Toshiro Iizuka

Benefits of endoscopic submucosal dissection according to size and location of gastric neoplasm, compared with conventional mucosal resection.

Background and Aims:  To clarify optimal therapeutic strategies for early gastric cancers without vestigial remnant or recurrence, we evaluated the benefits of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) according to tumor size and location.

Endoscopic submucosal dissection for residual/locally recurrent lesions after endoscopic therapy for colorectal tumors.

Background and Study Aim:  Residual or locally recurrent lesions may occur after endoscopic therapy for epithelial colorectal tumors. Additional endoscopic mucosal resection is difficult for large lesions. Endoscopic submucosal dissection may be useful for such lesions, but may be more technically difficult for residual/locally recurrent lesions than for primary lesions. This study evaluated the efficacy of endoscopic submucosal dissection for residual/locally recurrent lesions in comparison with primary lesions.

Endoscopic submucosal dissection for gastric submucosal tumor, endoscopic sub-tumoral dissection.

Gastric submucosal tumor (SMT) is frequently found during screening endoscopy, but definitive diagnosis based on histological confirmation is relatively difficult. Even without accurate diagnosis before treatment, open or laparoscopic surgery is currently carried out to remove SMT. The purpose of this study was to demonstrate the feasibility of endoscopic submucosal dissection (ESD) in diagnostic treatment for submucosal tumor (SMT) of the stomach. Subjects in this case study comprised nine patients who had undergone ESD for gastric SMT. Before treatment, endoscopic ultrasonography was carried out in all cases to evaluate depth and origin of the SMT. Then ESD was only indicated for tumors of submucosal layer or muscularis mucosa origin. Using an endoscopic sub‐tumoral dissection technique with a hook knife and a flex knife, local complete resections were achieved in all patients without severe complications. These results suggest the clinical benefits of ESD avoiding oversurgery for the diagnostic treatment of gastric SMT of the submucosal layer and muscularis mucosa origin.

Polyglycolic acid sheet application to prevent esophageal stricture after endoscopic submucosal dissection for esophageal squamous cell carcinoma

BACKGROUND AND STUDY AIM Esophageal stricture following endoscopic submucosal dissection (ESD) can be a serious complication in patients with large mucosal defects. This preliminary study examined the efficacy of using a polyglycolic acid (PGA) sheet with fibrin glue for the prevention of esophageal stricture after ESD. PATIENTS AND METHODS A total of 15 patients were enrolled. After resection, PGA sheets were placed over the surgical wound. The size of the mucosal defect was estimated by dividing the circumference of the esophagus into 12 parts of equal size. The occurrence of esophageal stricture at 6 weeks, along with the proportion of patients who had PGA sheet remaining in place 1 week and 2 weeks after ESD, and the occurrence of adverse events were investigated. RESULTS The size of mucosal defects in the 15 patients were 7/12 (n = 4), 8 /12 (n = 5), 9/12 (n = 4), 10/12 (n = 1) and 11/12 (n = 1). Esophageal stricture occurred in 1/13 patients (7.7 %; two patients were not included in the analysis because they had required surgical resection during the follow-up period). The PGA sheet remained at 1 week after ESD in 13/15 patients (86.7 %) and at 2 weeks after ESD in 6/15 patients (40 %). No adverse events were observed. CONCLUSION PGA sheets may have the potential to prevent esophageal stricture.

Endoscopic submucosal dissection for treatment of mesopharyngeal and hypopharyngeal carcinomas.

BACKGROUND AND STUDY AIMS Application of the endoscopic submucosal dissection (ESD) technique, as well as elevation of the larynx in cooperation with an otolaryngologist, under general anesthesia has enabled en-block resection of early mesopharyngeal and hypopharyngeal carcinomas. The aim of this study was to retrospectively evaluate the safety of ESD and the efficacy of the elevation of the larynx for treatment of early mesopharyngeal and hypopharyngeal carcinomas. PATIENTS AND METHODS The study included 16 lesions in 13 patients who underwent ESD. To provide a sufficient working space, the larynx was elevated under direct laryngoscopy, and a tube was inserted and fixed onto the laryngeal side using the slot on the back of the laryngoscope. RESULTS The median maximum diameter of the lesions was 12.5 mm (range 2 - 37 mm). The en-block resection rate was 93.8 %. Lateral surgical margins in two patients were difficult to evaluate for technical reasons. The tube could not be removed from four patients on the day of the procedure due to laryngeal edema caused by the local injection. No serious complications were observed. Oral food intake was possible after a mean of 3.3 postoperative days. CONCLUSIONS With adequate intraoperative and postoperative management, ESD with elevation of the larynx may be very efficient and safe for endoscopic treatment of pharyngeal lesions.

