Secondary endoscopic submucosal dissection for locally recurrent or incompletely resected gastric neoplasms

Table 1 Baseline characteristics

Characteristics	ESD	Secondary ESD	P value
	(n = 1595, %)	(n = 28, %)
Gender			0. 836
Male	1117 (70.0)	19 (67.9)
Female	478 (30.0)	9 (32.1)
Age [yr, mean (SD)]	64.8 (10.4)	63.5 (9.2)	0.528
Lesion location			0.217
Upper	127 (8.0)	3 (11.1)
Middle	633 (39.7)	15 (53.6)
Lower	835 (52.4)	10 (35.7)
Multiplicity	250 (15.7)	2 (7.1)	0.296
Lesion size [mm, mean (SD)]	17.4 (12.8)	16.4 (13.2)	0.664
Macroscopic type			< 0.001
Elevated	674 (42.3)	7 (25.0)
Flat	685 (42.9)	9 (32.1)
Depressed	236 (14.8)	12 (42.9)
WHO classification			< 0.001
Low grade dysplasia	610 (38.2)	8 (28.6)
High grade dysplasia	221 (13.9)	4 (14.3)
Well differentiated	356 (22.3)	4 (14.3)
Moderately differentiated	268 (16.8)	7 (25.0)
Poorly differentiated	76 (4.8)	3 (10.7)
Signet ring cell carcinoma	64 (4.0)	0 (0.0)
No residual lesion	0 (0.0)	2 (7.1)
Depth of invasion			< 0.001
Dysplasia	831 (52.1)	12 (42.9)
Mucosal cancer	609 (38.2)	14 (50.0)
Submucosal cancer	155 (9.7)	0 (0.0)
No residual lesion	0 (0.0)	2 (7.1)
LVI			1.000
No	1546 (96.9)	28 (100.0)
Yes	49 (3.1)	0 (0.0)
Lateral margin			0.381
Negative	1521 (95.4)	26 (92.9)
Positive	74 (4.6)	2 (7.1)
Vertical margin			0.615
Negative	1542 (96.7)	27 (96.4)
Positive	53 (3.3)	1 (3.6)

ESD: Endoscopic submucosal dissection; LVI: Lymphovascular invasion.

Table 2 Comparison of procedural outcomes and oncologic outcomes between the primary endoscopic submucosal dissection group and secondary endoscopic submucosal dissection group

	ESD	Secondary ESD	P value
	(n = 1595, %)	(n = 28, %)
Lesion size [mm, mean (SD)]	17.4 (12.8)	16.4 (13.2)	0.664
Specimen size [mm, mean (SD)]	38.1 (14.6)	47.8 (19.6)	0.001
Whole procedure time [min, mean (SD)]	55.1 (41.5)	78.2 (38.0)	0.004
Dissection time [min, mean (SD)]	36.7 (34.7)	63.4 (38.0)	< 0.001
Dissection speed [mm2/min, mean (SD)]	38.7 (32.8)	22.1 (12.7)	< 0.001
Complication	61 (3.8)	3 (10.7)	0.095
Perforation	37 (2.3)	0 (0.0)
Bleeding	15 (0.9)	1 (3.6)
Aspiration pneumonia	13 (0.8)	2 (7.1)
Hospital stay [d, mean (SD)]	3.6 (3.2)	3.9 (2.5)	0.639
En bloc resection	1574 (98.7)	26 (92.9)	0.058
Curative resection	1383 (86.7)	25 (89.3)	1.000
Additive salvage treatment	104 (6.5)	3 (10.7)	0.425
Additive surgery	85 (5.3)	2 (7.1)
Redo ESD	16 (1.0)	1 (3.6)
Argon plasma coagulation	3 (0.2)	0 (0.0)

ESD: Endoscopic submucosal dissection.

