Introduction
Malignant neoplasms of the pancreatic head often present with clinical and technical
challenges. Not infrequently, patients require upfront chemotherapy, either in preparation
for surgery or for palliative intent. Therefore, patients often require biliary drainage
through established modalities such as endoscopic retrograde cholangiopancreatography
(ERCP). However, ERCP may occasionally fail due to anatomical and technical challenges,
for example, in cases of inaccessible ampulla [1]. Traditionally, alternative minimally invasive methods for biliary drainage include
percutaneous transhepatic cholangiogram (PTC) placed by interventional radiology (IR).
Though effective, percutaneous biliary drainage has been associated with adverse events
such as biliary peritonitis, pneumothorax, tube dislodgement, patient discomfort,
need for ongoing drain care, as well as restrictions on bathing and swimming [2].
Recently, endoscopic ultrasound (EUS)-guided biliary drainage techniques have been
found to be effective in biliary decompression after unsuccessful ERCP [3]. However, techniques such as EUS rendezvous and antegrade stenting are still limited
by the need to advance a guidewire through a distal bile duct that may be completely
occluded by an obstructive mass. EUS transluminal drainage including choledochoduodenostomy
(EUS-CDS) and hepaticogastrostomy (EUS-HGS) are multi-stage procedures and result
in the creation of a permanent fistula – despite ongoing technique refinements, EUS-CDS
as well as EUS-HGS using conventional techniques carry a risk of stent dislodgement
and bile peritonitis. Novel single-stage EUS-guided techniques may avoid these adverse
events and provide a more effective means of biliary decompression.
Currently, there are limited data on the efficacy and outcomes of EUS-guided transmural
gallbladder drainage, specifically for biliary drainage in the setting of malignant
distal biliary obstruction. Recent studies have found that EUS-guided placement of
a lumen-apposing self-expandable metallic stent (LAMS) is technically feasible, and
a safe and effective alternative in the treatment of acute cholecystitis in patients
unsuitable for surgery or IR drain placement [4]
[5]. We report our experience with LAMS placement for retrograde biliary drainage via
the gallbladder (either cholecystoduodenostomy or cholecystogastrostomy) in a case
series of patients presenting with malignant obstruction requiring biliary decompression.
Methods
This is a retrospective case series from October 2016 to December 2017. Nine patients
underwent EUS-guided LAMS placement with transgastric/transduodenal gallbladder drainage
for malignant obstructive jaundice in the pancreatic head. The patients were initially
referred from both inpatient and outpatient settings for endoscopic attempt at biliary
drainage. All nine patients had native pancreaticobiliary anatomy (i. e. no prior
history of cholecystectomy nor biliary surgeries). At the time of initial consent
for traditional ERCP, patients were also consented for the possible off-label use
of a LAMS for biliary decompression. All procedures were performed by the same interventional
endoscopist (K.K.) at Kaiser Permanente Los Angeles Medical Center, a tertiary care
referral center for the Southern California region of the Kaiser Foundation Health
Plan.
The Olympus UCT-140 curvilinear echoendoscope (Olympus Corp., Center Valley, Pennsylvania,
United States) and electrocautery-enhanced AXIOS stent (Boston Scientific Co., Natick,
Massachusetts, United States) were used in all procedures. The AXIOS stent is an electrocautery-enhanced
LAMS, which consists of a fully covered, nitinol, braided stent with a “dumbbell”
configuration and bilateral anchor flanges that appose two lumens and minimize the
chance of stent migration ([Fig. 1]).
Fig. 1 Representative images of the 9F electrocautery-enhanced lumen apposing metal stent.
Cystic duct patency, which is a key requirement of this technique, was confirmed doubly.
First, during pre-procedure planning, there was meticulous review of cross-sectional
imaging (including magnetic resonance cholangiopancreatography (MRCP) which was available
in 8/9 patients) demonstrating the presence of a distended, hydropic gallbladder,
intrahepatic biliary dilation, as well as obstructing mass isolated only to the pancreatic
head. Second, when the decision was made to proceed with EUS-guided LAMS placement,
the gallbladder and cystic duct takeoff were interrogated in detail with EUS to confirm
the absence of obvious stones or obstructing masses. To reduce the potential of bile
leak or otherwise technical failure during device exchange, the senior author decided
against pre-puncture and contrast instillation with a fine needle aspiration (FNA)
needle before LAMS placement. To maximize patient safety, all procedures were performed
under general endotracheal anesthesia (GETA). All lumen apposing stents were placed
via the freehand technique.
