Endoscopic mucosal resection-precutting vs conventional endoscopic mucosal resection for sessile colorectal polyps sized 10-20 mm

Table 1 Baseline characteristics of the study population

Characteristic	EMR-P (n = 110), %	CEMR (n = 110), %	P value
Male (%)	67 (60.9)	70 (63.6)	0.676
Mean age (yr, ± SD)	60.4 ± 10.4	59.9 ± 11.5	0.735
Height (cm)	164.4 ± 7.7	165.0 ± 7.5	0.566
Weight (kg)	61.4 ± 10.5	63.5 ± 10.7	0.151
Location, n (%)			0.725
Cecum	6 (5.5)	5 (4.5)
Ascending	19 (17.3)	18 (16.4)
Transverse	24 (21.8)	28 (25.5)
Descending	7 (6.4)	9 (8.2)
Sigmoid	26 (23.6)	31 (28.2)
Rectum	28 (25.5)	19 (17.3)
Morphology, n (%)			0.858
0-Ip	3 (2.7)	3 (2.7)
0-Is	36 (32.7)	42 (38.2)
0-IIa	68 (61.8)	62 (56.4)
0-IIb	2 (1.8)	3 (2.7)
0-IIc	1 (0.9)	0 (0.0)
Institution, n (%)			0.570
A	16 (14.5)	9 (8.2)
B	31 (28.2)	28 (25.5)
C	6 (5.5)	5 (4.5)
D	19 (17.3)	16 (14.5)
E	9 (8.2)	14 (12.7)
F	13 (11.8)	18 (16.4)
G	16 (14.5)	20 (18.2)
Tumor size (mm)	14.0 ± 3.7	13.1 ± 3.1	0.055
Operator experience, n (%)			0.072
Experienced endoscopist	109 (99.1)	103 (93.6)
Non-experienced endoscopist	1 (0.9)	7 (6.4)

Institution A: The First Affiliated Hospital, College of Medicine, Zhejiang University, China; Institution B: Renmin Hospital of Yuyao City, Zhejiang, China; Institution C: Jinhua Municipal Central Hospital, Zhejiang, China; Institution D: Taizhou Hospital, Zhejiang, China; Institution E: The Central Hospital of Lishui City, Zhejiang, China; Institution F: Ningbo Medical Center, Lihuili Hospital, Zhejiang, China; Institution G: Ningbo First Hospital, Zhejiang, China. EMR-P: Endoscopic mucosal resection with circumferential precutting; CEMR: Conventional endoscopic mucosal resection.

Table 2 Procedure-related outcomes in this study

Parameter	EMR-P group, %	CEMR group, %	P value
ITT analysis	n = 110	n = 110
En bloc resection	103 (93.6) [87.5-96.9]	95 (86.4) [78.7-91.6]	0.072
R0 resection	89 (80.9) [72.6-87.2]	86 (78.2) [69.6-84.9]	0.616
R1 resection	9 (8.2) [4.4-14.8]	9 (8.2) [4.4-14.8]	> 0.999
RX resection	6 (5.5) [2.5-11.4]	6 (5.5) [2.5-11.4]	> 0.999
PP analysis	n = 106	n = 107
En bloc resection	100 (94.3) [88.2-97.4]	92 (86.0) [78.2-91.3]	0.041
R0 resection	86 (81.1) [72.6-87.4]	83 (77.6) [68.8-84.4]	0.521
R1 resection	9 (8.4) [4.5-15.4]	9 (8.5) [4.5-15.2]	0.983
RX resection	6 (5.7) [2.6-11.8]	6 (5.6) [2.6-11.7]	0.987
Histological type, n (%)	n = 110	n = 110	0.354
Adenoma	82 (74.5)	85 (77.3)
Tubular adenoma with low-grade dysplasia	62 (56.4)	63 (57.3)
Tubular adenoma with high-grade dysplasia	6 (5.5)	7 (6.4)
Villous adenoma with low-grade dysplasia	2 (1.8)	1 (0.9)
Villous adenoma with high-grade dysplasia	0 (0.0)	0 (0.0)
Tubular villous adenoma with low-grade dysplasia	10 (9.1)	12 (10.9)
Tubular villous adenoma with high-grade dysplasia	2 (1.8)	2 (1.8)
Hyperplastic	11 (10.0)	14 (12.7)
Serrated lesions	9 (8.2)	7 (6.4)
Cancer	4 (3.6)	4 (3.6)
Intramucosal adenocarcinoma	3 (2.7)	4 (3.6)
Submucosal invasive adenocarcinoma	1 (0.9)	0 (0.0)
Other	4 (3.6)	0 (0.0)
Procedure time (min)	6.4 (4.5, 10.3)	3.0 (1.9, 6.2)	< 0.001

EMR-P: Endoscopic mucosal resection with circumferential precutting; CEMR: Conventional endoscopic mucosal resection; ITT: Intention-to-treat analysis; PP: Per-protocol analysis; En bloc resection is defined as a once-piece resection; R0 resection is defined as en bloc resection with a histologically negative margin; R1 resection is defined as a positive resection margin; RX resection is defined as an unknown resection status.

Table 3 Adverse events in this study

Parameter	EMR-P group (n = 110)	CEMR group (n = 110)	P value
Intraprocedural bleeding	10 (9.1)	7 (6.3)	0.449
Postoperative bleeding	0	0	/
Intraprocedural perforation	1	0	/
Postoperative perforation	0	0	/

EMR-P: Endoscopic mucosal resection with circumferential precutting; CEMR: Conventional endoscopic mucosal resection.