Takashi Toyonaga

JGES guidelines for colorectal endoscopic submucosal dissection/endoscopic mucosal resection

Colorectal endoscopic submucosal dissection (ESD) has become common in recent years. Suitable lesions for endoscopic treatment include not only early colorectal carcinomas but also many types of precarcinomatous adenomas. It is important to establish practical guidelines in which the preoperative diagnosis of colorectal neoplasia and the selection of endoscopic treatment procedures are properly outlined, and to ensure that the actual endoscopic treatment is useful and safe in general hospitals when carried out in accordance with the guidelines. In cooperation with the Japanese Society for Cancer of the Colon and Rectum, the Japanese Society of Coloproctology, and the Japanese Society of Gastroenterology, the Japan Gastroenterological Endoscopy Society has recently compiled a set of colorectal ESD/endoscopic mucosal resection (EMR) guidelines using evidence‐based methods. The guidelines focus on the diagnostic and therapeutic strategies and caveat before, during, and after ESD/EMR and, in this regard, exclude the specific procedures, types and proper use of instruments, devices, and drugs. Although eight areas, ranging from indication to pathology, were originally planned for inclusion in these guidelines, evidence was scarce in each area. Therefore, grades of recommendation were determined largely through expert consensus in these areas.

Retrospective study of technical aspects and complications of endoscopic submucosal dissection for laterally spreading tumors of the colorectum

BACKGROUND AND STUDY AIMS Laterally spreading tumors - non granular type (LST-NG) are more often considered candidates for endoscopic submucosal dissection (ESD) than laterally spreading tumors - granular type (LST-G), because of their higher potential for submucosal invasion. However, ESD for LST-NG can be technically difficult. The aim of our study was to compare our ESD results for LST-NG and for LST-G. PATIENTS AND METHODS Ninety-nine LST-NG and 169 LST-G measuring 20 mm in size or more were removed by ESD. We retrospectively evaluated the clinicopathological features of the tumors and treatment results (en bloc resection rate, procedure time and speed, rate of use of ancillary devices, and complication and recurrence rates). RESULTS Histopathology revealed that there were more submucosally invasive lesions in the LST-NG than in the LST-G group (28 % vs. 9 %; P < 0.0001). The en bloc resection rate, en bloc R0 resection rate, and en bloc curative resection rate of LST-NG were similar to those of LST-G (LST-NG: 99 %, 98 %, and 88 %; LST-G: 99 %, 98 %, and 91 %). In LST-NG, the median procedure time tended to be longer (LST-NG: 69 min; LST-G: 60 min) and the median procedure speed was slower (LST-NG: 0.15 cm (2)/min; LST-G: 0.25 cm (2)/min; P < 0.0001). Use of ancillary devices was higher for LST-NG (38 % vs. 15 % for LST-G; P < 0.0001), as was the perforation rate (5.1 % vs. 0.6 % for LST-G; P = 0.027). No recurrence was seen in either group. CONCLUSIONS ESD was an effective treatment method for both LST-NG and LST-G. However, the degree of technical difficulty appears higher for LST-NG than for LST-G lesions, as shown by the lower dissection speed and higher perforation rate. ESD for LST-NG should probably be performed by those with significant experience of colorectal ESD.

The performance of a novel ball-tipped Flush knife for endoscopic submucosal dissection: a case-control study

Aliment Pharmacol Ther 2010; 32: 908–915

THE NEW RESOURCES OF TREATMENT FOR EARLY STAGE COLORECTAL TUMORS: EMR WITH SMALL INCISION AND SIMPLIFIED ENDOSCOPIC SUBMUCOSAL DISSECTION

Introduction:  Early stage colorectal tumors can be removed by endoscopic mucosal resection (EMR) but larger tumors (≧20 mm) may require piecemeal resection. The development of endoscopic submucosal dissection (ESD) has enabled en‐bloc resection of lesions regardless of size and shape. However ESD of colorectal tumor is technically difficult. As the resources, we perform EMR with small incision (EMR with SI) for more reliable EMR, and also ESD with snaring (simplified ESD) for easier and safer ESD.

