Keywords malignant extrahepatic bile duct obstruction - percutaneous transhepatic biliary drainage
- ultrasound-guided bile duct puncture
Introduction
Endoscopic drainage or stenting is the method of first choice in the therapy of malignant
bile duct obstruction in comparison with percutaneous transhepatic biliary drainage
(PTBD) ever since the study from Speer et al showed a significantly higher success
rate for relief of jaundice (81% versus 61%) and a significantly lower 30-day mortality
rate (15% versus 33%) in 1987.[1 ] From then on, PTBD was commonly used as a reserve method when endoscopic drainage
or stenting was not successful or otherwise was not possible for anatomic reasons
after abdominal surgery. Endoscopic ultrasound-guided biliary drainage (EUS-BD) was
first described in 2001 by Giovannini et al[2 ] and is now a rapidly evolving method for biliary drainage in patients with malignant
bile duct obstruction in this setting. A recent meta-analysis about efficacy and safety
in EUS-BD in comparison with PTBD included six completely published studies[3 ]
[4 ]
[5 ]
[6 ]
[7 ]
[8 ] and three abstracts with 483 patients and showed better clinical success, fewer
post-procedural adverse events, and a lower rate of re-interventions for EUS-BD.[9 ] The authors concluded that EUS-BD may be preferred to PTBD if adequate endoscopic
expertise and logistics are available. The question is rather—was the full potential
of PTBD exploited in these studies when it was compared with the different procedures
of EUS-BD?
Percutaneous transhepatic biliary drainage is usually performed under fluoroscopic
guidance in which the initial puncture of the intrahepatic bile duct is performed
with the help of anatomic landmarks without a direct view of the bile duct.[10 ] Color Doppler ultrasound-guided PTBD facilitates bile duct access, and injury of
intrahepatic vessels can be avoided more effectively.[11 ]
[12 ]
[13 ]
[14 ]
[15 ] External percutaneous drainages can both cause bad patient comfort and pain and
carry the risk of dislocation and other adverse events.[16 ] Therefore, external drainages should be avoided. Furthermore, success and complications
of PTBD are influenced by the liver entry segment.[17 ] Hence, the left-sided liver access should be preferred whenever possible. In patients
with malignant bile duct obstruction, a metal stent implantation can be performed
via PTBD as an effective palliative treatment.[18 ] In our institution, the placement of the self-expandable metal stent is always controlled
by endoscopic luminal guidance when the papilla is still accessible endoscopically.
Therefore, technical success can be documented immediately, no external drainage has
to be left behind, and it may be easier to perform endoscopic re-interventions in
case of an occluded metal stent. In what follows, we retrospectively screened all
prospectively documented PTBDs that were performed in our institution in the last
9 years. We extracted these ultrasound-guided PTBDs, which were performed in patients
with malignant bile duct obstruction with primary metal stent implantation by endoscopic
luminal guidance as a one step-procedure (mainly with left sided liver access). In
this cohort, the technical and clinical success of metal stent implantation via PTBD,
adverse events, and re-intervention rate as the follow-up after stent implantation
were analyzed.
Patients and Methods
Patients
The study (NCT03541590) was reviewed and approved by the local institutional review
board. Data collection was performed prospectively according to the updated 2013 World
Medical Association (WMA) Declaration of Helsinki.[19 ] Patients were not required to give informed consent to the study because the analysis
used anonymous clinical data that were obtained after each patient agreed to treatment
by written consent. Analysis of the data was performed retrospectively. A total of
116 color Doppler ultrasound-guided PTBD procedures in patients with benign and malign
bile duct obstruction were enrolled consecutively in the study from December 2008
to May 2018. Patient selection is shown in a flow chart ([Fig. 1 ]). Thirty color Doppler ultrasound-guided PTBDs in patients with inoperable, malignant
diseases with primary (i.e., inserted in the first session) and secondary (i.e., inserted
in a follow up session) metal stent implantation were extracted from this cohort of
participants. In 86 excluded PTBDs, plastic endoprosthesis (mainly internal drainages)
was inserted for different reasons. Out of 14 PTBDs with secondary metal stent implantation,
8 patients received PTBD with primary plastic endoprosthesis in referring hospitals,
and in 6 patients, metal stent implantation was not intended initially. Sixteen patients
with primary metal stent implantation met the following criteria for inclusion and
exclusion—inclusion criteria: age ≥18 years, not curatively operable, malignant disease
with proximal or distal bile duct obstruction, elevated serum bilirubin level and/or
elevated alkaline phosphatase to at least a two-fold degree, histologically verified
diagnosis (for example by biopsy), and at least one implemented cross-sectional imaging
method, such as computed tomography or magnetic resonance imaging of the abdomen and
exclusion criteria: uncorrectable coagulopathy (prothrombin time < 50%, platelet count
< 50.000/μL, and partial thromboplastin time (PTT) > 50 s), advanced tumor disease
with limited life expectancy (<1 month), diffuse liver metastasis, pregnant or breastfeeding
women, potentially curatively, operable, malignant bile duct obstruction, and diseases
which can be cured by chemotherapy (for example, aggressive non-Hodgkin lymphoma).
Fig. 1 Flow chart summarizing patient selection process. PTBD, percutaneous transhepatic
biliary drainage.
Methods
When endoscopic retrograde cholangiopancreatography (ERCP) failed due to tumor stenosis
or a difficult papilla or was otherwise anatomically impossible (altered anatomy after
abdominal surgery), PTBD was performed next in all patients. PTBD with initial color
Doppler ultrasound-guided bile duct puncture was conducted, as previously described.[15 ] Left-sided liver access was preferred ([Fig. 2 ]). After the guide wire was placed beyond the tumor stenosis, a second investigator
introduced a standard (outer diameter of the distal end: 9.9 mm) gastrointestinal
videoscope (GASTROINTESTINAL VIDEOSCOPE GIF-HQ190, Olympus) or a thin (outer diameter
of the distal end: 5.4 mm) pediatric gastrointestinal videoscope (GASTROINTESTINAL
VIDEOSCOPE GIF-HQ190) into the duodenum passing the tumor stenosis. Then an uncovered
or partially covered (8–10 mm × 60–100 mm) self-expandable metal stent (SEMS) (Boston
Scientific; Endoflex) was percutaneously inserted by fluoroscopic ([Fig. 3 ]) and endoscopic luminal guidance ([Fig. 4 ]) in the same session. In contrast, a duodenovideoscope (VIDEODUODENOS-COPE TJF-Q180V,
Olympus) with a larger diameter (13.7 mm) and a less flexible distal end could not
be introduced to the papilla in all patients with duodenal tumor obstruction. Only
in three patients with tumor recurrence at the biliodigestive anastomosis or status
post gastrectomy, stent release was performed without endoscopic luminal guidance
([Fig. 5 ]). Successful placement and unfolding of the SEMS was furthermore documented by contrast
medium injection through a newly inserted 5 F catheter. After successful SEMS implantation,
the percutaneous catheter and the guide wire were completely removed.
Fig. 2 Fluoroscopic image of PTBD with left sided liver access. PTBD, percutaneous transhepatic
biliary drainage.
Fig. 3 Percutaneous transhepatic metal stent implantation by endoscopic luminal guidance
(fluoroscopic image). The endoscope was introduced through a previously implanted
duodenal metal stent.
Fig. 4 Percutaneous transhepatic metal stent implantation by endoscopic luminal guidance
(endoscopic image).
Fig. 5 Percutaneous transhepatic metal stent implantation without endoscopic luminal guidance
in a 66-year-old patient with tumor recurrence at the biliodigestive anastomosis (fluoroscopic
image).
Analysis of Data
Selected patients were characterized by age, sex, the reason for impossible or unsuccessful
ERCP, and the underlying inoperable malignant disease.
The color Doppler ultrasound-guided PTBD procedure was characterized by liver access
side (left/right), utilized SEMS (diameter, length in mm, non-covered (nc) or partially
covered (pc), applied endoscopic control (yes/no), procedural time (defined as the
time from the injected local anesthesia to the attachment of the skin patch), applied
radiation exposure for the patient (μGy/m2 ), fluoroscopic time in minutes, and technical success. Technical success was defined
as successful implantation of a self-expanding metal stent to drain the obstructed
bile duct, measured by the successful drainage of the radiocontrast agent by the metal
stent; time frame: 1 minute after injection of a radiocontrast agent into the expanded
metal stent.
The outcome of the PTBD was characterized by clinical success (defined as the decrease
of serum bilirubin level ≥50% in comparison with the baseline level after 7 days),
the report of any adverse events in the period of 7 days after the procedure, grading
of adverse events according to the ASGE lexicon's severity grading system,[20 ] and the occurrence of adverse events and number of re-interventions in the period
of 6 months after the technical successful intervention.
The follow-up after PTBD was characterized by received chemotherapy (yes or no, chemotherapy
protocol), survival time in days, and cause of death (primary disease, other causes).
A Kaplan–Meier analysis was performed to estimate patient survival (program SAS 9.3).
Results
During the study period, 116 PTBDs were performed. Sixteen patients (mean age: 72
years and number of females: 7) with malignant biliary obstruction underwent color
Doppler ultrasound-guided PTBD with primary metal stent implantation. ERCP was not
successful or was impossible by duodenal tumor stenosis (n = 9), biliodigestive anastomosis after pancreaticoduodenectomy (n = 2), gastric outlet obstruction by tumor (n = 1), status post gastrectomy (n = 2), hilar cholangiocarcinoma (n = 1), or difficult papilla by tumor infiltration (n = 1). Malignant biliary obstruction was mainly caused by pancreas carcinoma (n = 10), hilar or distal cholangiocarcinoma (n = 2), duodenal carcinoma (n = 2), carcinoma of the duodenal papilla (n = 1), or gastric cancer (n = 1) ([Table 1 ]).
Table 1
Patients' characteristics
No.
Sex
Age (year)
Cause of unsuccessful/impossible ERCP
Inoperable carcinoma
Abbreviation: ERCP, endoscopic retrograde cholangiopancreatography; F, female; M,
male.
1
M
77
Duodenal tumor stenosis
Pancreas carcinoma
2
M
66
Gastric outlet obstruction by tumor
Pancreas carcinoma
3
F
63
Duodenal tumor stenosis
Pancreas carcinoma
4
F
79
Duodenal tumor stenosis
Pancreas carcinoma (metastasized)
5
M
77
Duodenal tumor stenosis
Carcinoma of the duodenal papilla
6
M
80
Status post gastrectomy
Pancreas carcinoma
7
F
71
Duodenal tumor stenosis
Duodenal carcinoma
8
F
66
Biliodigestive anastomosis/pancreaticoduodenectomy
Pancreas carcinoma (recurrence)
9
F
55
Duodenal tumor stenosis
Duodenal carcinoma
10
F
83
Duodenal tumor stenosis/gastroenterostomy
Pancreas carcinoma (ERCP stent occlusion)
11
M
77
Biliodigestive anastomosis/pancreaticoduodenectomy
Distal cholangiocarcinoma (recurrence)
12
M
52
Duodenal tumor stenosis
Pancreas carcinoma
13
M
75
Hilar cholangiocarcinoma
Hilar cholangiocarcinoma (metastasized)
14
F
80
Difficult papilla by tumor infiltration
Pancreas carcinoma
15
M
79
Duodenal tumor stenosis
Pancreas carcinoma (metastasized)
16
M
68
Status post gastrectomy
Gastric cancer (recurrence)
Percutaneous transhepatic biliary drainage with primary metal stent implantation was
mainly performed by endoscopic luminal guidance (13/16). In three patients, endoscopic
luminal guidance was not possible due to altered anatomy (biliodigestive anastomosis
or status post gastrectomy). Left liver side was mainly used as access route (14/16).
The metal stent that was used most had a diameter of 10 mm and a length of 80 mm.
Procedure time was on average 68.1 minutes (25–118), fluoroscopic time was on average
18.6 minutes (3–46), and the radiation exposure was on average 5957 μGy/m2 (471–17,569). The intervention was technically successful in 94% of cases (15/16).
In one patient, a second attempt was necessary (documented as re-intervention) ([Table 2 ]).
Table 2
Ultrasound–guided PTBD procedures with primary metal stent implantation by endoscopic
luminal guidance and follow–up
No.
Side of access to liver
SEMS (mm)
Endoscopic guidance
Procedural time (m)
Radiation exposure (μGy/m2)
Fluoroscopic time (m)
Technical success
Chemotherapy
Survival time (d)
Cause of death
Abbreviations: d, days; FLO, fluorouracil, folinic acid, oxaliplatin; FOLFOX, folinic
acid, fluorouracil and oxaliplatin; m, months; nc, non covered; PTBD, percutaneous
transhepatic biliary drainage; SEMS, self–expandable metal stent.
1
Left
nc 10 × 100
Yes
89
8889
22,1
Yes
No
36
Primary disease
2
Left
nc 10 × 80
Yes
90
7164
22,4
Yes
No
35
Primary disease
3
Right
nc 10 × 80
Yes
105
14130
41,9
Yes (2nd attempt)
No
46
Lung embolism
4
Left
nc 10 × 80
Yes
105
17569
46,0
Yes
Gem/Paclitaxel
125
Primary disease
5
Left
nc 10 × 80
Yes
60
5100
12,4
Yes
No
864
Sepsis
6
Left
nc 10 × 80
Yes
70
1341
13,6
Yes
No
44
Primary disease
7
Left
nc 10 × 80
Yes
40
2368
3,0
Yes
No
68
Primary disease
8
Left
nc 10 × 60
No
25
862
6,1
Yes
No
19
Primary disease
9
Left
pc 10 × 80
Yes
50
2428
13,6
Yes
FOLFOX
46
Primary disease
10
Right
nc 10 × 80
Yes
48
2112
11,2
Yes
No
430
Primary disease
11
Left
nc 10 × 80
No
67
7429
19,6
Yes
No
7
Primary disease
12
Left
nc 10 × 80
Yes
52
4607
10,3
Yes
No
17
Primary disease
13
Left
nc 8 × 100
Yes
118
10713
27,0
No
No
25
Primary disease
14
Left
nc 10 × 80
Yes
73
3747
29,4
Yes
Gemcitabine mono
342–still alive
15
Left
nc 10 × 80
Yes
68
6383
14,4
Yes
No
39
Primary disease
16
Left
nc 10 × 60
No
29
471
5,1
Yes
FLO
91–still alive
Clinical success could be documented in 88% of cases (14/16). In one patient with
a tumor stenosis at the biliodigestive anastomosis, in which the first metal stent
migrated (patient no. 11), a second metal stent could be inserted at the correct position
(grade of severity: mild). Another patient (patient no. 15) developed biliary ascites
after a technically successful stent implantation due to delayed stent expansion.
The delay was caused by diffuse tumor infiltration and by a duodenal metal stent in
direct vicinity to the inserted biliary stent ([Fig. 6 ]). Hospital stay was prolonged in this patient for 9 days due to several abdominal
paracenteses (grade of severity: modest). In the follow-up period of 6 months, just
one re-intervention and no stent occlusion could be documented.
Fig. 6 CT abdomen (coronal image) in a patient with biliary ascites due to the delayed expansion
of the biliary metal stent in the vicinity of a duodenal metal stent. CT, computed
tomography.
Four patients received palliative chemotherapy after normalization of serum bilirubin
levels. Survival time extended from 7 to 864 days. A Kaplan–Meier analysis was performed
to estimate patients’ overall survival ([Fig. 7 ]). The mean survival was 163.2 days (standard deviation [SD] 72.6 days and 95% confidence
interval [CI] of 20.98–305.42), and the median survival was 44.0 days (95% CI of 19.00
to 68.00). Death was mostly caused by primary tumor disease (n = 12), followed by sepsis (n = 1) and lung embolism (n = 1). Two patients are still alive ([Table 2 ]). Survival analysis could not be reasonably stratified in patients with and without
chemotherapy due to the small patient number.
Fig. 7 Kaplan–Meier analysis on overall survival probability after PTBD with primary metal
stent implantation in patients with malignant bile duct obstruction (n = 16). PTBD, percutaneous transhepatic biliary drainage
Discussion
We reported an optimized method of PTBD combining ultrasound-guided bile duct puncture
and percutaneous transhepatic biliary stenting by fluoroscopic and endoscopic luminal
guidance as a one step-procedure in patients with malignant bile duct obstruction
with good technical and clinical success rates in a small and detailed described sample
size of 16 PTBDs, extracted from 116 PTBDs in our single tertiary referral center
hospital. We documented just two adverse events (severity grade: mild 1× and modest:
1×) and only one re-intervention in an observational follow-up period of 6 months.
In the case when ERCP could not have been performed due to duodenal tumor obstruction
using a duodenovideoscope (outer diameter of the distal end: 13.7 mm), the duodenal
stenosis could still be passed by a gastrointestinal videoscope with a smaller outer
diameter (5.4–9.9 mm) and a more flexible distal end. Usually, it is not possible
to perform ERCP with a gastrointestinal videoscope without a forceps elevator. Therefore,
we just used the endoscope (in combination with the fluoroscopic image) to visualize
the papilla and to visualize the optimal percutaneous transhepatic stent placement.
Besides, it is crucial for endoscopic re-interventions in the follow-up (for example,
for the reopening of an occluded metal stent) that the metal stent does not stand
out too much out of the papilla. In our experience, unique fluoroscopic guidance is
not accurate enough for optimal metal stent implantation in relation to the papilla
(data not shown). However, we observed just one stent occlusion in the follow-up in
the extracted cohort of 16 PTBDs with primary stent implantation. This stent occlusion
could be managed with a gastrointestinal videoscope without a forceps elevator. A
further randomized study has to proof the hypothesis that the combined use of endoscopic
luminal and fluoroscopic guidance increases the rate of successful endoscopic re-interventions
in comparison with the unique use of fluoroscopic guidance. Since palliative tumor
therapies become more and more effective, it is presumed that re-interventions of
occluded metal stents will be necessary more often in the future due to longer patient
survival. According to our best knowledge, this is the first publication that describes
the combination of ultrasound-guided bile duct puncture and percutaneous transhepatic
biliary stenting by combination of fluoroscopic and endoscopic luminal guidance as
a one-step-procedure.
In three patients with altered abdominal anatomy after surgery (biliodigestive anastomosis
and status post gastrectomy), stent implantation by endoscopic luminal guidance was
not performed and attempted (even if it would have been possible with a single- or
double-balloon endoscope). On the one hand, there is enough space for bile drainage
at the distal end of the expanded metal stent in the anastomosed biliodigestive intestinal
loop, and on the other hand, endoscopic luminal re-interventions are rarely successful
in this situation; therefore, placement of the distal end of the metal stent was considered
as less relevant. Fortunately, we observed no stent occlusion in any of the three
patients in the follow-up. Balloon enteroscope-assisted endoscopic retrograde cholangiopancreatography
could be used as an alternative method in this setting, but the procedure time usually
is longer in comparison with percutaneous transhepatic biliary stenting and the procedure
can cause severe complications, such as perforation or pancreatitis.[23 ]
In a recent systematic review and meta-analysis about the efficacy and safety of EUS-guided
biliary drainage in comparison with percutaneous biliary drainage,[9 ] there was no difference in technical success between the two procedures, but PTBD
was associated with a lower level of clinical success, a higher level of post-procedural
adverse events, and a higher rate of re-interventions.[9 ] The important question is whether PTBD was performed in an appropriate way to allow
us to compare it adequately with EUS-BD. In the above-mentioned review, six completely
published studies (two prospective and four retrospective) were included ([Table 3 ]) with a PTBD case size from 12 to 51 (3–8). The post-procedural adverse event rate
accounted for between 10 and 54%. Re-intervention rate was reported in four studies
and ranged from 0.8 to 1.7 (mean frequency for additional PTBDs per patient).[3 ]
[4 ]
[7 ]
[8 ] A detailed description of the PTBD procedure was only reported in four out of six
studies.[3 ]
[5 ]
[6 ]
[7 ] PTBDs which were performed with ultrasound guidance had fewer adverse events (10–25%)
than PTBDs which only used fluoroscopic guidance (31–46%). In the study from Artifon
et al,[6 ] 4 of the 12 patients underwent external drainage catheter insertion before metal
stent implantation. According to our experience, external drainages should be strictly
avoided in PTBD because they could cause many adverse events such as bile leak, bilioma,
or dislocation, and this could result in the need for further PTBD sessions. In this
study, it was not reported whether PTBDs with external drainages caused the documented
adverse events or not. In the study from Bapaye et al,[5 ] just 12/26 (46%) metal stents and 14/26 (54%) external drainages were inserted,
which was probably the reason for the high figure of 12 adverse events (46%). Furthermore,
PTBD without metal stent implantation is worse when compared with EUS-BD, in which
metal stent implantation is performed regularly in patients with malignant bile duct
obstruction. In the study from Khashab et al,[4 ] it was not reported at all whether metal stents were used in PTBD or not. Furthermore,
a disproportionate amount of bile leaks and a high amount of scheduled re-interventions
were also reported, neither of which are necessary in a PTBD protocol as a one-step
procedure. In the study from Lee et al,[14 ] an external drainage was inserted regularly (which caused scheduled re-interventions)
before metal stent insertion, and only 15 (48%) metal stents were inserted overall.
In the study from Sharaih et al,[8 ] it was not reported how many metal stents were inserted, and how many benign and
malign diseases were mixed and not differentiated, which makes any comparison with
EUS-BD very difficult. Lastly, in the study from Sportes et al,[7 ] the external drainage was left after metal stent implantation and removed some days
later when stent implantation was clinically successful. This further procedure may
not be necessary when stent release is visualized by endoscopic luminal guidance as
discussed above.
Table 3
Overview on comparative studies between PTBD and EUS–BD
Authors and year
Study type
PTBDs (n )
Adverse events (n )
Reinterventions (mean frequency)
Method of PTBD access
Special comments
Abbreviations: EUS–BD, endoscopic ultrasound–guided biliary drainage; PTBD, percutaneous
transhepatic biliary drainage.
Artifon et al, 2012[6 ]
Prospective
12
3 (25%)
Not analyzed
Fluoroscopic and ultrasound guidance
Four external drainages before metal stent insertion
Bapaye et al, 2013[5 ]
Retrospective
26
12 (46%)
Not analyzed
Fluoroscopic guidance
Only 12/26 (46%) metal stents and 14/26 (54%) external drainages
Khashab et al, 2015[4 ]
Retrospective
51
20 (39%)
0.80 (n = 41)
No detailed description
Not reported whether metal stents were used or not, many scheduled re–interventions,
many bile leaks (n = 17)
Sharaiha et al, 2016[8 ]
Retrospective
13
7 (54%)
1.70 (n = 22)
no detailed description
Benign and malignant bile duct obstruction were mixed, number of metal stents remains
unclear
Lee et al, 2016[3 ]
Prospective
32
10 (31%)
0.93 (n = 29)
Fluoroscopic guidance
Two–step intervention: external drainage before metal stent insertion, just 15 (48%)
of metal stents inserted
Sportes et al, 2017[7 ]
Retrospective
20
2 (10%)
1.05 (n = 21)
Ultrasound guidance
External drain was left after metal stent implantation and removed some days later
when stent implantation was clinically successful, scheduled re–interventions were
mixed with unscheduled re–interventions
In conclusion, the way that we perform PTBD may have the following advantages. First,
color Doppler ultrasound-guided PTBD has the advantage of cannulating the bile duct
by ultrasound guidance and visualized intrahepatic vessels. Incidentally, this is
how EUS-guided biliary cannulation is performed regularly. In this way, injury of
intrahepatic blood vessels with severe intrahepatic bleeding or hemobilia can be better
prevented. Therefore, no severe bleeding event was documented in this study, and in
the study, we have already published on this topic.[15 ] Second, we favored the access to the intrahepatic bile duct from the left side of
the liver because on the right liver side, usually an intercostal access route has
to be chosen which causes more adverse events such as biliary effusion or pneumothorax,
as well as more patient discomfort and pain. This result corresponds with a recently
published study from Liu et al,[20 ] in which PTBD success was increased with left lobe entry (adjusted odds ratio [aOR]
= 1.853, 95% CI 1.167, 2.940) and complications were significantly decreased (aOR
= 0.450, 95% CI 0.263, 0.769). Therefore, the left liver is now our standard access
side for all PTBDs in patients with infrahilar bile duct obstruction. Third, we performed
PTBD with implantation of the self-expanding metal stent in the first session as a
one-step procedure. This has the advantage that no further re-intervention is necessary
after insertion of an external or an external/internal drainage, an outcome which
can cause further adverse events such as bile duct leak along the catheter, biliary
ascites, or catheter dislocation.[21 ] In one of our PTBD procedures, we documented biliary ascites, but this event was
caused by the delayed expansion of the metals stent in the vicinity of a duodenal
stent and a strong tumor infiltration of the bile duct. Fourth, we performed stent
release by endoscopic luminal guidance. In this way, the positioning and the correct
expansion of the distal tip of the metal stent can be observed directly in comparison
with the stent release, which is performed by fluoroscopic guidance alone.[22 ] In this strategy, some investigators leave behind an external drainage in the bile
duct until the clinical success of the procedure can be documented in the subsequent
days (as has been described above). This is not necessary when stent release is immediately
controlled endoscopically. Fifth, PTBD with antegrade stenting (metal stent through
tumor stenosis) is able to restore the “natural” bile duct route in comparison with
transluminal stenting in EUS-BD with EUS-guided hepatogastrostomy or EUS-guided choledochoduodenostomy.
Furthermore, these techniques can cause other severe adverse events such as stent
migration into the abdominal cave or pneumoperitoneum. But this question has to be
clarified in further studies which compare PTBD with EUS-BD as equivalent methods
in well-defined comparable diseases. Sixth, it should be mentioned that the technique
of ultrasound-guided peripheral portal vein-oriented non-dilated bile duct puncture
can be a further valuable method to improve bile duct access and to avoid bleeding
complications.[24 ]
The limitations of our study include the following—the retrospective character, the
single-center experience, and the extracted small sample size.
The further study should be a prospective, non-randomized multicenter study (e.g.,
one in which each center performs bile duct intervention with its best practice) as
a comparison between ultrasound-guided PTBD with primary metal stent implantation
with endoscopic luminal guidance on the one hand, and EUS-BD on the other hand (EUS-guided
antegrade, transpapillary drainage, EUS-guided transhepatic drainage and EUS-guided
choledochal drainage) in an adequate number of cases.
Conclusion
Percutaneous biliary drainage with ultrasound-guided ductal puncture and primary metal
implantation by endoscopic luminal guidance had a good technical and clinical success
rate in patients with malignant biliary obstruction in our selected patient cohort.
Adverse events were rare, and re-intervention rate was very low. A prospective, non-randomized,
comparative multicenter study with ultrasound-guided PTBD with primary metal stent
implantation by endoscopic luminal guidance and EUS-BD in patients with malignant
extrahepatic bile duct obstruction should be initiated to demonstrate relevant statistical
differences (or non-inferiority), with a particular focus on success, adverse events,
and the re-intervention rate.
Institutional Review Board Statement
This study was reviewed and approved by the ethics committee of the Mannheim University
Hospital on February 02, 2018 (2018–815R-MA).
Biostatistics Statement
The statistical methods and results were reviewed and verified by a member of the
Medical statistics, Biomathmatics and Information Processing of Mannheim University
Hospital.
