Roy
L. Gordon,
J.
Ernest
MD
#{149}
Ring,
MD
Jeanne
M. LaBerge,
#{149}
MD
Margaret
M. Doherty,
#{149}
RN
Malignant Biliary Obstruction: Treatment with Expandable Metallic StentsFollow-up of5O Consecutive Patients’ A consecutive with
series
malignant
bowed
up prospectively
intervals
over
months. died;
a period
overall patency the 50 patients 7.5 months, mortality
rate
successful were fob-
of 9-22
patients
(18%)
palliative indwelling
at 2-month
Forty-one nine
struction
of palliative expandable
Stent placement was patients. The patients
are
and were
still
(82%) living.
The
survival rates for 5.8 months and
respectively. was 8%
The
30-day
(n = 4), the mirate was 18%
nor complication (n = 9), and the rate was 8% (n had intrahepatic
=
(2%)
two patients (4%) had transient septic events. Stent occlusion requiring a second intervention occurred in 24% of patients (n = 12). Excellent palbia-
was
achieved
in most
patients.
No stent migration occurred. No great clinical advantages in pro-
longed patency compared with those of other published series involving the use of plastic stents were demonstrated. Ease of placement and versatility stent. Index dure, 76.33 ducts,
may
offset
the
high
cost
terms: Bile ducts, interventional 76.1299 #{149} Bile ducts, neoplasms, #{149} Bile ducts, prostheses, 76.1299 stenosis or obstruction, 76.289
(1-3).
of the
proce76.32, #{149} Bile
1992;
182:697-701
drainage stent
been
A variety
tubes
clinical
value,
available
plastic
to prolong and
the
facilitate
such
device
endoprosthesis
even-
Expandable inner luin an at-
duration stent
of stent place-
is the
USA,
Ply-
mouth, Minn), which is a self-expanding flexible tube constructed of woven stainless steel wires (4) (Fig 1). In its constrained state, mounted on its introducer, it has an outer diameter of only 7 F, but after deployment, it expands to a maximal lumen of 10 mm (30 F) in diameter. The stent, which has been used in Europe for a few years, was not available for clinical use in the United States until September 1989. Preliminary published artides from European centers have given somewhat variable durations of patency of these new stents (5-9). Oc-
RSNA,
1992
from
a variety
remaining
of
five
proximal
patients
(38%),
and
duct in five patients and 28 male patients
(mean,
the
common
common
70.7) years. placement
the
hepatic
bile duct distal
(10%). The were aged Four patients of the
in 19
common
stent
bile
22 female 37-89
(8%)
un-
as the
first
palliative treatment of their biliary obstruction, 25 (50%) already had undergone placement of an internal-external biliary drain elsewhere, four (8%) had obstructed plastic endoprostheses, 12 (24%) had undergone failed attempts at endoscopic placement of a stent, and five (10%) had previously undergone biliary surgery.
Methods Preliminary cholangiography was performed with any preexisting drainage catheter or by using fine-needle percutaneous transhepatic cholangiography. All procedures were performed with the use of broad-spectrum intravenous antibiotics, most often a compound from the cephabosporin family. Previously placed biliary drains were used as access routes for stent placement. In patients without drains, lesions in the common hepatic or common
bile ducts
were
approached
via a right
Between September 1989 and October 1990, 50 consecutive patients with malignant biliary obstruction were treated with the transhepatic placement of the Wallstent endoprosthesis. Twenty-four pa-
duct puncture, while hilar lesions were generally approached via a left duct puncture. The obstructing lesions were traversed by using standard guide-wire techniques (10). Once the guide wire was in position across the lesion and in the bowel, a multi-side-hole catheter and side-arm adaptor were employed to allow injection of contrast material over the wire for accurate delineation of the upper and lower margins of the obstructing lesion. The diagnostic catheter was removed, and an 8-F sheath with a side arm and a hemostasis valve was placed over the wire into the bile duct to allow recovery of the stent in the event of malfunction of the stent delivery system. The side arm provided a convenient portal for the injection of contrast material to opacify the biliary ducts.
tients
(48%)
This
(30%)
had
clusion
rates
7%-42% (5,7). ence with our
in these series have been We report our experifirst
all of whom
spective months.
study
and
50 consecutive
pa-
underwent follow-up
AND
profor
9-22
METHODS
Patients
‘
the
Wallstent
(Schneider
MATERIALS
From the Department of Radiology, University of California, San Francisco, 505 Parnassus Aye, Box 0628, San Francisco, CA 94143. Received August 9, 1991; revision requested September 18; revision received October 8; accepted October 9. Address reprint requests to R.L.G.
and
(52%),
and/or
derwent
all
stents
carcinoma
sites,
in 26 patients
enhave
but
metastatic
(10%) had gallbladder carcinoma. The obstructing lesion predominantly involved both the right and left main hepatic ducts
have
or retrograde These stents
had primary
biliary drainthrough the with a percuta-
tually become occluded. metallic stents with large mina have been developed patency ment. One
ob-
successful
of plastic
of great
currently
biliary
by means of an or endoprosthesis
neous transhepatic doscopic approach.
tients, Radiology
malignant
can undergo
been used to maintain age, by implantation obstructed bile ducts
tempt
major complication 4). One patient arterial bleeding
that required embolization, one (2%) had a right subphrenic abscess, and
tion
with
ATIENTS
obstruction
were treated by means drainage with a metallic stent. in all
P
of 50 patients
biliary
had
pancreatic
cholangiocarcinoma,
carcinoma,
six (12%)
15
often
Balloon
facilitated
dilation
stent
positioning.
of the obstructing
lesion 697
Patency
and Survival Patency Patient
Groups
Patients
All patients Patients with ventions
repeated
ficult in
stent
whose
to cross. cases,
most
Average
0.4-22
12 9
6.7 12.3 4.4
2-12 5-22 0.4-19
13.0 15.8 5.6
3-22 6-22 0.4-19
had been
in
age and allowed
dif-
raphy after 24-48 hours, before removal of all biliary drainage tubes. After hospital discharge, all patients were followed up at regular 2-month intervals by means of telephone interview with the patient or the treating physician.
was
used being
remainder. Dilation before placement, not a routine procedure, was performed in about half the patients who underwent stent placement. The Wallstent prosthesis has already been described in detail (4). The stents used in this study were cm long when expanded
state
stents
plastic membrane. 40% longer in their
than
in their
are woven
ble steel alloy
that
This con-
a biocompati-
is difficult
to see
at fluo-
roscopy.
were
The
stents
were
deployed,
paid to stent that occurs
expands
at release
Further
ticipated, pansion
with
position when
special
and the the stent
the delivery cathmust also be an-
from
shortening
since the stent after placement,
may undergo by means of
cx-
either balloon dilation or self-expansion over a period of time. The sometimes predictable nature of this shortening
unand
poor visibility at fluoroscopy can make stent positioning tricky, particularly for proximal lesions. A second stent was required to achieve adequate stent length for long lesions. The use of two overlapping stents allowed
more accurate positioning of the distal and then the proximal ends of the com-
Results
treated
with
length;
and
was
staged
end of the stent ampulla into the
severe initial
duodenum Although
in patients the stents
with low lesions. are self-expanding,
ited to the minimum quate external biliary
more
underwent narrowed
complete
balloon areas
dilation
and
expansion.
to
achieve
This
improved
the bile flow and ensured a better prediction of final stent position. In the initial cases, the stents were distended with a 10-mm balloon, but this distention proved to be quite painful and led to transient episodes of hemobibia. Subsequently, 8-mm balloons were used and were far better tolerated. A self-retaining catheter was then placed above the stent. Catheters were usually 8-10 F in diameter and of the
Cook-Cope ton, md) locking
loop type (Cook, or Amplatz Anchor Malecot)
tific, Watertown, provided temporary
698
#{149} Radiology
(Medi-tech/Boston Mass).
