Short-Term Healing Process of Artificial Ulcers after Gastric Endoscopic Submucosal Dissection

Similar documents
Is a Second-Look Endoscopy Necessary after Endoscopic Submucosal Dissection for Gastric Neoplasm?

Second-Look Endoscopy after Gastric Endoscopic Submucosal Dissection for Reducing Delayed Postoperative Bleeding

Delayed Perforation Occurring after Endoscopic Submucosal Dissection for Early Gastric Cancer

Usefulness of the Forrest Classification to Predict Artificial Ulcer Rebleeding during Second-Look Endoscopy after Endoscopic Submucosal Dissection

Delayed bleeding and hemorrhage of mucosal defects after gastric endoscopic submucosal dissection on second-look endoscopy

Early and long term outcomes of endoscopic submucosal dissection for early gastric cancer in a large patient series

Outcomes of Endoscopic Submucosal Dissection for Colorectal Epithelial Neoplasms in 200 Consecutive Cases

magnifying endoscopy with narrow-band imaging is more accurate for determination of horizontal extent of early gastric cancers than chromoendoscopy

Departmental and institutional affiliation: Departments of Medicine, Samsung Medical

Multicenter study of the long-term outcomes of endoscopic submucosal dissection for early gastric cancer in patients 80 years of age or older

Effective healing of endoscopic submucosal dissection-induced ulcers by a single week of proton pump inhibitor treatment: a retrospective study

Endoscopic Submucosal Dissection ESD

Factors for Endoscopic Submucosal Dissection in Early Colorectal Neoplasms: A Single Center Clinical Experience in China

Is it possible to perform gastric endoscopic submucosal dissection without discontinuation of a single antiplatelet of thienopyridine derivatives?

Endoscopic submucosal dissection for stomach neoplasms

Research Article Clinical Factors of Delayed Perforation after Endoscopic Submucosal Dissection for Gastric Neoplasms

New Techniques. Incidence of Peptic Ulcer. Changing. Contents - with an emphasis on peptic ulcer bleeding. Cause of death in peptic ulcer bleeding

Feasibility of endoscopic mucosa-submucosa clip closure method (with video)

Safety and short-term outcomes of endoscopic submucosal dissection for early gastric cancer in elderly patients

Endoscopic Submucosal Dissection of an Inverted Early Gastric Cancer-Forming False Gastric Diverticulum

EMR, ESD and Beyond. Peter Draganov MD. Professor of Medicine Division of Gastroenterology, Hepatology and Nutrition University of Florida

T. Shono, 1 K. Ishikawa, 1 Y. Ochiai, 1 M. Nakao, 1 O. Togawa, 1 M. Nishimura, 1 S. Arai, 1 K. Nonaka, 2 Y. Sasaki, 2 and H. Kita 1. 1.

Two electrosurgical endo-knives for endoscopic submucosal dissection of colorectal superficial neoplasms: a prospective randomized study

Traction-assisted colonic endoscopic submucosal dissection using clip and line: a feasibility study

We are IntechOpen, the world s leading publisher of Open Access books Built by scientists, for scientists. International authors and editors

Risk factors for non-curative resection of early gastric neoplasms with endoscopic submucosal dissection: Analysis of 1,123 lesions

Usefulness of Ready-to-Use 0.4% Sodium Hyaluronate (Endo-Ease) in the Endoscopic Resection of Gastrointestinal Neoplasms

INVITED REVIEW. Noriya Uedo, Yoji Takeuchi, Ryu Ishihara. Osaka Medical Center for Cancer and Cardiovascular Diseases, Osaka, Japan.

Clinical Outcomes of Endoscopic Submucosal Dissection for Superficial Esophageal Squamous Neoplasms

recurrence (range: 2 35%) in such cases, especially when resections are not accomplished en bloc or the margins are not clear [8].

