Mitsuyo Yoshizawa

ENDOSCOPIC SUBMUCOSAL DISSECTION FOR SUPERFICIAL DUODENAL NEOPLASMS

Endoscopic submucosal dissection (ESD) has emerged as a novel technique for achieving en bloc resection for superficial neoplasms limited to the mucosa. ESD was originally developed in Japan as a method of endoscopic resection of superficial gastric cancers. In our hospital, ESD has been used concurrently in other parts of the gastrointestinal tract, including the esophagus and colorectum from the beginning of its development. However, ESD in the duodenum is considered more challenging than other parts. From August 2005 to March 2008, a total of 15 superficial duodenal neoplastic lesions in 14 patients were treated with endoscopic resection. Of these, nine underwent ESD. We report our experience with duodenal ESD with a combination of ST hood and hook knife.

Assessment of Atrophic Gastritis Using the OLGA System

Background:  An international group of gastroenterologists and pathologists (Operative Link for Gastritis Assessment (OLGA)) proposed the staging system of atrophy. The aim of this study was to assess the severity of atrophic gastritis using the OLGA system.

Diagnosis of endoscopic Barrett's esophagus by transnasal flexible spectral imaging color enhancement

BackgroundThe diagnosis of endoscopic Barrett’s esophagus (BE) has been under discussion for the past decade because palisade vessels may be obscured by inflammation or the location of upper end of gastric fold may be diversely changed. The flexible spectral imaging color enhancement (FICE) system can reconstruct improved spectral images decomposed from ordinary endoscopic images with free selection of three wavelengths, and can provide non-magnified images with high light intensity.MethodsTo evaluate whether the transnasal FICE system enables easier diagnosis of endoscopic BE, 72 patients with endoscopic BE were observed prospectively with a transnasal endoscope using both conventional images and FICE images. The visualization of palisade vessels and the identification of the demarcation between endoscopic BE mucosa and gastric mucosa were compared between FICE images and conventional endoscopic images, and the CIELAB color differences were calculated among palisade vessels, background BE mucosa and gastric folds.ResultsPalisade vessels could be more clearly visualized in BE mucosa with transnasal FICE than with conventional endoscopy. Demarcation between whitish BE mucosa and the upper end of the brownish gastric mucosa could be clearly identified using transnasal FICE images. Greater color differences existed with FICE images between palisade vessels and background BE mucosa as well as between BE mucosa and gastric folds than with conventional images, leading to better contrasting images.ConclusionsThe transnasal FICE system enables clear visualization of palisade vessels and provides better contrasting images of the demarcation between the BE mucosa and the gastric mucosa, and thus contributes to easier diagnosis of endoscopic BE.

Diagnosis of elevated-type early gastric cancers by the optimal band imaging system

BACKGROUND The endoscopic diagnosis of an elevated-type early gastric cancer is often difficult. The optimal band imaging (OBI) system can reconstruct the best spectral images decomposed from ordinary endoscopic images with free selection of 3 wavelengths and provide unmagnified images with high light intensity as well as magnified images. OBJECTIVE To evaluate whether the OBI system facilitates detection of the demarcation lines between an elevated-type early gastric cancer and surrounding tissue and thus is more helpful for performing endoscopic therapy. DESIGN A prospective study. SETTING Jichi Medical University, Japan. PATIENTS Seventy-five patients, 81 lesions with an elevated-type early gastric cancer. MAIN OUTCOME MEASUREMENTS A comparison between OBI images and conventional endoscopic images in the identification of the demarcation lines of an elevated-type early gastric cancer without magnification and the rate of success in identifying the abnormal surface structure of cancer by using low-magnified OBI images. RESULTS Demarcation lines were easily identified in OBI images, even without magnification, because such cancers could be clearly distinguished from the surrounding whitish atrophic mucosa. Inexperienced endoscopists could determine demarcation lines with significantly greater accuracy with unmagnified OBI images than with conventional images. With 40-fold magnification, irregular microstructural or nonstructural patterns were also found within cancer lesions in all cases studied but in none of the cases in the surrounding noncancerous mucosa. CONCLUSIONS The new contrast images obtained with the OBI system enable better determination of the demarcation lines of elevated-type early gastric cancers, and this system may be useful for performing endoscopic therapy of this type of cancer as a new endoscopic modality.

Diagnosis of extent of early gastric cancer using flexible spectral imaging color enhancement

The demarcation line between the cancerous lesion and the surrounding area could be easily recognized with flexible spectral imaging color enhancement (FICE) system compared with conventional white light images. The characteristic finding of depressed-type early gastric cancer (EGC) in most cases was revealed as reddish lesions distinct from the surrounding yellowish non-cancerous area without magnification. Conventional endoscopic images provide little information regarding depressed lesions located in the tangential line, but FICE produces higher color contrast of such cancers. Histological findings in depressed area with reddish color changes show a high density of glandular structure and an apparently irregular microvessel in intervening parts between crypts, resulting in the higher color contrast of FICE image between cancer and surrounding area. Some depressed cancers are shown as whitish lesion by conventional endoscopy. FICE also can produce higher color contrast between whitish cancerous lesions and surrounding atrophic mucosa. For nearly flat cancer, FICE can produce an irregular structural pattern of cancer distinct from that of the surrounding mucosa, leading to a clear demarcation. Most elevated-type EGCs are detected easily as yellowish lesions with clearly contrasting demarcation. In some cases, a partially reddish change is accompanied on the tumor surface similar to depressed type cancer. In addition, the FICE system is quite useful for the detection of minute gastric cancer, even without magnification. These new contrasting images with the FICE system may have the potential to increase the rate of detection of gastric cancers and screen for them more effectively as well as to determine the extent of EGC.