These external
Bloomingsystem (with Sciencatheters biliary drain-
one
to allow
distal the
stents
in (68%)
stent;
14
patient
(2%)
needed four stents to achieve both adequate length and bilateral drainage. Five (62%) of the eight patients with bilateral drainage underwent stent placement in a Y configuration to drain both right and left ducts as previously described (11). The other three patients (38%) had bilateral tubes positioned side by side. Five patients (10%) had stents crossing the ampulla. In 44 patients (88%), implantation was successfully achieved at the first treatment session. In the remaining six patients (12%), stent placement
The across
eliminate
successful patients
a single
bined stent. was placed
most
cholangiog-
patients (28%) needed two stents (in six to achieve adequate length, in eight for bilateral drainage); one patient (2%) needed three stents for ad-
equate
attention shortening
eter.
Immediate
Stent placement was all patients. Thirty-four
state.
released
from
for follow-up
RESULTS
either 4.2 cm or 6.8 to their maximal
of 10 mm. The stents, as supplied manufacturer, are stretched on a delivery catheter and held in posi-
strained
The
Range
7.5
placement
lesions
An 8-mm balloon with 6-mm balloons
tion with a rolling makes them some
Average
0.4-21
stent
diameter by the flexible
Range
5.8
in the
used
(mo)
50
41
before
performed patients
Survival
(mo)
inter-
Living patients Dead patients
was those
of First Stent
No.of
was
for resolution
cholangitis. For biliary manipulation
combined
with
these required drainage
antibiotic
of
patients, was limfor adeand
therapy
and supportive care. Stents were placed a few days later when each patient’s condition had improved. The external drainage catheters
were removed after external drainage in (i = 26) and after 48 (n = 9). In the other venous bleeding from track was encountered removal was attempted. these cases, the catheter serted; it was removed
only 24 hours of 52% of patients hours in 18% 15 patients (30%), the catheter when catheter In each of was reinwithout bleed-
ing 1 week later. The average hospital stay was 3 days (range, 1-8 days),
Figure 1. cry catheter inch guide
(a) Stent
constrained
by a plastic wire is seen
on its deliv-
membrane. exiting from
eter tip. (b) The stent is partially from its catheter by rolling back straining
plastic
A 0.35the cath-
released the con-
membrane.
with the day of implantation counted as day 1. Five patients who underwent stent placement as outpatients were not included. The 30-day mortality was 8% (n = 4). These four patients were in the terminal stages of life, with sepsis and advanced cancer. The cause of death could not be directly related to the drainage procedure. Major complications occurred in four other patients (8%). One patient had intrahe-
patic
arterial
bleeding
requiring
blood
transfusion, and was successfully treated by means of selective intraarterial embolization. One patient deveboped a right subphrenic abscess, successfully treated by means of percutaneous drainage. Two patients had transient severe septic events requiring intravenous antibiotic and sup-
portive treatment care unit. Minor volved drainage
in the intensive complications in-
self-limited tube (not
bleeding requiring
into the transfu-
sion) in four patients (8%) and of less than 39#{176}C in five (10%). tient had placement.
cholecystitis
No problem was
encountered
with
after
stent
fever No pa-
stent
migration
as determined
from
March
1992
disimpaction the stent
or “sweeping
out”
of
1). Two of these tients were treated endoscopicalby, and the remaining 10 patients
under-
went Three
to have
(ii
transhepatic patients
catheterization. (6%) appeared
predominant
distal
growth, showed
pa-
=
tumor
over-
and seven patients (14%) both proximal overgrowth
and intraluminal filling defects (Fig 2). One patient (2%) had sludge and debris within the stent that were successfubly swept out with a balloon catheter used with the retrograde en-
doscopic (2%) had
approach. predominant
filling
defects.
In two
tients,
7-F endoscopes
a percutaneous inspect the
occluded
2.
year-old 6 months
Cholangiogram
obtained
in a 65-
man with cholangiocarcinoma. of excellent palliation without
symptoms,
the
patient
returned
with
After
and jaundice. A new percutaneous biliary drainage was performed from the right side. The drainage catheter is marked by a curved arrow. Filling defects, with probable proximal tumor overgrowth, are seen in the upper part of the stent (straight arrows).
radiographs obtained in patients who were reexamined because of stent occlusion. Radiographs to check for migration were not routinely obtained in asymptomatic patients. In 9% (seven of 77) of attempted stent placements, the stent could not be released completely from the delivery catheter. The system was exchanged through
the previously In each case, placed
positioned 8-F sheath. another stent was then
satisfactorily.
Follow-up Nine
patients
(18%)
are still alive,
and 41 (82%) have died. The longest time of survival was 22 months, and the minimum period of follow-up was 9 months. Stents were assumed to be functional and patent if patients had
relief
of symptoms
such
as jaundice,
pruritus, or fever. Such in all cases after initial instituted either before of stent placement.
relief occurred drainage was or at the time
Twelve patients (24%) subsequently had occluded stents that were treated
by means
tional
interventions
ment
of additional
Volume
182
of one
#{149} Number
such stents 3
or more
addi-
as place(ii = 11) or
were
stents,
but
obtained.
mens
and
aspirates
sisted mucus,
of nonspecific material sludge, or desquamated
nor
was obtained in fact invaded
patent
Biopsy
to
re-
speci-
of the debris
con-
such
histologic
as cells.
evidence
to prove that tumor the stent lumen.
additional
rent fever percutaneous giography
with
inconclusive
were
patients
were
studied transhepatic and shown
stents
on the
fever
was
due
sided
bile ducts,
with
recur-
means of cholanto have widely
left side.
which
had
by
to undrained
Their right-
were
subse-
quently drained. Previous left-sided placement of a stent did not preclude successful drainage of the right-sided ducts. The Table shows the detailed patency and survival data. For the
whole
group
of 50 patients,
of early
sessment
average
spondingly
low rate of stent
at different
as-
a corre-
occlusion.