Gastric Extremely Well-Diferentiated Intestinal-Type Adenocarcinoma: A Challenging Lesion to Achieve Complete Endoscopic Resection

Bleeding in patients who underwent scheduled second-look endoscopy 5 days after endoscopic submucosal dissection for gastric lesions

Clinical Study Endoscopic Submucosal Dissection for Early Colorectal Neoplasms: Clinical Experience in a Tertiary Medical Center in Taiwan

Local recurrence after endoscopic resection of colorectal tumors

Management of early gastric cancer with positive horizontal or indeterminable margins after endoscopic submucosal dissection: multicenter survey

A case of local recurrence and distant metastasis following curative endoscopic submucosal dissection of early gastric cancer

On-Call Upper GI Bleeding. Upper Gastrointestinal Bleeding

Prognostic analysis of gastric mucosal dysplasia after endoscopic resection: A single-center retrospective study

Yanfang Chen, 1,2 Ye Zhao, 1,2 Xiaojing Zhao, 2 and Ruihua Shi Introduction

B Barrett neoplasia, early, endoscopic mucosal resection of, in Europe, 297

ACG Clinical Guideline: Management of Patients with Ulcer Bleeding

Sangrado Gastrointestinal Alto Upper GI Bleeding

Efficacy and safety of endoscopic submucosal dissection for superficial cancer of the cervical esophagus

Toshihiro Nishizawa 1,2, Hidekazu Suzuki 2, Teppei Akimoto 1,3, Tadateru Maehata 1, Toshio Morizane 4, Takanori Kanai 2 and Naohisa Yahagi 1

Introduction. Piecemeal EMR (EPMR) Symposium

Risk factors for lymph node metastasis in histologically poorly differentiated type early gastric cancer

Clinical effectiveness of the pocket-creation method for colorectal endoscopic submucosal dissection

A bleeding ulcer: What can the GP do? Gastrointestinal bleeding is a relatively common. How is UGI bleeding manifested? Who is at risk?

How to treat early gastric cancer? Endoscopy

Endoscopic submucosal dissection for colorectal neoplasms

Clinical analysis of submucosal tunneling endoscopic resection in treating esophageal submucosal tumors.

Review article: management of peptic ulcer bleeding the roles of proton pump inhibitors and Helicobacter pylori eradication

Clinical Outcomes of Endoscopic Submucosal Dissection in Patients under 40 Years Old with Early Gastric Cancer

Barrett s Esophagus: Old Dog, New Tricks

Extended cold snare polypectomy for small colorectal polyps increases the R0 resection rate

Endoscopic diagnosis and management of early squamous cell carcinoma of esophagus

Metachronous Esophageal Cancer and Colon Cancer Treated by Endoscopic Mucosal Resection

Scottish Medicines Consortium

Non-exposed endoscopic wall-inversion surgery for gastrointestinal stromal tumor

Endoscopic Resection of Ampullary Neuroendocrine Tumor

Superficial Esophageal Neoplasms Overlying Leiomyomas Removed by Endoscopic Submucosal Dissection: Case Reports and Review of the Literature

Barrett s Esophagus. Abdul Sami Khan, M.D. Gastroenterologist Aurora Healthcare Burlington, Elkhorn, Lake Geneva, WI

Efficacy and Safety of Proton Pump Inhibitors (PPIs) Plus Rebamipide for Endoscopic Submucosal Dissection-induced Ulcers: A Meta-analysis

Helicobacter pylori Eradication in Patients with an Iatrogenic Ulcer after Endoscopic Resection and Peptic Ulcer

ESD for EGC with undifferentiated histology

Usefulness of training using animal models for colorectal endoscopic submucosal dissection: is experience performing gastric ESD really needed?

