Prediction and Treatment of Difficult Cases in Colorectal Endoscopic Submucosal Dissection

Table 3

Clinical outcomes of difficult and non-difficult groups in view of procedure speed.

	Difficult group; (≦0.03 cm^2/min)	Non-difficult group; (>0.03 cm^2/min)	P value
Case numbers (%)	52 (10.0)	466 (90.0)
Tumor size (mm), mean ± SD	17.2±5.0	32.5±13.5	<0.001
Tumor location (%); Right-sided/left-sided/rectum	36.5/25.0/38.5	50.4/18.9/30.7	NS
Morphology (%); Superficial/protruding	82.7/17.3	80.3/19.3	NS
Degree of fibrosis (%) (n); F0/F1/F2	34.6/42.3/23.1; (18/22/12)	55.2/36.9/7.9; (257/172/37)	<0.001
Experience of endoscopist (%) (n); Expert/nonexpert	26.9/73.1; (14/38)	35.4/65.6; (165/301)	NS
Procedure time (minutes), mean ± SD	136.7±66.0	88.7±52.6	<0.001
En bloc resection (%)	78.8	92.9	<0.001
Perforation (%) (n)	9.6 (3)	3.0 (14)	<0.01
Postoperative hemorrhage (%) (n)	5.8 (3)	1.9 (9)	NS
Histology (%) (n); Ad/M/SM	44.2/34.6/21.2; (23/18/11)	45.1/42.7/11.6; (210/199/54)	NS (0.07)

Right-sided: from cecum to transverse colon, left-sided: from descending to sigmoid colon, F0: no fibrosis, F1: mild fibrorsis, F2: severe fibrosis, Ad: adenoma, M: intramucosal cancer, SM: submucosal invaded cancer, and NS: not significant.