Recent advances of biliary stent management.

Abstract

Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to increased rates of stent occlusion. Even we employed metallic stents which contributed to higher rates and longer durations of patency, and occlusion of covered metallic stents now occurs in about half of all patients during their survival. We investigated the complication and patency rate for the removal of covered metallic stents, and found that the durations were similar for initial stent placement and re-intervention. In order to preserve patient quality of life, we currently recommend the use of covered metallic stents for patients with malignant biliary obstruction because of their removability and longest patency duration, even though uncovered metallic stents have similar patency durations.

Full text

Page 1

S62
Korean J Radiol 13(Suppl 1), Jan/Feb 2012
kjronline.org
Recent Advances of Biliary Stent Management
Mitsuhiro Kida, MD, PhD, Shiro Miyazawa, MD, Tomohisa Iwai, MD, PhD,
Hiroko Ikeda, MD, PhD, Miyoko Takezawa, MD, PhD, Hidehiko Kikuchi, MD,
Maya Watanabe, MD, PhD, Hiroshi Imaizumi, MD, PhD, Wasaburo Koizumi, MD, PhD
All authors: Department of Gastroenterology, Kitasato University East Hospital, Sagamihara, Kanagawa 228-8520, Japan
Recent progress in chemotherapy has prolonged the survival of patients with malignant biliary strictures, leading to
increased rates of stent occlusion. Even we employed metallic stents which contributed to higher rates and longer durations
of patency, and occlusion of covered metallic stents now occurs in about half of all patients during their survival. We
investigated the complication and patency rate for the removal of covered metallic stents, and found that the durations
were similar for initial stent placement and re-intervention. In order to preserve patient quality of life, we currently
recommend the use of covered metallic stents for patients with malignant biliary obstruction because of their removability
and longest patency duration, even though uncovered metallic stents have similar patency durations.
Index terms: Metallic stent; Stent obstruction; Re-intervention; Biliary stricture; Stent patency
Received October 23, 2011; accepted after revision December 9,
2011.
Corresponding author: Mitsuhiro Kida, MD, PhD, Department
of Gastroenterology, Kitasato University East Hospital, 2-1-1
Asamizodai, Sagamihara, Kanagawa 228-8520, Japan.
• Tel: (8142) 748-9111 • Fax: (8142) 749-8690
• E-mail: m-kida@kitasato-u.ac.jp
This is an Open Access article distributed under the terms of
the Creative Commons Attribution Non-Commercial License
(http://creativecommons.org/licenses/by-nc/3.0) which permits
unrestricted non-commercial use, distribution, and reproduction in
any medium, provided the original work is properly cited.
Review Article
Korean J Radiol 2012;13(S1):S62-S66
http://dx.doi.org/10.3348/kjr.2012.13.S1.S62
pISSN 1229-6929 · eISSN 2005-8330
INTRODUCTION
Since the initial report by Soehendra et al. (1), the
outcomes of endoscopic retrograde biliary drainage have
improved considerably with the development of large-
bore, metallic, and covered metallic stents. However, this
improvement has contributed to higher rates and longer
patency durations (2-11). Recent progress in chemotherapy
has prolonged the survival of patients with unresectable
malignant tumors associated with biliary obstruction (12-
15). The patency period of even metallic stents is shorter
than required, and about half of all patients now require
the placement of 2 or 3 stents during their lifetime.
Many studies concerning the management of occluded
or dislocated biliary stents have been reported (16-22).
Mechanical cleaning with a balloon and “stent-in-stent”
placement with a plastic tube or other devices have been
performed, but the patency duration was rather short. The
removal of metallic stents has been sporadically reported,
suggesting that stent removal followed by replacement may
be one way to manage occluded or dislocated stents (23-
29). We investigated the patency durations and rates of the
first stent as well as re-intervention, success rates of stent
removal, and complications, especially for the management
of patients with malignant biliary obstruction who have
survived more than the stent patency duration.
Necessity of Stent Exchange
Remarkable progress has been recently made in the
chemotherapy and radiotherapy of unresectable malignant
tumors of the biliary tract and pancreas, which has led to