A comparative study of treatment of gastrointestinal stromal tumors with laparoscopic surgery: a retrospective study

Recent Development of Techniques and Devices in Colorectal Endoscopic Submucosal Dissection

Endoscopic Resection of Subepithelial Tumors

EndoClot PHS A medical application on 74 patients march 2013

Mucosal Incision and Forceps Biopsy for Reliable Tissue Sampling of Gastric Subepithelial Tumors

We are IntechOpen, the world s leading publisher of Open Access books Built by scientists, for scientists. International authors and editors

Clinical Study Additional Gastrectomy after Endoscopic Submucosal Dissection for Early Gastric Cancer Patients with Comorbidities

The feasibility of colorectal endoscopic submucosal dissection for the treatment of residual or recurrent tumor localized in therapeutic scar tissue

Additional Surgery After Non-curative Resection of ESD for Early Gastric Cancer

Quality in upper gastrointestinal endoscopic submucosal dissection

Lymph node metastasis risk according to the depth of invasion in early gastric cancers confined to the mucosal layer

Current status of gastric ESD in Korea. Jun Haeng Lee. Department of Medicine Sungkyunkwanuniversity School of Medicie, Seoul, Korea

Fluoroscopy-Guided Endoscopic Removal of Foreign Bodies

NATIONAL INSTITUTE FOR HEALTH AND CLINICAL EXCELLENCE

Construction and external validation of a nomogram that predicts lymph node metastasis in early gastric cancer patients using preoperative parameters

The utility of a novel colonoscope with retroflexion for colorectal endoscopic submucosal dissection

malignant polyp Daily Challenges in Digestive Endoscopy for Endoscopists and Endoscopy Nurses BSGIE Annual Meeting 18/09/2014 Mechelen

Philip Chiu Associate Professor Department of Surgery, Prince of Wales Hospital The Chinese University of Hong Kong

AGA SECTION. Gastroenterology 2016;150:

Histopathology of Endoscopic Resection Specimens from Barrett's Esophagus

Endoscopic Mucosal Resection (EMR) & Endoscopic Submucosal Dissection (ESD)

The Influence of Snare Size on the Utility and Safety of Cold Snare Polypectomy for the Removal of Colonic Polyps in Japanese Patients

EMR is not inferior to ESD for early Barrett s and EGJ neoplasia: An extensive review on outcome, recurrence and complication rates

How to remove BE cancer: EMR or ESD? Expected outcome

Original Article INTRODUCTION

Continued Use of a Single Antiplatelet Agent Does Not Increase the Risk of Delayed Bleeding After Colorectal Endoscopic Submucosal Dissection

Peptic ulcers remain the most common cause of upper

Advanced techniques for resection of large polyps. John G. Lee, MD February 2, 2018

Anus,Rectum and Colon

Regression of Advanced Gastric MALT Lymphoma after the Eradication of Helicobacter pylori

Medicine. Factors Associated With Outcomes in Endoscopic Submucosal Dissection of Gastric Cardia Tumors. A Retrospective Observational Study

Clinical Outcome of Endoscopic Resection for Nonampullary Duodenal Tumors

3 Toshiki Kojima. 3 Rino Yamaoka

Gastric Polyps. Bible class

Transcription:

Gut and Liver, Vol. 5, No. 3, September 2011, pp. 293-297 ORiginal Article Short-Term Healing Process of Artificial Ulcers after Gastric Endoscopic Submucosal Dissection Osamu Goto*, Mitsuhiro Fujishiro, Shinya Kodashima*, Chihiro Minatsuki*, Keiko Niimi*, Satoshi Ono, Nobutake Yamamichi*, and Kazuhiko Koike* Departments of *Gastroenterology, Endoscopy and Endoscopic Surgery, and Center for Epidemiology and Preventive Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan Background/Aims: The relationship between the appearance of an ulcer and postoperative bleeding after gastric endoscopic submucosal dissection (ESD) is not well understood. To explore this potential relationship, we retrospectively analyzed the short-term healing process of ESD. Methods: A total of 520 consecutive lesions in 434 patients seen between January 2004 and December 2009 were retrospectively investigated. At the second-look endoscopy, which occurred between 1 and 8 days after ESD, artificial ulcers were categorized into 6 patterns according to Forrest s classification: spurting bleeding, oozing bleeding, non-bleeding visible vessel, adherent clot, black base/spot, and clean base. From these data, a short-term healing model of the artificial ulcer was generated. Results: Ulcer base changed gradually from a bloody to a clean one. The bleeding or non-bleeding visible vessel categories, which occurred in approximately one quarter of the ulcers within 3 days of ESD, were rarely observed 4 days after ESD. Conclusions: Ulcers that occur after gastric ESD heal in line with a specific time course, and it appears that most healing occurs without massive bleeding. (Gut Liver 2011;5:293-297) Key Words: Endoscopic submucosal dissection; Artificial ulcer; Healing process; Gastric neoplasm; Postoperative bleeding INTRODUCTION Endoscopic submucosal dissection (ESD) has been established as an alternative method to open surgery for a node-negative early gastric cancer, especially in Japan. 1-3 It is characterized by circumferential mucosal incision and submucosal dissection, which enables en bloc resection even for large or ulcerative lesions. One of major complications is postoperative bleeding, which generally occurred in approximately 5% of the patients. 4-6 Various countermeasures are empirically taken in order to prevent it, e.g., the use of proton pump inhibitor (PPI) around ESD, postendoscopic coagulation for visible vessels on a mucosal defect immediately after the resection of a lesion, a second-look endoscopy after ESD. PPI is thought to be effective from several studies including prospective randomized trials, 7,8 and its usefulness is generally gained acceptance in most hospitals, although there is still room for discussion about the suitable dose or duration. Postendoscopic coagulation immediately after the resection of the lesion also seems to be practiced in most hospitals and one retrospective analysis advocates the efficacy in post-esd bleeding. 5 The usefulness of a second-look endoscopy, however, is controversial because few analyses exist. 6 Referring to bleeding peptic ulcers, it is generally thought that a second-look endoscopy performed a few days after stopping initial bleeding may be useful especially for high-risk patients of rebleeding. 9-12 But, the thought that it was equally useful for an artificial ulcer as well as for a bleeding peptic ulcer may be not always applicable, because the information about the artificial ulcer is too little to evaluate its efficacy satisfactory. We, therefore, retrospectively investigated the time-sequence changes of it checked by the second-look endoscopy after ESD. MATERIALS AND METHODS Of 551 lesions in 457 patients treated by ESD after obtaining written informed consent in our hospital from January 2004 to December 2009 (the period in which ESD technique has been Correspondence to: Osamu Goto Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, Japan Tel: +81-3-3815-5411, Fax: +81-3-5800-8806, E-mail: ogotou-gi@umin.ac.jp Received on November 19, 2010. Accepted on January 15, 2011. pissn 1976-2283 eissn 2005-1212 http://dx.doi.org/10.5009/gnl.2011.5.3.293 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

