Abbreviations
AE:
adverse event
APC:
argon plasma coagulation
CBD:
common bile duct
DPPS:
double-pigtail plastic stent
EC-LAMS:
electrocautery-enhanced lumen-apposing metal stent
EDGE:
endoscopic ultrasound-directed transgastric endoscopic retrograde cholangiopancreatography
ERCP:
endoscopic retrograde cholangiopancreatography
ERP:
endoscopic retrograde pancreatography
ESGE:
European Society of Gastrointestinal Endoscopy
EUS:
endoscopic ultrasound
EUS-BD:
EUS-guided biliary drainage
EUS-CDS:
EUS-guided choledochoduodenostomy
EUS-GBD:
EUS-guided gallbladder drainage
EUS-GE:
EUS-guided gastroenterostomy
EUS-HGS:
EUS-guided hepaticogastrostomy
EUS-RV:
EUS-assisted rendezvous
FCSEMS:
fully covered self-expandable metal stent
FNA:
fine-needle aspiration
GI:
gastrointestinal
GOO:
gastric outlet obstruction
GRADE:
Grading of Recommendations Assessment, Development and Evaluation
LAMS:
lumen-apposing metal stent
MPD:
main pancreatic duct
OTS:
over-the-scope
PCSEMS:
partially covered self-expandable metal stent
PD:
pancreatic duct
PTBD:
percutaneous transhepatic biliary drainage
RV-ERP:
rendezvous-assisted endoscopic retrograde pancreatography
RYGB:
Roux-en-Y gastric bypass
SEMS:
self-expandable metal stent
USEMS:
uncovered self-expandable metal stent
WEST:
wireless endoscopic simplified technique
This Technical review complements the recent European Society of Gastrointestinal
Endoscopy (ESGE) Guideline on therapeutic endoscopic ultrasound. The aim of this Technical
review is to discuss the technical considerations of therapeutic endoscopic ultrasound
and the management of adverse events. The Grading of Recommendations Assessment, Development
and Evaluation (GRADE) system was adopted to define the strength of recommendations
and the quality of evidence.
1 Introduction
Endoscopic ultrasound (EUS) enables several therapeutic interventions in the pancreaticobiliary
and gastrointestinal (GI) tract. A recent European Society of Gastrointestinal Endoscopy
(ESGE) Guideline on therapeutic EUS provided an extensive overview of the indications
and outcomes of these procedures [1 ]. EUS-guided management of fluid collections in acute necrotizing pancreatitis has
been discussed in a previous ESGE guideline [2 ]. This review of the technical aspects of therapeutic EUS was commissioned by the
ESGE to complement the guideline [1 ] focusing on procedural features and management of adverse events (AEs).
2 Methods
ESGE assigned this technical review and appointed a coordinating team (S.v.d.M., J.H.,
R.W., M.Br.). A team of experts across different domains of therapeutic EUS convened
in May 2020. Two task force leaders (M.Ba. and M.P.M.) and their team members scrutinized
the available literature for relevant articles pertaining to their fields of expertise.
Topic-specific key questions were generated by each task force leader. Searches were
performed using Medline (via Pubmed) and the Cochrane library up to June 2021. The
level of evidence for each question was scored according to the Grading of Recommendations
Assessment, Development and Evaluation (GRADE) system into high, moderate, low, or
very low [3 ]. Recommendations were drafted and the strength of each was determined as strong
or weak. Various web meetings were held to discuss and resolve issues, and formulate
recommendations.
In October 2021, a final draft was sent to all group members for review. After all
authors approved the final version, the manuscript was submitted to Endoscopy for publication. ESGE acknowledges that the field of therapeutic EUS is rapidly changing
and that continued efforts will be required in the future to update and maintain these
guidelines as more high quality published data are generated.
3 General precautions and principles for therapeutic EUS
3 General precautions and principles for therapeutic EUS
3.1 Key question1: What are the general pre- and post-procedural precautions that
should be taken when performing therapeutic EUS?
ESGE recommends therapeutic EUS procedures should be performed by endoscopists with
adequate training and experience, at centers where interventional radiology and hepatopancreaticobiliary
surgical expertise are available.
Strong recommendation, low quality evidence.
3.1.1 General considerations
Patients considered for therapeutic EUS procedures should be carefully selected based
on criteria provided in the ESGE guideline [1 ]. In some settings, multidisciplinary discussions may be applicable before embarking
on these procedures. Patients should be made aware of specific procedure-related risks
and potential alternative therapeutic strategies when providing informed consent.
The endoscopist performing the procedure should have adequate experience in therapeutic
EUS and endoscopic retrograde cholangiopancreatography (ERCP), as the level of the
endoscopist’s experience determines procedural outcome [4 ]
[5 ]
[6 ]
[7 ]
[8 ]
[9 ]. In addition, the availability of hepatopancreaticobiliary surgical and interventional
radiological expertise is recommended in centers where therapeutic EUS procedures
are performed, in case AEs occur [10 ]
[11 ].
3.1.2 Preprocedural considerations
ESGE recommends temporary discontinuation of anticoagulant therapy before embarking
on therapeutic EUS procedures.
Strong recommendation, low quality evidence.
ESGE recommends temporarily switching dual antiplatelet therapy to aspirin monotherapy,
whenever possible, before embarking on therapeutic EUS procedures.
Strong recommendation, low quality evidence.
ESGE suggests prophylactic administration of an intravenous broad-spectrum antibiotic
in all patients undergoing therapeutic EUS procedures.
Weak recommendation, low quality evidence.
ESGE recommends a prolonged course of a prophylactic broad-spectrum antibiotic in
patients with ascites who are undergoing therapeutic EUS procedures.
Strong recommendation, low quality evidence.
According to the recent ESGE guideline on antiplatelet or anticoagulation therapy
use in endoscopy, therapeutic EUS procedures are classified “high risk” [12 ]. In accordance with this guideline, before embarking on a therapeutic EUS procedure,
anticoagulant therapy should be temporarily discontinued, while dual antiplatelet
therapy should be converted to aspirin monotherapy where possible. However, small
series have described the successful use of fully covered self-expandable metal stents
(FCSEMSs) or lumen-apposing metal stents (LAMSs) in bile duct and gallbladder drainage
procedures in patients on anticoagulant and/or antiplatelet therapy [13 ]
[14 ]. The inherent radial expansion forces of these stents will likely contribute to
a reduced risk of periprocedural bleeding by providing a tamponade effect on the intraparietal
blood vessels [13 ]
[15 ]. Even though these data are encouraging, more high quality evidence is needed before
the current ESGE recommendations can be reconsidered.
Prophylactic administration of broad-spectrum antibiotics may prevent infectious AEs
following a therapeutic EUS procedure. There are currently no data available that
have reported prophylactic antibiotics to be beneficial in therapeutic EUS. Until
more data become available, it is recommended that a single dose of intravenous antibiotics
is administered when a transmural therapeutic procedure is performed, analogous to
surgical and interventional radiology protocols [16 ]
[17 ]. Longer administration periods may be required in the presence of ascites, in immunocompromised
patients, or in those where adequate biliary drainage was not achieved.
A large volume of ascites may increase the difficulty of therapeutic EUS as it may
prevent access to the target organ with a fine-needle aspiration (FNA) needle or stent
catheter, and may lead to stent migration and cause bacterial peritonitis [18 ]
[19 ]. When a therapeutic EUS procedure is still deemed necessary, a preprocedural paracentesis
may be helpful before embarking on such a procedure.
3.1.3 Periprocedural considerations
Adequate support to protect the patient’s airway and prevent aspiration is regarded
as indispensable during therapeutic EUS. Many centers perform therapeutic EUS exclusively
in intubated and mechanically ventilated patients under general anesthesia, whilst
conscious/deep sedation is used in other experienced centers without compromising
safety outcomes. Procedures should ideally be performed in a fluoroscopy room, where
imaging may be especially helpful in providing guidance if endoscopic salvage procedures
are required.
3.1.4 Post-procedural considerations
The duration of post-procedural hospitalization for observation should be based on
a patient’s characteristics, such as medical co-morbidities, and procedural aspects,
including a higher risk and/or greater difficulty of the procedure. Imaging studies
(e. g. CT scan) should be performed when a post-procedural AE is suspected.
3.2 Key question 2: What are the general technical principles in therapeutic EUS?
3.2.1 Which interventional therapeutic techniques are used?
Therapeutic EUS uses various different approaches to obtain access to the target structure.
The “rendezvous” technique (or “EUS-assisted” procedure) refers to the use of EUS
to provide ductal access to facilitate subsequent ERCP, and is therefore considered
an “indirect technique.” “EUS-guided” interventions refer to procedures performed
under EUS guidance and therefore considered “direct techniques.”