The method of stent placement was modified depending on the degree of gallbladder
distension. If the ideal short axis diameter for all cases (linear distance between
the transducer and the distal gallbladder wall) was greater than 3.5 cm, then stent
deployment would proceed in standard fashion. However, if the short axis diameter
were less than 3.5 cm, the stent deployment method would be modified to allow partial
pre-deployment and prevent excess deployment against the distal gallbladder wall ([Fig. 2 – 5] and [Supplementary Videos 1] and 2). Due to the nature of the disease (pancreatic adenocarcinoma), in all cases, the
LAMS were either left in place for long-term biliary drainage, or removed as part
of the surgical explant.
Fig. 2 Initial EUS-guided stent deployment into gallbladder.
Fig. 3 Dilation of lumen apposing metal stent (LAMS) to 15 mm.
Fig. 4 EUS image of lumen apposing metal stent (LAMS) from gallbladder to duodenum.
Fig. 5 Endoscopic view of lumen apposing metal stent (LAMS) in duodenum.
Supplementary Video 1 Table-top depiction of stent deployment.
Supplementary Video 2 Stent deployment method. Step 1: Unlock locking catheter, tent mucosa. Step 2: Apply
electrocautery, enter gallbladder (stage 1). Step 3: Lock locking catheter. Step 4:
Unlock locking catheter and deployment hub (stage 2) to deploy stent without “jumping
forward”. Step 5: Retract catheter, tent internal flange, lock catheter lock (stage
3). Step 6: Unlock deployment hub, finish stent deployment inside scope (stage 4).
Step 7: Unlock locking catheter, simultaneously back away EUS scope while pushing
stent out of the channel.
The primary outcomes of interest included technical and clinical success, and the
incidence of procedural adverse events. Secondary outcomes included fluoroscopy time
and whether EUS rendezvous was previously attempted. Technical success was defined
as successful stent placement in accessing and draining the gallbladder. Clinical
success was defined as symptom and post-procedural liver chemistry improvement. The
patients were followed for post-procedure adverse events including stent migration,
perforation, and stent occlusion requiring re-intervention within a 30-day period.
All patients were censored at time of last follow-up within the integrated health
system or at study end (January 15, 2018).
The data were analyzed using descriptive statistics to calculate mean values for the
primary outcomes. This study was approved by the Institutional Review Board of Kaiser
Permanente Southern California (reference number 023563).
Results
Clinical characteristics
A total of nine patients (four women, five men, mean age 63.1 years) underwent LAMS
placement for gallbladder drainage in obstructive jaundice ([Table 1]). All patients were found to have tissue-proven pancreatic ductal adenocarcinoma.
During the study period, six of nine (66.7 %) patients underwent chemotherapy and
two of nine (22.2 %) patients underwent surgical resection during the study period.
One patient had undergone a loop gastrojejunostomy for gastric outlet obstruction
due to duodenal extension of pancreatic cancer before index endoscopic procedure and
another patient underwent pancreaticoduodenectomy after the end of our study period.
Three of nine (33.3 %) patients elected to go on hospice care with no cancer directed
therapy.
Table 1
Baseline characteristics of patients in study.
