New anti-reflux plastic stent to reduce the risk of stent-related cholangitis in the treatment of biliary strictures

Table 1 Detailed characteristics of patients in the anti-reflux plastic stent group and traditional plastic stent group

	ARPS group	TPS group	P value
Patients, n	67	66	-
Sex, male/female	39/28	37/29	0.8023
Age, yr1	63.4 (16.6); [24-99]	65.4 (14.7); [31-93]	0.2254
Etiologies			0.3243
MBS	48	42
BBS	19	24
Preoperative liver function test results2
Total bilirubin, mmol/L	126.0 (196.9); [7.2-523.3]	156.1 (224.3); [6.8-536.5]	0.7875
Direct bilirubin, mmol/L	117.3 (163.5); [2.1-417.7]	136.1 (217.9); [2.3-456.3]	0.8225
Alkaline phosphatase, IU/L	401.0 (456.0); [75.0-2240.0]	408.0 (400.7); [77.0-1928.0]	0.3025
Glutamyl-transpeptidase, IU/L	558.0 (543.0); [25.0-2067.0]	421.0 (546.7); [19.0-2488.0]	0.0915
Cholecystectomy history	14 (20.9%)	22 (33.3%)	0.1063
Cholangitis prior to ERCP	8 (11.9%)	15 (22.7%)	0.1003
Cholelithiasis	11 (16.4%)	16 (24.2%)	0.2623
Duodenal parapapillary diverticulum	4 (6.0%)	4 (6.1%)	1.0006
Endoscopic sphincterotomy	42 (62.7%)	38 (57.6%)	0.5473
Stricture location, proximal/distal	12/55	11/55	0.8503
Stent length, cm2	7.0 (3.0); [5.0-12.0]	7.0 (4.0); [5.0-14.0]	0.6925

¹Mean (standard deviation) [range].

²Median (interquartile range) [range].

³Chi-squared test.

⁴Student’s t test.

⁵Mann-Whitney U test.

⁶Fisher’s exact test. ARPS: Anti-reflux plastic stent; TPS: Traditional plastic stent; ERCP: Endoscopic retrograde cholangiopancreatography; MBS: Malignant biliary stricture; BBS: Benign biliary stricture.

Table 2 Etiologies of strictures in the anti-reflux plastic stent group and traditional plastic stent group

	Etiologies	ARPS group, n = 67	TPS group, n = 66	Total, n = 133	P value
MBS		48	42	90
	Pancreatic carcinoma	19	13	32	0.5651
	Cholangiocarcinoma	7	9	16
	Ampullary carcinoma	8	5	13
	Duodenal papilla carcinoma	7	7	14
	Metastatic carcinoma	5	8	13
	Gallbladder carcinoma	2	0	2
BBS		19	24	43
	Postoperative injury	11	12	23	0.9141
	Chronic pancreatitis	6	8	14
	Others	2	4	6

¹Fisher’s exact test. ARPS: Anti-reflux plastic stent; TPS: Traditional plastic stent; MBS: Malignant biliary stricture; BBS: Benign biliary stricture.

Table 3 Outcomes in the anti-reflux plastic stent group and traditional plastic stent group

	ARPS group, n = 67	TPS group, n = 66	P value
ERCP-related complications, n (%)	5 (7.5)	3 (4.5)	0.7184
Pancreatitis	4 (6.0)	2 (3.0)	1.0004
MBS/BBS	3/1	1/1
Cholangitis	1 (1.5)	1 (1.5)	1.0004
MBS/BBS	1/0	1/0
Stent-related cholangitis, n (%)	8 (11.9)	18 (27.3)	0.0303
MBS	7 (14.6)	13 (31.0)	0.0783
BBS	1 (5.3)	5 (20.8)	0.2053
Stent-related cholangitis, frequencies			0.1154
0	59	48
1	6	12
2	2	5
3	0	1
Time till the onset of first stent-related cholangitis, d1	128.5 (197.5); [65.0-347.0]	76.0 (72.8); [5.0-337.0]	0.0395
Stent distal migration, n (%)	3 (4.5)	4 (6.0)	0.7184
MBS/BBS	2/1	2/2
Stent dysfunction, n (%)	44 (65.7)	52 (78.8)	0.0913
MBS/BBS	29/15	33/19
Stent patency, d2	185.0 (8.6); [168.2-201.8]	133.0 (16.9); [99.8-166.2]	0.0016
MBS	173.0 (32.0); [110.3-235.7]	98.0 (11.6); [75.3-120.7]	0.0086
BBS	210.0 (23.8); [163.4-256.6]	155.0 (6.0); [143.3-166.8]	0.0496

¹Median (interquartile range) [range].

²Median (standard error) [95% confidence interval].

³Chi-squared test.

⁴Fisher’s exact test.

⁵Mann-Whitney U test.

⁶Log-rank test. ARPS: Anti-reflux plastic stent; TPS: Traditional plastic stent; ERCP: Endoscopic retrograde cholangiopancreatography; MBS: Malignant biliary stricture; BBS: Benign biliary stricture.