USE OF SHORT NEEDLE KNIFE FOR ESOPHAGEAL ENDOSCOPIC SUBMUCOSAL DISSECTION

Background:  The emergence of endoscopic submucosal dissection (ESD) has enabled en bloc resection of lesions, which were conventionally difficult. However, ESD has problems of technical difficulty and high incidence of complications. In order to improve the procedure of marking and submucosal dissection in the esophagus, we modified and adjusted the standard needle knife to a short needle knife having a tip portion with a projection length of 1.5 mm.

SEDATION WITH DEXMEDETOMIDINE HYDROCHLORIDE DURING ENDOSCOPIC SUBMUCOSAL DISSECTION OF GASTRIC CANCER

Aim:  Although the treatment of early gastric cancer with endoscopic submucosal dissection (ESD) has been widely carried out, a standardized method of sedation for ESD has not been established. The purpose of the present study was to evaluate the efficacy and safety of sedation with dexmedetomidine (DEX).

INTRAOPERATIVE BLEEDING IN ENDOSCOPIC SUBMUCOSAL DISSECTION IN THE STOMACH AND STRATEGY FOR PREVENTION AND TREATMENT

To control intraoperative bleeding is an important key to successful endoscopic submucosal dissection. The distribution of submucosal vessels encountered during the procedure differ in places in the stomach and are roughly categorized into three groups: those located in the antrum, those in the lesser curvature, and those on the anteroposterior corpus wall which consists of oblique muscle layers. Therefore, knowledge of a suitable setting of diathermy and adjusted depth of dissection in the submucosal layer for each site is imperative. The combination of utilizing the distal attachment forced or swift coagulation (trimming with coagulation mode) have enable the treatment with an insulation tipped knife safer.

MANAGEMENT TO PREVENT BLEEDING DURING ENDOSCOPIC SUBMUCOSAL DISSECTION USING THE FLUSH KNIFE FOR GASTRIC TUMORS

The gastric vasculature responsible for intraoperative bleeding in endosocpic submucosal dissection (ESD) is the ramified vascular network occupying the middle of the submucosal layer and large vessels penetrating the muscle layer. Appropriate management for these vessels must be addressed. The trimming of the ramified vascular network can be safely performed with coagulation mode following shallow mucosal cutting. A large penetrating vessel usually requires precoagulation prior to dissection. These procedures are effectively performed with the water jet short needle knife (Flush knife).

Endoscopic Submucosal Dissection (ESD) Versus Simplified/Hybrid ESD

The development of endoscopic submucosal dissection (ESD) has enabled en bloc resection of lesions regardless of size and shape. However, ESD of colorectal tumors is technically difficult. Early stage colorectal tumors can be removed by endoscopic mucosal resection (EMR) but larger tumors may require piecemeal resection. Therefore, ESD with snaring has been proposed for more reliable EMR and easier ESD. This is a good option to fill the gap between EMR and ESD, and a good step to the introduction of full ESD.

Principles of Quality Controlled Endoscopic Submucosal Dissection with Appropriate Dissection Level and High Quality Resected Specimen

Endoscopic submucosal dissection (ESD) has enabled en bloc resection of early stage gastrointestinal tumors with negligible risk of lymph node metastasis, regardless of tumor size, location, and shape. However, ESD is a relatively difficult technique compared with conventional endoscopic mucosal resection, requiring a longer procedure time and potentially causing more complications. For safe and reproducible procedure of ESD, the appropriate dissection of the ramified vascular network in the level of middle submucosal layer is required to reach the avascular stratum just above the muscle layer. The horizontal approach to maintain the appropriate depth for dissection beneath the vascular network enables treatment of difficult cases with large vessels and severe fibrosis. The most important aspect of ESD is the precise evaluation of curability. This approach can also secure the quality of the resected specimen with enough depth of the submucosal layer.