|
Characteristic
|
Number
|
|
Number of patients
|
9
|
|
Sex (M/F)
|
5/4
|
|
Mean age (range), years
|
63.1 (41 – 80)
|
|
Reason for referral – obstructive jaundice
|
9 (100 %)
|
|
Pathology with pancreatic ductal adenocarcinoma
|
9 (100 %)
|
|
Duodenal obstruction
|
2 (22.2 %)
|
|
Chemotherapy
|
6 (66.7 %)
|
|
Surgery post biliary decompression
|
2 (22.2 %) during study period
|
|
Hospice
|
3 (33.3 %)
|
|
Deaths due to underlying disease progression
|
4 (44.4 %)
|
Endoscopic features
In four of nine (44.44 %) patients, ERCP with EUS rendezvous was initially attempted
(transduodenal antegrade wire advancement to the ampulla), but was unsuccessful due
to suboptimal scope position, abnormal duodenal anatomy due to obstructing pancreatic
head mass, or inability to advance a guidewire antegrade through the ampullary orifice
into the duodenum. In the remaining patients (five of nine, 55.6 %), traditional ERCP
with EUS rendezvous was not attempted, and instead LAMS placement was the primary
modality of choice due to the presence of a markedly dilated biliary system with hydropic
gallbladder ([Fig. 6]) and anticipated difficulties with traditional methods (two referrals for repeated
ERCP failures, two for duodenal obstruction, and one for attempted but unsuccessful
standard ERCP by the senior author). In one patient, there was a stricture at the
juncture of the duodenal bulb and second portion that first required placement of
a Wallflex duodenal stent (22 mm × 60 mm, Boston Scientific Co). In another case,
there was an incomplete obstruction of the duodenal sweep that prevented adequate
duodenoscope advancement past the duodenal bulb and subsequently required Wallflex
duodenal stent placement at a repeat endoscopy 6 months later. In these cases, single
stage biliary decompression was preferred to decrease the risk of iatrogenic duodenal
stent migration and the technical difficulty of traditional ERCP.
Fig. 6 A representative patient with a pancreatic head mass resulting in a hydropic gallbladder.
Technical efficacy and clinical outcomes
Placement of the LAMS was technically successful in all nine patients. Either a transduodenal
or transgastric approach was used depending on where the largest window of gallbladder
access was identified. A 15 mm × 10 mm LAMS was placed in most of the patients (six
of nine, 66.7 %); in three of nine (33.3 %) patients, a double pigtail stent was placed
coaxially if there were concerns about either tissue overgrowth or stent embedment
that would prevent future stent removal if needed ([Table 2]). The LAMS was placed from the duodenal bulb to gallbladder in five of nine (55.6 %)
patients and from the gastric antrum to gallbladder in four of nine (44.4 %) patients.
Mean fluoroscopy time was 1.02 minutes.
Table 2
Interventions and outcomes for each patient in the study.
|
Age/sex
|
LAMS, mm
|
Coaxial stent (double pigtail plastic stent through LAMS)
|
Access route
|
Duodenal obstruction
|
EUS rendezvous attempted
|
Fluoroscopy time, min
|
Complications
|
Technical success
|
Clinical success
|
|
73 F
|
15 × 10
|
No
|
Transgastric
|
No
|
No
|
0.5
|
None
|
Yes
|
Lost to follow-up
|
|
57 F
|
15 × 10
|
Yes
|
Transgastric
|
Partial obstruction
|
No
|
0.17
|
None
|
Yes
|
Yes
|
|
68 F
|
10 × 10
|
No
|
Transduodenal
|
No
|
Yes
|
0.97
|
None
|
Yes
|
Yes
|
|
48 M
|
15 × 10
|
No
|
Transduodenal
|
No
|
No
|
0.15
|
None
|
Yes
|
Yes
|
|
57 M
|
15 × 10
|
No
|
Transgastric
|
Prior loop gastrojejunostomy
|
No
|
1.78
|
None
|
Yes
|
Yes
|
|
41 F
|
10 × 10
|
No
|
Transduodenal
|
No
|
Yes
|
1.63
|
None
|
Yes
|
Required IR drain
|
|
76 M
|
15 × 10
|
Yes
|
Transduodenal
|
No
|
Yes
|
1.55
|
None
|
Yes
|
Yes
|
|
80 M
|
10 × 10
|
No
|
Transduodenal
|
No
|
Yes
|
0.18
|
None
|
Yes
|
Yes
|
|
68 M
|
15 × 10
|
Yes
|
Transgastric
|
Duodenal stricture requiring stent
|
No
|
2.25
|
None
|
Yes
|
Yes
|
EUS, endoscopic ultrasound; IR, interventional radiology; LAMS, lumen-apposing self-expandable
metallic stent.
