Risk factors for Mallory-Weiss Tear during endoscopic submucosal dissection of superficial esophageal neoplasms

Table 2 Univariate analysis for risk factors of Mallory-Weiss Tear

	MWT	Non-MWT	P value
No. of patients	20	317
Age in yr, median (range)	65 (47-77)	62 (37-83)	0.065
Sex as male/female	6/14	222/95	a0.001
Concomitant disease, n
Atrophic gastritis	0	15	1.000
Hiatal hernia	0	2	1.000
History of distal gastrectomy	0	4	1.000
No. of lesions	20	353
Location of the center			0.566
Upper	2 (10.0)	19 (5.4)
Middle	13 (65.0)	239 (67.7)
Lower	5 (25.0)	95 (26.9)
Longitudinal diameter in cm, median (range)	5 (2-8)	4 (1-14)	0.125
Circumferential diameter in cm, median (range)	2.75 (1-5)	2.5 (0.5-7)	0.591
Size of specimen in cm2, median (range)	11.25 (2-32.5)	9.6 (0.5-70)	0.312
Circumferential extent of the mucosal defect			0.085
< 75%	11 (55)	257 (72.8)
≥ 75%	9 (45)	96 (27.2)
Depth of invasion			0.377
Intraepithelial neoplasia	4 (20)	127 (36.0)
Mucosa	13 (65)	182 (51.6)
Submucosa < 200 μm	1 (5)	20 (5.7)
Submucosa ≥ 200 μm	2 (10)	24 (6.8)
Submucosal adhesion, n	3 (15)	36 (10.2)	0.452
Procedure time in min, median (range)	90 (28-180)	58 (12-240)	a0.008
Type of resection			0.694
Conventional ESD	2 (10)	31 (8.8)
ESTD	18 (90)	322 (91.2)
Operators			0.635
Experienced	11(55)	213 (60.3)
Less-experienced	9 (45)	140 (39.7)

^aP < 0.05. ESD: Endoscopic submucosal dissection; MWT: Mallory-Weiss Tear; ESTD: Endoscopic submucosal tunnel dissection.