antrum was performed in 70 consecutive patients. Target biopsy specimens were also obtained from the assessed region and multiple H. pylori tests were performed. The normal endocytoscopy patterns of the corpus and antrum were divided into the normal pit-dominant type (n-Pit) or the normal papilla-dominant type (n-Pap), respectively characterized as either regular pits with capillary networks or round, smooth papillary structures with spiral capillaries. On the other hand, normal mucosa was defined as mucosa not demonstrating histological abnormalities, including inflammation and atrophy. RESULTS The sensitivity and specificity of n-Pit for normal mucosa in the gastric corpus were 94.4% and 97.1%, respectively, whereas those of n-Pap for normal mucosa in the antrum were 92.0% and 86.7%, respectively. The positive predictive values of n-Pit and n-Pap for H. pylori-negative tissue were 88.6% and 93.1%, respectively, and their negative predictive values for H. pylori-negative tissues were 42.9% and 41.5%, respectively. The inter-observer agreement for determining n-Pit and n-Pap for normal mucosa were 0.857 and 0.769, respectively, which is considered reliable. CONCLUSION N-Pit and n-Pap, seen using EC, are considered useful predictors of normal mucosa and the absence of H. pylori infection.
Endoscopy | 2013
Yuichi Mori; Shin-ei Kudo; Nobunao Ikehara; Kunihiko Wakamura; Yoshiki Wada; Makoto Kutsukawa; Masashi Misawa; Toyoki Kudo; Yasutoshi Kobayashi; Hideyuki Miyachi; Fuyuhiko Yamamura; Kazuo Ohtsuka; Haruhiro Inoue; Shigeharu Hamatani
Gastrointestinal Endoscopy | 2015
Hiroki Sato; Haruhiro Inoue; Bu Hayee; Haruo Ikeda; Chiaki Sato; Chainarong Phalanusitthepha; Esperanza Grace Santi; Yasutoshi Kobayashi; Shin-ei Kudo
Gastrointestinal Endoscopy | 2008
Kunihiko Wakamura; Shin-ei Kudo; Hiroshi Kashida; Nobunao Ikehara; Keita Sasajima; Yasutoshi Kobayashi; Yoshiki Wada; Ken-ichi Mizuno; Kenta Kodama; Orie Takemura; Noriyuki Ogata; Haruhiro Inoue; Shigeharu Hamatani
Gastrointestinal Endoscopy | 2009
Hideyuki Miyachi; Shin-ei Kudo; Nobunao Ikehara; Shigeharu Hamatani; Yui Kudo; Orie Takemura; Kenta Kodama; Toshihisa Hosoya; Kunihiko Wakamura; Yoshiki Wada; Takemasa Hayashi; Yasutoshi Kobayashi; Hiroshi Kanie; Fuyuhiko Yamamura; Kazuo Ohtsuka; Hiroshi Kashida
The Showa University Journal of Medical Sciences | 2011
Yasutoshi Kobayashi; Shin-ei Kudo; Hideyuki Miyachi; Toshihisa Hosoya; Takemasa Hayashi; Kunihiko Wakamura; Yoshiki Wada; Nobunao Ikehara; Fuyuhiko Yamamura; Kazuo Ohtsuka