Won Young Cho

Optical biopsies by confocal endomicroscopy prevent additive endoscopic biopsies before endoscopic submucosal dissection in gastric epithelial neoplasias: a prospective, comparative study.

BACKGROUND Confocal laser endomicroscopy (CLE) allows real-time in vivo histologic evaluation of GI lesions. To our knowledge, there is no reported prospective study comparing endoscopic and optical biopsy using CLE before endoscopic submucosal dissection (ESD) with post-ESD histopathology. OBJECTIVE We compared endoscopic and optical biopsy before ESD and thereby assessed the ability of CLE to effectively diagnose and differentiate gastric epithelial neoplasia. DESIGN Single tertiary-care center, prospective comparative study. SETTING Soonchunhyang University Hospital, between September 2009 and April 2010. PATIENTS This study involved 31 patients with 35 gastric epithelial neoplasias, previously diagnosed by endoscopic biopsy, who were scheduled for ESD. INTERVENTION Target lesions were imaged in vivo by using CLE. MAIN OUTCOME MEASUREMENTS The overall accuracy of endoscopic and CLE diagnosis was compared with post-ESD histopathology. RESULTS In histopathology after ESD, 11 of 35 lesions (31.5%) were adenomas and 24 (68.5%) were adenocarcinomas. The overall accuracy of CLE diagnosis of gastric adenomas and adenocarcinomas was significantly higher at 94.2% (95% confidence interval [CI], 81.3-98.4), versus 85.7% (95% CI, 70.6-93.7) for endoscopic biopsy (P = .031). The overall accuracy of CLE diagnosis of differentiated and undifferentiated adenocarcinomas also was higher (95.4%; 95% CI, 78.2-99.1) than that of endoscopic biopsy (84.2%; 95% CI, 62.4-94.4) but did not differ significantly (P = .146). LIMITATIONS Single tertiary-care center experience and small patient number. CONCLUSION This study demonstrates the high accuracy of diagnosis of gastric epithelial neoplasia by using CLE. The use of CLE could possibly thus reduce the number of unnecessary biopsies and mistaken diagnoses before ESD.

Appropriate indications for endoscopic submucosal dissection of early gastric cancer according to tumor size and histologic type.

BACKGROUND Endoscopic submucosal dissection (ESD) is increasingly being performed for early gastric cancers (EGCs) that are larger than 2 cm and those that are not intestinal-type (IT) cancers by Laurens classification. The technical feasibility of ESD for these EGCs has not been fully evaluated. OBJECTIVE To identify appropriate expanded indications for ESD of EGC. DESIGN AND SETTING A retrospective analysis of prospectively collected data was performed on consecutive patients who underwent ESD at a single tertiary center. PATIENTS AND METHODS In total, 487 EGCs in 461 patients treated by ESD were classified by size and histologic type: IT EGCs 2 cm or less (257 lesions in 235 patients), IT EGCs larger than 2 cm (172 lesions in 168 patients), and non-IT EGCs (58 lesions in 58 patients). MAIN OUTCOME MEASUREMENTS Curative resections were assessed among the 3 groups, and logistic regression analysis was used to analyze factors related to curative resection. RESULTS The rates of curative resection significantly decreased from IT EGCs 2 cm or less (88.7%) to IT EGCs larger than 2 cm (73.3%) to non-IT EGCs (37.9%). Tumor size (>3 cm), ulceration, histologic type (non-IT), and piecemeal resection were independently unfavorable factors in curative resection. LIMITATIONS Small sample size and short-term duration of follow-up study. CONCLUSIONS ESD with curative intent is technically most feasible for nonulcerative and IT EGCs smaller than 3 cm.