Direct EUS-guided interventions typically involve transmural stent placement. These
procedures can either be performed by a multistep approach, where access to the target
organ is obtained using an FNA needle and guidewire that allows over-the-wire insertion
of various tools and placement of a stent, or alternatively, an all-in-one approach
using an electrocautery-enhanced lumen-apposing metal stent (EC-LAMS), which permits
“free-hand” insertion of this device into the target structure without prior placement
of a guidewire. The latter technique obviates the need for multiple accessory exchanges,
thereby potentially reducing the risk of procedural failure and AEs. Some EUS-guided
interventions may be further assisted by the use of additional accessories such as
catheters (i. e. nasobiliary) or balloons.
When the target structures of interventional EUS are the pancreatic and biliary ducts,
direct techniques may allow antegrade, as well as transmural, drainage. In addition
to retrograde procedures by ERCP, antegrade procedures reinstate the normal flow direction
by bridging a stenosis and/or papilla, whereas transmural drainage redirects flow
away from the normal route by creating a new anastomosis.
3.2.2 General technical principles in EUS-assisted and EUS-guided techniques
ESGE suggests a fistulous tract be created using a 6-Fr cystotome or alternatively
by mechanical dilation.
Weak recommendation, low quality evidence.
ESGE recommends that endoscopists should undergo rigorous training in lumen-apposing
metal stent placement and the management of adverse events before undertaking therapeutic
EUS procedures using these devices.
Strong recommendation, low quality evidence.
During EUS-assisted rendezvous (EUS-RV), access to the target structure is obtained
using an EUS-FNA needle (most commonly a 19 G needle as it accommodates guidewires
up to 0.035-inch diameter). Before the injection of contrast, adequate positioning
of the needle tip inside the target lumen should be confirmed by EUS. When a bile
duct is punctured, aspiration of bile may further confirm proper needle positioning.
Correct needle placement is followed by contrast injection to depict the anatomy of
the target structure (pancreatic or biliary duct, gallbladder, small intestine, or
stomach). The needle is ideally rinsed with saline every time contrast is injected,
to prevent subsequent difficulties with guidewire advancement due to the adhesive
properties of the contrast medium. Because of its stiffness, some endoscopists favor
the use of a 0.035-inch guidewire of 450 cm in length with an 19 G FNA needle. However,
this may shear easily, hampering wire manipulation and leaving residual foreign material
behind in the target when a beveled needle is being used. In order to overcome shearing,
an atraumatic “access” needle may be used. Alternatively, a 19G FNA needle may be
combined with a thinner 0.025-inch monofilament guidewire that is less prone to shearing
[20 ].
When the diameter of the target organ is limited, such as for biliary access, a thinner
22 G needle may be preferred over a 19 G needle, which can accommodate small 0.021-inch
or 0.018-inch guidewires [21 ]. However, subsequent device advancement can be considerably more challenging when
using small caliber guidewires. In addition, small caliber guidewires are not insulated
against electrical current and are therefore not compatible with the concomitant use
of cautery-based devices such as cystotomes.
Guidewire manipulation in EUS-guided biliary drainage (EUS-BD) is critical, especially
in EUS-RV and antegrade transpapillary (or transanastomotic) stent placement, as successful
passage of the stricture and/or papilla is required to complete the procedure. If
the direction of the wire is undesirable, a wire with an angulated tip or a torque
device may aid in steering it across a stricture. Recently, a steerable access needle
has been developed, which facilitates guidewire advancement in the desired direction
and appears to be especially useful in EUS-RV, where cystotomes or sphincterotomes
are not commonly used [22 ]
[23 ].
In EUS-RV, the wire is advanced via the pancreatic or biliary duct into the duodenum,
after which the echoendoscope is removed and exchanged for a duodenoscope, while leaving
the guidewire in place for subsequent ERCP. In EUS-guided procedures, successful guidewire
placement is followed by the creation of a fistulous tract, which enables subsequent
transmural or antegrade stent placement.
Fistula tract dilation can be achieved using mechanical or cautery devices. For mechanical
dilation, a tapered dilating catheter or a hydrostatic balloon may be used [20 ]
[24 ]. Mechanical dilation limits damage to surrounding structures. These devices are
however sometimes difficult to insert across the puncture tract, which may then compromise
the stability of the endoscope.
Cautery devices enable the application of pure cutting current to overcome this problem.
A coaxial cystotome is preferred over a needle-knife because the latter has been identified
as a risk factor for AEs in EUS-BD [25 ]. More specifically, the 6-Fr cystotome is an ideal accessory that creates a tract
that allows the introduction of various tools and stent-introducing catheters, without
leading to clinically significant bile leakage or capnoperitoneum/pneumoperitoneum
if the procedure should fail [26 ]. The 6-Fr cystotome is however not universally available and, in this specific context,
mechanical dilation is preferred over the use of a 10-Fr cystotome, as such a large
caliber device may lead to significantly more thermal injury to the surrounding structures,
potentially resulting in leakage of GI contents and free air if the procedure should
fail.
The development of EC-LAMSs has enabled one-step direct access and drainage of the
common bile duct and gallbladder; they are also used to create anastomoses in the
GI tract. The development of EC-LAMSs has revolutionized the field of therapeutic
EUS owing to their following unique characteristics. First, the all-in-one device
obviates the need to use multiple tools, avoiding device exchanges that could potentially
lead to procedural failure and AEs. Second, their dumbbell shape prevents migration
and fuses the individual wall layers together, forming a mature anastomosis. Third,
LAMSs are fully covered and leakage of bile or gastric acid intra-abdominally is rare.
This characteristic also facilitates stent removal when indicated [27 ]. EC-LAMSs are available in various sizes in order to meet specific procedural needs
([Table 1 ]).
Table 1
The currently available electrocautery-enhanced lumen-apposing metals stents.
Stent
Manufacturer
Stent measurements, mm
Delivery system
Internal diameter
Flange diameter
Saddle length
Profile, Fr
Usable length, cm
Hot Axios
Boston Scientific, Marlborough, Massachusetts, USA
6
14
8
9
138
8
17
8
9
138
10
21
10
10.8
138
15
24
10
10.8
138
15
24
15
10.8
138
20
29
10
10.8
138
Hot Spaxus
Taewoong Medical, Gyeonggi-do, South Korea
8
23
20/7[* ]
10
180
10
25
20/7[* ]
10
180
16
31
20/7[* ]
10
180
* The saddle length of the Hot Spaxus stent is variable between 7 and 20 mm.
Initially, EC-LAMSs were introduced over a guidewire, but this technique has fallen
out of favor as the guidewire may actually push the target structure away from the
GI wall, leading to stent maldeployment [28 ]. Therefore, EC-LAMSs are preferably introduced directly into the target structure
using pure cutting current, referred to as the “free-hand technique.” An endosonographic
window where the target organ is within 10–20 mm from the GI wall (depending on the
stent design), without intervening large blood vessels or ascites, should be sought.
Placement of the LAMS is performed by applying pure cutting current (Autocut 100–150 W,
effect 3–5) just before advancing the cautery tip to ensure rapid bridging of the
GI layers into the target structure and to lessen coagulation artefacts that may obscure
the view of the device. When the electrocautery tip is in position within the target
structure, the distal flange of the LAMS can be deployed under endosonographic control.
When adequately deployed, the distal flange is pulled towards the GI wall until its
shape changes from flat to oval, indicating adequate approximation of the layers to
allow for safe release of the proximal flange inside the GI lumen. More control over
the stent position can be achieved by the proximal flange of the LAMS being deployed
inside the working channel of the echoendoscope and slowly expelled under endoscopic
control [29 ].
After successful placement of LAMSs, adequate stent position should be confirmed by
either endoscopic confirmation of recognizable fluid (e. g. bile, or blue-dyed liquid
in the case of EUS-GE) being released from the stent, or contrast injection through
the stent, which will fluoroscopically confirm correct placement within the target
structure. It is of utmost importance to immediately recognize stent maldeployment
during the procedure, so that adequate salvage measures may be undertaken as described
in the sections below. Therefore, adequate training in LAMS placement and the management
of AEs should be a prerequisite before performing therapeutic EUS procedures.
3.2.3 When should a therapeutic EUS procedure be aborted?
ESGE recommends discontinuation of the procedure when tumor infiltration, significant
ascites, or large intervening blood vessels are identified at the desired puncture
site of the gastrointestinal wall or target organ.
Strong recommendation, low quality evidence.
Certain findings during the procedure may prevent successful completion and will require
the endoscopist to abort. These include identifying infiltrating tumor or large blood
vessels in the GI wall or target organ along the trajectory of the desired puncture
site. Under these circumstances, the procedure should be aborted owing to an increased
risk of stent maldeployment and bleeding [20 ]. The same risks apply, when the target structure is located at a distance of more
than 15–20 mm, if a significant volume of ascites is present, or if intervening bowel
loops are detected.