Page 2

Korean J Radiol 13(Suppl 1), Jan/Feb 2012
kjronline.orgS63
Recent Advances of Biliary Stent Management
increasing numbers of long-term survivors. Although the
patency duration of metallic stents has been prolonged, the
patency duration of a single stent is often too short, and
the number of patients who clinically require the placement
of second or third metallic stents is increasing. According
to our data, the stent-occlusion rate was 36.0% (67/186)
overall and 49.0% (67/137) among the survivors. Thus,
nearly half of all surviving patients had a stent occlusion.
The main causes of stent occlusion were debris or food
residue (25 patients, 37%), dislocation (13 patients, 19%),
and migration with hyperplasia (13 patients, 19%) (Tables 1,
2) (35).
Historical Review of Stent Management
Stent occlusion due to debris or food residue is usually
treated by lavage with a balloon-tipped catheter or a
“stent-in-stent” procedure. Previous studies reported
that the stent patency duration was 21 to 34 days after
mechanical lavage with a balloon-tipped catheter, 90 days
after the placement of a plastic stent in an self-expandable
metal stent (SEMS), and 75 to 192 days after a “stent-in-
stent” placement of a SEMS (17, 18). The patency duration
after these procedures was slightly shorter than after
placement of the initial SEMS. However, because SEMSs
have the longest patency duration, they are considered
clinically useful for the treatment of initial stent occlusion
(17, 18, 33). From the viewpoint of cost effectiveness and
patient quality of life, SEMSs are also recommended as the
second stent (34).
Metallic Stent Removal
Ideally, the first metallic stent should be removed and
then replaced by an SEMS. In previous studies, stent
removal was performed only if a stent was misplaced soon
after placement. This procedure was considered risky and
was unsuccessful in many patients (16). In subsequent
studies, stents were removed or cut to treat complications
such as ulcers or stent occlusion due to migration or
dislocation. In the case reports, laser treatment (19),
forceps (24), suture-cutting devices (26), snares (25, 28),
and argon plasma coagulation (20-23) have been used to
remove or cut stents.
In 2004, Kahaleh et al. (29) reported the results of stent
removal in a series of 18 patients. The period of time from
stent placement to removal ranged from 1 week to 16
months in 4 patients with uncovered SEMSs and 1 to 11
months in 14 with covered SEMSs. In prospective studies,
Familiari et al. (31) and Shin et al. (32) reported that 0% to
38.4% of uncovered SEMSs and 86.4% to 92.3% of covered
SEMSs could be removed with no serious complications.
According to our data, we have attempted metallic stent
removal in 50 cases and 78.0% (39/50) of the covered
SEMSs could be removed (35) (Fig. 1). Ten stents had
migrated into the bile duct and had hyperplastic-tissue
ingrowth of the uncovered portion at the distal end of the
SEMS, and 1 stent that had remained in place for 2 years
5 months and was suspected to have tumor ingrowth and
could not be removed. Our results and those of previous
studies suggest that a covered Wallstent or Wallflex
stent can be removed within 1.0-1.5 years after initial
placement if there is no stent migration with hyperplastic-
tissue ingrowth of the uncovered portion. Even stents with
hyperplastic-tissue ingrowth of the uncovered portion could
be removed if the stent slightly protruded towards the
duodenum, allowing the protruding portion to be grasped
with a snare. The hyperplastic tissue inside the stent was
then incised with a needle knife, allowing the stent to be
removed with the snare. Another technique so called the
“inversion technique”, in which the inner end of the stent
Table 1. Complications Associated with First Covered
Metallic Stent (Endoscopy 2011;43:1039-1044)
Stent occlusion rate (in patients)
Stent occlusion rate (survivors)
Cholecystitis
Post-ERCP pancreatitis
Stent-induced ulcer
Liver abscess
Cholangitis
Perforated duodenal ulcer
Note.— ERCP = endoscopic retrograde
cholangiopancreatography
36% (67/186)
49% (67/137)
7% (13/186)
3% (6/186)
3% (5/186)
1% (2/186)
1% (2/186)
0.5% (1/186)
Table 2. Causes of Occlusion of First Covered Metallic
Stent (total n = 67) (Endoscopy 2011;43:1039-1044)
Debris
Dislocation
“Migration + hyperplasia”
Overgrowth
Ingrowth
Axial force
Unknown
25 (37%)
13 (19%)
13 (19%)
6 (9%)
2 (3%)
1 (1.5%)
7 (10%)