Adam
with
et al
malignant
bili-
ary obstruction, (n = 3) needed
of whom only 7% reintervention because of stent occlusion (7). The median survival of their patients, however, was only 3.5 months. nod precluded of stent patency. patients
The short survival pea meaningful assessment Gillams et al treated 40
with
five with
malignant
benign
obstruction
obstructing
and
lesions
(5).
They found recurrent jaundice, indicative of stent occlusion, in 42% (16 of 38) of their patients. Lameris et ab divided their patients into two groups according to the site of obstruction. For lesions in the common bile duct they found a 5% (two of 41) occlusion rate but, like Adam et al, had a short median survival of
only their
3.2 months for this group (9). For group of hilar lesions, the occlu-
sion
rate
was
28%
(eight
of 28).
Lammer
et al observed recurrent jaundice in I I % (ii = 6) of their 53 patients with malignant obstruction (6). Our experience so far has not shown a great improvement in patency for the Wallstent prosthesis compared with
stents.
Our
reintervention
were 24% for this study previous study involving in
100
consecutive
rates
and 12% in a plastic stents
patients
(1).
In
view
of the short survival of most patients and the scatter of results in different
studies,
however,
it is too early
final conclusions about Larger series that focus surviving patients and
going vide
repeated a better
In the
DISCUSSION The use of nonsurgically placed endoprostheses to provide palliative drainage of malignant biliary obstruction is an established clinical procedure
to reach
patency attention patients
interventions measure
current
rates. on under-
may
of actual
pro-
expected
issues
in the consider-
may
represent
tion
to the
safety,
early
of placement, question is difficult
and
stent
cost.
of duration to answer,
of since
study, patients
all “repeatedunderwent
con-
trast studies that showed whether the stent was occluded and thus allowed accurate determination of stent patency. Duration of patency was thus not limited by supervening death. The average duration of patency before repeated intervention was 6.7 months. This value
ation of any new biliary endoprosthesis include duration of patency, resistance to migration, efficacy of palliation, The central stent patency
centers.
41 patients
intervention”
ease
with
patency.
14.2 months.
(3). Important
is an optimistic
patency
There has been a considerable range in the reported number of repeated interventions required to treat occluded
plastic
patency of the initial stent was 5.8 months and average survival was 7.5 months. The 41 patients who died had an average survival of only 5.6 months. Nine patients continue to survive an average of 15.8 months after stent insertion. The average stent patency in this group was 12.3 months. In the subset of six survivors who have not needed an additional intervention, the average patency was
death
of stent
treated
pa-
used
result
stents
route partially
sults
Two fever
of these
transhepatic lumina of the
No cytologic Figure
Another patient intrabuminal
the survival of most patients presenting with obstructive jaundice caused by malignant disease is short, averaging less than 6 months in most reports (1,2,57,9). This short survival makes it difficult to compare the patency rates of different stents because most patients die before their stents have been in place long enough to become occluded (1). The
the closest true
measure
approximaof average
patency, since the influence death is eliminated.
In this study, we assumed that period during which the patient Radiology
of the re#{149} 699
mained free from recurrent symptoms such as jaundice, fever, or pruritus was equivalent
to the
tency.
Patency the
necessarily survived
only
had
have
a few
to
status
of their
studies
or
and
of their
establish
may
in the
lives.
with
stents
It was not the
certainty
without
autopsies.
not
patients tumors
symptoms
or two
possible
pa-
were
months
recurrent
last week
of stent
survival
same. Some or aggressive
advanced
with
period
and
contrast
Such
studies
were
not undertaken in obviously terminally ill patients. In patients who underwent a second intervention to treat a blocked stent, survival was longer than the mitial stent patency. We were unable to correlate patency or survival with tumor type because of the small number of patients. Occlusion of the stent by overgrowth of proximal or distal ends of the stent can be readily demonstrated and understood. Accurate positioning of the stent with generous
lengths
the
lesion
sions,
stent
of
accurate
peripheral
to the
taken
not
to
from that
leave
the
the duct
into
placed
Vater
into
most
treated
hilar
type
of
the
distal
duodenum. lesions
stent
end
the liver
low
lesions
end
of
the
of
In our
were
because
to
Care
the ampulla
across
the
bea
system
end.
Treatment
require be
high
ductal
free upper
parenchyma. stent
below
For
requires
a long be
and 3).
positioning
protruding may
(Fig
entry
achieve must
above
is critical
of the
most
low
a.
series,
Figure 3. Cholangiograms obtained in a 65-year-old woman after cholecystectomy at which carcinoma of the gallbladder was discovered. (a) injection of contrast material delineates the upper and lower margins of the obstructing lesions, which involve the confluence of the right and left biliary ducts and the proximal common hepatic duct. (b) The 6.8-cm stent drains the left side and was placed by means of an ipsilateral approach. Generous margins of stent project above and below the lesion without crossing the ampulla.
high
lesions
at
our institution are treated with a retrograde endoscopic approach. Since the number of distal lesions treated was small,
we
whether
the
were
unable
crossing
the of stent
likelihood
by reflux stent.
or pancreatitis
addition
stent ing
increased caused
ends,
to
the
defects cases,
and
overgrowth
thesis.
consist
fill-
radiolucent
stent
lumen
was
(Fig
material
of desquamated
2).
was
shown
cells,
mucus,
cations
to
and
(Fig
prove
2) (5,6).
that
tumor
occlusion
who
found
at autopsy
by
sible
the
when are
The (18%
700
better
nature
#{149} Radiology
8%
of
these
rates major)
great
other The
stent
was
painful
appear
study to be
from 7% to appears to be but offers no in safety compared
delivery
only outer
system
7 F in caliber. easier than
endoprostheses study
in this
mortality series were
stents.
stent
be pos-
sepsis,
thus device,
improvement
Imfilling
Fever,
to
ranging
prosthesis a reasonably safe
only
understood.
complication minor,
may
are difficult listed compli-
study.
similar,
. The
pros-
however, are the complito all reports about placed endoprostheses serious, are not usually
common
and
found
studies and
and inserting
used
flexible the
appeared to be less the 12-F plastic
in our previous
Although the 8-F sheath diameter of almost (1).
