Risk factors for bleeding after endoscopic submucosal dissection of colorectal neoplasms

Table 1 Indications for colorectal endoscopic submucosal dissection

Large lesions (diameter > 20 mm) for which endoscopic treatment is indicated but en bloc resection by snare endoscopic mucosal dissection would be difficult

Laterally spreading tumor of the non-granular type, particularly the pseudo-depressed type

Lesions showing a type V I pit pattern

Cancer with submucosal infiltration

Large depressed type tumor

Large lesions of the protruded type suspected to be carcinoma1

Mucosal lesions with fibrosis caused by prolapse due to biopsy or peristalsis of the lesions2

Local residual early cancer after endoscopic resection

Sporadic localized tumors with chronic inflammation, such as ulcerative colitis

¹Including laterally spreading tumors of the granular type consisting of large nodules;

²Caused by biopsy or peristalsis of the lesion (prolapse).

Table 2 Baseline characteristics of the 325 superficial colorectal neoplasms in 317 patients n (%)

Characteristic	n
Patient characteristics
Number	317
Age (yr)
Mean ± SD	65.5 ± 10.9
Median (range)	67 (29-86)
Gender
Male	183 (57.7)
Female	134 (42.3)
Comorbidities
Hypertension	103 (32.5)
Diabetes mellitus	31 (9.8)
Hyperlipidemia	54 (17.0)
Cardiovascular disease	16 (5.0)
Liver cirrhosis	0 (0)
Chronic renal failure	0 (0)
Use of antithrombotic drugs	26 (8.2)
Use of intravenous heparin	5 (1.6)
Lesion characteristics
Number	325
Lesion size, mm
Mean ± SD	34.1 ± 16.6
Median (range)	30 (7-115)
Location
Cecum	23 (7.1)
Ascending colon	58 (17.8)
Transverse colon	51 (15.7)
Descending colon	12 (3.7)
Sigmoid colon	59 (18.2)
Rectum	122 (37.5)
Morphology
Protruded	31 (9.5)
Depressed	4 (1.2)
LST-G	180 (55.4)
LST-NG	110 (33.8)
Histology and depth
Serrated lesion	5 (1.5)
Adenoma	26 (8.0)
M	249 (76.6)
SM < 1000 μm	27 (8.3)
SM ≥ 1000 μm	18 (5.5)
Resectability
En bloc resection	284 (87.4)
Complete resection	282 (86.8)
Procedure time, min
Mean ± SD	101.0 ± 80.2
Median (range)	80 (10-630)
Procedure-related adverse events
Delayed bleeding	14 (4.3)
Patients needed transfusion	1 (0.3)
Death related to the procedure	0 (0)

M: Intra-mucosal adenocarcinoma; SM < 1000 μm: Submucosal, minutely invasive adenocarcinoma; SM ≥ 1000 μm: Submucosal, deeply invasive adenocarcinoma.

Table 3 Univariate analysis for risk factors of delayed bleeding n (%)

Variable	Delayed bleeding	Non-bleeding	P value
Number of patients	14	303
Number of lesions	14	311
Patient-related factors
Median age (yr) (range)	68 (29-79)	67 (31-86)	0.871
Gender (male/female)	7/6	175/124	> 0.999
Comorbidities
Hypertension	5 (35.7)	103 (33.1)	> 0.999
Diabetes mellitus	1 (7.1)	34 (10.9)	> 0.999
Hyperlipidemia	2 (14.3)	52 (16.7)	> 0.999
Cardiovascular disease	1 (7.1)	17 (5.5)	0.557
Use of antithrombotic drugs	1 (7.1)	27 (8.7)	> 0.999
Use of intravenous heparin	0 (0)	6 (1.9)	> 0.999
Lesion related factors
Mean size of tumor (mm) (range)	40.9 (20-70)	33.8 (7-115)	0.070
Mean size of specimen (mm) (range)	45.4 (20-75)	38.4 (8-120)	0.142
Location			0.042
Cecum	4 (28.6)	19 (6.1)
Ascending colon	3 (21.4)	55 (17.7)
Transverse colon	2 (14.3)	49 (15.8)
Descending colon	0 (0)	12 (3.9)
Sigmoid colon	1 (7.1)	58 (18.6)
Rectum	4 (28.6)	118 (37.9)
Morphology			0.897
Protruded	1 (7.1)	30 (9.6)
Depressed	0 (0)	4 (1.3)
LST-G	9 (64.3)	171 (55.0)
LST-NG	4 (28.6)	106 (34.1)
Histology and depth			0.312
Serrated lesion	0 (0)	5 (1.6)
Adenoma	2 (14.3)	24 (7.7)
M	8 (57.1)	241 (77.5)
SM < 1000 μm	3 (21.4)	24 (7.7)
SM ≥ 1000 μm	1 (7.1)	17 (5.5)
Treatment-related factors
Device used
Needle type1/scissor type2	12/2	280/31	0.642
Mean procedure time (min) (range)	90.4 (20-180)	101.5 (10-630)	0.965
Significant bleeding during ESD	2 (14.3)	4 (1.3)	0.024

¹Including Flush knife, Dual knife, Hook knife, and B knife;

²SB knife Jr. LST-G: Laterally spreading tumor granular type; LST-NG: Laterally spreading tumor nongranular type; M: Intra-mucosal adenocarcinoma; SM < 1000 μm, submucosal, minutely invasive adenocarcinoma; SM ≥ 1000 μm, submucosal, deeply invasive adenocarcinoma; ESD: Endoscopic submucosal dissection.

Table 4 Univariate analysis of specific locations in the colon as risk factors for delayed bleeding n (%)

Location of the lesions	Delayed bleeding	Non-bleeding	P value
Cecum	4 (28.6)	19 (6.1)	0.012
Ascending colon	3 (21.4)	55 (17.7)	0.722
Transverse colon	2 (14.3)	49 (15.8)	> 0.999
Descending colon	0 (0)	12 (3.9)	> 0.999
Sigmoid colon	1 (7.1)	58 (18.6)	0.479
Rectum	4 (28.6)	118 (37.9)	0.581

Table 5 Multivariate analysis of risk factors for delayed bleeding

Variable	OR (95%CI)	P value
Lesion size (per mm)	1.02 (0.99-1.05)	0.212
Location in the cecum (yes vs no)	7.26 (1.99-26.55)	0.003
Significant bleeding during ESD (yes vs no)	16.41 (2.60-103.68)	0.003

ESD: Endoscopic submucosal dissection.