Page 3

Korean J Radiol 13(Suppl 1), Jan/Feb 2012
kjronline.org S64
Kida et al.
is caught by forceps and removed. Futhermore, the problem
of hyperplastic-tissue ingrowth may be solved if we employ
a “full covered” stent.
In order to prevent stent migration, it was reported that
stents one size longer than the length was required (32).
We also inserted longer metallic stents measuring 6 or 8 cm
in length in most patients because the axial force of a 4-cm
metallic stent has caused biliary obstruction. Nonetheless,
proximal migration with hyperplasia occurred in 19% of
cases; however, we should emphasize that none of the
second stents have shown proximal migration at the time of
this writing.
Using a duodenal endoscope with a 3.7-mm channel, most
stents could be removed through the channel by snaring
the stent (Fig. 1). Furthermore, all stents could be removed
when a duodenal endoscope with a 4.2-mm channel was
used. Removal of a Wallflex stent might require the use of a
duodenal endoscope with a 4.2-mm channel.
Re-Intervention with a Metallic Stent
Ornellas et al. (33) compared 48 patients with initially
placed covered SEMSs with 56 different patients on
their second stents and found that the patency duration
did not differ significantly between the groups (p =
0.057). However, the initial placement group included a
significantly higher proportion of patients with advanced
disease, whereas the re-intervention group included a
significantly higher proportion of patients with proximal
biliary strictures.
We also studied the effectiveness of primary stent
placement, as well as the effectiveness and safety of
secondary stent placement (re-intervention) in patients
with unresectable malignant biliary obstructions (35).
In our study, there was no difference in demographic
characteristics between the initial placement group and the
re-intervention group, and all patients in the latter group
were included in the former. Because a longer time had
elapsed since the diagnosis in the re-intervention group,
the disease stage was more advanced than at the time of
initial placement. However, demographic characteristics
such as age, sex, and underlying disease were similar in
these groups. The patency rates and patency durations
also did not differ significantly between these groups (p =
0.08) (Fig. 2). There was also no significant difference in
the patency rates and patency durations between initially
placed stents and secondarily placed stents in the same
patients (p = 0.07) (Fig. 3). Although the patency durations
Fig. 1. Distal end of Covered SEMS was caught by snare and removed through duodenal endoscope channel.
100
90
80
70
60
50
40
30
20
10
0
0 100 200 300 400 500 600 700 800 900
Patency time
Patency rate
MPT
Initial placement (n = 186) 352 days
Re-intervention (n = 36) 263 days
p = 0.08
Fig. 2. Kaplan-meier curves comparing cumulative patency of
first and second metallic stents in all 186 cases (Endoscopy
2011;43:1039-1044). MPT = median patency time