In some instances, the procedure needs to be abandoned after an EUS needle, cystotome,
or electrocautery device has already been used to puncture a structure. In such circumstances,
mucosal closure may be considered and the patient should be observed for longer for
any evidence of AEs. Diagnostic imaging should be performed immediately in such cases
and interventional radiology or surgery may be warranted in rare instances.
4 Biliary and pancreatic duct drainage
4 Biliary and pancreatic duct drainage
EUS-guided drainage of the biliary system (EUS-BD) or the pancreatic ducts (EUS-guided
PD drainage) may be required when conventional ERCP fails. How these procedures compare
with percutaneous and surgical alternatives, and when they should be undertaken is
discussed in greater detail in the ESGE guideline on therapeutic EUS [1 ].
4.1 Key question 3: How should EUS-BD be performed?
4.1.1 EUS-assisted rendezvous
Almost all EUS-RVs are accomplished with the linear echoendoscope positioned in the
duodenal bulb [30 ]
[31 ] ([Fig. 1a ]). The procedure is also possible by approaching the left intrahepatic bile ducts
from the proximal stomach and advancing the wire across the papilla for subsequent
ERCP, provided that the intrahepatic bile ducts are sufficiently dilated.
Fig. 1a–c Illustrations of therapeutic endoscopic ultrasound (EUS) interventions of the pancreaticobiliary
and gastrointestinal tract showing: a EUS-assisted rendezvous (biliary); b EUS-guided antegrade stenting; c EUS-guided choledochoduodenostomy. Source: Martha Meisen.
The common bile duct (CBD) or intrahepatic ducts are generally punctured with a 19 G
FNA needle, although, when only mildly dilated, a thinner 22 G needle may be preferred
[21 ]. After adequate needle positioning has been confirmed, a cholangiogram is performed.
The guidewire should then be manipulated across the papilla into the duodenum where
it is coiled. At this point, the echoendoscope is carefully removed leaving the guidewire
behind. A duodenoscope is then introduced alongside the guidewire and advanced up
to the level of the papilla. A sphincterotome can then be advanced directly adjacent
to the guidewire where it protrudes from the papilla, which may allow CBD cannulation.
Alternatively, the guidewire protruding from the papilla and coiled in the duodenum
may be grasped using a forceps or snare and pulled through the working channel of
the duodenoscope, over which a sphincterotome may then be advanced into the CBD. During
this step, care should be taken to grasp an adequate length of the guidewire, in order
to prevent wire fracture near its floppy tip.
4.1.2 EUS-guided antegrade stenting
For EUS-guided antegrade stenting, the echoendoscope is positioned in the stomach
and directed so that the intrahepatic bile ducts of the left liver lobe can be visualized
([Fig. 1b ]), whilst at the same time avoiding a transesophageal puncture, which may carry a
higher risk of AEs [32 ]. The intrahepatic bile ducts are punctured preferably at a depth of 2.5–3 cm, so
that the surrounding liver parenchyma will contain any potential bile leakage [33 ]. A cholangiogram will provide a “roadmap” that will aid in guidewire passage across
the stricture and/or papilla. When the guidewire is safely coiled up within the small
intestine or positioned deep into the intrahepatic bile ducts, a fistulous tract can
be created using a cystotome or dilation balloon, which allows the introduction of
the accessories that will aid in performing sphincteroplasty, stricture dilation,
brush cytology, stone removal, and/or SEMS placement.
Adequate dilation of a distal stricture should be considered before placement of a
transpapillary stent as the direction of the stent catheter away from the papilla
can lead to loss of stiffness and ability to advance the stent catheter. When intraductal
pressure is relieved from the biliary system by downstream stent placement, the risk
of bile leakage from the puncture tract is negligible. Conversely, when stent placement
across the obstruction fails, the risk of bile leakage is of concern and warrants
salvage biliary drainage, either with EUS-guided hepaticogastrostomy (EUS-HGS) or
percutaneous transhepatic biliary duct drainage (PTBD).
4.1.3 EUS-guided choledochoduodenostomy
ESGE recommends the placement of partially or fully covered self-expandable metal
stents or small caliber lumen-apposing metal stents during EUS-guided choledochoduodenostomy.
Strong recommendation, moderate quality evidence.
In EUS-guided choledochoduodenostomy (EUS-CDS), a biliodigestive anastomosis is created
with either a biliary metal stent or LAMS ([Fig. 1c ]). The distal CBD is visualized from the duodenal bulb, and an optimal window for
EUS-CDS is sought, avoiding intervening tumor tissue. The CBD is punctured, a cholangiogram
performed, and a guidewire placed, facilitating dilation of the tract for stent placement.
Plastic stents, uncovered and covered biliary metal stents, and LAMSs have all been
used in performing EUS-CDS ([Table 2 ]). Plastic stents and uncovered SEMSs (USEMSs) may however fail to adequately seal
the biliodigestive anastomosis and may increase the risk of bile leakage [34 ]. Studies using FCSEMSs, usually 6 cm in length, have reported satisfactory outcomes.
Partially covered SEMSs (PCSEMSs) have also been used, where anchoring fins and minimal
foreshortening of the stent counteract stent migration [35 ]
[36 ]
[37 ].
Table 2
Stents advised for each therapeutic endoscopic ultrasound (EUS) procedure.
Procedure
Plastic stents
Biliary self-expandable metal stents
Lumen-apposing metal stent[* ]
internal diameter × saddle length
EUS-CDS
Not advised for primary drainage
Fully covered
length: 6 cm
diameter: 8–10 mm
Hot Axios 6 × 8 mm, 8 × 8 mm, 10 × 10 mm
Hot Spaxus 8 × 20/7 mm
EUS-HGS
Not advised for primary drainage
Fully covered
length: 8–10 cm
diameter: 8–10 mm
Not advised for primary drainage
Partially covered
EUS-guided PD drainage (antegrade)
Straight or double pigtail
5, 7, 8.5, and 10 Fr
length 7–20 cm
Not advised for primary drainage
Not advised for primary drainage
EUS-GBD
Not advised for primary drainage
Not advised for primary drainage
Hot Axios 10 × 10 mm, 15 × 10 mm
Hot Spaxus 8 × 20/7 mm, 10 × 20/7 mm
EUS-GE
Not advised for primary drainage
Not advised for primary drainage
Hot Axios 15 × 10 mm, 20 × 10 mm
Hot Spaxus 16 × 20/7 mm
EUS-CDS, EUS-guided choledochoduodenostomy; EUS-HGS, EUS-guided hepaticogastrosomy;
PD, pancreatic duct; EUS-GBD, EUS-guided gallbladder drainage; EUS-GE, EUS-guided
gastroenterostomy.
* Lumen-apposing metal stents (LAMSs) detailed here are all electrocautery-enhanced
as their all-in-one design renders them ideal for therapeutic EUS procedures. LAMSs
without the electrocautery-enhanced delivery system (Axios, Spaxus) are also available
in various sizes, but would require multiple accessory exchanges.
More recently, all-in-one EC-LAMSs have enabled the performance of direct EUS-CDS,
eliminating the need for accessory exchanges, theoretically reducing the risk of procedural
failure and AEs. Only small caliber LAMSs should be used for EUS-CDS regardless of
the diameter of the CBD. EUS-CDS will significantly reduce the diameter of the CBD
and the use of larger caliber LAMSs may result in damage to the CBD wall. Data from
one retrospective comparative study and a meta-analysis comparing outcomes with LAMSs
versus biliary SEMSs for EUS-CDS have failed however to show significant differences
between these two techniques [35 ]
[38 ].
For EUS-CDS using an EC-LAMS, the free-hand technique allows direct access to the
CBD. EUS-CDS using a LAMS may be challenging in small diameter CBDs (< 12 mm), as
deployment of the distal flange of the stent inside the duct may be difficult. Two
procedural adjustments that may be considered to overcome this limitation are: (i)
performing LAMS deployment in a stepwise manner, with the distal flange being opened
into the duct in incremental steps; (ii) advancing a guidewire through the LAMS-introducing
catheter, which will allow the operator to direct the catheter towards the liver hilum
and open the stent flange perpendicular to the main axis of the CBD.
4.1.4 EUS-guided hepaticogastrostomy
ESGE recommends placement of partially or fully covered self-expandable metal stents
(SEMSs) during EUS-guided hepaticogastrostomy for biliary drainage in malignant disease.
Strong recommendation, moderate quality evidence.
ESGE recommends temporary placement of fully covered SEMSs during EUS-guided hepaticogastrostomy
for biliary drainage in benign disease.
Strong recommendation, low quality evidence.
During EUS-HGS, the dilated intrahepatic bile ducts are visualized from the left liver
lobe ([Fig. 1d ]). The position of the tip of the echoendoscope should be located in the stomach
to prevent inadvertent placement of a SEMS into the esophagus, which may result in
dysphagia and vomiting. The basic steps are similar to those for EUS-guided antegrade
stent placement. Access is secured by placement of a guidewire through a 19 G needle,
deep into the biliary system, over which accessories can be advanced to permit deployment
of a stent between the dilated left ductal system and the stomach.