Table 3 Clinicopathologic characteristics according to surgical strategy

Characteristics	Early salvage ESD (n = 6, %)	Late salvage ESD (n = 8, %)	Late secondary ESD (n = 14, %)	P value
Gender				0. 909
Male	4 (66.7)	5 (62.5)	10 (71.4)
Female	2 (33.3)	3 (37.5)	4 (28.6)
Age [yr, mean (SD)]	65.4 (10.8)	61.6 (7.3)	63.8 (9.9)	0.749
Lesion location				0.255
Upper	2 (33.3)	0 (0.0)	1 (7.1)
Middle	2 (33.3)	4 (50.0)	9 (64.3)
Lower	2 (33.3)	4 (50.0)	4 (28.6)
Multiplicity	0 (0.0)	1 (12.5)	1 (7.1)	0.668
Lesion size [mm, mean (SD)]	19.8 (22.4)	13.6 (10.9)	16.4 (9.8)	0.701
Initial method				0.341
EMR	0 (0.0)	0 (0.0)	2 (14.3)
ESD	6 (100.0)	8 (100.0)	12 (85.7)
Macroscopic type				0.014
Elevated	0 (0.0)	0 (0.0)	7 (50.0)
Flat	4 (66.7)	2 (25.0)	3 (21.4)
Depressed	2 (33.3)	6 (75.0)	4 (28.6)
WHO classification				0.081
Low grade dysplasia	2 (33.3)	3 (37.5)	3 (21.4)
High grade dysplasia	0 (0.0)	1 (12.5)	3 (21.4)
Well differentiated	1 (16.7)	0 (0.0)	3 (21.4)
Moderately differentiated	1 (16.7)	4 (50.0)	2 (14.3)
Poorly differentiated	0 (0.0)	0 (0.0)	3 (21.4)
Signet ring cell carcinoma	0 (0.0)	0 (0.0)	0 (0.0)
No residual lesion	2 (33.3)	0 (0.0)	0 (0.0)
Depth of invasion				0.090
Dysplasia	2 (33.3)	4 (50.0)	6 (42.9)
Mucosal cancer	2 (33.3)	4 (50.0)	8 (57.1)
Submucosal cancer	0 (0.0)	0 (0.0)	0 (0.0)
No residual lesion	2 (33.3)	0 (0.0)	0 (0.0)
LVI				1.000
No	6 (100.0)	8 (100.0)	14 (100.0)
Yes	0 (0.0)	0 (0.0)	0 (0.0)
Lateral margin				0.341
Negative	6 (100.0)	8 (100.0)	12 (85.7)
Positive	0 (0.0)	0 (0.0)	2 (14.3)
Vertical margin				0.617
Negative	6 (100.0)	8 (100.0)	13 (92.9)
Positive	0 (0.0)	0 (0.0)	1 (7.1)

EMR: Endoscopic mucosal resection; ESD: Endoscopic submucosal dissection; LVI: Lymphovascular invasion.

Table 4 Comparison of procedural outcomes and oncologic outcomes according to surgical strategy

	Early salvage ESD (n = 6, %)	Late salvage ESD (n = 8, %)	Late secondary ESD (n = 14, %)	P value
Lesion size [mm, mean (SD)]	19.8 (22.4)	13.6 (10.9)	16.4 (9.8)	0.701
Specimen size [mm, mean (SD)]	63.0 (33.0)	46.4 (11.6)	42.1 (12.8)	0.084
Whole procedure time [min, mean (SD)]	81.7 (48.5)	85.9 (24.3)	72.3 (41.1)	0.714
Dissection time [min, mean (SD)]	73.2 (46.8)	73.0 (23.4)	53.8 (40.7)	0.421
Dissection speed [mm2/min, mean (SD)]	19.4 (6.8)	19.0 (7.5)	24.9 (12.7)	0.512
Method				0.341
ESD only	6 (100.0)	8 (100.0)	12 (85.7)
ESD plus snaring	0 (0.0)	0 (0.0)	2 (14.3)
Complication	0 (0.0)	1 (12.5)	2 (14.3)	0.627
Perforation	0 (0.0)	0 (0.0)	0 (0.0)
Bleeding	0 (0.0)	0 (0.0)	1 (7.1)
Aspiration pneumonia	0 (0.0)	1 (12.5)	1 (7.1)
Hospital stay [d, mean (SD)]	7.2 (2.9)	3.0 (1.8)	3.0 (1.2)	< 0.001
Median interval [d, mean (SD)]	6.5 (3.1)	129.0 (133.6)	712.8 (546.5)	0.001
En bloc resection	6 (100.0)	8 (100.0)	12 (85.7)	0.341
Curative resection	6 (100.0)	8 (100.0)	11 (78.6)	0.186
Additive treatment	0 (0.0)	0 (0.0)	3 (21.4)	0.186
Additive surgery	0 (0.0)	0 (0.0)	2 (14.3)
Redo ESD	0 (0.0)	0 (0.0)	1 (7.1)

ESD: Endoscopic submucosal dissection.