Page 4

Korean J Radiol 13(Suppl 1), Jan/Feb 2012
kjronline.org S65
Recent Advances of Biliary Stent Management
of the first stent in the removed group, where the first
stents were removed and a second stent was inserted, was
shorter than that of all the first stents and hence must be
biased. Therefore, we also compared the patency durations
of the second stents with all the first stents, and a log-rank
analysis confirmed the lack of a significant difference (Figs.
2, 3).
CONCLUSIONS
A consensus has not been reached as to whether covered
metallic stents have a significantly longer patency duration
than uncovered metallic stents (7-11). Futhermore, covered
metallic stents are also considered to have a significantly
higher risk of migration and dislocation (9-11). However we
confirmed that stents could be removed easily and safely.
Given that further prolongation of the patency duration is
unlikely in the foreseeable future, covered metallic stents
are best suited for re-intervention because they have the
longest durations of patency.
We believe that our results have important implications
for clinical practice. However, additional prospective studies
comparing re-interventions after the removal of metallic
stents with “stent-in-stent” placement of metallic stents
are needed. Studies with a larger number of patients are
also necessary. At present, the covered metallic stents
can be relatively easily reinserted after the removal of the
initially placed covered metallic stents, without causing
complications. Patency rates and durations of the second
stents are similar to those of the initially placed stents. To
preserve patient quality of life, we currently recommend
covered metallic stents for patients with malignant biliary
obstruction because of their removability and longest
durations of patency, although uncovered metallic stents
have similar patency durations.
REFERENCES
1. Soehendra N, Reynders-Frederix V. [Palliative biliary duct
drainage. A new method for endoscopic introduction of a new
drain]. Dtsch Med Wochenschr 1979;104:206-207
2. Huibregtse K, Haverkamp HJ, Tytgat GN. Transpapillary
positioning of a large 3.2 mm biliary endoprosthesis.
Endoscopy 1981;13:217-219
3. Huibregtse K, Cheng J, Coene PP, Fockens P, Tytgat GN.
Endoscopic placement of expandable metal stents for biliary
strictures--a preliminary report on experience with 33
patients. Endoscopy 1989;21:280-282
4. Neuhaus H, Hagenmüller F, Classen M. Self-expanding
biliary stents: preliminary clinical experience. Endoscopy
1989;21:225-228
5. Davids PH, Groen AK, Rauws EA, Tytgat GN, Huibregtse
K. Randomised trial of self-expanding metal stents versus
polyethylene stents for distal malignant biliary obstruction.
Lancet 1992;340:1488-1492
6. Knyrim K, Wagner HJ, Pausch J, Vakil N. A prospective,
randomized, controlled trial of metal stents for malignant
obstruction of the common bile duct. Endoscopy 1993;25:207-
212
7. Isayama H, Komatsu Y, Tsujino T, Sasahira N, Hirano K, Toda
N, et al. A prospective randomised study of “covered” versus
“uncovered” diamond stents for the management of distal
malignant biliary obstruction. Gut 2004;53:729-734
8. Yoon WJ, Lee JK, Lee KH, Lee WJ, Ryu JK, Kim YT, et al.
A comparison of covered and uncovered Wallstents for
the management of distal malignant biliary obstruction.
Gastrointest Endosc 2006;63:996-1000
9. Park do H, Kim MH, Choi JS, Lee SS, Seo DW, Kim JH, et al.
Covered versus uncovered wallstent for malignant extrahepatic
biliary obstruction: a cohort comparative analysis. Clin
Gastroenterol Hepatol 2006;4:790-796
10. Telford JJ, Carr-Locke DL, Baron TH, Poneros JM, Bounds BC,
Kelsey PB, et al. A randomized trial comparing uncovered
and partially covered self-expandable metal stents in the
palliation of distal malignant biliary obstruction. Gastrointest
Endosc 2010;72:907-914
11. Kullman E, Frozanpor F, Söderlund C, Linder S, Sandström
P, Lindhoff-Larsson A, et al. Covered versus uncovered
self-expandable nitinol stents in the palliative treatment
of malignant distal biliary obstruction: results from
a randomized, multicenter study. Gastrointest Endosc
2010;72:915-923
12. Burris HA 3rd, Moore MJ, Andersen J, Green MR, Rothenberg
ML, Modiano MR, et al. Improvements in survival and clinical
benefit with gemcitabine as first-line therapy for patients
with advanced pancreas cancer: a randomized trial. J Clin
Oncol 1997;15:2403-2413
100
90
80
70
60
50
40
30
20
10
0
0 100 200 300 400 500 600 700
Patency time
Patency rate
MPT
Initial placement (n : 36) 133 days
Re-intervention (n : 36) 263 days
p = 0.07
Fig. 3. Kaplan-meier curves comparing cumulative patency
of first and second metallic stents in same patients out of
186 patients (Endoscopy 2011;43:1039-1044). MPT = median
patency time

