Page 57 - Read Online

Page 2 of 13 Shichijo et al. Mini-invasive Surg 2022;6:19 https://dx.doi.org/10.20517/2574-1225.2021.121

resection is desired. The indications are the following: (1) lesions for which en bloc resection with snare
endoscopic mucosal resection is difficult to perform [e.g., laterally spreading tumor, non-granular type,
particularly pseudo-depressed type, lesions with a Vi-type pit pattern (suggesting the possibility of
invasion)], carcinoma with shallow T1 (submucosal) invasion, large depressed-type tumors, and large
protruded-type lesions suspected to be carcinoma; (2) mucosal tumors with submucosal fibrosis; (3)
sporadic tumors in conditions of chronic inflammation such as ulcerative colitis; and (4) local residual or
recurrent early carcinomas after endoscopic resection . Small lesions (≤ 15 mm) with submucosal fibrosis,
[2]
and small local residual or recurrent early carcinomas after endoscopic resection can be managed by
underwater EMR ; therefore, ESD is primarily performed for large lesions. ESD is widely performed in
[3-5]
[6,7]
Japan, other Asian countries, and several Western countries . However, ESD sometimes results in
deleterious adverse events such as perforation and delayed bleeding . Therefore, determining precise
[8,9]
indications for ESD preoperatively is vitally important. Here, we reviewed devices, techniques, traction,
suturing, and countermeasures for complications that facilitate easier and safer ESD.

DEVICES
Endoscopy
A single-channel colonoscope with a water jet function is used to perform ESD. In some facilities, a
gastroscope is also used for ESD in the distal colon because a shorter endoscope can be easily maneuvered.
A colonoscope is also useful even for cases of the distal colon, because the colonoscope has a wider down
angle. In the proximal colon, straightening and shortening of the endoscope are important for precise
maneuverability, and single-balloon or double-balloon endoscopy systems are sometimes used,
[11]
[10]
particularly in difficult cases.
Distal attachments
Distal attachments are very useful for performing ESD because they facilitate good visibility of the operative
field and stabilize the tip of the endoscope by attaching to the mucosa or submucosa. Transparent hoods
rather than black ones are preferred because they enable visibility through the hood. There are various types
of hoods currently commercially available [Figure 1]. The small-caliber transparent hood (ST hood;
Fujifilm, Tokyo, Japan) is particularly useful for accessing narrow spaces.

Endoknives
Various types of endoknives are commercially available. Short-needle knives, such as DualKnife (Olympus,
Tokyo, Japan), HookKnife (Olympus, Tokyo, Japan), FlushKnife (Fujifilm, Tokyo, Japan), Splashneedle
[12]
(Pentax Medical, Tokyo, Japan), Proknife (Boston scientific Japan), and Endosaber (Sumitomo Bakelite,
Tokyo, Japan) are most commonly used for colorectal ESD. These knives also possess a water-jet function
that facilitates submucosal injection of saline after mucosal incision. A water-jet function is very useful for
injection without changing devices, but only saline is available as high viscosity products such as hyaluronic
acid are hard to pass through knives. Other types of knives, such as IT-nano (Olympus) and mucosectome
(Pentax) are also used together with short-needle knives for easy and rapid submucosal dissection. Scissor-
type knives, such as SB knife Jr. (Sumitomo Bakelite) and Clutch Cutter (Fujifilm) are easily used by
[13]
inexperienced endoscopists . A detailed explanation of endoknives is available in other sections by
experienced authors.

Technique
Basically, colorectal ESD is similar to gastric ESD and comprises mucosal incision and submucosal
dissection. The most distinct aspect of colorectal ESD is that maintaining elevation by submucosal injection
is difficult after mucosal incision, resulting in difficulty accessing the submucosal layer during submucosal
dissection. To overcome this challenge, creating a flap before the circumferential incision is crucial.