7 F, the
is
Inserting
of of
77) of deliveries. The safe clinical use of the stent thus necessitated a sheath, and the resultant transparenchymal liver
comparisons
life-threatening. Thirty-day rates in this (8%) and other 12%
compli-
Wallstent
in each
transhepatically and, although
with
been
et al (6).
design
study,
ingrowth
also
vary
bleeding,
remarkably In
place-
of this obstruction Tumor
Lammer
in stent
stent
patients.
stent
has
provement defects
of 50
completion causing
obstruction
to
caused
group
at autopsy.
without
unable
underwent
after the ingrowth
was
were
ingrowth
in this
a patient
ment tumor
We
the
numerical
as definitions
cations
These
sheath is important to allow recovery stents that fail to deploy satisfactorily, an event that occurred in 9% (seven
or me-
transhepatic appear to be spe-
not to
different
make,
and other sludge. It has been speculated that these defects may be caused by tumor ingrowth through the mesh of the stent
between
In
do
Direct
plastic
of the
a result
related
the
this
stents.
are
to those
frequency
expandable
cations
of the
and
of either
drainage
at cholangiography
some
tallic
type
studies
cifically
by
within
of
in
of other
across the ampubla, have cholecystitis.
occlusion
observed
similar
the ul-
as a result
placement of a stent nor did our patients In
determine
of duodenal content into did not observe duodenal
We
ceration
to
ampulla occlusion
stent system is used has an 10 F. Use of the
tract tract stent.
was not required
The current
much smaller than the to place a 12-F plastic
delivery
system
involves
a number of preparatory steps with syringes and a pressure gauge (4). Failed deployment occurred when the rolling membrane could not be fully retracted to allow complete release of the stent. Subsequent examination of failed dclivcry systems showed a perforation in the rolling membrane in about half of
them,
which
fluid
and
tion.
Careful
led to leakage
incomplete
handling
system and meticulous delivery system may dence of incomplete
An improved, delivery system the preliminary
syringes rently
and
of priming
membrane
retrac-
of the delivery priming of the reduce the mcirelease.
simplified
single-step
that does not require steps of priming with
a pressure
at an advanced
gauge stage
is curof develop-
March
1992
been separately adjunct in the
lesions
described, treatment
was a useful of these hilar
(11). The open-mesh
configura-
tion of the stent allows free drainage from any side branches of the biliary tree that drain into the stent-bearing duct (Fig 4). Stents coated with membranes to limit tumor ingrowth are under development. These stents may sacrifice the advantage of good side drainage, which may also be of importance in the region of the pancreatic duct. The metallic stent showed no tendency to migrate once placed in position. This stability was a clear advantage over that of plastic stents, which migrate in 3%-5.2% of cases (1,2). We were usually able to place the stent at the first treatment session and remove all tubes within 24-48 hours in most patients. The tubes were removed after cholangiography showed free flow through the stent and into the bowel. We did not cap external drainage tubes to test the patient’s tolerance of internal
drainage, since internal drainage was satisfactorily assessed by means of cholangiography with fluoroscopy and a delayed drainage study at 20 minutes. The external drainage tube was capped
in those
b. Figure
4.
Percutaneous
transhepatic
cho-
langiograms obtained in a 37-year-old woman with cholangiocarcinoma involving the hilum and obstructing multiple ducts. (a) Part of the ductal system is opacified. (b) A stent placed from the left side allows
excellent
drainage
from from
right-sided left side.
the the
through component,
new
may
system of failed
enough
draining
usually system
bilateral
as well
as
proves reliable, deployment
that
the use of the
8-F sheath will no longer We prefer to treat hilar
cause
were
mesh
duct
a single-sided
be required. lesions that
obstructions duct
by system,
on the left side. If the undrained causes cholangitis, it can be
drained later, as was performed in two patients. The metallic stent can be used in a configuration to treat bilateral hilar obstructions with a single-sided approach (11). This technique, which has
Volume
182
ing
usually the
move
ment. If the the prevalence
be low
the open
#{149} Number
3
patients
who
from their tracks tempted removal In these patients, were retained for the tract to mature. The Wallstent ably more expensive and is even more than one stent is first
prosthesis is considerthan plastic stents costly when more required. Since we
able to place
all tubes
the stent
session
within
24-48
dur-
and
re-
hours
in
most patients, short hospital stays were common. Reduced hospitalization is an important factor in overall cost considerations. Lower occlusion rates, as found by Adam et al (7), could offset the high initial cost of the stent (7). Our occlusion rates, however, were not much lower with the Wallstent prosthesis than with smaller plastic stents used in
a group
of patients
expensive
previously
reported
life, and treatment.
In conclusion,
the metallic
stent
stays.
It eliminates
the problem
1.
2.
3.
4.
5.
6.
a 12-F plastic
stent.
The
the cost-effectiveness
of their
U
Dick BW, Gordon RL, LaBerge JM, Doherty M, Ring EJ. Percutaneous transhepatic placement of biliary endoprostheses: resuIts in 100 consecutive patients. JVIR 1990; 1:97-100. Lammer J, Neumayer K. Biliary drainage endoprostheses: experience with 201 placements. Radiology 1986; 159:625-629. McLean GK, Burke DR. Role of endoprostheses in the management of malignant biliary obstruction. Radiology 1989; 170: 961-967. Rousseau H, Puel J, Joifre F, et al. Selfexpanding endovascular prosthesis: an cxperimental study. Radiology 1987; 164:709714. Gillams A, Dick R, Dooley JS, Wallsten H, El-Din A. Self-expandable stainless steel braided endoprosthesis for biliary strictures. Radiology 1990; 174:137-140. Lammerj, Klein GE, Kleinert R, Hausegger K, Einspieler R. Obstructive jaundice: use of expandable metal endoprosthesis for biliary drainage. Radiology 1990; 177:789792.
7.
Adam A, Chetty N, Roddie M, Yeung E, Benjamin IS. Self-expandable stainless steel endoprostheses for treatment of malignant bile duct obstruction. AJR 1991; 156: 321-325.
8.
9.
10.
11.
pro-
of mi-
than
References
(1). vides good palliative drainage and is well tolerated by patients. It is simple and safe to use and may reduce hospital
Cost is a major factor, as prosthesis is not only cxalso about five times more
anticipated advantage of prolonged patency has not been adequately substantiated and may not be critical for most patients with a limited life expectancy. A number of patients, however, survive for considerably longer than 6 months; for them, prolonged stent patency is critical to their survival, their quality of
had bleeding
at the time of atof the external tube. the external tubes about 1 week to allow
treatment
disadvantages. the Wallstent pensive but
12.
Neuhaus H, Hagenmuller F, Griebel M, Classen M. Percutaneous cholangioscopic or transpapillary insertion of self-expanding biliary metal stents. Gastrointest Endosc 1991; 37:31-37. Lameris JS, Stoker J, Nijs HGT, et al. Malignant biliary obstruction: percutaneous use of self-expandable stents. Radiology 1991; 179:703-707. Ring EJ, Oleaga JA, Freiman DB, et al. Therapeutic applications of catheter cholangiography. Radiology 1978; 128:333338. LaBergeJM, Doherty M, Gordon RL, Ring EJ. Hilar malignancy: treatment with an expandable metallic transhepatic biliary stent. Radiology 1990; 177:793-797. Mueller PR, Ferrucci JT Jr, Teplick SK, et al. Biliary stent endoprosthesis: analysis of complications in 113 patients. Radiology 1985; 156:637-639.
gration seen with plastic stents (12). Shortening and poor positioning leading to proximal or distal overgrowth are
Radiology
#{149} 701
L. Gordon,
J.
