Ligation therapy for GI SMTs is developed from the band ligation treatment of esophageal varices. Principle is to block the blood supply of SMT through ligation leading to resection by local necrosis. It provides an easy method for treating SMT and reduces the risk of bleeding and perforation (Fig. 5.12). However, ligation for large tumors may have a risk of incomplete resection. The biggest drawback of endoloop ligation is that it cannot obtain tissue for pathological diagnosis. Nevertheless, with the help of preoperative fine needle aspiration (FNA) this may be overcome.

EUS can provide useful information that help decide the endoscopic treatment. SMTs originating from deep layers (beyond muscularis propria) can be treated by ESE or even full-thickness resection, but mucosal and most submucosal lesions can be resected by EMR/ESD technique. Submucosal injection can be useful to determine lesion origin. If it can be lifted by submucosal injection, the lesion is superficial, otherwise, it arises from deep layers thus requiring ESE. CT scan can differentiate submucosal lesion from extrinsic compression (Fig. 5.17).

ESE for SMTs originating from the muscularis propria is similar to ESD procedure.

Due to the deep location of tumors, it is a challenging endoscopic procedure hence only to be carried out by expert endoscopist. Larger SMTs (>3 cm) should be resected by SME technique in collaboration with surgical team. If complications such as perforation or massive bleeding cannot be dealt with endoscopically, it may be necessary to convert to surgery.

For intraluminal large (>3 cm) SMT, it is not necessary to mark lesions before ESE. For small and deep lesions (<1 cm), marking is recommended to avoid losing them after submucosal injection (Fig. 5.18).

Saline mixture is used for injection. Main purpose of submucosal cushion is to provide space for submucosa dissection and to avoid perforation (Fig. 5.19).

The mucosa is incised outside the marker dots with an ESD knife. Some superficial submucosal lesions can be exposed after mucosa incision (Fig. 5.20). Be careful to avoid cutting too deep for gastric fundal lesions, as the wall of fundus is thin and a single cut can cause perforation. Some deep lesions could not be easily exposed after mucosa incision, snare removal of the overlying mucosa then can expose the lesion. If this doesn’t work, the tumor may be located in deep muscular layer, cautious cutting into the muscle could then help to expose the tumor (Fig. 5.21).

Dissect around the lesion and excavate it under direct visualization after further submucosal injection to seperate submucosal layer from muscle layer. If it is difficult to excavate deeper lesions or lesions protruding into serosa, further dissection can be facilitated using combination of different knives. If the endoscopic view is suboptimal, switching to dual channel scope for passage of forceps to apply traction facilitate dissection and excavation of tumors.

If it is difficult to incise the proximal mucosa of lower esophageal SMTs, the tumors can be pushed into gastric cavity after partially dissection, then use ESD knives to dissect in the stomach (Figs. 5.22, 5.23, 5.24, 5.25, 5.26, 5.27, 5.28, 5.29, 5.30, and 5.31).

It is also feasible and safe to perform piecemeal resection for large irregular SMTs (Figs. 5.32 and 5.33).

For larger tumors with obscure tumor border or endoscopic features of malignancy or excessive bleeding that is difficulty to stop, it is wise to stop the procedure and convert to surgery (Figs. 5.34, 5.35, and 5.36).

Small blood vessels visible in wounds after resection should be coagulated by hemostatic forceps or APC. When the bleeding spot is too deep for APC or hemostatic forceps to grasp, metallic clips can achieve successful hemostasis (Fig. 5.37).

Patients are kept nil by mouth for 1 day after procedure. We routinely use of hemocoagulase injection in all cases for 24 h along with PPI in case of gastric lesions. Clear liquids allowed if no complication occurred on day 2. Patients are followed up at 3, 6 and 12 months afterwards.

Bleeding and perforation are the major complications. Hemostasis can be achieved by contact coagulation of bleeding spots with knife or by using hemostatic forceps. If the bleeding is too brisk to identify the exact bleeding spot, flush the wound with iced saline help locate it, then hemostatic forceps is applied to stop the bleeding. Hemostatic clips can be used for brisk arterial bleeding, but this will influence dissection in the subsequent procedure (Figs. 5.38 and 5.39).

If perforation occurred during ESE, it is safe to continue and complete en bloc endoscopic resection if the patient’s observation are satisfactory. Otherwise, piecemeal resection with snare can be attempted to reduce procedure time and ensure safety. In such difficult situation sometimes it is safer to stop the procedure prematurely with incomplete resection, but to retrieve a piece of specimen for pathological diagnosis. If the repair of perforation fails, salvage laparoscopic surgical repair is required urgently (Figs. 5.40, 5.41, 5.42, and 5.43).

Endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) techniques are widely used for en bloc resection of superficial GI carcinomas and premalignant lesions from mucosal and submucosal layers. However these techniques are suboptimal in resecting subepithelial tumors originating from muscularis propria (MP) layer. Limitations include an increased risk of perforation and failure to achieve R0 resection margins. Endoscopic full-thickness resection (EFTR) has the potential to overcome these limitations, although closure of the resulting wall defect can be difficult and remains the main challenge. EFTR can be laparoscopic-assisted endoscopic full-thickness resection (LAEFTR) and without laparoscopic assistance. For small SMTs, some endoscopic surgeons perform LAEFTR, which uses endoscopic techniques to resected GI SMTs followed by laparoscopic suture of the wound. EFTR without laparoscopic assistance gets rid of the dependence of the laparoscopic technique.

EFTR offers an alternative option to traditional surgical resection treatment in selected patients. However, closure of wall defect remain a challenge and with availability of newer devices will help to overcome this shortcoming.

EFTR has been in clinical use in centers with advanced endoscopic expertise, but there is no consensus about indication or suitability of EFTR. EFTR allows complete resection of tumors, hence reduces the risk of residual tumor and improves accuracy of pathological diagnosis and staging. Suzuki et al. reported EFTR of rectal and duodenal carcinoids and endoscopic complete closure (ECDC) [4]. Sumiyama proposed that EFTR technique can be used to resect submucosal tumor and large laterally spreading tumor involving the submucosa or muscularis propria [5]. We propose the following as indications of EFFTR: