Gastroenterol Res

Gastroenterology Research, ISSN 1918-2805 print, 1918-2813 online, Open Access

Article copyright, the authors; Journal compilation copyright, Gastroenterol Res and Elmer Press Inc

Journal website https://gr.elmerpub.com

Original Article

Volume 18, Number 4, August 2025, pages 192-201

Endoscopic Biliary Drainage in Malignant Biliary Strictures: A Prospective Analysis Based on Real-World Data

Figure 1. Multivariate Cox regression model for predicting variables associated with stent dysfunction in patients with malignant biliary stricture. Variables with statistical significance in the univariate model (represented in red) were applied in the multivariate model, which are represented in blue. For patients with malignant stenosis, the height of the distal stenosis is designated as the reference point. This distinction is vital for understanding the analyses and interpretations presented in the study, as it underscores the importance of comparing results across different statistical models. Such clarity enhances the reader’s ability to interpret the findings meaningfully and informs subsequent discussions on the implications of the data.

Figure 2. Multivariate Cox regression model for predicting variables associated with mortality in patients with malignant biliary stricture. Variables with statistical significance in the univariate model (represented in red) were applied in the multivariate model, which are represented in blue. For patients with malignant stenosis, the height of the distal stenosis is designated as the reference point. This distinction is vital for understanding the analyses and interpretations presented in the study, as it underscores the importance of comparing results across different statistical models. Such clarity enhances the reader’s ability to interpret the findings meaningfully and informs subsequent discussions on the implications of the data.

**Table 1.** Characteristic of Patients With Malignant Biliary Stenosis Based on Location of the Malignant Biliary Stricture
Variable	Total	Distal stenosis (n = 109)	Hilar stenosis (n = 38)	P-value
*P < 0.05. ERCP: endoscopic retrograde cholangiopancreatography; IQR: interquartile range; NET: neuroendocrine tumor.
Age (years) (IQR)	70.5 (60 - 78)	72 (61 - 79)	66 (55 - 73)	0.03*
Sex				0.414
Male	69 (46.9%)	49 (44.9%)	20 (52.6%)
Female	78 (53.1%)	60 (55.1%)	18 (47.4%)
Diagnosis				0.031*
Pancreas cancer	68 (46.3%)	64 (58.7%)	4 (10.5%)
Cholangiocarcinoma	54 (36.7%)	27 (25.7%)	27 (71.1%)
Gallblader cancer	6 (4.1%)	3 (2.8%)	3 (7.9%)
Ampulla carcinoma	7 (4.8%)	7 (6.4%)	0
NET	2 (1.4%)	2 (1.8%)	0
Metastasis	7 (4.8%)	2 (1.8%)	5 (13.2%)
High-grade lymphoma	3 (2.0%)	3 (2.8%)	0
Type of biliary stent				0.226
Plastic stent	128 (87.1%)	96 (88.8%)	35 (92.1%)
Metalic stent	19 (12.9%)	13 (11.2%)	3 (7.9%)
Succesful functional drainage				0.050*
Yes	109 (74.1%)	85 (77.9%)	24 (63.2%)
No	38 (34.8%)	24 (22.0%)	14 (36.8%)
Succesful technical deployment				0.001*
Yes	118 (80.3%)	104 (95.4%)	13 (34.2%)
No	29 (19.7%)	5 (4.6%)	25 (65.8%)
Total bilirrubin (mg/dL) (IQR)	17 (12 - 22.9)	17.5 (12 - 23.1)	15.2 (10.2 - 22.4)	0.686
CA19-9 (U/mL)	337 (61 - 1,515)	219 (42 - 1,425)	679 (35 - 1,945)	0.018*
ERCP complication				0.002*
Yes	29 (19.7%)	15 (13.7%)	14 (36.8%)
No	118 (80.3%)	94 (86.2%)	24 (63.2%)
Stent dysfunction				0.005*
Yes	69 (46.9%)	46 (42.2%)	23 (60.5%)
No	78 (53.1%)	63 (57.8%)	15 (39.5%)
Mortality	64 (43.5%)	46 (42.2%)	18 (47.4%)	0.003*

Table 1. Characteristic of Patients With Malignant Biliary Stenosis Based on Location of the Malignant Biliary Stricture

Variable

Total

Distal stenosis (n = 109)

Hilar stenosis (n = 38)

P-value

*P < 0.05. ERCP: endoscopic retrograde cholangiopancreatography; IQR: interquartile range; NET: neuroendocrine tumor.