Ernest
MD
#{149}
Ring,
MD
Jeanne
M. LaBerge,
#{149}
MD
Margaret
M. Doherty,
#{149}
RN
Malignant Biliary Obstruction: Treatment with Expandable Metallic StentsFollow-up of5O Consecutive Patients’ A consecutive with
series
malignant
bowed
up prospectively
intervals
over
months. died;
a period
overall patency the 50 patients 7.5 months, mortality
rate
successful were fob-
of 9-22
patients
(18%)
palliative indwelling
at 2-month
Forty-one nine
struction
of palliative expandable
Stent placement was patients. The patients
are
and were
still
(82%) living.
The
survival rates for 5.8 months and
respectively. was 8%
The
30-day
(n = 4), the mirate was 18%
nor complication (n = 9), and the rate was 8% (n had intrahepatic
=
(2%)
two patients (4%) had transient septic events. Stent occlusion requiring a second intervention occurred in 24% of patients (n = 12). Excellent palbia-
was
achieved
in most
patients.
No stent migration occurred. No great clinical advantages in pro-
longed patency compared with those of other published series involving the use of plastic stents were demonstrated. Ease of placement and versatility stent. Index dure, 76.33 ducts,
may
offset
the
high
cost
terms: Bile ducts, interventional 76.1299 #{149} Bile ducts, neoplasms, #{149} Bile ducts, prostheses, 76.1299 stenosis or obstruction, 76.289
(1-3).
of the
proce76.32, #{149} Bile
1992;
182:697-701
drainage stent
been
A variety
tubes
clinical
value,
available
plastic
to prolong and
the
facilitate
such
device
endoprosthesis
even-
Expandable inner luin an at-
duration stent
of stent place-
is the
USA,
Ply-
mouth, Minn), which is a self-expanding flexible tube constructed of woven stainless steel wires (4) (Fig 1). In its constrained state, mounted on its introducer, it has an outer diameter of only 7 F, but after deployment, it expands to a maximal lumen of 10 mm (30 F) in diameter. The stent, which has been used in Europe for a few years, was not available for clinical use in the United States until September 1989. Preliminary published artides from European centers have given somewhat variable durations of patency of these new stents (5-9). Oc-
RSNA,
1992
from
a variety
remaining
of
five
proximal
patients
(38%),
and
duct in five patients and 28 male patients
(mean,
the
common
common
70.7) years. placement
the
hepatic
bile duct distal
(10%). The were aged Four patients of the
in 19
common
stent
bile
22 female 37-89
(8%)
un-
as the
first
palliative treatment of their biliary obstruction, 25 (50%) already had undergone placement of an internal-external biliary drain elsewhere, four (8%) had obstructed plastic endoprostheses, 12 (24%) had undergone failed attempts at endoscopic placement of a stent, and five (10%) had previously undergone biliary surgery.
Methods Preliminary cholangiography was performed with any preexisting drainage catheter or by using fine-needle percutaneous transhepatic cholangiography. All procedures were performed with the use of broad-spectrum intravenous antibiotics, most often a compound from the cephabosporin family. Previously placed biliary drains were used as access routes for stent placement. In patients without drains, lesions in the common hepatic or common
bile ducts
were
approached
via a right
Between September 1989 and October 1990, 50 consecutive patients with malignant biliary obstruction were treated with the transhepatic placement of the Wallstent endoprosthesis. Twenty-four pa-
duct puncture, while hilar lesions were generally approached via a left duct puncture. The obstructing lesions were traversed by using standard guide-wire techniques (10). Once the guide wire was in position across the lesion and in the bowel, a multi-side-hole catheter and side-arm adaptor were employed to allow injection of contrast material over the wire for accurate delineation of the upper and lower margins of the obstructing lesion. The diagnostic catheter was removed, and an 8-F sheath with a side arm and a hemostasis valve was placed over the wire into the bile duct to allow recovery of the stent in the event of malfunction of the stent delivery system. The side arm provided a convenient portal for the injection of contrast material to opacify the biliary ducts.
tients
(48%)
This
(30%)
had
clusion
rates
7%-42% (5,7). ence with our
in these series have been We report our experifirst
all of whom
spective months.
study
and
50 consecutive
pa-
underwent follow-up
AND
profor
9-22
METHODS
Patients
‘
the
Wallstent
(Schneider
MATERIALS
From the Department of Radiology, University of California, San Francisco, 505 Parnassus Aye, Box 0628, San Francisco, CA 94143. Received August 9, 1991; revision requested September 18; revision received October 8; accepted October 9. Address reprint requests to R.L.G.
and
(52%),
and/or
derwent
all
stents
carcinoma
sites,
in 26 patients
enhave
but
metastatic
(10%) had gallbladder carcinoma. The obstructing lesion predominantly involved both the right and left main hepatic ducts
have
or retrograde These stents
had primary
biliary drainthrough the with a percuta-
tually become occluded. metallic stents with large mina have been developed patency ment. One
ob-
successful
of plastic
of great
currently
biliary
by means of an or endoprosthesis
neous transhepatic doscopic approach.
tients, Radiology
malignant
can undergo
been used to maintain age, by implantation obstructed bile ducts
tempt
major complication 4). One patient arterial bleeding
that required embolization, one (2%) had a right subphrenic abscess, and
tion
with
ATIENTS
obstruction
were treated by means drainage with a metallic stent. in all
P
of 50 patients
biliary
had
pancreatic
cholangiocarcinoma,
carcinoma,
six (12%)
15
often
Balloon
facilitated
dilation
stent
positioning.
of the obstructing
lesion 697
Patency
and Survival Patency Patient
Groups
Patients
All patients Patients with ventions
repeated
ficult in
stent
whose
to cross. cases,
most
Average
0.4-22
12 9
6.7 12.3 4.4
2-12 5-22 0.4-19
13.0 15.8 5.6
3-22 6-22 0.4-19
had been
in
age and allowed
dif-
raphy after 24-48 hours, before removal of all biliary drainage tubes. After hospital discharge, all patients were followed up at regular 2-month intervals by means of telephone interview with the patient or the treating physician.
was
used being
remainder. Dilation before placement, not a routine procedure, was performed in about half the patients who underwent stent placement. The Wallstent prosthesis has already been described in detail (4). The stents used in this study were cm long when expanded
state
stents
plastic membrane. 40% longer in their
than
in their
are woven
ble steel alloy
that
This con-
a biocompati-
is difficult
to see
at fluo-
roscopy.
were
The
stents
were
deployed,
paid to stent that occurs
expands
at release
Further
ticipated, pansion
with
position when
special
and the the stent
the delivery cathmust also be an-
from
shortening
since the stent after placement,
may undergo by means of
cx-
either balloon dilation or self-expansion over a period of time. The sometimes predictable nature of this shortening
unand
poor visibility at fluoroscopy can make stent positioning tricky, particularly for proximal lesions. A second stent was required to achieve adequate stent length for long lesions. The use of two overlapping stents allowed
more accurate positioning of the distal and then the proximal ends of the com-
Results
treated
with
length;
and
was
staged
end of the stent ampulla into the
severe initial
duodenum Although
in patients the stents
with low lesions. are self-expanding,
ited to the minimum quate external biliary
more
underwent narrowed
complete
balloon areas
dilation
and
expansion.
to
achieve
This
improved
the bile flow and ensured a better prediction of final stent position. In the initial cases, the stents were distended with a 10-mm balloon, but this distention proved to be quite painful and led to transient episodes of hemobibia. Subsequently, 8-mm balloons were used and were far better tolerated. A self-retaining catheter was then placed above the stent. Catheters were usually 8-10 F in diameter and of the
Cook-Cope ton, md) locking
loop type (Cook, or Amplatz Anchor Malecot)
tific, Watertown, provided temporary
698
#{149} Radiology
(Medi-tech/Boston Mass).
