Fully covered metal biliary stents confer a higher risk of post-endoscopic retrograde cholangiopancreatography pancreatitis

Table 1 Baseline characteristics by type of stent, n (%)

	No stent (n = 1979)	Plastic (n = 984)	FCSEMS (n = 319)	UCSEMS (n = 154)
Age, mean ± SD, years	63.5 ± 18.1	63.9 ± 17.2	66.6 ± 15.8	70.7 ± 12.1
Female	1127 (57)	506 (51)	148 (46)	62 (40)
Indication
Benign	1888 (95)	835 (85)	186 (58)	1 (1)
Malignant	91 (5)	149 (15)	133 (42)	153 (99)
Intact papilla	1123 (57)	613 (62)	193 (61)	93 (60)
Sphincterotomy
Precut sphincterotomy	70 (4)	47 (5)	11 (3)	6 (4)
Biliary sphincterotomy	1040 (53)	593 (60)	190 (60)	85 (55)
Sphincteroplasty	114 (6)	81 (8)	20 (6)	5 (3)
PEP prophylaxis
Rectal indomethacin	514 (26.0)	270 (27.4)	77 (24.1)	30 (19.5)
PD stent	152 (7.7)	132 (13.4)	34 (10.7)	2 (1.3)

FCSEMS: Fully covered self-expanding metal stents; PD: Pancreatic duct stent; PEP: Post-endoscopic retrograde cholangiopancreatography pancreatitis; UCSEMS: Uncovered self-expanding metal stents; SD: Standard deviation.

Table 2 Adverse events, n (%)

	Overall (n = 3397)	No stent (n = 1979)	Plastic (n = 984)	FCSEMS (n = 319)	UCSEMS (n = 154)
PEP	107 (3.1)	47 (2.4)	33 (3.4)	25 (7.8)	6 (3.9)
Mild	57	30	14	11	3
Moderate	37	12	13	11	2
Severe	13	5	6	3	1
Stent migration	57 (1.7)	NA	29 (2.9)	27 (8.5)	1 (0.1)
Proximal	17		8	8	1
Distal	40		21	19	0
Cholangitis	66 (1.9)	26 (1.3)	18 (1.8)	17 (5.3)	9 (5.8)
Perforation	9 (0.3)	5 (0.3)	2 (0.2)	2 (0.6)	0 (0)
Death	4 (0.1)	2 (0.1)	2 (0.2)	0 (0)	0 (0)

FCSEMS: Fully covered self-expanding metal stents; NA: Not available; PEP: Post-endoscopic retrograde cholangiopancreatography pancreatitis; UCSEMS: Uncovered self-expanding metal stents.

Table 3 Predictors of post-endoscopic retrograde cholangiopancreatography pancreatitis in all patients

Variable	Odds ratio	95% confidence interval	P value
Age < 50 years	0.43	0.07-1.54	0.263
Female sex	0.89	0.43-1.86	0.757
Intact papilla	1.81	0.86-3.84	0.120
Precut sphincterotomy	2.73	0.57-9.87	0.155
Biliary sphincterotomy	1.30	0.41-4.19	0.661
Sphincteroplasty1	4.20	1.38-11.44	0.007
Rectal indomethacin	1.34	0.55-3.07	0.500
Pancreatic duct stent	1.40	0.38-4.05	0.566
FCSEMS placement1	5.49	2.10-16.99	0.001
UCSEMS placement	3.19	0.63-13.00	0.12
Plastic stent placement	1.45	0.45-3.99	0.49

¹Significant predictor of post-endoscopic retrograde cholangiopancreatography pancreatitis on multivariate analysis.

FCSEMS: Fully covered self-expanding metal stents; UCSEMS: Uncovered self-expanding metal stents.

Table 4 Comparison of baseline characteristics after propensity score matching, n (%)

	Unmatched cohort			Matched cohort
	FCSEMS (n = 319)	Non-FCSEMS (n = 3082)	SMD	FCSEMS (n = 319)	Non-FCSEMS (n = 319)	SMD
Age, mean ± SD, years	66.6 ± 15.8	63.2 ± 18.3	0.198	66.6 ± 15.8	66.9 ± 15.2	0.021
Female	148 (46)	1682 (55)	0.165	148 (46)	150 (47)	0.031
Benign indication	186 (58)	1800 (58)	0.708	186 (58)	203 (64)	0.109
Biliary sphincterotomy	190 (60)	1710 (56)	0.087	190 (60)	171 (54)	0.120
Precut sphincterotomy	11 (4)	222 (7)	0.027	11 (4)	23 (7)	0.168
Sphincteroplasty	20 (6)	155 (5)	0.004	20 (6)	16 (5)	0.054
Rectal indomethacin	77 (24)	820 (27)	0.047	77 (24)	85 (27)	0.058
PD stent	34 (11)	0 (0)	0.050	34 (11)	0 (0)	0.050

FCSEMS: Fully covered self-expanding metal stents; PD: Pancreatic duct stent; SD: Standard deviation; SMD: Standardized mean difference.

Table 5 Predictors of post-endoscopic retrograde cholangiopancreatography pancreatitis following fully covered self-expanding metal stent placement (n = 319)

Variable	Odds ratio	95% confidence interval	P value
Age < 50 years	0.49	0.07-1.92	0.369
Female sex	0.67	0.27-1.61	0.368
Benign indication	1.30	0.50-3.52	0.593
Intact papilla	0.35	0.09-1.43	0.143
Precut sphincterotomy1	6.48	1.17-30.32	0.021
Biliary sphincterotomy	1.19	0.31-4.41	0.795
Sphincteroplasty1	3.70	0.99-12.59	0.041
Rectal indomethacin	1.07	0.34-2.93	0.904
Pancreatic duct stent	2.33	0.58-7.71	0.190

¹Significant predictor of post-endoscopic retrograde cholangiopancreatography pancreatitis on multivariate analysis.