Feasibility of gastric endoscopic submucosal dissection in elderly patients aged ≥ 80 years

Table 6 Relative risks of location and size for bleeding or perforation

(A) Relative risk of location lower third, size > 40 mm, macroscopic shape, presence or absence of ulceration, and depth of invasion for bleeding
	Bleeding (+)	Relative risk	P value
Location
Lower third	5.9% (5/85)	5.3	0.11
Upper third, middle third	1.1% (1/90)
Dissected size
≥ 41 mm	9.5% (4/42)	6.3	0.030
≤ 40 mm	1.5% (2/133)
Macroscopic shape
Depressive component (+)	8.2% (6/73)		0.005
Depressive component ()	0% (0/102)
Ulceration
UL (+)	18.2% (4/22)	13.9	0.003
UL ()	1.3% (2/153)
Depth of invasion
≥ SM	3.9% (6/152)		1
M	0% (0/23)
(B) Relative risk of location upper third, size > 40 mm, macroscopic shape, presence or absence of ulceration, and depth of invasion for perforation
	Perforation (+)	Relative risk		P value
Location
Upper third	6.3% (2/32)			0.033
Middle third, lower third	0% (1/143)
Dissected size
≥ 41 mm	2.4% (1/42)	3.2		0.423
≤ 40 mm	0.8% (1/133)
Macroscopic shape
Depressive component (+)	0% (0/73)	-		0.511
Depressive component ()	2.0% (2/102)
Ulceration
UL (+)	0% (0/22)	-		1
UL ()	1.3% (2/153)
Depth of invasion
≥ SM	0.7% (1/152)	6.6		0.246
M	4.3% (1/23)

UL: Ulceration; M: Mucosa; SM: Submucosa.