Novel intermittent electrocoagulation technique reduces post-endoscopic submucosal dissection electrocoagulation syndrome in colorectal neoplasms

Table 1 Baseline demographic and clinical characteristics of patients, n (%)/median (interquartile range)

	I-ESD (n = 94)	C-ESD (n = 105)	P value
Age, years	62 (53-68)	60 (53-67)	0.3952
Sex			0.196
Male	46 (48.9)	61 (58.1)
Female	48 (51.1)	44 (41.9)
Body mass index, kg/m2	23.5 (21.3-25.1)	23.9 (21.5-25.5)	0.366
History of malignancy	12 (12.8)	9 (8.6)	0.336
ASA			1.0001
1	46 (48.9)	52 (49.5)
2	48 (51.1)	53 (50.5)
3	0	0
Location			0.115
Right side of colon	48 (51.1)	47 (44.8)
Left side of colon	20 (21.3)	15 (14.3)
Rectum	26 (27.7)	43 (41.0)
Origination			0.8551
Mucosa	78 (83.0)	86 (81.9)
Submucosa	16 (17.0)	19 (18.1)
Muscularis propria	0	0
Macroscopic type
LST classification			0.002
LST-G	6 (11.8)	22 (37.3)
LST-NG	45 (88.2)	37 (62.7)
Paris classification			0.359
0-I	22 (28.2)	30 (28.6)
0-II	56 (71.8)	56 (65.1)
NICE classification			0.2581
1	6 (7.7)	4 (4.7)
2	66 (84.6)	69 (80.2)
3	6 (7.7)	13 (15.1)

¹Fisher’s exact test.

²Wilcoxon rank-sum test.

I-ESD: Intermittent electrocoagulation; C-ESD: Conventional continuous electrocoagulation; ASA: American Society of Anesthesiologists physical status classification; LST: Laterally spreading tumor; NICE: Narrow-band imaging International colorectal endoscopic classification.

Table 2 Endoscopic procedure-related and lesion characteristics between groups, mean ± SD/n (%)/median (interquartile range)

	I-ESD (n = 94)	C-ESD (n = 105)	P value
Size, mm	20.2 ± 9.4	20.4 ± 7.4	0.1762
Procedural time, minute	42.0 (30.0-60.0)	49.0 (35.0-62.0)	0.0572
Procedural speed, mm2/minute	4.9 (2.9-7.6)	4.6 (3.0-7.4)	0.6472
En bloc resection	93 (98.9)	104 (99.0)	1.0001
R0 resection	87 (92.6)	98 (93.3)	0.830
Histopathology			0.8881
Serrated lesion	23 (24.5)	29 (27.6)
Adenoma	54 (57.4)	54 (51.4)
Carcinoma
Tis	1 (1.1)	2 (1.9)
SM1	0	1 (1.0)
Others	16 (17.0)	19 (18.1)
Adverse events			0.031
Bleeding	2 (2.1)	6 (5.7)
Perforation	0	0
PECS	8 (8.5)	20 (19.0)	0.033
Abdominal pain (NRS ≥ 4)	9 (9.6)	24 (22.9)	0.012
Postoperative max temperature, °C	37.0 (36.9-37.2)	37.1 (37.0-37.4)	0.0032
			0.013
≥ 37.8	6 (6.4)	19 (18.1)
< 37.8	88 (93.6)	86 (81.9)
WBC ≥ 10000/μL	2 (2.1)	8 (7.6)	0.1061
CRP ≥ 1 mg/dL	4 (4.3)	15 (14.3)	0.016
Intraoperative adverse event	0	0
Muscle layer exposure	6 (6.4)	6 (5.7)	0.843
NPO duration, days	1 (1-1)	1 (1-1)	0.2362
Length of hospital stay, days	5 (4-6)	5 (4-7)	0.4572

¹Fisher’s exact test.

²Wilcoxon rank-sum test.

The P value for “adverse events” represents the overall comparison of all adverse events, including bleeding, perforation, post-endoscopic submucosal dissection electrocoagulation syndrome, and other events. Others including neuroendocrine tumors, lipomas, lymphangiomas, and schwannomas. I-ESD: Intermittent electrocoagulation; C-ESD: Conventional continuous electrocoagulation; Tis: Tumor in situ; SM1: Submucosal invasion depth level 1; PECS: Post-endoscopic submucosal dissection electrocoagulation syndrome; NRS: Numerical rating scale; WBC: White blood cell; CRP: C-reactive protein; NPO: Nil per os.

Table 3 Univariate and multivariate analysis of risk factors of post-endoscopic submucosal dissection electrocoagulation syndrome

Factors	Univariate analysis		Multivariate analysis
	OR (95%CI)	P value	OR (95%CI)	P value
Electrocoagulation method		0.037		0.041
C-ESD	1.00 (reference)		1.00 (reference)
I-ESD	0.40 (0.17-0.95)		0.38 (0.15-0.96)
Sex		0.043		0.028
Male	1.00 (reference)		1.00 (reference)
Female	2.36 (1.03-5.41)		2.72 (1.12-6.61)
Age, years		0.543
≤ 60	1.00 (reference)
> 60	0.78 (0.35-1.74)
ASA		0.467
1	1.00 (reference)
2	1.35 (0.60-3.02)
History of malignancy		0.976
No	1.00 (reference)
Yes	1.02 (0.28-3.72)
Location
Right side of colon	1.00 (reference)
Left side of colon	1.45 (0.53-3.95)	0.471
Rectum	0.65 (0.25-1.72)	0.387
Size, mm		0.016		0.019
< 20	1.00 (reference)		1.00 (reference)
≥ 20	3.04 (1.23-7.51)		3.43 (1.22-9.61)
Procedural time, minute		0.040		0.242
≤ 60	1.00 (reference)		1.00 (reference)
> 60	2.38 (1.04-5.44)		1.72 (0.69-4.24)
LST classification		0.964
LST-G	1.00 (reference)
LST-NG	1.03 (0.30-3.49)
Histopathology		0.801
Serrated lesion	1.00 (reference)
Adenoma	0.89 (0.35-2.25)
Muscle layer exposure		0.009		0.008
No	1.00 (reference)		1.00 (reference)
Yes	5.09 (1.49-17.39)		7.10 (1.65-30.57)

OR: Odds ratio; CI: Confidence interval; I-ESD: Intermittent electrocoagulation; C-ESD: Conventional continuous electrocoagulation; ASA: American Society of Anesthesiologists physical status classification; LST: Laterally spreading tumor.