Age (years) (IQR)

70.5 (60 - 78)

72 (61 - 79)

66 (55 - 73)

0.03*

Sex

0.414

Male

69 (46.9%)

49 (44.9%)

20 (52.6%)

Female

78 (53.1%)

60 (55.1%)

18 (47.4%)

Diagnosis

0.031*

Pancreas cancer

68 (46.3%)

64 (58.7%)

4 (10.5%)

Cholangiocarcinoma

54 (36.7%)

27 (25.7%)

27 (71.1%)

Gallblader cancer

6 (4.1%)

3 (2.8%)

3 (7.9%)

Ampulla carcinoma

7 (4.8%)

7 (6.4%)

NET

2 (1.4%)

2 (1.8%)

Metastasis

7 (4.8%)

2 (1.8%)

5 (13.2%)

High-grade lymphoma

3 (2.0%)

3 (2.8%)

Type of biliary stent

0.226

Plastic stent

128 (87.1%)

96 (88.8%)

35 (92.1%)

Metalic stent

19 (12.9%)

13 (11.2%)

3 (7.9%)

Succesful functional drainage

0.050*

Yes

109 (74.1%)

85 (77.9%)

24 (63.2%)

38 (34.8%)

24 (22.0%)

14 (36.8%)

Succesful technical deployment

0.001*

Yes

118 (80.3%)

104 (95.4%)

13 (34.2%)

29 (19.7%)

5 (4.6%)

25 (65.8%)

Total bilirrubin (mg/dL) (IQR)

17 (12 - 22.9)

17.5 (12 - 23.1)

15.2 (10.2 - 22.4)

0.686

CA19-9 (U/mL)

337 (61 - 1,515)

219 (42 - 1,425)

679 (35 - 1,945)

0.018*

ERCP complication

0.002*

Yes

29 (19.7%)

15 (13.7%)

14 (36.8%)

118 (80.3%)

94 (86.2%)

24 (63.2%)

Stent dysfunction

0.005*

Yes

69 (46.9%)

46 (42.2%)

23 (60.5%)

78 (53.1%)

63 (57.8%)

15 (39.5%)

Mortality

64 (43.5%)

46 (42.2%)

18 (47.4%)

0.003*

**Table 2.** Characteristic of Patients With Biliary Malignant Strictures According to Stricture Location and Type of Stent
Variable	High stricture (n = 38)	P-value	Lower stricture (n = 109)	P-value
*P < 0.05. ERCP: endoscopic retrograde cholangiopancreatography; PS: plastic stents; uSEMS: uncovered self-expanding metal stents.
Pancreas cancer			0.572			0.532
Resecable	0	0		19 (17.4%)	0
Irresecable	1 (2.6%)	3 (7.9%)		36 (33.0%)	9 (8.3%)
Borderline	0	0		6 (5.5%)	1 (0.9%)
Cholangiocarcinoma			0.342			0.453
Distal	0	0		5 (4.6%)	0
I	0	0		18 (22.9%)	2 (1.8%)
II	10 (26.3%)	1 (2.6%)		1 (0.9%)	0
IIIA	3 (7.9%)	0		0	0
IIIB	3 (7.9%)	1 (2.6%)		0	0
IV	8 (28.9%)	1 (2.6%)		0	0
NA	0	0		1 (0.9%)	0
ERCP complication
Bleeding	2 (5.7%)	1 (33.3%)	0.075	5 (4.6%)	0	0.032*
Bacteremia	8 (22.8%)	0		3 (2.7%)	0
Perforation	1 (2.9%)	0		1 (0.9%)	0
Pancreatitis	2 (5.7%)	0		5 (4.6%)	1 (7.7%)
No	22 (62.9%)	2 (66.7%)		82 (75.2%)	12 (92.3%)
Stent diameter			0.121			0.005*
7 Fr	5 (14.3%)	0		2 (1.8%)	0
8.5 Fr	20 (57.1%)	0		20 (18.3%)	0
10 Fr	10 (28.5%)	0		74 (67.8%)	0
30 Fr	0	3 (100%)		0	13 (11.9%)
Patency (days)	28 (4 - 37)	84 (84 - 84)	0.333	86 (38 - 139)	249 (150 - 250)	0.0001*
Stent dysfunction
Migration	7 (21.2%)	0	0.146	16 (14.7%)	0	0.455
Obstruction	15 (45.4%)	1 (33.3%)		24 (22.0%)	5 (38.4%)
Perforation	0	0		1 (0.9%)	0
No	13 (33.3%)	2 (66.7%)		55 (50.5%)	8 (61.5%)
Succesful technical deployment						0.089
Yes	11 (31.4%)	2 (66.7%)	0.487	91 (94.7%)	13 (100%)
No	24 (68.5%)	1 (33.3%)		5 (5.2%)	0
Succesful functional deployment						0.050*
Yes	25 (71.4%)	3 (100%)	0.322	74 (77.1%)	11 (84.6%)
No	10 (28.5%)	0		22 (22.9%)	2 (15.4%)