There were no procedural adverse events. Seven of nine (77.8 %) patients showed clinical
improvement following the procedure with improvement in symptoms and immediate improvement
in liver enzymes on repeat blood work done within a week of the procedure. One patient
presented with a persistently elevated bilirubin level and had ongoing abdominal pain
despite LAMS placement, requiring an IR percutaneous transhepatic cholangiogram and
external biliary drainage catheter placement within 2 weeks of LAMS placement. The
final patient elected to proceed with hospice care and did not have follow-up lab
evaluation. Another patient improved clinically after the initial LAMS placement for
biliary decompression, but developed recurrent biliary obstruction with progressive
disease 7 months after the index procedure, necessitating repeat endoscopic intervention
with choledochoduodenostomy. She again demonstrated improvement in symptoms and liver
enzymes after the repeat procedure.
There was no need for any endoscopic re-intervention due to stent malfunction in any
of the cases. To date, no stents required endoscopic removal due to malfunction. Of
note, two stents were uneventfully removed as part of the surgical explant specimen
in two patients who underwent a pancreaticoduodenectomy. The average time of follow-up
was 130.7 days with a mortality rate of four of nine (44.44 %) due to underlying disease
progression.
Discussion
In this retrospective case series, we found that EUS-guided LAMS placement for transmural
gallbladder drainage in malignant obstruction was technically successful and improved
clinical outcomes, either as a temporizing measure to facilitate neoadjuvant chemotherapy
or as a definitive, palliative measure. Of the six patients who sought full cancer
therapy post biliary decompression, five were able to proceed with planned chemotherapy
with LAMS placement alone. Only in one case was there a need to undergo re-intervention
with IR percutaneous transhepatic drain placement within 2 weeks of LAMS placement.
However, recurrent biliary obstruction may also have been related to the aggressive
nature of that patient’s pancreatic ductal adenocarcinoma.
This procedure was technically successful in all nine cases, including four of nine
cases where EUS rendezvous was initially attempted but unsuccessful. There were no
procedural adverse events or stent malfunctions that required re-intervention. In
one case of eventual tumor progression leading to recurrent obstructive jaundice,
repeat endoscopic intervention with EUS-guided choledochoduodenostomy using LAMS placement
also proved to be technically and clinically successful. Additionally, the mean fluoroscopy
time of 1.02 minutes is significantly lower than published fluoroscopy times in ERCP
cases with failed biliary cannulation [6]. This reduction in fluoroscopy time is an important safety consideration to the
interventional endoscopist as well as the nursing team, since radiation exposure is
cumulative over a lifetime [ALARA (As Low As Reasonably Achievable) principle].
Current methods of EUS-guided biliary drainage include rendezvous, transduodenal choledochoduodenostomy,
and antegrade techniques. EUS rendezvous techniques have a reported overall success
rate of 81 % with a complication rate of 10 % [7]. EUS transluminal biliary drainage via CDS or HGS has higher success rates, up to
84 – 94 % depending on the access route [3]
[8]. However, techniques such as EUS-CDS or HGS have been associated with up to 23 %
risk of adverse events such as bile peritonitis, pneumoperitoneum, hemobilia, cholangitis,
or stent migration [9]
[10]. There is also a higher risk of stent migration with the use of traditional plastic
stents or covered self-expandable metallic stents [3]. Bile leakage in these cases may be a result of the prolonged multi-staged procedure
including bile duct puncture, fistula creation and dilation, and stent deployment.
For these reasons, we believe that, in the properly selected patient, cholecystoduodenostomy
through a single-stage, electrocautery enhanced EUS-guided LAMS may be a useful adjunct
to alternative endoscopic methods of non-ampullary biliary drainage (choledochoduodenostomy
and hepaticogastrostomy) and offer key efficiency and safety advantages. First, EUS-guided
LAMS placement can be done as a single-stage procedure by utilizing the cautery-enhanced
tip of the LAMS, which allows transmural gallbladder penetration and stent deployment
to be completed in one step, without the need for multi-step fistulous tract dilation.
This allows for a shorter procedure that not only decreases fluoroscopy time, but
also minimizes the risk of bile leak leading to peritonitis. Second, because the LAMS
design facilitates rapid lumen apposition, it may be a technically feasible option
in patients with malignant ascites. Third, the gallbladder and gastrointestinal lumen
are both capacious enough to accommodate a 24-mm inner and outer flange, thereby reducing
the risk of variable biliary obstruction from stent-duct size mismatch and possible
cholangitis. Fourth, in the absence of cholecystitis, up to 75 % of hepatic bile flow
typically enters the gallbladder, and thus, we believe this endoscopic drainage technique
can more closely mimic normal enterohepatic bile circulation [11]. In fact, this may explain why patients with malignant distal biliary obstruction
often present with markedly hydropic gallbladders, the diameter of which is typically
much larger than the bile duct upstream from the obstruction.