These external
Bloomingsystem (with Sciencatheters biliary drain-
one
to allow
distal the
stents
in (68%)
stent;
14
patient
(2%)
needed four stents to achieve both adequate length and bilateral drainage. Five (62%) of the eight patients with bilateral drainage underwent stent placement in a Y configuration to drain both right and left ducts as previously described (11). The other three patients (38%) had bilateral tubes positioned side by side. Five patients (10%) had stents crossing the ampulla. In 44 patients (88%), implantation was successfully achieved at the first treatment session. In the remaining six patients (12%), stent placement
The across
eliminate
successful patients
a single
bined stent. was placed
most
cholangiog-
patients (28%) needed two stents (in six to achieve adequate length, in eight for bilateral drainage); one patient (2%) needed three stents for ad-
equate
attention shortening
eter.
Immediate
Stent placement was all patients. Thirty-four
state.
released
from
for follow-up
RESULTS
either 4.2 cm or 6.8 to their maximal
of 10 mm. The stents, as supplied manufacturer, are stretched on a delivery catheter and held in posi-
strained
The
Range
7.5
placement
lesions
An 8-mm balloon with 6-mm balloons
tion with a rolling makes them some
Average
0.4-21
stent
diameter by the flexible
Range
5.8
in the
used
(mo)
50
41
before
performed patients
Survival
(mo)
inter-
Living patients Dead patients
was those
of First Stent
No.of
was
for resolution
cholangitis. For biliary manipulation
combined
with
these required drainage
antibiotic
of
patients, was limfor adeand
therapy
and supportive care. Stents were placed a few days later when each patient’s condition had improved. The external drainage catheters
were removed after external drainage in (i = 26) and after 48 (n = 9). In the other venous bleeding from track was encountered removal was attempted. these cases, the catheter serted; it was removed
only 24 hours of 52% of patients hours in 18% 15 patients (30%), the catheter when catheter In each of was reinwithout bleed-
ing 1 week later. The average hospital stay was 3 days (range, 1-8 days),
Figure 1. cry catheter inch guide
(a) Stent
constrained
by a plastic wire is seen
on its deliv-
membrane. exiting from
eter tip. (b) The stent is partially from its catheter by rolling back straining
plastic
A 0.35the cath-
released the con-
membrane.
with the day of implantation counted as day 1. Five patients who underwent stent placement as outpatients were not included. The 30-day mortality was 8% (n = 4). These four patients were in the terminal stages of life, with sepsis and advanced cancer. The cause of death could not be directly related to the drainage procedure. Major complications occurred in four other patients (8%). One patient had intrahe-
patic
arterial
bleeding
requiring
blood
transfusion, and was successfully treated by means of selective intraarterial embolization. One patient deveboped a right subphrenic abscess, successfully treated by means of percutaneous drainage. Two patients had transient severe septic events requiring intravenous antibiotic and sup-
portive treatment care unit. Minor volved drainage
in the intensive complications in-
self-limited tube (not
bleeding requiring
into the transfu-
sion) in four patients (8%) and of less than 39#{176}C in five (10%). tient had placement.
cholecystitis
No problem was
encountered
with
after
stent
fever No pa-
stent
migration
as determined
from
March
1992
disimpaction the stent
or “sweeping
out”
of
1). Two of these tients were treated endoscopicalby, and the remaining 10 patients
under-
went Three
to have
(ii
transhepatic patients
catheterization. (6%) appeared
predominant
distal
growth, showed
pa-
=
tumor
over-
and seven patients (14%) both proximal overgrowth
and intraluminal filling defects (Fig 2). One patient (2%) had sludge and debris within the stent that were successfubly swept out with a balloon catheter used with the retrograde en-
doscopic (2%) had
approach. predominant
filling
defects.
In two
tients,
7-F endoscopes
a percutaneous inspect the
occluded
2.
year-old 6 months
Cholangiogram
obtained
in a 65-
man with cholangiocarcinoma. of excellent palliation without
symptoms,
the
patient
returned
with
After
and jaundice. A new percutaneous biliary drainage was performed from the right side. The drainage catheter is marked by a curved arrow. Filling defects, with probable proximal tumor overgrowth, are seen in the upper part of the stent (straight arrows).
radiographs obtained in patients who were reexamined because of stent occlusion. Radiographs to check for migration were not routinely obtained in asymptomatic patients. In 9% (seven of 77) of attempted stent placements, the stent could not be released completely from the delivery catheter. The system was exchanged through
the previously In each case, placed
positioned 8-F sheath. another stent was then
satisfactorily.
Follow-up Nine
patients
(18%)
are still alive,
and 41 (82%) have died. The longest time of survival was 22 months, and the minimum period of follow-up was 9 months. Stents were assumed to be functional and patent if patients had
relief
of symptoms
such
as jaundice,
pruritus, or fever. Such in all cases after initial instituted either before of stent placement.
relief occurred drainage was or at the time
Twelve patients (24%) subsequently had occluded stents that were treated
by means
tional
interventions
ment
of additional
Volume
182
of one
#{149} Number
such stents 3
or more
addi-
as place(ii = 11) or
were
stents,
but
obtained.
mens
and
aspirates
sisted mucus,
of nonspecific material sludge, or desquamated
nor
was obtained in fact invaded
patent
Biopsy
to
re-
speci-
of the debris
con-
such
histologic
as cells.
evidence
to prove that tumor the stent lumen.
additional
rent fever percutaneous giography
with
inconclusive
were
patients
were
studied transhepatic and shown
stents
on the
fever
was
due
sided
bile ducts,
with
recur-
means of cholanto have widely
left side.
which
had
by
to undrained
Their right-
were
subse-
quently drained. Previous left-sided placement of a stent did not preclude successful drainage of the right-sided ducts. The Table shows the detailed patency and survival data. For the
whole
group
of 50 patients,
of early
sessment
average
spondingly
low rate of stent
at different
as-
a corre-
occlusion.