Fig. 1d–f Illustrations of therapeutic endoscopic ultrasound (EUS) interventions of the pancreaticobiliary
and gastrointestinal tract showing: d EUS-guided hepaticogastrostomy; e EUS-assisted rendezvous (pancreas); f EUS-guided pancreaticogastrostomy. Source: Martha Meisen.
Various types of stents have been used in EUS-HGS. Double-pigtail stents are difficult
to place and USEMSs carry an unacceptably high risk of bile leakage. A purposely developed
single-pigtail stent for HGS is available in some countries, where excellent outcomes
have been reported using these stents [39 ]
[40 ]. On the other hand, FCSEMSs may obstruct distal bile duct branches and cause cholangitis,
but their removability after fistulous tract maturation makes them especially suitable
for benign indications. In this way EUS-HGS may serve as a “portal” to the biliary
system, allowing direct cholangioscopy-guided lithotripsy, as well as the evaluation
of strictures in surgically altered anatomy [41 ]
[42 ]
[43 ]
[44 ].
Standard FCSEMSs appear less suited for long-term drainage because stent dysfunction
and dislocation, which may be more common with certain FCSEMS types, may occur in
up to 50 % of cases [45 ]. A hybrid stent has been developed with the aim of improving the outcomes of long-term
drainage in malignant settings. It is made of an uncovered (± 30 %) intraductal portion
that prevents bile duct branch obstruction, while the remaining part is fully covered
to prevent bile leakage at the anastomotic transparietal site [46 ].
When EUS-HGS is performed, it is important to deploy the stent inside the working
channel of the scope, whilst simultaneously retracting the scope so that at least
2–3 cm of the stent protrudes into the gastric lumen to prevent stent migration [47 ]
[48 ]. In some instances, when the right and left liver lobes are non-communicating and
are disconnected by tumor, it may be possible to place a bridging stent to reconnect
both systems to optimize biliary drainage [49 ]
[50 ].
4.1.5 EUS-guided hepaticoduodenostomy
ESGE recommends EUS-guided hepaticoduodenostomy be performed only at expert centers
and after careful consideration of all therapeutic options.
Strong recommendation, low quality evidence.
The right liver lobe can only be partially visualized via the duodenal bulb in the
long position. Similarly to EUS-HGS, the bile duct is punctured with a 19 G needle
and a cholangiogram performed. After a guidewire has been advanced into the bile duct,
a tract is created using a 6-Fr cystotome or dilation balloon. An FCSEMS is placed
with the proximal tip in the dilated bile duct and the distal tip about 2–3 cm inside
the duodenum. There is currently only very limited experience with this technically
demanding technique; for this indication PTBD remains the gold standard [51 ]
[52 ].
4.2 Key question 4: What adverse events may occur when EUS-BD is performed and how
should these be managed?
4.2.1 Stent maldeployment and perforation
ESGE recommends endoscopic stent-in-stent therapy when maldeployment occurs during
EUS-guided hepaticogastrostomy and, if this is not feasible, that percutaneous transhepatic
biliary drainage or emergency salvage surgery should be considered.
Strong recommendation, low quality evidence.
Stent maldeployment may lead to bile leakage, which may increase the distance between
the duodenum and CBD, preventing a successful second attempt at LAMS placement. In
this setting, the CBD defect may be closed by performing EUS-RV with placement of
an FCSEMS by ERCP, or alternatively EUS-guided antegrade stent placement may be performed
followed by LAMS removal and endoscopic closure of the duodenal defect with the most
appropriate clip [53 ].
EUS-BD performed in a small diameter CBD increases the risk of accidental perforation
of the portal vein, which can induce substantial blood loss via the LAMS into the
duodenum. The same salvage procedure as described above can ensure resolution of both
the CBD and portal vein defects, although hospitalization and close monitoring will
be required in such instances, given the potential risk of severe bleeding [54 ].
Interventional radiology with PTBD should be used if endoscopic salvage therapy fails.
In EUS-CDS, this is especially warranted for all punctures crossing the peritoneal
cavity. Punctures in the retroperitoneal portion of duodenum and distal CBD may be
managed conservatively, as these can usually be resolved by same-session EUS-guided
CBD drainage, targeting an area adjacent to the site of the failed attempt.
Stent maldeployment in EUS-HGS usually occurs when the proximal end of the stent is
deployed inside the peritoneal cavity, instead of in the gastric lumen, leading to
biliary peritonitis that may potentially be fatal [55 ]. Inadequate stent placement may become apparent when the “candy sign” is observed
on fluoroscopy, whereby the liver capsule and gastric wall are not adjacent to each
other and appear as two distinct indentations [48 ]. This can be prevented by applying tension on the delivery catheter and retracting
the echoendoscope in a stepwise manner to ensure that the proximal end of the stent
opens in the stomach during deployment.
When the proximal end of the stent is still visible in the gastric wall, it can be
pulled towards the gastric lumen using a grasping forceps before an additional stent-in-stent
is placed to anchor the primary stent and prevent migration [56 ]
[57 ]. If the stent is completely outside the gastric wall but the guidewire is still
in place, one may attempt to release a second FCSEMS over the wire in order to bridge
the maldeployed stent to the stomach [58 ]. If this is not possible, access to the dislocated stent can be regained by puncturing
it under EUS guidance, followed by guidewire advancement into the liver and placement
of a second bridging stent [59 ]. When these procedures fail, emergency salvage surgery, with repositioning of the
stent may be indicated [58 ]. The principal objective of all salvage procedures should be to achieve bile duct
drainage and to secure closure of the puncture defects on both sides of adjacent organs,
either by means of surgical drainage or PTBD in order to relieve intraductal pressure,
thereby reducing the risk of delayed bile leakage.
Bleeding may occur during the procedure or may be delayed, but in most cases conservative
treatment and observation will suffice. Rarely, bleeding can be severe or persistent
and interventional radiology management may be required to manage an arteriobiliary
fistula.
4.2.2 Endoscopic treatment of long-term adverse events
ESGE recommends placement of a stent through the metal stent when EUS-guided choledochoduodenostomy
or EUS-guided hepaticogastrostomy is complicated by stent occlusion.
Strong recommendation, low quality evidence.
EUS-CDS stents may become occluded by food remnants or sludge, or due to compression
of the contralateral wall of the CBD, especially when a large diameter LAMS has been
used [60 ]
[61 ]. LAMSs placed for EUS-CDS have been sporadically reported to migrate, though without
bile leakage, which implies that the dislocation has occurred after the fistulous
tract had matured [62 ]
[63 ]. When the fistula is still open, a new stent can be placed. Double-pigtail plastic
stents (DPPSs) may be placed through the metal stent to maintain stent patency [60 ]
[61 ]. Prophylactic DPPS placement through a LAMS was however not found to improve any
procedural outcome in a multicenter retrospective cohort study [64 ].
Stent occlusion in EUS-HGS can be treated by placing DPPSs or SEMSs coaxially through
the occluded metal stent. Stent ingrowth or overgrowth can be addressed by the use
of intraductal radiofrequency ablation to regain stent patency. Cannulation of the
occluded metal stent can sometimes be challenging if a relatively long portion of
the metal stent protrudes into the stomach. In these cases, a small incision made
with a needle-knife along the side of the stent, or trimming by argon plasma coagulation
(APC) may provide easy access into the stent lumen, which then facilitates further
interventions, such as guidewire passage and stent-in-stent placement [65 ]
[66 ].
4.3 Key question 5: How should EUS-guided PD drainage be performed?
4.3.1 General principles of EUS-guided PD
ESGE recommends EUS-guided pancreatic duct drainage should only be performed at high
volume expert centers, owing to the complexity of this technique and the high risk
of adverse events.
Strong recommendation, low quality evidence.
Chronic pancreatitis-related pain may be due to ductal hypertension caused by obstruction
of the main pancreatic duct (MPD) by stones, congenital anomalies, and/or strictures.
Ductal decompression represents the main treatment modality and can be provided by
endoscopic retrograde pancreatography (ERP) or surgical decompression [67 ]. In 2007, a randomized comparison of these two techniques showed superior efficacy
of surgical drainage, with technical success of ERP achieved in only 53 % of cases
at an academic expert setting [67 ]. Surgically altered anatomy, duct disruption, large stones, or tight strictures
are all typical causative features leading to ERP failure.
EUS-guided PD drainage facilitates access to the MPD, thereby leading to EUS-guided
PD drainage becoming an invaluable rescue procedure when ERP fails [68 ]
[69 ]
[70 ]. EUS-guided PD drainage procedures are however technically demanding and lead to
high morbidity in comparison to other therapeutic EUS procedures, and should only
be performed in high volume expert centers. The (contra)indications, comparisons with
alternatives, and potential AEs have been discussed in the ESGE guideline [1 ]. The aim of the following sections is to provide guidance on how EUS-guided PD drainage
should be performed.