Comparison of the Clinicopathological Characteristics and Results of Endoscopic Submucosal Dissection for Esophagogastric Junction and Non-Junctional Cancers

Background: Esophagogastric junction (EGJ) cancers are not only located in regions anatomically difficult for endoscopic submucosal dissection (ESD), but they also have higher clinicopathological malignant potential than non-junctional gastric cancers (NJC). Despite this, no ESD-based comparative studies of junctional cancer (JC) and NJC have been conducted to date. The aims of this study were to clarify the clinicopathological characteristics of EGJ cancers and the short- and long-term outcomes after ESD. Methods: Between April 2005 and December 2010, ESD was performed on 1,463 lesions that were divided into the following three groups: Barrett’s adenocarcinoma (BA; n = 25); JC (n = 103), and NJC (n = 1,335). They were assessed for short-term outcomes, clinicopathological malignancy and long-term outcomes. Results: Rates of complete and curative resection were significantly lower for BA than for JC and NJC (64.0 vs. 96.1 and 96.0%; and 48.0 vs. 80.6 and 85.8%, respectively). The perforation rate was significantly higher for BA than for JC and NJC (20.0 vs. 2.9 and 2.7%). Clinicopathologically, submucosal invasion rates were higher in BA and JC than in NJC (32.0 and 30.1 vs. 13.6%), and positive rates of lymphatic and/or vascular invasion were remarkably higher in BA and JC versus NJC (24.0 vs. 9.7 vs. 4.8%, respectively). The 5-year survival rate in all patients with curative resection was 100%. Conclusion: This study confirmed the technical and theoretical validity of ESD for EGJ as a diagnostic treatment. However, we have to pay attention to the high rates of submucosal and lymphovascular invasive malignant potential of these cancers.

Endoscopic submucosal dissection for nonampullary large superficial adenocarcinoma/adenoma of the duodenum: feasibility and long-term outcomes.

Background and study aims: The clinical benefit of endoscopic submucosal dissection (ESD) for superficial duodenal neoplasias has not yet been verified. The aims of this study were to validate the feasibility and long-term outcomes of ESD for nonampullary superficial duodenal neoplasias, larger than 20 mm. Patients and methods: 41 patients, with 41 nonampullary large superficial duodenal neoplasias, who underwent ESD between April 2005 to March 2013 were included in the study. The short- and long-term outcomes were retrospectively evaluated, related to tumor size, resection size, histological type, invasion depth, complete resection rate, operation time, perforation rate, delayed bleeding rate, local recurrence rate, distant metastasis, and survival rate. Results: ESD was successfully completed in 38 of 41 patients (92.7 %). The median sizes of tumors and resected specimens were, respectively, 26 mm (range 20 – 70 mm) and 36.5 mm (range 23 – 80 mm). Histopathological findings showed 13 adenocarcinomas (12 mucosal, 1 submucosal) and 28 adenomas (26 high grade dysplasia, 2 low grade dysplasia). The complete resection rate was 89.5 % (34 /38 tumors). The mean operation time was 128.3minutes. Perforation during ESD occurred in 39 % and delayed bleeding occurred in 18.4 %. The median observation period was 48 months (range 3.2 – 94.1 months), and no local recurrence or distant metastasis was seen during this time, representing a disease-free survival rate of 100 %. Conclusions: ESD for nonampullary large superficial duodenal adenocarcinoma/adenoma is feasible with favorable long-term outcomes. However, because of the high complication rate due to its technical difficulty, experience and skill of the operator, along with adequate perioperative management, are essential.

Feasibility and safety of laparoscopic and endoscopic cooperative surgery for gastric submucosal tumors, including esophagogastric junction tumors.

Recently, the use of endoscopic submucosal dissection (ESD) for gastric submucosal tumor (gSMT) and the development of laparoscopic and endoscopic cooperative surgery (LECS) have enabled either preservation of the stomach or minimization of the extent of partial resection. In the present study, the outcomes following the recent introduction of LECS for gSMT are presented. The aim of this retrospective study was to evaluate the feasibility and safety of LECS for gSMT, including esophagogastric junction (EGJ) SMT.

The acetic acid + indigocarmine method in the delineation of gastric cancer

Background and Aim:  For the purpose of precise preoperative diagnosis that ensures complete endoscopic resection, it is important to accurately determine the lateral spread of gastric cancer lesions. The acetic acid + indigocarmine (AI) method used by us has been found to meet this need. This paper reports its usefulness in the determination of lateral spread of gastric cancer before endoscopic submucosal dissection (ESD).

Diagnostic algorithm of magnifying endoscopy with narrow band imaging for superficial non-ampullary duodenal epithelial tumors.

A novel diagnostic algorithm for magnifying endoscopy with narrow band imaging (ME‐NBI) for superficial non‐ampullary duodenal epithelial tumors (SNADET) is needed because of diagnostic difficulties.