Recent Advances in Image-enhanced Endoscopy

The desire to better recognized such malignancies, which may be difficult to distinguish from inflammation or trauma, has accelerated the development of endoscopy with new optical technologies. Narrow-band imaging is a novel endoscopic technique that may enhance the accuracy of diagnosis using narrow-bandwidth filters in a red-green-blue sequential illumination system. Autofluorescence imaging is based on the detection of natural tissue fluorescence emitted by endogenous molecules. I-scan technology using a digital filter that modifies normal images through software functions, is the newly developed image-enhanced endoscopic technology from PENTAX. Flexible spectral imaging color enhancement enhances the visualization of mucosal structure and microcirculation by the selection of spectral transmittance with a dedicated wavelength. Confocal laser endomicroscopy images were collected with an argon beam with a scanning depth of 0 (epithelium) to 250 µm (lamina propria) and analyzed using the reflected light.

A Case of Asymptomatic Aspiration of a Capsule Endoscope with a Successful Resolution

Aspiration is a very rare complication of capsule endoscopy, but it is potentially life-threatening and should be considered an emergency requiring immediate intervention since it can evolve into major airway compromise and obstructive pneumonitis. We experienced a case of asymptomatic aspiration of a capsule in a 75-year-old man. The aspirated capsule was diagnosed on routine chest and abdomen X-rays to confirm its position after ingestion. The capsule was removed via bronchoscopy using a net, without sequelae, after inducing the patient to cough. To prevent this complication, a thorough history of swallowing disorders is needed before capsule ingestion, and patients with swallowing difficulties should have the capsule placed in the duodenum endoscopically. Moreover, on capsule aspiration, cough induction is the most effective method of capsule removal.

Gastric Schwannoma Diagnosed by Endoscopic Ultrasonography-Guided Trucut Biopsy

Schwannomas of the gastrointestinal (GI) tract are rare subepithelial tumors comprising approximately 3.3% to 12.8% of all mesenchymal tumors of the GI tract. On endoscopic ultrasound (EUS) they are seen as hypoechoic tumors arising most commonly from the 4th proper muscle layer. Although EUS helps to distinguish tumor characteristics, tissue sampling is required for differentiation with other more common tumors such as GI stromal tumors. Both EUS-guided fine needle aspiration and EUS-guided trucut biopsy (EUS-TCB) can be used for tissue sampling. However, only EUS-TCB allows core biopsy and a high yield of immunohistochemical staining. We report a case of a gastric schwannoma diagnosed by EUS-TCB.

TOWARD THE GLOBAL STANDARDIZATION OF ENDOSCOPIC SUBMUCOSAL DISSECTION PROPOSAL FOR 10 YEARS FROM NOW – PRESENT AND FUTURE VIEW OF KOREA

Endoscopic submucosal dissection (ESD) is the main treatment of early gastric cancer in Korea. The Korean Society of Gastrointestinal Endoscopy (KSGE) has organized an ESD research group and made several plans to standardize pathologic and therapeutic points of view. This article is to introduce the present and future view of ESD in Korea.

Rectal hyposensitivity and functional anorectal outlet obstruction are common entities in patients with functional constipation but are not significantly associated

Background/Aims The causes of functional anorectal outlet obstruction (outlet obstruction) include functional defecation disorder (FDD), rectocele, and rectal intussusception (RI). It is unclear whether outlet obstruction is associated with rectal hyposensitivity (RH) in patients with functional constipation (FC). The aim of this study was to determine the association between RH and outlet obstruction in patients with FC. Methods This was a retrospective study using a prospectively collected constipation database, and the population comprised 107 patients with FC (100 females; median age, 49 years). We performed anorectal manometry, defecography, rectal barostat, and at least two tests (balloon expulsion test, electromyography, or colon transit time study). RH was defined as one or more sensory threshold pressures raised beyond the normal range on rectal barostat. We investigated the association between the presence of RH and an outlet obstruction such as large rectocele (> 2 cm in size), RI, or FDD. Results Forty patients (37.4%) had RH. No significant difference was observed in RH between patients with small and large rectoceles (22 [44.9%] vs. 18 [31%], respectively; p = 0.140). No significant difference was observed in RH between the non-RI and RI groups (36 [36.7%] vs. 4 [30.8%], respectively; p = 0.599). Furthermore, no significant difference in RH was observed between the non-FDD and FDD groups (19 [35.8%] vs. 21 [38.9%], respectively; p = 0.745). Conclusions RH and outlet obstruction are common entities but appear not to be significantly associated.