ESGE recommends the use of rectal nonsteroidal anti-inflammatory drugs in patients
undergoing EUS-guided pancreatic duct drainage.
Strong recommendation, low quality evidence.
EUS-guided PD drainage can be done by either EUS-assisted (i. e. rendezvous-assisted
ERP [RV-ERP]) or EUS-guided antegrade or transmural approaches. Although no formal
comparison exists between these three approaches, it is generally accepted that RV-ERP
may hold significant advantages over antegrade or transmural drainage with regards
to safety and efficacy [69 ]
[71 ]
[72 ]
[73 ]. The latter techniques are therefore only recommended in patients where RV-ERP fails
or is not technically feasible [1 ]
[68 ]
[72 ].
Patients undergoing EUS-guided PD drainage may benefit from rectal nonsteroidal anti-inflammatory
prophylaxis and broad-spectrum antibiotics [69 ]
[73 ]
[74 ]
[75 ]
[76 ], although this has not been systematically studied.
4.3.2 Rendezvous-assisted ERP
After the PD has been accessed with a preflushed 19G or 22G FNA needle under EUS guidance,
the anatomy is defined fluoroscopically by contrast injection. A 0.035/0.025-inch
or 0.021/0.018-inch guidewire is then advanced into the PD ([Fig. 1e ]). The use of 22G needles and smaller caliber guidewires is generally discouraged
as these wires may not be sufficiently rigid to allow for the advancement of dilation
balloons, rigid dilators, and stents [68 ]
[75 ]
[77 ]. The main goal is to advance the guidewire deep into the duodenum, to achieve a
stable transpapillary or transanastomic platform, and prevent guidewire dislocation
while the echoendoscope is exchanged for the duodenoscope. During the process of guidewire
manipulation, it can be extremely challenging to advance the guidewire beyond stones
and/or strictures. If attempts are unsuccessful, despite extensive guidewire manipulation,
a fistulous tract can be created using a 6-Fr cystotome or mechanical dilation. This
will allow instruments, such as the cystotome or an ERCP catheter, to be advanced
into the PD, which will provide a more stable platform for guidewire manipulation.
If the guidewire still cannot be advanced across the stricture or beyond the stone
with the aid of the cystotome, this tract may immediately facilitate transmural PD
drainage to the stomach or duodenal bulb.
4.3.3 EUS-guided PD drainage
ESGE recommends rendezvous-assisted endoscopic retrograde pancreatography (RV-ERP)
in patients with favorable anatomy, followed by antegrade or transmural EUS-guided
pancreatic duct drainage only when RV-ERP fails or is not feasible.
Strong recommendation, low quality evidence.
In patients with surgically altered anatomy, an inaccessible papilla, or where RV-ERP
has failed, EUS-guided PD drainage should be considered. Variations of this technique
depend on the puncture site and whether a stent will eventually be placed transmurally
or in antegrade fashion across an anastomosis or papilla. Variations include pancreaticogastrostomy
([Fig. 1f ]), pancreaticoenterostomy, gastropancreaticoenterostomy (also called “ring drainage”),
and pancreaticobulbostomy [71 ]. The MPD diameter should at least be 4 mm, as this increases the technical success
rate and decreases morbidity.
When previous RV-ERP has been attempted, the cystotome tract can be used to perform
EUS-guided PD drainage. Various authors have however suggested first attempting non-cautery-assisted
tract dilation with rigid dilators or 4–6-mm balloons to prevent potential thermal
injury to the pancreas [69 ]
[74 ]
[78 ]. Following tract preparation, straight plastic stents (5–10 Fr) are inserted, depending
on the MPD caliber, and may be directed towards the pancreatic tail or head. FCSEMSs
have also been successfully used, although only in a small number of patients [79 ]. Transmural drainage by transgastric or transenteric stent placement will create
a pancreaticogastrostomy, pancreaticoenterostomy, or pancreaticobulbostomy, depending
on the scope position, anatomy, and needle access.
In gastropancreaticoenterostomy or “ring drainage,” a pancreaticogastrostomy and pancreaticoenterostomy
are created simultaneously by passing the distal end of the DPPS through the papilla
or anastomosis into the small bowel and deploying the proximal end into the gastric
lumen, creating a secure gastropancreaticoenterostomy [74 ]. For this technique, transpapillary or transanastomotic access is required, but
it carries significant advantages compared with the classic pancreaticogastrostomy
or pancreaticoenterostomy techniques owing to the double-sided drainage and secure
DPPS placement, which prevents migration [69 ].
4.4 Key question 6: What are the adverse events and possible rescue procedures in
EUS-guided PD drainage?
4.4.1 Intraprocedural challenges and rescue procedures
Accessing the MPD with a 19 G-needle can be challenging owing to significant pancreatic
fibrosis and/or calcified parenchyma, which can complicate smooth needle insertion,
tract dilation, and stent placement [74 ]. In such patients, or where the MPD is only minimally dilated, a 22 G FNA needle
may prove more successful in accessing the MPD; however, it only allows insertion
of a 0.018-inch guidewire, which is often inadequate, as described above for other
techniques [68 ]
[80 ].
Guidewire access may be extremely difficult because of large MPD obstructing stones.
Preprocedural stone fragmentation by extracorporeal shockwave lithotripsy may potentially
improve the technical and clinical success rates of RV-ERP [81 ]
[82 ]. The most crucial steps during RV-ERP require successful advancement of the guidewire
across strictures/stones deep into the duodenum, followed by careful exchange of the
echoendoscope for a duodenoscope, avoiding guidewire dislocation.
For EUS-guided PD drainage specifically, the difficulty lies in the ability to dilate
the transmural tract sufficiently to insert a stent deep enough into the MPD to prevent
stent dislocation [69 ]
[74 ]. In the unfortunate situation where the plastic stent dislocates beyond the gastric
wall during EUS-guided PD drainage, a snare over the guidewire or a digital cholangioscope
may be used in an attempt to recover the stent. If the MPD is successfully punctured
but subsequent drainage fails, the risk for the development of peripancreatic collections
increases and may become evident only over the ensuing days. These patients should
be observed more closely, the antibiotic course extended, and transgastric drainage
considered, especially if these collections become symptomatic or infected.
4.4.2 Endoscopic treatment of long-term adverse events
Most AEs are known to occur immediately following unsuccessful drainage, while limited
long-term safety data are available [63 ]. In RV-ERP, classic stent exchanges are required with re-interventions scheduled
every 3–6 months [81 ]. Long-term AEs in this group are therefore related to ERP only. Antegrade approaches,
such as pancreaticogastrostomy and pancreaticobulbostomy, are known to exhibit a significant
risk of stent dysfunction over time owing to obstruction and/or migration [78 ]. In one of the initial retrospective studies reporting EUS-guided PD drainage (n = 36),
clinical success was obtained in 69.4 % of patients, although in 55 % stent dysfunction
occurred after a mean follow-up of 14 months [73 ]. Stent exchange management among experts varies from scheduled exchanges every 6
months to exchanges “on-demand” when symptoms recur. Migration can be problematic
in these patients, as the MPD diameter will have decreased, complicating repeat EUS-guided
PD drainage. In this population, few further therapeutic options currently exist,
given the low technical success associated with ERP and the difficulties associated
with rescue surgery.
5 Gallbladder drainage
EUS-guided gallbladder drainage (EUS-GBD) has become a valuable alternative for patients
with acute cholecystitis at high surgical risk, with several demonstrated advantages
compared with percutaneous and transpapillary drainage [83 ]
[84 ]
[85 ]
[86 ]
[87 ]
[88 ]
[89 ]. In addition to its use within the context of acute cholecystitis, this technique
can also be considered as a rescue procedure in patients with unresectable distal
malignant biliary obstruction in the exceptional case of failed ERCP, PTBD, or EUS-BD
[90 ]
[91 ].
The indications for EUS-GBD have become more clearly defined and are discussed extensively
in the ESGE guideline on therapeutic EUS [1 ]. This section is aimed at providing a framework on the various techniques for performing
EUS-GBD and will discuss the roles of DPPSs and complete stone clearance, as well
as subsequent rescue procedures in the advent of a complication.
5.1 Key question 7: How should EUS-GBD be performed?
5.1.1 LAMS placement
ESGE suggests the use of an electrocautery-enhanced lumen-apposing metal stent (LAMS)
or dedicated SEMS in EUS-guided gallbladder drainage (EUS-GBD), given their enhanced
ease of use and safety compared with alternatives.
Weak recommendation, low quality evidence.
ESGE suggests performing transduodenal EUS-GBD with a LAMS, rather than using the
transgastric route, as this may reduce the risk of stent dysfunction.
