Chapter 18

Basic Principles of Endoscopic Submucosal Dissection Technique

Hiroyuki Ono, MD, PhD

Introduction

Endoscopic therapy for early gastrointestinal (GI) cancer has been attempted since the 1960s, but came to be performed widely after the development of endoscopic mucosal resection (EMR) in the 1980s. However, en bloc resection with EMR is difficult for lesions larger than 1 cm in diameter and lesions arising from ulcer scars.¹ To overcome these challenges, the Endoscopy Group of the National Cancer Center Hospital, Tokyo, Japan, first developed and used the ITKnife^2,3 (Olympus) in endoscopic submucosal dissection (ESD) for early gastric cancer in the mid-1990s.

The first electrosurgical knife developed for use with ESD was the ITKnife (Olympus).³ The improved ITKnife2 (Olympus) for treatment of early gastric cancer followed,⁴ and later the ITKnife-nano was introduced for treatment of esophageal and colon cancer.⁵ Several other designs of knives were subsequently developed^6–8 in Japan and Germany. Scissors-type devices have also appeared.^9,10

Because surgical treatment such as esophagectomy, gastrectomy, and colectomy causes some patient morbidity despite clinical benefit, and because ESD is associated with a much better quality of life with a comparable outcome, ESD has become widely accepted as a standard treatment for early cancer or dysplasia in the GI tract. Thus, its use has rapidly spread throughout not only Japan but many other East Asian countries.

Doctors in Western countries tend not to see or treat many early-stage cancers or superficial lesions of the GI tract. Because these lesions are not as common in the West, they have not provoked physicians’ interest. However, the situation is changing to a certain degree. In the last 10 years, ESD has been applied to various endoscopic treatment techniques such as endoscopic full-thickness resection for submucosal tumor,¹¹ per-oral endoscopic myotomy for achalasia,¹² and antireflux mucosectomy for reflux esophagitis.¹³ Interest in ESD seems to be growing in Western countries as well.

In a multicenter prospective study for expanded-indication gastric cancer, the en bloc resection rate of ESD was 99%, and the long-term prognosis was equivalent to surgical resection.14 However, ESD is more technically difficult than EMR, and sufficient knowledge and skill are necessary. Details of devices, equipment, and techniques are described in other chapters, and this chapter focuses on the basic principle.

Informed Consent

The patient should be provided an oral written explanation and opportunity to ask questions. The information provided should cover the following points: the diagnosis; description, and purpose of the treatment; expected outcome and general condition after treatment; and the risks and benefits compared with EMR and surgical resection. The description of risks or possible complications should include their frequency (in general and, if applicable, in the context of comorbidities) and methods for treating them. The risk of complications should be based on data specific to the institution if possible. Thus, the informed consent document may state, for example, “Risk of perforation, 5%; postprocedural bleeding, 5%; need for blood transfusion, less than 1%; bleeding or perforation requiring emergency surgery, 0.3% or less; death, 0.1% or less.” The difference between resection and cure should be fully explained. For example, an R0 resection may be considered noncurative because of the risk of metastasis. The possibility of a metastatic recurrence even after a curative resection should also be discussed.

Medical History and Preoperative Examination

Obtaining a thorough medical history is important. This should include inquiries about medical conditions (heart disease, glaucoma, hypertensive disease, cerebrovascular disease, and benign prostatic hyperplasia), surgical history, medications, drug allergies, and the presence of implanted devices such as cardiac pacemakers.

For management of antithrombotic drugs (warfarin, aspirin, ticlopidine, clopidogrel, etc), around the time of the procedure refer to medication guidelines and consult with the prescribing physicians on the pros and cons of withdrawal or continuation of oral administration.

Preprocedural laboratory evaluation should include blood typing, tests for infectious diseases (eg, hepatitis B virus, hepatitis C virus, syphilis test), a general metabolic panel, coagulation test, Helicobacter pylori antibody, etc. Additional necessary tests include an electrocardiogram, respiratory function test, and chest x-ray. If there is a risk of metastasis, abdominal computed tomography or ultrasound should be performed.

Medical Equipment

For high-frequency cautery power-supply devices, end cut mode or PulseCut mode (mixed mode of soft coagulation and incision wave) (ESG series [Olympus], VIO series [Erbe], etc) are recommended. High-frequency settings that are compatible with electrosurgical knives vary among different facilities or operators even for the same knife, so refer to other chapters for details.

The endoscope should be equipped with a forward water supply function, but should also be capable of an ordinary direct view. Depending on the site of the lesion, a 2-channel scope and multibending scope may be useful.

The electrosurgical knives have an insulator at the tip; different models include the so-called ITKnife (Olympus), which cuts in the lateral direction using blades; and a so-called needle type (eg, Needle Knife [Olympus], DualKnife [Olympus], FlushKnife [Fujifilm], HybridKnife [Erbe]), scissors (SB Knife [Sumitomo Bakelite Co]), and Clutch Cutter [Fujifilm]) (Figure 18-1).

Related posts:

Introduction and History of Endoscopic Resection Techniques Per-Oral Endoscopic Myotomy Devices and Accessories for Endoscopic Submucosal Dissection Endoscopic Submucosal Dissection Technique in the Esophagus Full-Thickness Endoscopic and Combined Laparoscopic-Endoscopic Techniques Endoscopic Submucosal Dissection Technique to Conquer Difficult Cases

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