Table 2. Characteristic of Patients With Biliary Malignant Strictures According to Stricture Location and Type of Stent

Variable

High stricture (n = 38)

P-value

Lower stricture (n = 109)

P-value

PS (n = 35)

uSEMS (n = 3)

PS (n = 109)

uSEMS (n = 13)

*P < 0.05. ERCP: endoscopic retrograde cholangiopancreatography; PS: plastic stents; uSEMS: uncovered self-expanding metal stents.

Pancreas cancer

0.572

0.532

Resecable

19 (17.4%)

Irresecable

1 (2.6%)

3 (7.9%)

36 (33.0%)

9 (8.3%)

Borderline

6 (5.5%)

1 (0.9%)

Cholangiocarcinoma

0.342

0.453

Distal

5 (4.6%)

18 (22.9%)

2 (1.8%)

10 (26.3%)

1 (2.6%)

1 (0.9%)

IIIA

3 (7.9%)

IIIB

3 (7.9%)

1 (2.6%)

8 (28.9%)

1 (2.6%)

1 (0.9%)

ERCP complication

Bleeding

2 (5.7%)

1 (33.3%)

0.075

5 (4.6%)

0.032*

Bacteremia

8 (22.8%)

3 (2.7%)

Perforation

1 (2.9%)

1 (0.9%)

Pancreatitis

2 (5.7%)

5 (4.6%)

1 (7.7%)

22 (62.9%)

2 (66.7%)

82 (75.2%)

12 (92.3%)

Stent diameter

0.121

0.005*

7 Fr

5 (14.3%)

2 (1.8%)

8.5 Fr

20 (57.1%)

20 (18.3%)

10 Fr

10 (28.5%)

74 (67.8%)

30 Fr

3 (100%)

13 (11.9%)

Patency (days)

28 (4 - 37)

84 (84 - 84)

0.333

86 (38 - 139)

249 (150 - 250)

0.0001*

Stent dysfunction

Migration

7 (21.2%)

0.146

16 (14.7%)

0.455

Obstruction

15 (45.4%)

1 (33.3%)

24 (22.0%)

5 (38.4%)

Perforation

1 (0.9%)

13 (33.3%)

2 (66.7%)

55 (50.5%)

8 (61.5%)

Succesful technical deployment

0.089

Yes

11 (31.4%)

2 (66.7%)

0.487

91 (94.7%)

13 (100%)

24 (68.5%)

1 (33.3%)

5 (5.2%)

Succesful functional deployment

0.050*

Yes

25 (71.4%)

3 (100%)

0.322

74 (77.1%)

11 (84.6%)

10 (28.5%)

22 (22.9%)

2 (15.4%)