Helicobacter pylori eradication on iatrogenic ulcer by endoscopic resection of gastric tumour: A prospective, randomized, placebo-controlled multi-centre trial

INTRODUCTION The role of Helicobacter pylori (H. pylori) eradication has not been clarified in the healing of iatrogenic ulcer after endoscopic resection of gastric neoplasm. The aim of this study was to evaluate whether H. pylori eradication could facilitate the healing of iatrogenic ulcer after endoscopic resection of gastric neoplasm. METHODS A total of 232 patients with H. pylori-positive early gastric cancer or gastric adenoma underwent endoscopic resection and were randomly allocated to eradication or placebo group in a prospective, double-blinded, and placebo-controlled manner. The primary outcome was measured by healing rate of ulcer, and the secondary outcomes by reduction rate of ulcer size, relief rate from ulcer-related symptoms, and adverse event rates. RESULTS The healing rate of ulcer was 53% in eradication group and 51.6% in placebo group, respectively (p value=0.95). The reduction rate of ulcer size, relief rate from ulcer-related symptoms and adverse event rates were also not different between two groups. In multivariate analysis, initial ulcer size more than 3 cm and histology of cancer were significant factors affecting iatrogenic ulcer healing. CONCLUSIONS H. pylori eradication did not facilitate iatrogenic ulcer healing at early and late phase after endoscopic resection of gastric neoplasm.

Submucosal Endoscopy, a New Era of Pure Natural Orifice Translumenal Endoscopic Surgery (NOTES)

Natural orifice translumenal endoscopic surgery (NOTES) involves the intentional perforation of the viscera with an endoscope to access the abdominal cavity and perform an intraabdominal operation. In a brief time period, NOTES has been shown to be feasible in laboratory animal and human studies. Easy access to the peritoneal cavity and complete gastric closure should be secured before NOTES can be recommended as an acceptable alternative in clinical practice. The concept of submucosal endoscopy has been introduced as a solution to overcome these two primary barriers to human NOTES application. Its offset entry/exit access method effectively prevents contamination and allows the rapid closure of the entry site with a simple mucosal apposition. In addition, it could be used as an endoscopic working space for various submucosal conditions. Herein, the detailed procedures, laboratory results and human application of the submucosal endoscopy will be reviewed.

Does immunohistochemical staining have a clinical impact in early gastric cancer conducted endoscopic submucosal dissection

AIM To evaluate clinicopathologic parameters and the clinical significance related lymphovascular invasion (LVI) by immunohistochemical staining (IHCS) in endoscopic submucosal dissection (ESD). METHODS Between May 2005 and May 2010, a total of 348 lesions from 321 patients (mean age 63 ± 10 years, men 74.6%) with early gastric cancer (EGC) who met indication criteria after ESD were analyzed retrospectively. The 348 lesions were divided into the absolute (n = 100, differentiated mucosal cancer without ulcer ≤ 20 mm) and expanded (n = 248) indication groups after ESD. The 248 lesions were divided into four subgroups according to the expanded ESD indication. The presence of LVI was determined by factor VIII-related antigen and D2-40 assessment. We compared LVI IHCS-negative group with LVI IHCS-positive in each group. RESULTS LVI by hematoxylin-eosin staining (HES) and IHCS were all negative in the absolute group, while was observed in only the expanded groups. The positive rate of LVI by IHCS was higher than that of LVI by HES (n = 1, 0.4% vs n = 11, 4.4%, P = 0.044). LVI IHCS-positivity was observed when the cancer invaded to the mucosa 3 (M3) or submucosa 1 (SM1) levels, with a predominance of 63.6% in the subgroup that included only SM1 cancer (P < 0.01). In a univariate analysis, M3 or SM1 invasion by the tumor was significantly associated with a higher rate of LVI by IHCS, but no factor was significant in a multivariate analysis. There were no cases of tumor recurrence or metastasis during the median 26 mo follow-up. CONCLUSION EGCs of the absolute group are immunohistochemically stable. The presence of LVI may be carefully examined by IHCS in an ESD expanded indication group with an invasion depth of M3 or greater.