Intra-biliary cleansing during secondary duodenoscopic removal of duodenal bend biliary stents: A retrospective cohort study

Table 1 Baseline patient demographics and disease characteristics, n (%)

Variable	Total (n = 546)	SPBSG (n = 228)	DBBSG (n = 318)	P value
Age, median (Q1, Q3)	62.00 (51.00, 70.00)	61.00 (51.00, 69.00)	62.00 (51.00, 71.00)	0.320
Sex				0.875
Female	290 (53.11)	122 (53.51)	168 (52.83)
Male	256 (46.89)	106 (46.49)	150 (47.17)
BMI (kg/m²), median (Q1, Q3)	21.56 (20.07, 23.23)	21.83 (20.07, 23.23)	21.30 (19.84, 23.23)	0.501
TC, median (Q1, Q3)	4.34 (3.65, 5.25)	4.27 (3.58, 5.14)	4.43 (3.71, 5.26)	0.116
TG, median (Q1, Q3)	1.19 (0.87, 1.72)	1.16 (0.86, 1.63)	1.20 (0.88, 1.87)	0.222
Duodenal papilla length (cm), median (Q1, Q3)	1.00 (0.78, 1.30)	1.02 (0.80, 1.39)	1.00 (0.76, 1.30)	0.111
Length of EST incision (mm), median (Q1, Q3)	3.00 (2.00, 3.58)	2.40 (1.00, 3.00)	3.00 (2.00, 4.00)	< 0.001
Diameter of EPBD (mm), median (Q1, Q3)	6.00 (6.00, 7.80)	6.00 (6.00, 7.12)	6.00 (6.00, 8.00)	0.888
Time (week), median (Q1, Q3)	11.00 (7.00, 14.00)	12.00 (7.25, 14.00)	11.00 (7.00, 14.00)	0.010
EST				< 0.001
No	139 (25.46)	78 (34.21)	61 (19.18)
Yes	407 (74.54)	150 (65.79)	257 (80.82)
EPBD				0.162
No	82 (15.02)	40 (17.54)	42 (13.21)
Yes	464 (84.98)	188 (82.46)	276 (86.79)
Diameter of the stents				< 0.001
5 Fr	35 (6.41)	35 (15.35)	0 (0)
7 Fr	193 (35.35)	172 (75.44)	21 (6.6)
8.5 Fr	105 (19.23)	19 (8.33)	86 (27.04)
10 Fr	213 (39.01)	2 (0.88)	211 (66.35)
Hyperlipidaemia				0.070
No	474 (86.81)	205 (89.91)	269 (84.59)
Yes	72 (13.19)	23 (10.09)	49 (15.41)
DM				0.100
No	481 (88.10)	207 (90.79)	274 (86.16)
Yes	65 (11.90)	21 (9.21)	44 (13.84)
CHD				0.408
No	504 (92.31)	213 (93.42)	291 (91.51)
Yes	42 (7.69)	15 (6.58)	27 (8.49)
Fatty liver				0.414
No	486 (89.01)	200 (87.72)	286 (89.94)
Yes	60 (10.99)	28 (12.28)	32 (10.06)
Gallstones				< 0.001
No	264 (48.35)	139 (60.96)	125 (39.31)
Yes	282 (51.65)	89 (39.04)	193 (60.69)
Congenital choledochal cysts				1.000
No	544 (99.63)	227 (99.56)	317 (99.69)
Yes	2 (0.37)	1 (0.44)	1 (0.31)
Extrahepatic bile duct stenosis				0.059
No	484 (88.64)	209 (91.67)	275 (86.48)
Yes	62 (11.36)	19 (8.33)	43 (13.52)
History of pancreatitis				0.327
No	503 (92.12)	207 (90.79)	296 (93.08)
Yes	43 (7.88)	21 (9.21)	22 (6.92)
History of ERCP				0.983
No	460 (84.25)	192 (84.21)	268 (84.28)
Yes	86 (15.75)	36 (15.79)	50 (15.72)
History of cholecystectomy				0.002
No	359 (65.75)	133 (58.33)	226 (71.07)
Yes	187 (34.25)	95 (41.67)	92 (28.93)
History of common bile duct exploration				0.165
No	527 (96.52)	223 (97.81)	304 (95.60)
Yes	19 (3.48)	5 (2.19)	14 (4.40)
DP				0.138
Simple or acute type	301 (55.13)	126 (55.26)	175 (55.03)
Hyperplastic or sclerotic type	118 (21.61)	58 (25.44)	60 (18.87)
Constrictive type	41 (7.51)	13 (5.70)	28 (8.81)
Atrophic type	86 (15.75)	31 (13.60)	55 (17.30)
PAD				0.377
No	384 (70.33)	165 (72.37)	219 (68.87)
Yes	162 (29.67)	63 (27.63)	99 (31.13)
Location of DP to PAD				0.406
Outside	392 (71.79)	168 (73.68)	224 (70.44)
Inside	154 (28.21)	60 (26.32)	94 (29.56)
SOD				0.209
No	477 (87.36)	204 (89.47)	273 (85.85)
Yes	69 (12.64)	24 (10.53)	45 (14.15)
PBM				0.152
No	506 (92.67)	207 (90.79)	299 (94.03)
Yes	40 (7.33)	21 (9.21)	19 (5.97)
PDS				< 0.001
No	256 (46.89)	74 (32.46)	182 (57.23)
Yes	290 (53.11)	154 (67.54)	136 (42.77)
Metal-covered stents				0.239
No	534 (97.80)	221 (96.93)	313 (98.43)
Yes	12 (2.20)	7 (3.07)	5 (1.57)

