Endoscopic management of occluded metal biliary stents: Metal versus 10F plastic stents

Table 1 Costs of procedures and stents in US dollars¹

	Year
	2000	2001	2002	2003	2004	2005	2006	2007	2008	2009
ERCP	56.45	53.69	53.62	58.14	62.18	71.57	79.48	83.61	76.89	71.45
ERBD	175.48	153.70	153.50	166.46	178.02	204.88	227.50	239.33	204.24	178.73
PTBD	91.66	81.60	81.48	88.37	94.51	108.77	120.77	127.06	150.52	168.09
PTBD tube change	26.65	34.61	34.57	37.49	40.09	46.14	51.23	53.90	67.71	77.82
SEMS	697.80	611.19	628.53	661.92	689.23	770.21	825.67	810.86	688.32	641.93
PS	60.47	52.96	54.46	57.36	59.72	66.74	71.55	74.02	59.55	55.54

¹Costs converted from Korean won to US dollars according to annual medical fee schedules and the annual average exchange rate. ERCP: Endoscopic retrograde cholangiopancreatography; ERBD: Endoscopic retrograde biliary drainage; PTBD: Percutaneous transhepatic biliary drainage; SEMS: Self-expandable metal stent; PS: Plastic stent.

Table 2 Patient characteristics

	SEMS group	PS group	P value
No. of patients	29	27
Gender (M:F)	18:11	19:8	0.512
Age at initial SEMS insertion, median (yr)	66	66	0.352
Diagnoses			0.277
Pancreatic cancer	15	6
Common bile duct cancer	3	5
Hilar cholangiocarcinoma	4	4
Gallbladder cancer	3	6
Metastatic lymph nodes	3	2
Ampulla of Vater cancer	1	3
Hepatocellular carcinoma	0	1
Anti-cancer therapy	21	15	0.188

SEMS: Self-expandable metal stent; PS: Plastic stent.

Table 3 Comparison of self-expandable metal stent and plastic stent in subsequent endoscopic retrograde biliary drainage (mean ± SD) n (%)

	SEMS group (n = 29)	PS group (n = 27)	P value
Follow-up period, median (d)	200	133	0.993
Stent occlusion	16 (55.2)	18 (66.7)	0.379
Time to stent occlusion, median (d)1	186	101	0.118
Overall stent patency, median (d)1,2	79	66	0.379
No. of additional biliary drainage procedures	2.54 ± 4.12	1.85 ± 1.95	0.457
Total cost of subsequent biliary drainage procedures ($)	410.04 ± 692.60	630.16 ± 671.63	0.260
Survival after subsequent ERBD, median (d)1	200	133	0.225

¹Results of log-rank test;

²Period between stent insertion and stent occlusion or death of the patient. SEMS: Self-expandable metal stent; PS: Plastic stent; ERBD: Endoscopic retrograde biliary drainage.

Table 4 Univariate analysis of factors associated with time to second stent occlusion

Factor	Time to second stent occlusion, median (d)	P value
Sex		0.273
Male (n = 37)	103
Female (n = 19)	137
Age at initial SEMS insertion (yr)		0.697
≥ 65 (n = 31)	137
< 65 (n = 25)	104
Diagnosis		0.363
Pancreatic cancer (n = 21)	137
Others (n = 35)	103
Biliary drainage prior to initial SEMS insertion		0.924
Yes (n = 24)	137
No (n = 32)	104
Cause of initial SEMS occlusion		0.008
Ingrowth (n = 44)	101
Not ingrowth (n = 12)	268
Anti-cancer therapy		0.444
Yes (n = 36)	137
No (n = 20)	103
Cholangitis on initial SEMS occlusion		0.244
Yes (n = 33)	103
No (n = 23)	186
Covered initial SEMS		0.918
Yes (n = 4)	186
No (n = 52)	104

Results of log-rank test. SEMS: Self-expandable metal stent.