294 Gut and Liver, Vol. 5, No. 3, September 2011 regarded as established at our hospital), consecutive 520 lesions in 434 patients were retrospectively investigated. Excluded were 10 lesions in which perforation occurred after change of PPI due to the patient s condition, 14 lesions without second-look endoscopy, and 7 lesions with bleeding that occurred within 24 hours after ESD because those lesions less contributed to the elucidation of the natural course of artificial ulcers. The indication of ESD were determined according to the endoscopic findings including chromoendoscopy with indigo carmine and biopsy, referring to the criteria of possible nodenegative early gastric cancer by Gotoda et al. 13 as followed: 1) intramucosal intestinal-type cancer without ulcerative findings, regardless in size; 2) intramucosal intestinal-type cancer with ulcerative findings, 3 cm or less in size; 3) slight invasive intestinal-type cancer into submucosa less than 500 μm from muscularis mucosa, 3 cm or less in size; and 4) intramucosal diffuse-type cancer without ulcer findings, 2 cm or less in size. In addition, 5) adenoma difficult to distinguish from cancer or 6) technically resectable cancer endoscopically out of the above criteria for which the patients strongly desired to be resected were indicated for ESD. Clinicopathological features of the eligible lesions are shown in Table 1. ESD techniques were precisely described elsewhere. 1-3 In brief, a flex-knife (KD-630L; Olympus, Tokyo, Japan) was used as the main electrosurgical knife for mucosal cutting of surrounding non-neoplastic mucosa and for submucosal dissection beneath Table 1. Characteristics of the Enrolled Cases Characteristic No. (Total 520 lesions) Patient-related Age, mean±sd, yr 68.5±9.1 Sex, M:F 396:124 Comorbidities (present:absent) Hypertension 116:404 Diabetes mellitus 49:471 Heart disease 44:476 Chronic renal failure 8:512 Liver cirrhosis 20:500 Anticoagulants/platelets (used:not used) 66:454 Lesion-related Location (U or R:M:L) 118:182:220 Circumference (AW:GC:LC:PW) 97:90:196:137 Gross type (I/IIa:IIb/IIc:combined) 193:292:35 Ulcerative findings (present:absent) 57:463 Tumor size, mean±sd, mm 19.0±13.9 Tumor depth (mucosa:submucosa) 428:92 Histological type (carcinoma:adenoma) 447:73 SD, standard deviation; U, upper third; R, remnant stomach; M, middle third; L, lower third; AW, anterior wall; GC, greater curve; LC, lesser curve; PW, posterior wall. the lesion. 2 A mixture of 10% glycerin plus 5% fructose and 0.9% saline preparation (Glyceol; Chugai Pharmaceutical Co., Tokyo, Japan) or hyaluronic acid was injected into submucosa under the lesion to make submucosal fluid cushion. 14,15 Hemostatic forceps (HDB2422W; Pentax, Tokyo, Japan) or hemostatic clips (HX-610-135 or HX-610-090L; Olympus) were used to stop bleeding or to cauterize visible vessels on the mucosal defect. If the patient s symptoms, laboratory findings, and chest and abdominal X-rays were unremarkable at the next day of ESD, a light meal was permitted and the patients were discharged within one week. From the day before ESD to at least 2 weeks after ESD, 10 mg of rabeprazole, 20 mg of omeprazole, or 30 mg of lansoprazole once daily was administered orally. Occasionally, 20 mg of intravenous omeprazole twice daily was administered during the fasting period including the day of ESD, according to the decision of doctors in charge. A second-look endoscopy was performed to check bleeding or non-bleeding visible vessel on the artificial ulcer once between the day and 8 days after ESD. The day of second-look endoscopy was irregularly decided taking into account the day of the week when ESD was performed and the operator s convenience. If bleeding occurred or non-bleeding visible vessel was detected, (prophylactic) thermocoagulation with hemostatic forceps or mechanical hemostasis with hemostatic clips was executed. The way of hemostasis was flexibly selected according to the condition of bleeding. The treatment of (prophylactic) hemostasis was continued until active bleeding was stopped for several seconds even after flushing water or visible vessels apparently disappeared. In case of tightly adherent clot, presence of an apparent visible vessel beneath the clot was checked by removing it. If complications occurred, the schedules were changed according to the individual patient s conditions. The patient was seen as an outpatient 2 weeks after discharge, and was checked by a follow-up endoscopy 2 months after ESD. Postoperative bleeding was defined as bleeding or non-bleeding visible vessel with massively accumulated blood in the stomach on emergency endoscopy performed due to hematemesis or melena, or progression of anemia with vital changes. We investigated the artificial ulcers on the second-look endoscopy and categorized these ulcers into 6 patterns according to Forrest s classification. 16,17 These ulcers were allocated into; spurting bleeding, oozing bleeding, non-bleeding visible vessel, adherent clot, black base/spot, and clean base. The ulcers which caused postoperative bleeding confirmed by emergency endoscopy were allocated into spurting bleeding, regardless of active bleeding during endoscopy. Based on the allocation, the proportion of those patterns on each postoperative day was investigated to elucidate the natural healing process on the artificial ulcer s surface. Subsequently, the bleeding rates after the second-look endoscopy according to these patterns of the ulcer were investigated.