Although a cholecystoduodenostomy/cholecystogastrostomy may result in a slightly more
challenging pancreaticoduodenectomy dissection due to adhesions, the same can occur
with a choledochoduodenostomy as well as hepaticogastrostomy. With proper pre-procedure
planning, the LAMS can be removed as part of the en bloc surgical explant without
additional intervention on the part of the surgeon, as was seen in two of nine patients
in this case series. In fact, this method of transluminal endoscopic drainage may
be preferable as the stent is fully contained within the explanted specimen, thereby
reducing the likelihood of surgeon injury that may result from inadvertently transecting
the indwelling metal stent. Finally, deploying a fully covered LAMS preserves all
options, including stent removal at a later date if a patient is deemed inoperable
despite neoadjuvant chemotherapy.
Although historically there was limited data on the efficacy of EUS-guided transmural
gallbladder drainage in malignant obstruction, there is increasing awareness of this
technique’s utility in biliary decompression for malignant obstruction. A retrospective
review of 12 patients with obstructive jaundice demonstrated the technical and clinical
success of EUS-guided gallbladder drainage using an electrocautery-unenhanced LAMS
in cases of failed ERCP due to malignant distal biliary obstruction [12]. In that series, the technical and clinical success rates were 100 % and 92 %, respectively;
the 16.7 % adverse event rate (2/12) was similar to previously published data on EUS-CDS/EUS-HGS. We
believe that the electrocautery enhancement to the LAMS delivery system is crucial
to an efficient and safe procedure, to reduce the likelihood of bile leakage and peritonitis
that may occur during multi-stage delivery using first-generation devices. The first
prospective multicenter study using an electrocautery-enhanced LAMS for EUS-CDS reported
100 % technical and 95 % clinical success rates with 15.8 % procedure-related adverse
event rate [13]. We suspect the adverse event rate in that trial (3/29 cases) may have been attributable
either to smaller LAMS diameters (6 mm and 8 mm, neither of which are currently available
in the United States), or potentially to the angle of deployment resulting in variable
stent obstruction, due to the relatively smaller bile duct diameter compared with
a hydropic gallbladder. It is worth noting that the LAMS design (which has a “dumbbell”
shape) requires an oversized inner and outer flange to maintain lumen apposition.
For example, in the prospective multicenter study, even the 6 mm LAMS (not currently
available in the United States) has a 14 mm flange diameter; the 10 and 15 mm LAMS
in use in the United States have up to a 24 mm flange diameter [13]. Nevertheless, this study demonstrated that EUS-CDS using the LAMS was superior
to EUS-CDS with conventional tubular stents; previously reported technical success
rate and procedure-related adverse event rate were 84.3 % and 32.6 %, respectively
[8]
[13]. Additionally, for acute cholecystitis, there is increasing literature to support
the view that EUS-guided transmural gallbladder drainage with LAMS placement resulted
in shorter hospital stays, lower pain scores, need for fewer interventions, and decreased
adverse events compared to percutaneous transhepatic gallbladder drainage [5]
[13]
[14]
[15]
[16]
[17].
There were some limitations to this retrospective case series, including small sample
size and limited follow-up time. Additionally, due to the heterogeneity of patients
and retrospective design, we were not able to perform case matching with similar patients
who underwent alternative endoscopic methods of biliary decompression (e. g. traditional
ERCP, EUS-CDS).
In conclusion, EUS-guided LAMS placement for transmural gallbladder drainage in malignant
obstruction appears to be a safe and effective technique. Patients were able to reach
desired treatment end points with this method of biliary decompression, whether in
pursuing further chemotherapy and surgery or transitioning to hospice care. In the
properly selected patient, this method may be a reasonable alternative when patients
are poor candidates for percutaneous transhepatic drain placement or previously described
EUS-guided techniques are suboptimal. Future comparative effectiveness studies are
needed to define the role of transmural gallbladder LAMS placement, in comparison
to EUS-CDS or EUS-HGS, for biliary decompression in malignant obstruction.