Weak recommendation, low quality evidence.
The initial studies in the management of acute cholecystitis using EUS-GBD used fully
or partially covered SEMSs and plastic stents, and showed high clinical success rates
[88 ]. However, plastic stents were associated with higher AE rates when compared with
the placement of LAMSs, and both stent types required more procedural steps [88 ].
EUS-GBD using LAMSs was derived from EUS-guided drainage of pancreatic fluid collections
and EUS-CDS [90 ]
[91 ]
[92 ]
[93 ]
[94 ]
[95 ]. The gallbladder is located, either from the distal stomach or duodenal bulb, using
EUS, and an FNA needle (either 22 G or 19 G) can then be used to aspirate gallbladder
content, inject contrast to fluoroscopically define the anatomy, and to introduce
a 0.025-inch or 0.035-inch guidewire, over which the LAMS will be placed [85 ]
[96 ]
[97 ]
[98 ]
[99 ]. More commonly, an EC-LAMS is placed using the “free-hand” technique in one single
step ([Fig. 1g ]), which has been reported to reduce the procedural time [85 ]
[96 ]
[100 ]
[101 ]. It is imperative to ensure that the distal flange is sufficiently pulled back to
approximate the gallbladder wall against the duodenal or gastric wall before slowly
releasing the stent.
With both techniques, care should be taken to adjust the puncture distance to the
LAMS saddle length, which in most cases should not exceed 15 mm and preferably be
a short as possible ([Table 1 ]). In the exceptional case where the puncture distance exceeds 15 mm and EUS-GBD
is deemed necessary, the gallbladder lumen may be filled with saline or placement
of a covered SEMS may be considered. Alternatively, given the increased potential
risk of misplacement, the procedure may be aborted, with the patient referred for
percutaneous drainage.
Fig. 1g–i Illustrations of therapeutic endoscopic ultrasound (EUS) interventions of the pancreaticobiliary
and gastrointestinal tract showing: g EUS-guided gallbladder drainage; h EUS-guided gastroenterostomy; i EUS-guided gastrogastrostomy. Source: Martha Meisen.
Transduodenal access is usually preferred over transgastric EUS-GBD, as antral LAMS
placement has been associated with more symptom recurrence owing to food impaction
and a higher risk of a buried LAMS [96 ]
[98 ]
[100 ]. Notably, no head-to-head comparisons have been performed between the two EUS-GBD
drainage routes, with placement often governed by the most stable echoendoscope position.
Patient-related factors, such as the interposition of vessels, malignant duodenal
obstruction, more optimal apposition, or even improved ergonomics for the endoscopist,
can be valid reasons to settle for transgastric LAMS placement [102 ].
5.1.2 LAMS diameter
Several landmark papers have based their selection of LAMS diameter on the size of
the gallbladder stones to allow for stone evacuation following placement: when stones
are smaller than 10 mm, a 10-mm LAMS would suffice; when stones are larger than 10 mm,
a 15-mm LAMS, but no larger, should be considered [84 ]
[85 ]
[103 ]. When the gallbladder is not sufficiently dilated or is filled with multiple large
stones, it may not be feasible to safely deploy a 15-mm LAMS. In these cases, a smaller
caliber LAMS should be placed to resolve cholecystitis. When it is not feasible to
place a LAMS because of stones that would prohibit deployment, the gallbladder can
be punctured with a 19G FNA needle and filled with saline in order to induce sufficient
distension to facilitate stent deployment.
Regardless of the stone size, some patients with a longer expected survival time may
benefit from re-intervention aimed at treating residual stones [92 ]
[96 ]
[104 ]. Clearing gallbladder stones, with or without the use of lithotripsy, and replacing
the LAMS with DPPSs may potentially prevent LAMS-related AEs and preclude future biliary
events. In this specific context, a 15-mm LAMS, as opposed to a 10-mm LAMS, will more
readily accommodate transluminal endoscopic re-interventions.
5.1.3 Stent dysfunction
ESGE suggests considering pre-emptive placement of coaxial double-pigtail plastic
stents in patients with a higher expected risk of SEMS or LAMS occlusion.
Weak recommendation, low quality evidence.
Some patients are at increased risk of LAMS obstruction. This is especially the case
in patients with a high stone burden or who have had a LAMS inserted through the stomach,
where food impaction may lead to an increased risk of stent dysfunction [96 ]
[98 ]. In these situations, coaxial placement of DPPSs may be considered to prevent stent
occlusion by stones or food debris. Few efficacy data are currently available to systematically
support this approach [85 ]
[98 ]
[99 ].
5.1.4 Stone clearance and LAMS replacement
ESGE suggests considering complete stone clearance and LAMS exchange for double-pigtail
plastic stents when long-term drainage is required after EUS-guided gallbladder drainage.
Weak recommendation, low quality evidence.
Gallbladder stones may persist in almost half of cases following EUS-GBD [96 ]. Peroral cholecystoscopy through the LAMS provides the unique opportunity to evaluate
the luminal surface of the gallbladder and permits complete stone clearance, potentially
reducing future biliary events in patients who require prolonged gallbladder drainage
[92 ]
[96 ]
[104 ]. These procedures can be performed as soon as 1–2 weeks after LAMS placement, although
most data suggest that postponing stent removal to 4 weeks may be ideal [85 ]
[92 ]
[96 ]. Access through the EUS-GBD tract may sometimes require LAMS removal, with or without
balloon dilation of the fistulous tract, to facilitate passage of the devices to aid
in stone removal. Various endoscopic devices can be introduced to retrieve stones,
ranging from a basket to tripods [103 ]. In some instances, multiple lithotripsy sessions may be required to achieve complete
stone clearance.
Limited data exist regarding the long-term efficacy and safety of EUS-GBD with a LAMS. Consequently,
several authors have suggested that LAMSs should be exchanged after stone removal
and replaced with a DPPS (7–10 Fr), provided that there is enough residual gallbladder
lumen to accommodate these stents [85 ]
[92 ]
[96 ]
[99 ]
[104 ].
In patients with a limited expected survival time or advanced malignant disease, EUS-GBD
can be used as a definitive therapy without further surveillance. To date, no comparative
studies have been performed to compare the outcomes between these different approaches.
5.2 Key question 8: What are the adverse events and possible rescue procedures in
EUS-GBD?
Overall AEs following EUS-GBD vary, with most studies reporting rates between 8 %
and 18 % [83 ]
[94 ]
[97 ]
[105 ]. Bleeding, stent migration, capnoperitoneum, and stent occlusion with recurrent
cholecystitis represent the most frequent AEs following EUS-GBD [83 ]
[94 ]
[97 ].
Recurrent cholecystitis has been reported in up to 8 % of cases following LAMS placement
and is mostly related to either LAMS obstruction or a “buried” LAMS [106 ]. The risk may be reduced by intraduodenal LAMS placement, use of coaxial DPPSs,
and/or planned re-interventions with stone clearance [85 ]
[92 ]
[96 ]
[99 ]
[104 ].
Intraprocedural bleeding near the puncture site is generally minimized by tamponade
from the LAMS. Extraluminal bleeding due to trauma to the cystic artery is rare, but
requires embolization [97 ].
Other AEs associated with maldeployment that may occur include perforation, bile leak,
and peritonitis, all of which may require urgent surgery [93 ]
[94 ]
[106 ]
[107 ]
[108 ]
[109 ]
[110 ]. If only the gastric or duodenal wall is perforated and the gallbladder is still
intact, immediate endoscopic closure with an over-the-scope (OTS) clip can be considered.
If endoscopic salvage has been successfully performed, capnoperitoneum can usually
be treated conservatively, but transabdominal needle decompression may be required
in cases of tension capnoperitoneum [111 ].
If stent deployment fails after the gallbladder has already been punctured by a LAMS,
it will be imperative to proceed to either emergency percutaneous gallbladder drainage
or surgery as bile leakage is inevitable and may result in potentially fatal peritonitis.
6 Gastrointestinal anastomoses
6 Gastrointestinal anastomoses
EUS-guided gastroenterostomy (EUS-GE) is used in the management of gastric outlet
obstruction (GOO) and afferent loop syndrome [1 ]. The next sections provide guidance on how EUS-GE procedures should be performed.
EUS-guided gastrogastrostomy has also been developed to facilitate ERCP in the setting
of Roux-en-Y gastric bypass (RYGB), commonly referred to as the EDGE procedure (EUS-directed
transgastric ERCP).
6.1 Key question 9: How should EUS-GE procedures be performed?
6.1.1 General principles for the creation of EUS-GE anastomoses
There are currently no definitive guidelines nor consensus on the preprocedural management
of patients undergoing EUS-guided lumen-to-lumen anastomoses. However, similarly to
other endoscopic procedures in patients with GOO, the following preprocedural precautions
would apply. Patients should be kept on a clear liquid diet for a few days before
the procedure and “nil per mouth” 24 hours before performing EUS-GE, to minimize the
presence of residual gastric content and the risk of aspiration. A large-bore nasogastric
tube may be needed to clear the stomach contents in some patients with persistent
vomiting despite being maintained on a clear fluid diet.