Goto O, et al: Short-Term Healing Process of Post-ESD Gastric Ulcers 295 Table 2. Patterns of Artificial Ulcers after Endoscopic Submucosal Dissection according to Postoperative Day Postoperative day 1 2 3 4 5 6 7 8 Spurting bleeding* 5 (2.7) 1 (3.7) 3 (5.6) 0 (0.0) 0 (0.0) 0 (0.0) 1 (1.3) 0 (0.0) Oozing bleeding 15 (8.2) 0 (0.0) 4 (7.4) 0 (0.0) 0 (0.0) 0 (0.0) 0 (0.0) 0 (0.0) Non-bleeding visible vessel 24 (13.1) 1 (3.7) 5 (9.3) 0 (0.0) 0 (0.0) 2 (2.0) 1 (1.3) 0 (0.0) Adrehent clot 45 (24.6) 6 (22.2) 4 (7.4) 0 (0.0) 2 (14.3) 5 (5.0) 6 (7.5) 0 (0.0) Black base/spot 69 (37.2) 15 (55.6) 21 (38.9) 18 (72.0) 5 (35.7) 51 (51.0) 35 (43.8) 8 (21.6) Clean base 25 (14.2) 4 (14.8) 17 (31.5) 7 (28.0) 7 (50.0) 42 (42.0) 37 (46.3) 29 (78.4) Total 183 (100) 27 (100) 54 (100) 25 (100) 14 (100) 100 (100) 80 (100) 37 (100) Data are presented as number (%). *These numbers contained the emergency endoscopy performed due to postoperative bleeding. Table 3. Bleeding Rate after the Second-Look Endoscopy for Each Artificial Ulcer Pattern Bleeding after the second-look endoscopy The appearance of the artificial ulcer No. (12/520) % 95% CI Spurting bleeding* 0/10 0.0 0-27.8 Oozing bleeding* 0/19 0.0 0-16.8 Non-bleeding visible vessel* 1/33 3.0 0.5-15.3 Adherent clot 0/68 0.0 0-5.4 Black base/spot 8/222 3.6 1.8-7.0 Clean base 3/168 1.8 0.6-5.1 CI, confidence interval. *Endoscopic intervention was performed; Endoscopic intervention was principally not performed. Fig. 1. Proportion of the 6 artificial ulcer patterns according to postoperative day. Over time, the number of ulcers with a bloody appearance decreases, and a greater number are observed to have a clean base. Statistical analysis was performed by chi-square test for categorical variables and p-value of less than 5% was considered significant. JMP version 8.0 software (SAS Institute, Cary, NC, USA) was used for all analyses. RESULTS The patterns of the artificial ulcer after ESD related to the postoperative day were showed in Table 2. The second-look endoscopy was performed most on the postoperative day 1 (183 lesions), and secondly on the postoperative day 6 (100 lesions). The numbers of the second-look endoscopies contained the emergency endoscopy performed due to possible postoperative bleeding. The proportion of the patterns on each postoperative day was showed in Fig. 1. As a natural course, the ulcer seemed to change gradually from bloody to clean base. Active bleeding or non-bleeding visible vessel, which was intended for endoscopic hemostatic treatment, appeared on approximately a quarter of the ulcers within 3 days after ESD, but were rarely observed 4 days after ESD or later. Bleeding after the second-look endoscopy occurred in 12 lesions. The relationship between the findings on the second-look endoscopy and bleeding after that showed in Table 3. There was no apparent tendency for bleeding after the second-look endoscopy among the patterns of the ulcers. DISCUSSION In the present analysis, we demonstrated the model of shortterm healing process on the artificial ulcer after gastric ESD, owing to perform the second-look endoscopy once after ESD without any strict criteria. The previous studies have demonstrated that the artificial ulcer usually heals within 2 months from active stage to scarring stage, 18 but this is the first report about the information of it during short interval of active stage. As Fig. 1 showed, the ulcer gradually changed from bloody appearance to clean surface covered with mucoid cap. The reason why the proportion of bloody patterns has made a dip on post-

