Comparison of outcomes among secondary covered metallic, uncovered metallic, and plastic biliary stents in treating occluded primary metallic stents in malignant distal biliary obstruction.
BACKGROUND
The self-expandable metallic stent (SEMS) has been widely used for unresectable malignant biliary obstruction but eventually becomes occluded by tumor ingrowth/overgrowth and sludge. Therefore, we aimed to determine the therapeutic effectiveness of secondary stents and to find differences according to various combinations of the first and second stents for the management of occluded SEMSs in patients with malignant distal biliary obstruction.


METHODS
Between 1999 and November 2008, 77 patients with malignant biliary obstruction underwent secondary biliary stent placement as "stent-in-stent" at three university hospitals in Korea (40 covered, 26 uncovered, and 11 plastic stents). The membrane of the covered SEMS was regarded as the barrier against tumor ingrowth. We categorized the patients into three groups based on whether the covered SEMS was either the first or the second stent: membrane-SEMS (18 covered-covered; 9 covered-uncovered; 22 uncovered-covered SEMS), bare-SEMS (17 uncovered-uncovered SEMS), and plastic stent (3 covered-plastic; 8 uncovered-plastic).


RESULTS
The median patency of second stents was 138, 109, and 88 days (covered, uncovered, and plastic stents). The second covered SEMSs had a significantly longer patency than plastic stents (p=0.047). In a multivariate analysis including membrane-SEMS, bare-SEMS, and plastic stent groups, the bare-SEMS had a worse cumulative stent patency (HR=2.04, CI=1.08-3.86) and survival time (HR=2.37, CI=1.25-4.49) than the membrane-SEMS. Patients with ampulla of Vater cancer had better stent patency (HR=0.27, CI=0.08-0.98) and survival (HR=0.17, CI=0.04-0.77) than those with other pancreatobiliary malignancies. In addition, antitumor treatment prolonged survival time (HR=0.50, CI=0.26-0.99).


CONCLUSIONS
The placement of additional biliary stents using the "stent-in-stent" method is an effective treatment for an occluded metallic primary stent. In addition, double biliary SEMS placement using at least one covered SEMS (in the primary and/or secondary procedure) might provide longer cumulative stent patency and survival than using uncovered SEMSs in both procedures.
Cho
Jae Hee
JH
Department of Internal Medicine, Graduate School, Yonsei University College of Medicine, and Sanggye Paik Hospital, 250 Seongsanno (134 Sinchon-Dong), Seodaemun-Ku, 120-752, Seoul, South Korea.
Jeon
Tae Joo
TJ
Park
Jeong Youp
JY
Kim
Hee Man
HM
Kim
Yoon Jae
YJ
Park
Seung Woo
SW
Chung
Jae Bock
JB
Song
Si Young
SY
Bang
Seungmin
S
D000368:Aged; D000369:Aged, 80 and over; D001661:Biliary Tract Neoplasms / Q000150:complications / Q000473:pathology*; D002780:Cholestasis, Intrahepatic / Q000401:mortality / Q000473:pathology* / Q000601:surgery*; D020099:Coated Materials, Biocompatible; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D008670:Metals; D008875:Middle Aged; D009367:Neoplasm Staging; D010166:Palliative Care / Q000379:methods; D010969:Plastics; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D011475:Prosthesis Failure; D019919:Prosthesis Implantation / Q000379:methods*; D012086:Reoperation; D012189:Retrospective Studies; D018570:Risk Assessment; D015607:Stents; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome
D020099:Coated Materials, Biocompatible; D008670:Metals; D010969:Plastics