Post-procedurally, patients should ideally be hospitalized overnight for observation,
even though there is currently no consensus; in some high volume centers, patients
with no post-procedural abdominal pain are discharged the same day. Some experts advise
24 hours of fasting before initiating a clear liquid diet. In the days following the
procedure, this can be slowly broadened as tolerated up to a normal diet [112 ]. In some centers, in the absence of pain, fluid intake is permitted within hours
after the procedure, and rapidly escalated to a liquid and soft low-fiber diet thereafter.
With the availability of the 20-mm LAMS, most patients may ultimately return to normal
diets. The routine use of proton pump inhibitors in these patients is not supported
by any evidence.
ESGE recommends using saline instillation for small-bowel distension during EUS-guided
gastroenterostomy.
Strong recommendation, low quality evidence.
Various techniques have been developed to create an EUS-GE aimed at overcoming two
main difficulties: (i) locating the segment distal to the GOO; (ii) stabilizing the
targeted loop for subsequent puncture and stent introduction. A crucial step in the
successful performance of EUS-GE is providing sufficient dilation of the target loop. A
nasojejunal feeding tube or nasobiliary catheter that contains more side holes and
infuses larger volumes of saline is placed across the stricture beyond the ligament
of Treitz over a previously placed guidewire. Alternatively, saline is instilled into
the small bowel directly through the endoscope by placing it at the level of the stricture
[113 ]. For either the catheter- or endoscope-based technique, saline is instilled using
prefilled syringes or a waterjet. Dye can be added to the mixture (most often methylene
blue or indigo carmine) to allow for visual confirmation of successful LAMS placement
when the proximal flange opens into the stomach. Furthermore, contrast can be mixed
with saline in order to fluoroscopically depict the small-bowel anatomy. In general,
250–500 mL of saline is needed to achieve sufficient distension of the target segment,
although this may vary. Intravenous administration of antimotility agents, such as
butyl scopolamine or glucagon (0.5–3.0 mg), can be considered to decrease intestinal
contractions.
6.1.2 Direct EUS-GE technique
ESGE recommends the use of electrocautery-enhanced LAMSs in EUS-guided gastroenterostomy.
Strong recommendation, low quality evidence.
ESGE recommends the use of LAMSs of at least 15 mm in diameter in EUS-guided gastroenterostomy.
Strong recommendation, low quality evidence.
A linear echoendoscope is introduced and positioned under fluoroscopic and EUS guidance
to visualize the intended small-bowel loop. A transgastric puncture is performed with
a 19 G FNA needle and the small-bowel loop is filled with saline mixed with contrast.
The endoscopist can then proceed with placement of a guidewire through the FNA needle,
over which the electrocautery tip of the LAMS is advanced into the jejunum, using
the Autocut setting. Alternatively, the FNA needle can be removed and the electrocautery-tipped
delivery device (Autocut 100–150 W, effect 3–5) can be advanced into the jejunum using
the “free-hand” technique ([Fig. 1h ]). LAMS insertion over the wire has mostly been abandoned as this may push the jejunum
further away, which may lead to stent maldeployment. Should the endoscopist still
elect to perform over-the-wire placement, we advise slow withdrawal of the guidewire
when advancing the EC-LAMS to minimize displacement of the jejunum. After the delivery
device is confirmed to be inside the lumen of the jejunum on EUS, the distal flange
is deployed. The device is then gently retracted, approximating the small-bowel wall
to the gastric wall before releasing the proximal flange under EUS or endoscopic control.
6.1.3 Wireless endoscopic simplified technique
After the small bowel distal to the GOO has been filled with saline, a linear echoendoscope
is advanced into the stomach. After the saline filled duodenum/jejunum has been located,
the electrocautery tip is advanced directly using a free-hand technique into the targeted
small-bowel lumen under EUS control, without the aid of an FNA needle or guidewire
([Fig. 1h ]). The same deployment steps described above are followed to release the stent [112 ]
[114 ].
6.1.4 Assisted EUS-GE techniques
Assisted EUS-GE techniques refer to approaches using dilation balloons or double-balloon
devices that are inserted through a gastroscope or enteroscope (e. g. endoscopic ultrasound-guided
double-balloon-occluded gastroenterostomy bypass; EPASS) [115 ]
[116 ]
[117 ]. In the balloon-assisted technique, a guidewire is inserted across the GOO and the
balloon catheter is advanced under fluoroscopic guidance into the jejunum. Under EUS
guidance, the fluid-filled balloon or occluded jejunal segment is punctured with a
19G FNA needle and a guidewire is advanced into the jejunal lumen. A LAMS is then
inserted and deployed over the guidewire.
6.1.5 What size LAMS should be used to create an EUS-GE?
For EUS-GE, both 15-mm and 20-mm LAMSs have been used. The diameter of surgically
created gastroenterostomies ranges between 25 and 35 mm. Therefore, from a theoretical
standpoint, a 20-mm LAMS should be preferred. Comparative data are limited, although
a recent retrospective study demonstrated improved clinical efficacy with 20-mm stents
compared with 15-mm stents [112 ].
6.2 Key question 10: How should EDGE procedures be performed?
EUS-directed transgastric ERCP (EDGE) can be offered to patients with RYGB in expert
centers in an attempt to overcome the invasiveness of laparoscopy-assisted ERCP and
the limitations of enteroscopy-assisted ERCP [1 ]. This section is aimed at providing technical guidance regarding EDGE, the timing
of subsequent ERCP, and management following successful therapy.
6.2.1 What is the optimal technique to perform an EDGE procedure?
ESGE recommends the use of saline instillation with a 19 G needle and an electrocautery-enhanced
LAMS for EDGE procedures.
Strong recommendation, low quality evidence.
In 2011, prior to the development of LAMSs, a percutaneous approach was developed
using insufflation of the gastric remnant via a 19 G needle, followed by subsequent
placement of a 16-Fr PEG gastrostomy. Through this percutaneous route, ERCP could
be performed [118 ]
[119 ]
[120 ]. This first attempt provided the basis for the subsequent development of a completely
endoscopic approach.
The advent of LAMSs has led to the development of an endoscopic technique to join
the excluded stomach to the gastric pouch, with the formation of a stable anastomosis,
under EUS guidance. This creates a conduit through which a duodenoscope can be inserted
[121 ]. Once the excluded stomach has been located by the echoendoscope positioned in the
pouch or proximal jejunum, a 19G needle is advanced and 250–500 mL of saline, with
or without dye, is instilled, until the excluded stomach is adequately distended.
The needle is then retracted and the EC-LAMS is advanced into the excluded stomach
lumen under sonographic control. Although an over-the-wire placement has been reported,
the “free-hand” technique is nowadays mostly employed and the stent is released in
the same way as for EUS-GE ([Fig. 1i ]) [122 ]
[123 ]
[124 ]. Care should be taken not to deploy the LAMS too caudally in the antrum or distal
gastric body, as this may complicate subsequent insertion of the duodenoscope.
6.2.2 Is there a preference for LAMS diameter?
ESGE recommends the use of either 15- or 20-mm LAMSs for EDGE, with a preference for
20-mm LAMSs when considering a same-session ERCP.
Strong recommendation, low quality evidence.
In a recent large multicenter retrospective analysis of 178 EDGE procedures, the use
of a smaller caliber 15-mm LAMS was an independent risk factor for intraprocedural
stent dislodgement [125 ]. Placement of a 20-mm stent is therefore preferred as it provides easier access
for the duodenoscope into the gastric remnant, which decreases the risk of stent migration.
Placement of a 20-mm LAMS is strongly advised when a same-session ERCP is considered,
with balloon dilation to facilitate safe passage of the duodenoscope through the stent.
6.2.3 What is the optimal time that should be allowed before performing an ERCP following
LAMS placement?
ESGE suggests considering a delay of at least 7 days before performing ERCP following
EDGE whenever possible.
Weak recommendation, low quality evidence.
In early 2021, a systematic review showed that intraprocedural stent migration occurred
in 16 % of EDGE procedures and was mainly due to stent dislodgement when a same-session
ERCP was performed [126 ]. A recent study suggested that large caliber 20-mm LAMSs and stent fixation techniques
may allow for safe same-session ERCP compared to smaller 15-mm stents [127 ]. When permitted, a low risk strategy can be adopted by delaying ERCP for up to 7
days following LAMS placement, which allows the gastrogastrostomy LAMS to fully expand
and the fistulous tract to mature. However, for patients with cholangitis or in other
urgent settings, a same-session ERCP should always be considered. This can be accomplished
by adequate balloon dilation at least up to 15 mm to allow the duodenoscope to be
carefully manipulated through the LAMS. Overdilation of the stent should however be
avoided. Anchoring techniques, such as clipping or suturing, have also been reported
to prevent migration when same-session ERCP is required [125 ]
[128 ], although a recent large retrospective analysis did not identify fixation techniques
as beneficial in preventing this AE [127 ].