296 Gut and Liver, Vol. 5, No. 3, September 2011 operative day 4 is thought that the number of the second-look endoscopy performed on that day has been fewer compared to the other days. Fig. 1 implies that the second-look endoscopy should be performed relatively soon after ESD (if it was expected to be worth to be done). Although the second-look endoscopy late after ESD (and almost before discharge) may be reasonable to check the possible bleeding spot, more effective timing of it is thought to be within 3 days after ESD, because the second-look endoscopy soon after ESD can frequently meet the targets for endoscopic intervention, whereas those rarely exist on it late after ESD. From the other side of view, Fig. 1 reflects the natural healing process of a single artificial ulcer. If clinically apparent postoperative bleeding such as spurting bleeding does not occur, the ulcer can be expected to heal without massive bleeding to some extent, even though oozing bleeding has occurred or non-bleeding visible vessel exists. That is, the figure implies that oozing bleeding may stop spontaneously, or non-bleeding visible vessel may disappear. For example, we can imagine that 217 lesions checked on the postoperative day from 6 to 8 have almost improved spontaneously without clinically-problematic bleeding, in spite of the possibility that approximately a quarter of those may has had oozing bleeding or non-bleeding visible vessel. Hemostasis for oozing bleeding or prophylactic homostasis for non-bleeding visible vessel may be certainly effective against further bleeding, but it may merely provide subclinical benefit. Many previous studies about bleeding peptic ulcer suggest that active bleeding and non-bleeding visible vessel should be indicated for endoscopic intervention because these have high potential of rebleeding, 9-12,17 and that is why we empirically performed the second-look endoscopy after ESD. But, the suitable treatment to a bleeding peptic ulcer cannot be applicable to the artificial ulcer because both ulcers are quite different in many features, e.g., the cause of genesis, the circumstance in the stomach, and the depth. In that point, we need to construct another new strategy of caring for the artificial ulcer, and it will become relatively looser than that for a peptic ulcer. There is still room for discussion about the clinical efficacy of the second-look endoscopy. Fig. 1 speculates that almost all the artificial ulcers after ESD heal without massive bleeding. But, we cannot discuss about the necessity of the second-look endoscopy after ESD only from this retrospective study. Another method to explain necessity of second-look endoscopy after ESD will be needed. A prospective study with more delicate groups, fixed time of second-look endoscopy, and patient s clinical details is desired. On the other side, advanced endoscopic tool and new therapeutic strategy for hemostasis may be invented in the future, which will help to prevent postoperative bleeding after ESD more effectively. These advancements may also decrease necessity of second-look endoscopy. The limitation is that this study is formed by a single-centered, retrospective analysis, although this is consecutive data. Besides, the change of the appearance on the artificial ulcer which we have showed is not an accumulation of data from longitudinal observation of a single ulcer, but from each one finding of many, various ulcers. In that point, the healing process in Fig. 1 is still an assumption. Longitudinal observations of the single ulcer are ideal, but it would impossible either clinically or ethically. In conclusion, we could suggest the model of the short-term healing process on the artificial ulcer after gastric ESD from the findings of the second-look endoscopy. The ulcer changes from bloody to clean surface in line, and most of the ulcers are expected to heal without massive bleeding. CONFLICTS OF INTEREST No potential conflict of interest relevant to this article was reported. REFERENCES 1. Ono H, Kondo H, Gotoda T, et al. Endoscopic mucosal resection for treatment of early gastric cancer. Gut 2001;48:225-229. 2. Yahagi N, Fujishiro M, Kakushima N, et al. Merits and demerits of endoscopic submucosal dissection using a flex-knife. Stomach Intest 2004;39:39-43. 3. Oyama T, Tomori A, Hotta K, et al. Endoscopic submucosal dissection of early esophageal cancer. Clin Gastroenterol Hepatol 2005;3(7 Suppl 1):S67-S70. 4. Oka S, Tanaka S, Kaneko I, et al. Advantage of endoscopic submucosal dissection compared with EMR for early gastric cancer. Gastrointest Endosc 2006;64:877-883. 5. Takizawa K, Oda I, Gotoda T, et al. Routine coagulation of visible vessels may prevent delayed bleeding after endoscopic submucosal dissection--an analysis of risk factors. Endoscopy 2008;40:179-183. 6. Goto O, Fujishiro M, Kodashima S, et al. A second-look endoscopy after endoscopic submucosal dissection for gastric epithelial neoplasm may be unnecessary: a retrospective analysis of postendoscopic submucosal dissection bleeding. Gastrointest Endosc 2010;71:241-248. 7. Uedo N, Takeuchi Y, Yamada T, et al. Effect of a proton pump inhibitor or an H2-receptor antagonist on prevention of bleeding from ulcer after endoscopic submucosal dissection of early gastric cancer: a prospective randomized controlled trial. Am J Gastroenterol 2007;102:1610-1616. 8. Jeong HK, Park CH, Jun CH, et al. A prospective randomized trial of either famotidine or pantoprazole for the prevention of bleeding after endoscopic submucosal dissection. J Korean Med Sci 2007;22:1055-1059. 9. Marmo R, Rotondano G, Bianco MA, Piscopo R, Prisco A, Cipolletta L. Outcome of endoscopic treatment for peptic ulcer bleeding:

Goto O, et al: Short-Term Healing Process of Post-ESD Gastric Ulcers 297 is a second look necessary? A meta-analysis. Gastrointest Endosc 2003;57:62-67. 10. Romagnuolo J. Routine second look endoscopy: ineffective, costly and potentially misleading. Can J Gastroenterol 2004;18:401-404. 11. Adamsen S, Bendix J, Kallehave F, Moesgaard F, Nilsson T, Wille- Jørgensen P. Clinical practice and evidence in endoscopic treatment of bleeding peptic gastroduodenal ulcer. Scand J Gastroenterol 2007;42:318-323. 12. Chiu PW, Lam CY, Lee SW, et al. Effect of scheduled second therapeutic endoscopy on peptic ulcer rebleeding: a prospective randomised trial. Gut 2003;52:1403-1407. 13. Gotoda T, Yanagisawa A, Sasako M, et al. Incidence of lymph node metastasis from early gastric cancer: estimation with a large number of cases at two large centers. Gastric Cancer 2000;3:219-225. 14. Fujishiro M, Yahagi N, Kashimura K, et al. Comparison of various submucosal injection solutions for maintaining mucosal elevation during endoscopic mucosal resection. Endoscopy 2004;36:579-583. 15. Fujishiro M, Yahagi N, Nakamura M, et al. Successful outcomes of a novel endoscopic treatment for GI tumors: endoscopic submucosal dissection with a mixture of high-molecular-weight hyaluronic acid, glycerin, and sugar. Gastrointest Endosc 2006;63:243-249. 16. Forrest JA, Finlayson ND, Shearman DJ. Endoscopy in gastrointestinal bleeding. Lancet 1974;2:394-397. 17. Laine L, Peterson WL. Bleeding peptic ulcer. N Engl J Med 1994;331:717-727. 18. Kakushima N, Yahagi N, Fujishiro M, et al. The healing process of gastric artificial ulcers after endoscopic submucosal dissection. Dig Endosc 2004;16:327-331.