Adam
with
et al
malignant
bili-
ary obstruction, (n = 3) needed
of whom only 7% reintervention because of stent occlusion (7). The median survival of their patients, however, was only 3.5 months. nod precluded of stent patency. patients
The short survival pea meaningful assessment Gillams et al treated 40
with
five with
malignant
benign
obstruction
obstructing
and
lesions
(5).
They found recurrent jaundice, indicative of stent occlusion, in 42% (16 of 38) of their patients. Lameris et ab divided their patients into two groups according to the site of obstruction. For lesions in the common bile duct they found a 5% (two of 41) occlusion rate but, like Adam et al, had a short median survival of
only their
3.2 months for this group (9). For group of hilar lesions, the occlu-
sion
rate
was
28%
(eight
of 28).
Lammer
et al observed recurrent jaundice in I I % (ii = 6) of their 53 patients with malignant obstruction (6). Our experience so far has not shown a great improvement in patency for the Wallstent prosthesis compared with
stents.
Our
reintervention
were 24% for this study previous study involving in
100
consecutive
rates
and 12% in a plastic stents
patients
(1).
In
view
of the short survival of most patients and the scatter of results in different
studies,
however,
it is too early
final conclusions about Larger series that focus surviving patients and
going vide
repeated a better
In the
DISCUSSION The use of nonsurgically placed endoprostheses to provide palliative drainage of malignant biliary obstruction is an established clinical procedure
to reach
patency attention patients
interventions measure
current
rates. on under-
may
of actual
pro-
expected
issues
in the consider-
may
represent
tion
to the
safety,
early
of placement, question is difficult
and
stent
cost.
of duration to answer,
of since
study, patients
all “repeatedunderwent
con-
trast studies that showed whether the stent was occluded and thus allowed accurate determination of stent patency. Duration of patency was thus not limited by supervening death. The average duration of patency before repeated intervention was 6.7 months. This value
ation of any new biliary endoprosthesis include duration of patency, resistance to migration, efficacy of palliation, The central stent patency
centers.
41 patients
intervention”
ease
with
patency.
14.2 months.
(3). Important
is an optimistic
patency
There has been a considerable range in the reported number of repeated interventions required to treat occluded
plastic
patency of the initial stent was 5.8 months and average survival was 7.5 months. The 41 patients who died had an average survival of only 5.6 months. Nine patients continue to survive an average of 15.8 months after stent insertion. The average stent patency in this group was 12.3 months. In the subset of six survivors who have not needed an additional intervention, the average patency was
death
of stent
treated
pa-
used
result
stents
route partially
sults
Two fever
of these
transhepatic lumina of the
No cytologic Figure
Another patient intrabuminal
the survival of most patients presenting with obstructive jaundice caused by malignant disease is short, averaging less than 6 months in most reports (1,2,57,9). This short survival makes it difficult to compare the patency rates of different stents because most patients die before their stents have been in place long enough to become occluded (1). The
the closest true
measure
approximaof average
patency, since the influence death is eliminated.
In this study, we assumed that period during which the patient Radiology
of the re#{149} 699
mained free from recurrent symptoms such as jaundice, fever, or pruritus was equivalent
to the
tency.
Patency the
necessarily survived
only
had
have
a few
to
status
of their
studies
or
and
of their
establish
may
in the
lives.
with
stents
It was not the
certainty
without
autopsies.
not
patients tumors
symptoms
or two
possible
pa-
were
months
recurrent
last week
of stent
survival
same. Some or aggressive
advanced
with
period
and
contrast
Such
studies
were
not undertaken in obviously terminally ill patients. In patients who underwent a second intervention to treat a blocked stent, survival was longer than the mitial stent patency. We were unable to correlate patency or survival with tumor type because of the small number of patients. Occlusion of the stent by overgrowth of proximal or distal ends of the stent can be readily demonstrated and understood. Accurate positioning of the stent with generous
lengths
the
lesion
sions,
stent
of
accurate
peripheral
to the
taken
not
to
from that
leave
the
the duct
into
placed
Vater
into
most
treated
hilar
type
of
the
distal
duodenum. lesions
stent
end
the liver
low
lesions
end
of
the
of
In our
were
because
to
Care
the ampulla
across
the
bea
system
end.
Treatment
require be
high
ductal
free upper
parenchyma. stent
below
For
requires
a long be
and 3).
positioning
protruding may
(Fig
entry
achieve must
above
is critical
of the
most
low
a.
series,
Figure 3. Cholangiograms obtained in a 65-year-old woman after cholecystectomy at which carcinoma of the gallbladder was discovered. (a) injection of contrast material delineates the upper and lower margins of the obstructing lesions, which involve the confluence of the right and left biliary ducts and the proximal common hepatic duct. (b) The 6.8-cm stent drains the left side and was placed by means of an ipsilateral approach. Generous margins of stent project above and below the lesion without crossing the ampulla.
high
lesions
at
our institution are treated with a retrograde endoscopic approach. Since the number of distal lesions treated was small,
we
whether
the
were
unable
crossing
the of stent
likelihood
by reflux stent.
or pancreatitis
addition
stent ing
increased caused
ends,
to
the
defects cases,
and
overgrowth
thesis.
consist
fill-
radiolucent
stent
lumen
was
(Fig
material
of desquamated
2).
was
shown
cells,
mucus,
cations
to
and
(Fig
prove
2) (5,6).
that
tumor
occlusion
who
found
at autopsy
by
sible
the
when are
The (18%
700
better
nature
#{149} Radiology
8%
of
these
rates major)
great
other The
stent
was
painful
appear
study to be
from 7% to appears to be but offers no in safety compared
delivery
only outer
system
7 F in caliber. easier than
endoprostheses study
in this
mortality series were
stents.
stent
be pos-
sepsis,
thus device,
improvement
Imfilling
Fever,
to
ranging
prosthesis a reasonably safe
only
understood.
complication minor,
may
are difficult listed compli-
study.
similar,
. The
pros-
however, are the complito all reports about placed endoprostheses serious, are not usually
common
and
found
studies and
and inserting
used
flexible the
appeared to be less the 12-F plastic
in our previous
Although the 8-F sheath diameter of almost (1).