6.2.4 When should the LAMS be removed and should endoscopic closure be provided?
ESGE recommends that LAMSs should not be removed within the first 7 days of placement
and thereafter only when no additional pancreaticobiliary interventions are required.
Strong recommendation, low quality evidence.
LAMSs should be removed when no additional re-interventions are required, although
some patients may benefit from leaving the stent for longer periods. Many methods
have been described to close the gastrogastric or jejunogastric fistulous tract, although
various studies suggest that these tracts may spontaneously close in most cases. Wang
and colleagues proposed the technique of “spontaneous closure guided by double-pigtail
plastic stents,” with an efficiency of more than 70 % [129 ], whilst James and co-workers applied APC to the margins of the fistula tract in
order to promote re-epithelialization and closure [130 ]. In their study, 61 % of fistulas “spontaneously” closed thereafter. Some authors
propose suturing or APC followed by OTS clip placement in cases of failed closure.
Kedia et al. used an OTS clip system to close the gastrogastric or jejunogastric fistula
after removal of the LAMS, although this may seldom be required [121 ].
LAMSs should be removed as soon as it becomes apparent that no additional pancreaticobiliary
interventions will be required. Practices around the world are diverse, varying from
systematic follow-up by upper GI series 8 weeks after LAMS removal, to immediate closure,
to no follow-up or closure only in the setting of weight gain. More prospective data
are required in this specific context. Until such data become available, in patients
with symptoms or weight gain, the presence of an open fistulous tract should be confirmed,
either by upper GI series or endoscopy, prior to definitive closure.
6.3 Key question 11: What are the adverse events and possible rescue procedures in
EUS-guided gastrointestinal anastomoses?
6.3.1 Stent maldeployment
LAMS maldeployment can be decreased by careful patient selection and use of proper
endoscopic techniques [5 ]
[28 ]
[131 ]
[132 ]
[133 ]
[134 ]
[135 ]
[136 ]
[137 ]. In the largest available retrospective study on EUS-GE, performed in 16 expert
centers, distal or proximal LAMS flange maldeployment occurred in 44 out of 467 patients
(9.4 %) [138 ]. This AE was endoscopically managed in the majority of cases, with success largely
dependent on its immediate recognition during the procedure. Indeed, surgery was required
in only five patients (11.4 %) [138 ]. A high index of suspicion for stent maldeployment should be considered especially
under the circumstances presented in [Table 3 ]
[28 ]. Needle decompression of the capnoperitoneum may be necessary and systemic broad-spectrum
antibiotics should be administered. In cases where the stent cannot be bridged or
the defect cannot be securely closed, surgical management should be undertaken with
removal of the LAMS, closure of the defect, and creation of a surgical anastomosis.
This may be challenging for the surgeon in the setting of surgically altered upper
GI anatomy and may require conversion to an open procedure [121 ]
[136 ]
[139 ]
[140 ].
Table 3
Circumstances when a high index of suspicion for stent maldeployment should be considered.
1 Appearance of pneumoperitoneum on fluoroscopy immediately after distal flange deployment
2 Failure of the distal flange to anchor to the small bowel or excluded stomach, with
it being impossible to advance a guidewire into its lumen (guidewire appearing extraluminal
and intraperitoneal on fluoroscopy)
3 No evidence of previously infused blue-tinged fluid flowing into the stomach after
full deployment of the stent
4 Lack of visualization of the target luminal structure through the stent on the contralateral
side after balloon dilation of the central part of the LAMS
5 Endoscopic visualization of the peritoneum through the LAMS
LAMS, lumen-apposing metal stent.
Diagnostic laparoscopy may be warranted when there is doubt about puncture of the
duodenum or jejunum with an EC-LAMS. Whereas closure of the stomach is usually easily
managed endoscopically, it is more challenging to recognize the level of a duodenal
or jejunal injury. Delayed perforations at the level of the enteric access point may
occur late due to thermal necrosis. In fragile patients with a short-term poor overall
prognosis, stent maldeployment may be fatal, even if salvaged endoscopically [141 ].
Maldeployment of a stent into the colon is usually recognized late, after the patient
has developed diarrhea associated with meals. Surgery is generally not required, as
simple stent removal and endoscopic fistula tract closure may be performed once the
fistula and anastomotic tract have matured (typically after 7 days or more).
With EDGE, intraprocedural LAMS dislodgement is a common AE, almost entirely related
to same-session ERCP. Its severity is related to the lack of a mature fistulous tract,
which results, if not recognized, in free perforation. Most cases can be managed endoscopically
as long as guidewire access to the remnant stomach is preserved [121 ].
The endoscopic actions presented in [Table 4 ] may be useful to salvage a situation where maldeployment has occurred [121 ]
[123 ]
[126 ]
[129 ]
[142 ]
[143 ]
[144 ]
[145 ]
[146 ]. There are a few reports where perforation could not be managed endoscopically and
surgical repair was necessary, with no related fatalities reported thus far [121 ]
[126 ]
[142 ]
[144 ]
[146 ]
[147 ].
Table 4
Steps that can be performed for endoscopic management of intraprocedural stent dislodgement.
1 Maintain the guidewire in the gastric remnant with over-the-wire exchange of the
duodenoscope/echoendoscope with a therapeutic gastroscope
2 Perform complete LAMS dilation, if not performed before
3 In cases with complete LAMS dislodgement, the LAMS should be removed
4 In cases with incomplete LAMS dislodgement, an attempt should be made to reposition
the misdeployed flange using a grasping forceps, which can be highly effective when
there is a mature anastomotic tract
5 In cases with LAMS misdeployment, insert (through the previously positioned LAMS,
if still in place) a fully covered esophageal stent or a new LAMS of the same or larger
size to bridge both wall defects; this can be further secured by placing double-pigtail
plastic stents through it
6 When the guidewire is lost, enter the peritoneal cavity with a therapeutic gastroscope
and search for the excluded stomach perforation. Once detected, a transfistula guidewire
should be inserted, followed by NOTES techniques to complete the procedure, as highlighted
for stent maldeployment cases
7 Fluoroscopic confirmation of the absence of a leak should be obtained at the end
of the procedure
LAMS, lumen-apposing metal stent; NOTES, natural orifice transluminal endoscopic surgery.
6.3.2 Management of intra- and post-procedural bleeding
Intra- or post-procedural hemorrhage is a rare AE encountered in EUS-guided lumen-to-lumen
anastomoses. It can be a direct consequence of: (i) fistula creation [148 ], (ii) LAMS balloon dilation [149 ], or (iii) LAMS-induced ulcer or erosion of the GI tract mucosa [139 ]
[149 ]
[150 ]. For the latter, standard endoscopic hemostatic techniques are usually highly effective,
in association with proton pump inhibitor administration. Rarely, LAMS removal or
exchange is needed. Intraprocedural bleeding following LAMS dilation can be successfully
treated by balloon tamponade or through-the-scope SEMS placement to compress the bleeding
vessel [151 ]. When conservative measures fail, especially in cases of extraluminal bleeding,
emergent angiography with vessel embolization is usually effective, while surgical
exploration is rarely needed.
6.3.3 Endoscopic treatment of long-term adverse events
ESGE suggests long-term clinical follow-up and/or intermittent stent surveillance,
with or without stent exchange, after EUS-guided gastroenterostomy for benign disease.
Weak recommendation, low quality evidence.
Long-term AEs in EUS-guided lumen-to-lumen anastomoses include stent migration [126 ]
[142 ]
[149 ], obstruction by food residue [149 ], and tissue ingrowth [150 ] or overgrowth [140 ]. Recurrence of GOO symptoms, requiring a repeat procedure, occurs in 9 %–11.4 %
of EUS-GE procedures [152 ]
[153 ]. However, long-term data on procedural outcomes beyond several months are scanty,
which is an important consideration, especially in the management of benign GOO [154 ]. Cases of stent obstruction can be managed by endoscopic clearance of debris/food,
by stent removal and replacement, or by insertion of a second stent bridging the initially
placed LAMS [140 ]
[149 ].
In patients with benign GOO, LAMS removal should be considered if the initial obstruction
has resolved, as proven by upper GI series or cross-sectional imaging studies. Otherwise,
clinical follow-up or intermittent stent surveillance (with or without exchange) should
be performed at regular intervals [149 ]. For most malignant indications, stents should be left in place indefinitely, as
stenosis/closure of the anastomotic tract would likely occur after stent removal [155 ].
Disclaimer
The legal disclaimer for ESGE guidelines [156 ] applies to this technical review.