What can be the criteria of outpatient-based endoscopic resection for colon polyp?

Table 1 Baseline characteristics of patients with colon polyps removed by endoscopic mucosal resection n (%)

	n = 3015
Age, mean ± SD, yr	59.6 ± 10.4
Male	1771 (70.0)
Comorbidity
Hypertension	564 (18.7)
Cardiovascular or cerebrovascular disease	389 (12.9)
Chronic renal failure	23 (0.8)
Liver cirrhosis	75 (2.5)
Diabetes mellitus	157 (5.2)
Cancer history	353 (11.7)
Anti-coagulants and anti-platelets
Aspirin	253 (8.3)
Clopidogrel	57 (1.9)
Warfarin	43 (1.4)
Size of lesion, mean ± SD, mm	11.1 ± 6.8
Locations
Right side colon	1296 (43.0)
Cecum	109 (3.6)
Ascending colon	805 (26.7)
Transverse colon	382 (12.7)
Left side colon	1719 (57.0)
Descending colon	346 (11.5)
Sigmoid colon	817 (25.9)
Rectum	556 (18.4)
Morphologic classification
Pedunculated type	550 (18.2)
Piecemeal resection	130 (4.3)
Pathologic complete resection	2956 (98.0)
Horizontal margin involvement	31 (1.0)
Vertical margin involvement	10 (0.3)
Serious immediate bleeding1	78 (2.6)
Prophylactic hemostatic clipping	345 (11.4)
Delayed bleeding	25 (0.8)
Spurting, n	2
Oozing, n	13
Clots with or without vessel exposure, n	10
Onset of delayed post-EMR bleeding, mean ± SD (range), h	9.9 ± 0.4
	(7-72)
Perforation	6 (0.2)
Histology
Adenoma	2357 (78.2)
Tubular adenoma	2026 (67.2)
Tubulovillous adenoma	233 (7.7)
Villous adenoma	99 (3.3)
Serrated adenoma	66 (2.2)
Carcinoma	89 (3.0)
Submucosal invasive carcinoma	10 (0.3)
Hyperplastic polyp	413 (13.6)
Others	90 (3.0)

¹Serious immediate bleeding was defined as bleeding which required hemostatic clip application just after EMR. EMR: Endoscopic mucosal resection.