Among various electrocautery knives specialized for ESD, pointed tip-type knives would be suitable especially for esophageal ESD due to the narrow lumen and the thin wall of the esophagus (Fig. 14.3) [21–23].

Successful resection requires accurate endoscopic diagnosis of a tumor extent. Although promising image-enhancement endoscopy techniques have been introduced, conventional chromoendoscopy using iodine spraying would be still most useful in determining the extent of the lesion. Using a tip of the knife, markings are made 2–3 mm outside the lesion at intervals of approximately 3 mm.

In creating a submucosal fluid cushion, an injection needle is gently advanced into the submucosa at the outside of markings, and a fluid colored with a small amount of indigo carmine, which is helpful to visualize the submucosa, is injected into the submucosa to make sufficient submucosal space for incision and dissection. Hypertonic or viscous injection fluid such as Glyceol™ (Chugai Pharmaceutical Co., Japan; consisted of 10 % glycerine, 5 % fructose, and 0.9 % sodium chloride) or hyaluronic acid solution is desirable for long-lasting submucosal cushion. Injection directly through the cancerous area should be avoided in order to prevent cancer cell implantation in the deeper layer.

The mucosa 1–2 mm outside of markings is usually cut with cutting current using specific knife. Right after partial mucosal incision, initial submucosal dissection should be made along the incision line with coagulation current. To make sure the end point of submucosal dissection, it is better to cut the anal side of the lesion first and subsequently continue the procedure from the oral side.

It is very important to conduct submucosal dissection under direct vision using transparent hood. The knife should be moved parallel to the plane of the muscular layer during submucosal dissection to avoid muscular injury or perforation. Repeat submucosal injection, mucosal incision, and submucosal dissection step by step until end of the procedure.

Unlike gastric ESD, the rate of postoperative bleeding is relatively low (0–2 %) [24–27]. In case of minor bleeding, hemostasis using the retracted tip of the knife is firstly attempted. When it is difficult to stop bleeding or it bleeds massively, hemostatic forceps should be used. After the retrieval of the resected specimen, the resection wound should be carefully inspected to check for visible vessels. And every thick exposed blood vessels should be coagulated, avoiding excessive thermal damage.

Perforation should be paid more attention especially in esophageal ESD. Because the esophagus has no serosa, exposure of the muscular layer may cause pneumomediastinum [28, 29]. Indeed, pneumomediastinum was found by CT scan in a half of treated cases after esophageal ESD, although fortunately these were almost subclinical [28]. Damage of the muscular layer might lead to delayed perforation, which could become fatal mediastinitis. Therefore, it is necessary to follow up the patient carefully, especially after perforation, muscular injury, and severe thermal damage. In case of perforation, patients are treated at rest with fasting and administered antibiotics until a fever and inflammation are relieved. Generally, emergency endoscopy for the purpose of detection and closure of a perforation site is not indicated because it may be not only ineffective but also a cause of spread of mediastinitis.

The risk of postoperative stricture is particularly higher in esophageal ESD (Fig. 14.4) [10, 11]. Because the probability of stricture mostly depends on the resected size, a lesion over three-fourths of circumference is relative indication of ESD as previously mentioned. Several attempts to prevent postoperative stricture have been tried [30–35], e.g., prophylactic endoscopic balloon dilatation and local injection or oral administration of steroids. Preclinical trials are also considered such as adipose tissue stem cell transplantation [36] or cultured cell sheet transplantation [37, 38], but there has been no decisive method so far. Further investigation would be necessary to overcome this problem.

Favorable treatment results have been reported from high-volume centers particularly in Japan [24–27]. In short-term outcomes such as a technical feasibility of esophageal ESD, over 90 % of complete resection rate is obtained, whereas the rates of major complications such as delayed bleeding or perforation keep below 2 % in leading centers for ESD. Even if complication occurred, it can be managed conservatively and thus hardly becomes a life-threatening condition. Technically, ESD for the lesion near the esophagogastric junction is sometimes difficult and time-consuming because intraoperative bleeding from abundant collecting vessels occurs frequently. The lesion located in the cervical esophagus, one of natural constrictions, is also difficult to resect because of poor visualization. Furthermore, the risk of aspiration pneumonia becomes extremely high by reflux of fluids (e.g., blood, rinsing water, submucosal fluid). In that case, ESD with general anesthesia should be considered.