DBBSG: Duodenal bend biliary stent group; SPBSG: Single pigtail biliary stent group; BMI: Body mass index; TC: Total cholesterol; TG: Total triglycerides; EST: Endoscopic sphincterotomy; EPBD: Endoscopic papillary balloon dilation; ERCP: Endoscopic retrograde cholangiopancreatography; DP: Duodenal papillopathy; DM: Diabetes mellitus; CHD: Coronary heart disease; PAD: Periampullary diverticula; SOD: Sphincter of Oddi dysfunction; PBM: Pancreaticobiliary maljunction; PDS: Pancreatic duct stent.

Table 2 Primary and secondary outcomes, n (%)

Variable	Total (n = 546)	SPBSG (n = 228)	DBBSG (n = 318)	P value
Chyme				< 0.001
No	450 (82.42)	206 (90.35)	244 (76.73)
Yes	96 (17.58)	22 (9.65)	74 (23.27)
CBDS				< 0.001
No	362 (66.30)	180 (78.95)	182 (57.23)
Yes	184 (33.70)	48 (21.05)	136 (42.77)
Acute cholangitis				0.816
No	521 (95.42)	217 (95.18)	304 (95.60)
Yes	25 (4.58)	11 (4.82)	14 (4.40)
Stent displacement				0.335
No	524 (95.97)	221 (96.93)	303 (95.28)
Yes	22 (4.03)	7 (3.07)	15 (4.72)

DBBSG: Duodenal bend biliary stent group; SPBSG: Single pigtail biliary stent group; Chyme: Chyme reflux into the bile duct; CBDS: Common bile duct stones.

Table 3 Incidence of postoperative adverse events in both groups, n (%)

Variable	Total (n = 546)	SPBSG (n = 228)	DBBSG (n = 318)	P value
Post-ERCP acute cholangitis				0.311
No	532 (97.44)	224 (98.25)	308 (96.86)
Yes	14 (2.56)	4 (1.75)	10 (3.14)
PEP				0.418
No	545 (99.82)	227 (99.56)	318 (100.00)
Yes	1 (0.18)	1 (0.44)	0 (0.00)
Bleeding				1.000
No	544 (99.63)	227 (99.56)	317 (99.69)
Yes	2 (0.37)	1 (0.44)	1 (0.31)
Duodenal perforation
No	546 (100)	228 (100)	318 (100)	NA
Yes	0 (0)	0 (0)	0 (0)

DBBSG: Duodenal bend biliary stent group; SPBSG: Single pigtail biliary stent group; ERCP: Endoscopic retrograde cholangiopancreatography; PEP: Post-endoscopic retrograde cholangiopancreatography pancreatitis; NA: Not available.

Table 4 Hazard ratios and 95% confidence interval of chyme reflux into the bile duct according to types of biliary stents

Group	Model 1		Model 2		Model 3
	HR (95%CI)	P value	HR (95%CI)	P value	HR (95%CI)	P value
0	1.00 (reference)	-	1.00 (reference)	-	1.00 (reference)	-
1	2.643 (1.641-4.255)	< 0.001	2.868 (1.774-4.637)	< 0.001	2.793 (1.695-4.603)	< 0.001

Model 1 was unadjusted; model 2 was based on model 1 and additionally adjusted for age, sex, pancreaticobiliary maljunction, and extrahepatic bile duct stricture; model 3 was based on model 2 and further adjusted for duodenal papilla length, length of endoscopic sphincterotomy incision, duodenal papillopathy, sphincter of Oddi dysfunction, metal-covered biliary stents, and diameter of the stents and pancreatic duct stent. HR: Hazard ratio; CI: Confidence interval.

Table 5 Hazard ratios and 95% confidence intervals of common bile duct stones according to types of biliary stents

Group	Model 1		Model 2		Model 3
	HR (95%CI)	P value	HR (95%CI)	P value	HR (95%CI)	P value
0	1.00 (reference)	-	1.00 (reference)	-	1.00 (reference)	-
1	2.275 (1.632-3.172)	< 0.001	2.319 (1.659-3.242)	< 0.001	2.475 (1.732-3.536)	< 0.001

Model 1 was unadjusted; model 2 was based on model 1 and additionally adjusted for age, sex, pancreaticobiliary maljunction, and extrahepatic bile duct stricture; model 3 was based on model 2 and further adjusted for duodenal papilla length, length of endoscopic sphincterotomy incision, duodenal papillopathy, sphincter of Oddi dysfunction, metal-covered biliary stents, and diameter of the stents and pancreatic duct stent. HR: Hazard ratio; CI: Confidence interval.