7 F, the
is
Inserting
of of
77) of deliveries. The safe clinical use of the stent thus necessitated a sheath, and the resultant transparenchymal liver
comparisons
life-threatening. Thirty-day rates in this (8%) and other 12%
compli-
Wallstent
in each
transhepatically and, although
with
been
et al (6).
design
study,
ingrowth
also
vary
bleeding,
remarkably In
place-
of this obstruction Tumor
Lammer
in stent
stent
patients.
stent
has
provement defects
of 50
completion causing
obstruction
to
caused
group
at autopsy.
without
unable
underwent
after the ingrowth
was
were
ingrowth
in this
a patient
ment tumor
We
the
numerical
as definitions
cations
These
sheath is important to allow recovery stents that fail to deploy satisfactorily, an event that occurred in 9% (seven
or me-
transhepatic appear to be spe-
not to
different
make,
and other sludge. It has been speculated that these defects may be caused by tumor ingrowth through the mesh of the stent
between
In
do
Direct
plastic
of the
a result
related
the
this
stents.
are
to those
frequency
expandable
cations
of the
and
of either
drainage
at cholangiography
some
tallic
type
studies
cifically
by
within
of
in
of other
across the ampubla, have cholecystitis.
occlusion
observed
similar
the ul-
as a result
placement of a stent nor did our patients In
determine
of duodenal content into did not observe duodenal
We
ceration
to
ampulla occlusion
stent system is used has an 10 F. Use of the
tract tract stent.
was not required
The current
much smaller than the to place a 12-F plastic
delivery
system
involves
a number of preparatory steps with syringes and a pressure gauge (4). Failed deployment occurred when the rolling membrane could not be fully retracted to allow complete release of the stent. Subsequent examination of failed dclivcry systems showed a perforation in the rolling membrane in about half of
them,
which
fluid
and
tion.
Careful
led to leakage
incomplete
handling
system and meticulous delivery system may dence of incomplete
An improved, delivery system the preliminary
syringes rently
and
of priming
membrane
retrac-
of the delivery priming of the reduce the mcirelease.
simplified
single-step
that does not require steps of priming with
a pressure
at an advanced
gauge stage
is curof develop-
March
1992
been separately adjunct in the
lesions
described, treatment
was a useful of these hilar
(11). The open-mesh
configura-
tion of the stent allows free drainage from any side branches of the biliary tree that drain into the stent-bearing duct (Fig 4). Stents coated with membranes to limit tumor ingrowth are under development. These stents may sacrifice the advantage of good side drainage, which may also be of importance in the region of the pancreatic duct. The metallic stent showed no tendency to migrate once placed in position. This stability was a clear advantage over that of plastic stents, which migrate in 3%-5.2% of cases (1,2). We were usually able to place the stent at the first treatment session and remove all tubes within 24-48 hours in most patients. The tubes were removed after cholangiography showed free flow through the stent and into the bowel. We did not cap external drainage tubes to test the patient’s tolerance of internal
drainage, since internal drainage was satisfactorily assessed by means of cholangiography with fluoroscopy and a delayed drainage study at 20 minutes. The external drainage tube was capped
in those
b. Figure
4.
Percutaneous
transhepatic
cho-
langiograms obtained in a 37-year-old woman with cholangiocarcinoma involving the hilum and obstructing multiple ducts. (a) Part of the ductal system is opacified. (b) A stent placed from the left side allows
excellent
drainage
from from
right-sided left side.
the the
through component,
new
may
system of failed
enough
draining
usually system
bilateral
as well
as
proves reliable, deployment
that
the use of the
8-F sheath will no longer We prefer to treat hilar
cause
were
mesh
duct
a single-sided
be required. lesions that
obstructions duct
by system,
on the left side. If the undrained causes cholangitis, it can be
drained later, as was performed in two patients. The metallic stent can be used in a configuration to treat bilateral hilar obstructions with a single-sided approach (11). This technique, which has
Volume
182
ing
usually the
move
ment. If the the prevalence
be low
the open
#{149} Number
3
patients
who
from their tracks tempted removal In these patients, were retained for the tract to mature. The Wallstent ably more expensive and is even more than one stent is first
prosthesis is considerthan plastic stents costly when more required. Since we
able to place
all tubes
the stent
session
within
24-48
dur-
and
re-
hours
in
most patients, short hospital stays were common. Reduced hospitalization is an important factor in overall cost considerations. Lower occlusion rates, as found by Adam et al (7), could offset the high initial cost of the stent (7). Our occlusion rates, however, were not much lower with the Wallstent prosthesis than with smaller plastic stents used in
a group
of patients
expensive
previously
reported
life, and treatment.
In conclusion,
the metallic
stent
stays.
It eliminates
the problem
1.
2.
3.
4.
5.
6.
a 12-F plastic
stent.
The
the cost-effectiveness
of their
U
Dick BW, Gordon RL, LaBerge JM, Doherty M, Ring EJ. Percutaneous transhepatic placement of biliary endoprostheses: resuIts in 100 consecutive patients. JVIR 1990; 1:97-100. Lammer J, Neumayer K. Biliary drainage endoprostheses: experience with 201 placements. Radiology 1986; 159:625-629. McLean GK, Burke DR. Role of endoprostheses in the management of malignant biliary obstruction. Radiology 1989; 170: 961-967. Rousseau H, Puel J, Joifre F, et al. Selfexpanding endovascular prosthesis: an cxperimental study. Radiology 1987; 164:709714. Gillams A, Dick R, Dooley JS, Wallsten H, El-Din A. Self-expandable stainless steel braided endoprosthesis for biliary strictures. Radiology 1990; 174:137-140. Lammerj, Klein GE, Kleinert R, Hausegger K, Einspieler R. Obstructive jaundice: use of expandable metal endoprosthesis for biliary drainage. Radiology 1990; 177:789792.
7.
Adam A, Chetty N, Roddie M, Yeung E, Benjamin IS. Self-expandable stainless steel endoprostheses for treatment of malignant bile duct obstruction. AJR 1991; 156: 321-325.
8.
9.
10.
11.
pro-
of mi-
than
References
(1). vides good palliative drainage and is well tolerated by patients. It is simple and safe to use and may reduce hospital
Cost is a major factor, as prosthesis is not only cxalso about five times more
anticipated advantage of prolonged patency has not been adequately substantiated and may not be critical for most patients with a limited life expectancy. A number of patients, however, survive for considerably longer than 6 months; for them, prolonged stent patency is critical to their survival, their quality of
had bleeding
at the time of atof the external tube. the external tubes about 1 week to allow
treatment
disadvantages. the Wallstent pensive but
12.
Neuhaus H, Hagenmuller F, Griebel M, Classen M. Percutaneous cholangioscopic or transpapillary insertion of self-expanding biliary metal stents. Gastrointest Endosc 1991; 37:31-37. Lameris JS, Stoker J, Nijs HGT, et al. Malignant biliary obstruction: percutaneous use of self-expandable stents. Radiology 1991; 179:703-707. Ring EJ, Oleaga JA, Freiman DB, et al. Therapeutic applications of catheter cholangiography. Radiology 1978; 128:333338. LaBergeJM, Doherty M, Gordon RL, Ring EJ. Hilar malignancy: treatment with an expandable metallic transhepatic biliary stent. Radiology 1990; 177:793-797. Mueller PR, Ferrucci JT Jr, Teplick SK, et al. Biliary stent endoprosthesis: analysis of complications in 113 patients. Radiology 1985; 156:637-639.
gration seen with plastic stents (12). Shortening and poor positioning leading to proximal or distal overgrowth are
Radiology
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