Predictive factors for the failure of endoscopic stent-in-stent self-expandable metallic stent placement to treat malignant hilar biliary obstruction

Table 1 Comparison of the characteristics and the target biliary duct status of patients in the success and failure groups

	Success (n = 49)	Failure (n = 13)	P value
Age, median (range), yr	74 (42-88)	71 (16-76)	0.45
Sex (male), n (%)	33 (67.3)	8 (61.5)	0.75
Diagnoses
Primary lesion (Biliary tract or pancreatic cancer)	40	10	0.70
Metastases	9	3
Pancreatic cancer	1
Lung cancer	1
Tracheal cancer	1
Colon cancer	3	2
Uterine cancer	1
Gastric cancer	1	1
Prostatic cancer	1
Bismuth classification			0.98
II	12	3
III	18	5
IV	19	5
Target biliary duct status,
Diameter of the target biliary duct, median (range), mm	6.4 (2.0-15.9)	6.6 (4.4-17.3)1	0.45
Diameter of the target biliary stricture, median (range), mm	0 (0-1.6)	0 (0-0.9)	0.94
Diameter of the first implanted SEMS, median (range), mm	5.8 (3.1-11.7)	6.7 (3.4-12.6)	0.25
Length of the target biliary stricture, median (range), mm	11.0 (3.0-69.6)	7.9 (1.7-34.2)1	0.44
Angle between the target biliary duct stricture and the first implanted SEMS, median (range), degree	44.4 (7-119)	75.3 (28-109.3)1	< 0.01

¹Data of one of the patient were not available. SEMS: Self-expandable metallic stent.