Diagnosis of depressed-type early gastric cancer using small-caliber endoscopy with flexible spectral imaging color enhancement

Background and Aim:  Small‐caliber endoscopy has lower resolution than normal‐caliber endoscopy, limiting its use in routine outpatient practice. Flexible spectral imaging color enhancement (FICE) strengthens the color contrast of depressed‐type early gastric cancer without magnification. The aim of the present study was to evaluate the detection of depressed‐type early gastric cancer using small‐caliber endoscopy with the FICE system.

Phlegmonous gastritis after endoscopic submucosal dissection for early gastric cancer

A 74-year-old man with diabetic nephropathy developed epigastric pain and high fever after endoscopic submucosal dissection (ESD) for early gastric cancer. Gastroscopy, endoscopic ultrasonography and computed tomography showed ulceration with a purulent lake, thickened entire gastric mucosal layers suggesting focal abscess formation, leading to the diagnosis of phlegmonous gastritis. He underwent total gastrectomy as an emergency. Histological findings of the resected specimen showed severe inflammatory cell infiltration and multiple focal abscess formation spreading to the entire gastric wall. In patients with poorer general conditions, phlegmonous gastritis should be considered as a serious complication after ESD, indicating a requirement of antibiotic prophylaxis.

Endoscopic submucosal dissection using sodium hyaluronate, a new technique for en bloc resection of a large superficial tumor in the colon

Abstract.En bloc resection of superficial tumors in the colon is challenging but beneficial for the precise diagnosis and treatment. We have been using a novel technique of endoscopic submucosal dissection with a viscous substance, sodium hyaluronate, and a needle knife in combination with a small-caliber-tip transparent hood and succeeded in the endoscopic en bloc resection of large superficial tumors in the colon. We endoscopically treated superficial tumors larger than 20 mm in diameter of the colon in 166 patients between June 1998 and March 2005. All the lesions were successfully resected endoscopically and en bloc resection was achieved in 77 % of them. Even large superficial tumors in the colon can be resected in one piece by using this technique.

NEW TECHNIQUE FOR DIRECT PERCUTANEOUS ENDOSCOPIC JEJUNOSTOMY USING DOUBLE-BALLOON ENDOSCOPY AND MAGNETIC ANCHORS IN A PORCINE MODEL

Direct percutaneous endoscopic jejunostomy (D-PEJ) is not yet globally carried out because of two technical difficulties in the procedure.The first is difficulty in reaching the jejunum with good maneuverability by conventional endoscopy. The second involves the anatomical features of the jejunum. The jejunal lumen is much smaller than that of the stomach. In addition, the location of the jejunal loop is not stable in relation to the abdominal wall. To solve these problems, we developed a new technique for D-PEJ using double-balloon endoscopy (DBE) and magnetic anchors. DBE was used for the access to the jejunum.Two magnetic anchors were prepared for the inside and outside anchors. The inside anchor was tied to the tip of the endoscope. Two anchors were used to fix the jejunal wall to the abdominal wall. Puncture was carried out from the abdominal wall beside the outside anchor without fluoroscopy. The jejunal wall was fixed to the abdominal wall by suturing the fixing thread. Percutaneous endoscopic gastrostomy (PEG) tube was placed through the overtube of DBE (Fig. 1). To evaluate the feasibility and safety, placement of D-PEJ using DBE and magnetic anchors was carried out on eight pigs with survival. Procedure of the animal experiments was investigated and permitted by The Judging Committee of Experimental Animal Ethics of Jichi Medical University. D-PEJ was successfully placed in all eight pigs. DBE and magnetic anchors were useful for stabilization of the maneuvers. PEG tube placement through the overtube was useful for preventing contamination of the tube and trauma of the intestinal wall. The mean procedure time was 89 min. There were no complications. D-PEJ using DBE and magnetic anchors was feasible and safe in the porcine model.

NEWLY DEVELOPED OPTIMAL BAND IMAGING SYSTEM FOR THE DIAGNOSIS OF EARLY GASTRIC CANCER

Background:  Magnifying narrow band imaging system is useful for the diagnosis of early gastric cancer. However, it is difficult for the operator of the scope to maintain the correct distance between the tip of the endoscope and the gastric mucosa for appropriate visualization. The newly developed optimal band imaging system can reconstruct good spectral images derived from ordinary endoscopic images and enhance the mucosal surface without magnification as well as with low magnification. This imaging technique is based on narrowing the bandwidth of the conventional image arithmetically, using spectral estimation technology.