Page 5

Korean J Radiol 13(Suppl 1), Jan/Feb 2012
kjronline.orgS66
Kida et al.
13. Moore MJ, Goldstein D, Hamm J, Figer A, Hecht JR, Gallinger S,
et al. Erlotinib plus gemcitabine compared with gemcitabine
alone in patients with advanced pancreatic cancer: a phase
III trial of the National Cancer Institute of Canada Clinical
Trials Group. J Clin Oncol 2007;25:1960-1966
14. Valle JW, Wasan H, Johnson P, Jones E, Dixon L, Swindell R,
et al. Gemcitabine alone or in combination with cisplatin in
patients with advanced or metastatic cholangiocarcinomas or
other biliary tract tumours: a multicentre randomised phase II
study - The UK ABC-01 Study. Br J Cancer 2009;101:621-627
15. Valle J, Wasan H, Palmer DH, Cunningham D, Anthoney
A, Maraveyas A, et al. Cisplatin plus gemcitabine versus
gemcitabine for biliary tract cancer. N Engl J Med
2010;362:1273-1281
16. Schöfl R, Brownstone E, Reichel W, Fortunat W, Doblhofer F,
Samec HJ, et al. Malignant bile-duct obstruction: experience
with self-expanding metal endoprostheses (Wallstents) in
Austria. Endoscopy 1994;26:592-596
17. Tham TC, Carr-Locke DL, Vandervoort J, Wong RC, Lichtenstein
DR, Van Dam J, et al. Management of occluded biliary
Wallstents. Gut 1998;42:703-707
18. Bueno JT, Gerdes H, Kurtz RC. Endoscopic management of
occluded biliary Wallstents: a cancer center experience.
Gastrointest Endosc 2003;58:879-884
19. Yarze JC, Poulos AM, Fritz HP, Herlihy KJ. Treatment of
metallic biliary stent-induced duodenal ulceration using
endoscopic laser therapy. Dig Dis Sci 1997;42:6-9
20. Demarquay JF, Dumas R, Peten EP, Rampal P. Argon plasma
endoscopic section of biliary metallic prostheses. Endoscopy
2001;33:289-290
21. Vanbiervliet G, Piche T, Caroli-Bosc FX, Dumas R, Peten EP,
Huet PM, et al. Endoscopic argon plasma trimming of biliary
and gastrointestinal metallic stents. Endoscopy 2005;37:434-
438
22. Chen YK, Jakribettuu V, Springer EW, Shah RJ, Penberthy J,
Nash SR. Safety and efficacy of argon plasma coagulation
trimming of malpositioned and migrated biliary metal stents:
a controlled study in the porcine model. Am J Gastroenterol
2006;101:2025-2030
23. Rerknimitr R, Naprasert P, Kongkam P, Kullavanijaya P.
Trimming a metallic biliary stent using an argon plasma
coagulator. Cardiovasc Intervent Radiol 2007;30:534-536
24. Ahmed A, Keeffe EB, Imperial JC. A novel technique
for endoscopic removal of expandable biliary Wallstent.
Gastrointest Endosc 1999;50:279-281
25. Egan LJ, Baron TH. Endoscopic removal of an embedded
biliary Wallstent by piecemeal extraction. Endoscopy
2000;32:492-494
26. Levy MJ, Wiersema MJ. Endoscopic removal of a biliary
Wallstent with a suture-cutting device in a patient with
primary pancreatic lymphoma. Endoscopy 2002;34:835-837
27. Wamsteker EJ, Elta GH. Migration of covered biliary self-
expanding metallic stents in two patients with malignant
biliary obstruction. Gastrointest Endosc 2003;58:792-793
28. Trentino P, Falasco G, d’orta C, Coda S. Endoscopic removal
of a metallic biliary stent: case report. Gastrointest Endosc
2004;59:321-323
29. Kahaleh M, Tokar J, Le T, Yeaton P. Removal of self-expandable
metallic Wallstents. Gastrointest Endosc 2004;60:640-644
30. Costamagna G, Pandolfi M. Endoscopic stenting for biliary and
pancreatic malignancies. J Clin Gastroenterol 2004;38:59-67
31. Familiari P, Bulajic M, Mutignani M, Lee LS, Spera G, Spada
C, et al. Endoscopic removal of malfunctioning biliary self-
expandable metallic stents. Gastrointest Endosc 2005;62:903-
910
32. Shin HP, Kim MH, Jung SW, Kim JC, Choi EK, Han J, et al.
Endoscopic removal of biliary self-expandable metallic stents:
a prospective study. Endoscopy 2006;38:1250-1255
33. Ornellas LC, Stefanidis G, Chuttani R, Gelrud A, Kelleher TB,
Pleskow DK. Covered Wallstents for palliation of malignant
biliary obstruction: primary stent placement versus
reintervention. Gastrointest Endosc 2009;70:676-683
34. Arguedas MR, Heudebert GH, Stinnett AA, Wilcox CM. Biliary
stents in malignant obstructive jaundice due to pancreatic
carcinoma: a cost-effectiveness analysis. Am J Gastroenterol
2002;97:898-904
35. Kida M, Miyazawa S, Iwai T, Ikeda H, Takezawa M, Kikuchi
H, et al. Endoscopic management of malignant biliary
obstruction by means of covered metallic stents: primary
stent placement vs. re-intervention. Endoscopy 2011;43:1039-
1044