Present situation of minimally invasive surgical treatment for early gastric cancer

Table 1 Summary of minimally invasive treatment modalities for early gastric cancer

Initial	Upgrade	Indications	Advantages	Disadvantages	Results
EMR	EMR	Tumors confined to the mucosa, without vascular and lymphatic metastatic foci	Simple operation and short operation time	Incomplete resection (tumor diameters ≥ 2 cm)	The rate of local recurrence was 2%-35% after the operation[5]
	BA-EMR	SMT (< 1.2 cm)[6]	Simplify the treatment procedure, shorten the duration of the procedure, hospitalization and reduce complications	Not mentioned	Safe and effective
	EMR-P	Small gastric adenomas (≤ 15 mm in diameter)	Shorter operative time than ESD	Less effective in proximal gastric adenomas[7]	Effective
	mEMR-C	Small (≤ 20 mm) intraluminal gGISTs	Shorter operative time and lower cost than ESD	Not mentioned	A new variant of standard EMR
UEMR	UEMR	The resection of esophageal, gastric, duodenum, ampullary, small intestinal and colorectal lesions[10]	Obtain sufficient submucosal tissue without needle injection to provide accurate pathologic diagnosis	Not mentioned	Feasible, safe and effective
ESD	ESD	Gastrointestinal tumors; the elderly patients[20]	Expands the scope of lesion resection and improves overall lesion resection; reduce serum CA125 levels, regulate PG secretion	Its intraoperative procedures are more complex and time-consuming than EMR[22]; the incidence of intraoperative bleeding in ESD is significantly higher than that in EMR	Reduces the risk of local recurrence[18], provides complete pathological data and accurate pathological evaluation[19]; promote the recovery of gastric gland function[21]
EFTR	EFTR	Gastrointestinal subepithelial tumors with malignant potential SET[27]	Allows minimal resection of the gastric wall; facilitate postoperative recovery	Carry a risk of peritoneal infection or dissemination	Safe and reliable
	EFTR-L	Small gastric SET (≤ 1.5 cm) originating from the intrinsic muscularis propria	A shorter operative time and lower cost than EFTR[28]	Not mentioned	Efficacy
	OTSC-assisted EFTR	Gastrointestinal stromal tumors	Especially suit for gastrointestinal stromal tumors < 20 mm in size[29]	Not mentioned	Safely and effectively resected
	Clip-and snare-assisted EFTR	MP-GISTs	Provide unique endoscopic visualization, adequate exposure of the cutting line and sufficient maneuvering space[30]	Not mentioned	Safe and effective
	EFTR-C	GIST	The treatment outcome, AEs, hospital stay and postoperative recovery of patients with GIST were better than those in the group of EFTR	Not mentioned	The first choice for small (≤ 1.5 cm) gastric GIST
	NT-EFTR	GISTs	No-touch	Large tumors with extraluminal growth and large gastric defects impact procedural difficulty	A feasible method
	NESS-EFTR	EGC	Prevent tumors from being exposed to the peritoneal cavity	Not mentioned	NESS-EFTR combined with sentinel pelvic dissection for EGC results in safe margins and prevents intraoperative perforation
	TAMIC	The closure of large perforations after gastric EFTR	Twin-grasper assisted mucosal inverted closure technique[36]	Tumor size ≥ 3 cm and the position of gastric body are the risk factors for the treatment	Safe and novel
	TT method adjunctive to EFTR	Gastric SMT	Effectively shorten the operative time and reduce the risk of complications[38]	Not mentioned	Effective
	Eo-EFTR	Deep gastric submucosal tumors	High complete resection rates and low surgical conversion rates	Not mentioned	Relatively safe
	DFC assist with traction	When EFTR treatment for SMT has limitations in the gastric fundus	Relieve tumor borders, simplify the procedure and shorten the procedure time, and reduce the risk of post-EFTR electrocoagulation syndrome[40,41]	Not mentioned	Decipher the limitations, increase the effectiveness of EFTR
	The modified method named ZIP	SMT smaller than 2.5 cm	The mucosal layer of gastric wall defects after EFTR can be effectively closed	Not mentioned	Achieve the goal of successful closure of gastric wall defects
	Third-space EFTR	Small gastric submucosal tumors	Involves multiple procedures[43]	Not mentioned	Feasible and safe
	"Shao-Mai" closure method	The defect closure after EFTR for gastric SMT in the gastric wall	An endo-loop was anchored onto the edge of the gastric defect with grasping forceps assistance and closed tightly	Not mentioned	A novel and simplified closure method[44]
ESE	ESE	Gastric lesions in the intrinsic muscular layer	More extensive, earlier postoperative feedings, shorter postoperative hospital stays, and lower hospitalization costs compared with EFTR[49] (gastric SETs < 3 cm)	Not suitable for deeper lesions	Safe and effective
STER	STER	Resect SMT located in the esophagus and cardia, both cardia and non-cardia gastric SMT; obese patients	A low incidence of complications and can be conservatively treated when encountering complications	It is more difficult to perform a STER in the stomach than in the esophagus	Easible
LECS	LECS	Gastric SMT with ulcerative lesions and early stage T1a GC[63,64]	Minimal intraoperative bleeding, reasonable surgical time and good postoperative outcomes	Not mentioned	Ideal for the treatment of G-GIST up to 5 cm

EMR: Endoscopic mucosal resection; BA-EMR: band-assisted endoscopic mucosal resection; ESD: Endoscopic submucosal dissection; SET: Subepithelial tumor; EFTR: Endoscopic full-thickness resection; MP-GISTs: Muscularis propria layer gastrointestinal stromal tumors; OTSC: Over-the-scope clip; EFTR-C: Cap-assisted endoscopic full-thickness resection; AEs: Adverse events; GIST: Gastrointestinal stromal tumor; NT-EFTR: No-touch endoscopic full-thickness resection; NESS-EFTR: Non-exposure simple suturing endoscopic full-thickness resection; TAMIC: Twin-grasper assisted mucosal inverted closure; TT: Thread-traction; Eo-EFTR: Exposed endoscopic full-thickness resection; DFC: Dental floss and a hemoclip; SMT: Submucosal tumor; STER: Submucosal tunnel endoscopic resection; EMR-P: Endoscopic mucosal resection with circumferential precutting; mEMR-C: Modified cap-assisted endoscopic mucosal resection; gGISTs: Gastric gastrointestinal stromal tumors; UEMR: Underwater endoscopic mucosal resection; EFTR-L: Ligation-assisted endoscopic full-thickness resection.