Introduction
Malignant biliary obstruction is a common complication of pancreatic cancer, often
requiring decompression for symptomatic relief of jaundice and to allow for safe administration
of chemotherapy [1]. Transpapillary stenting via endoscopic retrograde cholangiopancreatography (ERCP)
is the recommended modality for decompression [2]; however, it is associated with significant adverse events including post-ERCP pancreatitis
in 5 – 15 % of patients [3]
[4]. Furthermore, recurrent obstruction due to delayed stent dysfunction occurs in up
to 41 % [5] and is associated with considerable morbidity in this frail patient population while
also representing a significant cost burden to the health care system [6].
Endoscopic ultrasound (EUS)-guided biliary drainage (BD), first described by Giovannini
et al. in 2001 [7], is an increasingly popular technique which creates a trans-duodenal (choledochoduodenostomy)
or trans-gastric (hepatogastrostomy) bypass to the bile duct. In addition to its high
technical and clinical success rate when performed in expert centers [8], this modality obviates the need for manipulation at the level of the papilla and
bypasses the tumor site, which may decrease the risk of pancreatitis and delayed stent
dysfunction from tumor tissue stent ingrowth or overgrowth. When compared to percutaneous
transhepatic biliary drainage (PTBD) as second-line modality after failed ERCP in
a recent meta-analysis [9], EUS-BD was associated with a decreased risk of reintervention and procedure-related
adverse events, while demonstrating better clinical success. Only recently have the
first randomized controlled trials (RCTs) been published comparing EUS-BD to ERCP
as first-line therapy [10]
[11]
[12]; however, small sample sizes limit comparisons of critical outcomes. Previously
reported systematic reviews evaluating EUS-BD [9]
[13] are limited by mostly retrospective uncontrolled data; moreover, there are currently
no meta-analyses comparing EUS-BD to first-line ERCP. We therefore conducted a systematic
review and meta-analysis of RCTs to assess the efficacy and safety of EUS-BD compared
to either PTBD or ERCP for decompression of distal malignant biliary obstruction.
Methods
This study was performed in accordance with the PRISMA statement for reporting systematic
reviews and meta-analyses of RCTs [14].
Search strategy
Systematic searches were performed through September 2018 using MEDLINE, EMBASE, Cochrane,
and ISI Web of knowledge. A highly sensitive search strategy was used to identify
reports of RCTs with a combination of Medical Subject Heading terms and text words
related to EUS and pancreatic cancer or common bile duct diseases (Appendix 1). Recursive searches, cross-referencing, and hand-searches were performed.
Study selection
All RCTs were included, both fully published and in abstract form, that compared EUS-BD
to either PTBD or ERCP for decompression of distal malignant biliary obstruction.
Trials were excluded if they included non-human subjects or were reported in neither
English nor French. The eligibility of the studies was assessed independently by two
investigators (CSM and MM), and if discrepancies were encountered, they were resolved
by a third assessor (YC).
Data extraction and validity assessment
Data were extracted from included studies in a predetermined data sheet by one investigator
and verified by a second. Extracted data included study information, comparator intervention,
baseline characteristics, and outcome events. The Jadad score and Cochrane risk of
bias tool were used to grade the quality of studies and to assess for potential bias,
respectively.
Choice of outcomes
The primary outcome was risk of stent or catheter dysfunction requiring biliary reintervention,
defined as the need for any unscheduled endoscopic, interventional or surgical procedure
to improve biliary drainage after the index drainage. Secondary outcomes included
technical success, clinical success, procedure time, adverse events, post-procedure
pancreatitis, tumor tissue stent in/overgrowth, stent clogging, and stent migration.
Clinical success was defined as a 50 – 75 % reduction in serum bilirubin within 1 – 4
weeks post-drainage. Adverse events were defined according to the ASGE report [15] or the Common Terminology Criteria for Adverse Events [16]. Post-procedure pancreatitis was generally defined as typical abdominal pain post-procedure
with an elevated amylase or lipase of greater than three times the upper limit of
normal [15].
Addressing clinical heterogeneity
Qualitative comparisons were performed to assess the heterogeneity of patient populations,
interventions, and outcomes across studies, guiding possible subgroup analyses. A
priori subgroup analyses by comparator were performed. Sensitivity analyses were performed
according to full publication status of trials. Post hoc sensitivity analyses were
performed excluding a trial that used a stent apparatus available only in South Korea
[11]. The identification and handling of statistical heterogeneity are described below.
Statistical analysis
For each outcome and in every comparison, effect sizes were calculated with risk ratios
(RR) for categorical variables. Random effects models were applied to all comparisons
to determine corresponding overall effect sizes and their confidence intervals using
the DerSimonian and Laird method [17]. If no heterogeneity was noted, results from the corresponding fixed effects models
using the Mantel–Haenszel method were also reported. The presence of heterogeneity
across studies for a given outcome was defined using Chi-squared tests of homogeneity
with a 0.10 significance level [18]. The Higgins I
2 statistic [19] was calculated to quantify the proportion of variation in treatment effects attributable
to between-study heterogeneity. Values of 25 %, 50 %, and 75 % represent low, moderate,
and high heterogeneity, respectively. To identify possible sources of statistical
heterogeneity, sensitivity analyses were performed, excluding studies one by one.
A continuity correction was added to each trial with zero events using the reciprocal
of the opposite treatment arm size to ensure that comparisons with double-zero events
did not significantly affect the heterogeneity or P value [20]. For all comparisons, publication bias was evaluated using the Begg adjusted rank
correlation test [21] and the Egger regression asymmetry test [22]. Summary statistics were expressed as means and standard deviations. All statistical
analyses were done using Meta package in R version 3.2.1 (R Foundation for Statistical
Computing, Vienna, Austria, 2008).
Results
Included studies, quality assessment and publication bias
The search yielded 1264 citations ([Fig. 1]). After screening based on title and abstract, 14 articles were reviewed in full.
Of these, six trials randomizing 354 patients were included [10]
[11]
[12]
[23]
[24]
[25]. Three trials (n = 222) compared EUS-BD to ERCP-BD for first-line therapy [10]
[11]
[12], and three trials (n = 132) compared EUS-BD to PTBD after failed ERCP-BD [23]
[24]
[25]. One of the latter was reported only in abstract form [25]. In terms of EUS-BD technique, all studies specified the use of self-expanding metal
stents, with the exception of one study [25] which did not specify this. Three trials used only choledochoduodenostomy [10]
[12]
[23], two further included hepatogastrostomy [11]
[24], and one included even antegrade transpapillary stenting [25]. [Table 1] summarizes the studies included.
Fig. 1 Flow diagram of study selection. BD, biliary drainage; EUS, endoscopic ultrasound.
Table 1
Characteristics of studies included in the systematic review.
Authors
|
Year
|
Country
|
Groups
|
ITT Patients, n
|
Female, %
|
Mean age, y
|
Median follow-up, d
|
Mean, CBD, mm
|
Artifon et al. [23]
|
2012
|
Brazil
|
EUS-BD
|
13
|
31
|
63.4
|
80[1]
|
13.7
|
PTBD
|
12
|
33
|
71.0
|
75[1]
|
11.9
|
Bang et al. [10]
|
2018
|
USA
|
EUS-BD
|
33
|
48
|
69.4
|
190
|
13.3
|
ERCP-BD
|
34
|
32
|
69.2
|
174
|
12.5
|
Giovannini et al. [25]
|
2015
|
France
|
EUS-BD
|
20
|
10
|
NR
|
NR
|
NR
|
PTBD
|
21
|
52
|
Lee et al. [24]
|
2016
|
Korea
|
EUS-BD
|
34
|
24
|
66.5
|
≥ 3 mo
|
11.2
|
PTBD
|
32
|
25
|
68.4
|
≥ 3 mo
|
12.6
|
Paik et al. [11]
[38]
|
2018
|
Korea
|
EUS-BD
|
64
|
36
|
64.8
|
144
|
15.7
|
ERCP-BD
|
61
|
57
|
68.4
|
165
|
15.0
|
Park et al. [12]
|
2018
|
Korea
|
EUS-BD
|
15
|
33
|
66.8
|
95
|
NR
|
ERCP-BD
|
15
|
40
|
65.4
|
147
|
BD, biliary drainage; CBD, common bile duct; ERCP, endoscopic retrograde cholangiopancreatography;
ITT, intention-to-treat; NR, not reported, PTBD, percutaneous transhepatic biliary
drainage.
1 Mean value.
The modified Jadad quality scores ranged from 1 to 3 points out of a possible score
of 5, with a mean of 2.5 ± 0.8. The Cochrane risk of bias tool revealed a low potential
for selection bias across studies (Appendix 2). All trials were single-blinded; however, double-blinding in this clinical context
is not feasible. No statistical heterogeneity was noted with the exception of the
stent clogging analysis (P = 0.07) ([Table 2]). Publication bias was noted for the primary outcome analysis (Begg, P < 0.01).
Table 2
Primary and secondary outcomes, subgroup and sensitivity analyses.
|
Studies, n
|
Patients, n
|
RR (95 %CI)
|
Heterogeneity
|
Egger
|
Beggs
|
|
|
|
|
P value
|
I
2 (%)
|
|
|
Primary outcome
|
Stent/catheter dysfunction
|
5
|
311
|
0.39 (0.27; 0.57)
|
0.89
|
0
|
P = 0.08
|
P < 0.01
|
|
5
|
311
|
0.39 (0.27; 0.57)
|
0.89
|
0
|
|
|
|
5
|
311
|
0.39 (0.27; 0.57)
|
0.93
|
0
|
|
|
|
5
|
311
|
0.39 (0.27; 0.58)
|
0.89
|
0
|
|
|
|
3
|
220
|
0.41 (0.23; 0.74)
|
0.76
|
0
|
|
|
|
2
|
95
|
0.59 (0.16; 2.25)
|
0.65
|
0
|
|
|
|
2[1]
|
39
|
0.37 (0.22; 0.61)
|
–
|
–
|
|
|
Secondary outcome
|
Technical success
|
6
|
352
|
1.00 (0.95; 1.06)
|
0.60
|
0
|
P = 0.46
|
P = 0.48
|
|
5
|
211
|
0.99 (0.94; 1.05)
|
0.82
|
0
|
|
|
|
6
|
352
|
1.00 (0.95; 1.06)
|
0.60
|
0
|
|
|
|
6
|
352
|
1.01 (0.96; 1.07)
|
0.60
|
0
|
|
|
|
3
|
220
|
1.00 (0.93; 1.08)
|
0.52
|
0
|
|
|
|
2
|
95
|
0.95 (0.85; 1.07)
|
0.76
|
0
|
|
|
|
3
|
132
|
1.01 (0.92; 1.11)
|
0.27
|
27
|
|
|
Clinical success
|
5
|
311
|
1.02 (0.95; 1.09)
|
0.92
|
0
|
P = 0.73
|
P = 0.40
|
|
5
|
311
|
1.02 (0.95; 1.09)
|
0.92
|
0
|
|
|
|
5
|
311
|
1.02 (0.95; 1.09)
|
0.92
|
0
|
|
|
|
5
|
311
|
1.01 (0.93; 1.09)
|
0.92
|
0
|
|
|
|
3
|
220
|
1.03 (0.94; 1.12)
|
0.70
|
0
|
|
|
|
2
|
95
|
1.05 (0.94; 1.16)
|
0.61
|
0
|
|
|
|
2
|
91
|
0.99 (0.88; 1.12)
|
0.82
|
0
|
|
|
Procedure duration[2]
|
2
|
95
|
3.73 ( – 4.10; 11.55)
|
0.26
|
23
|
–
|
|
|
2
|
95
|
3.73 ( – 4.10; 11.55)
|
0.26
|
23
|
|
|
|
2
|
95
|
3.73 ( – 4.10; 11.55)
|
0.26
|
23
|
|
|
|
2
|
95
|
2.80 ( – 2.44; 8.04)
|
0.26
|
23
|
|
|
|
2
|
95
|
2.80 ( – 2.44; 8.04)
|
0.26
|
23
|
|
|
|
2
|
95
|
2.80 ( – 2.44; 8.04)
|
0.26
|
23
|
|
|
|
0
|
|
|
|
|
|
|
Adverse events
|
6
|
352
|
0.56 (0.34; 0.94)
|
0.15
|
40
|
P = 0.26
|
P = 0.66
|
|
5
|
311
|
0.55 (0.25; 1.22)
|
0.16
|
42
|
|
|
|
5
|
311
|
0.50 (0.22; 1.14)
|
0.25
|
25
|
|
|
|
5
|
311
|
0.53 (0.30; 0.94)
|
0.16
|
42
|
|
|
|
3
|
220
|
0.67 (0.16; 2.79)
|
0.06
|
71
|
|
|
|
2[1]
|
95
|
1.44 (0.51; 4.09)
|
–
|
–
|
|
|
|
3
|
132
|
0.59 (0.39, 0.87)
|
0.16
|
42
|
|
|
Post-procedure pancreatitis
|
5
|
311
|
0.34 (0.03; 3.65)
|
0.16
|
46
|
P = 0.46
|
P = 0.34
|
|
5
|
311
|
0.34 (0.03; 3.65)
|
0.16
|
46
|
|
|
|
5
|
311
|
0.43 (0.08; 2.16)
|
0.34
|
12
|
|
|
|
5
|
311
|
0.21 (0.05; 0.81)
|
0.16
|
46
|
|
|
|
3
|
220
|
0.12 (0.01; 0.97)
|
0.35
|
0
|
|
|
|
2[1]
|
95
|
0.34 (0.01; 8.13)
|
–
|
–
|
|
|
|
2[1]
|
91
|
2.83 (0.12; 67.01)
|
–
|
–
|
|
|
Tumor in/overgrowth
|
3
|
219
|
0.18 (0.06; 0.62)
|
0.92
|
0
|
P = 1.00
|
P = 0.53
|
|
3
|
219
|
0.18 (0.06; 0.62)
|
0.92
|
0
|
|
|
|
3
|
219
|
0.18 (0.06; 0.62)
|
0.92
|
0
|
|
|
|
3
|
219
|
0.18 (0.05; 0.60)
|
0.92
|
0
|
|
|
|
2
|
153
|
0.18 (0.05; 0.69)
|
0.69
|
0
|
|
|
|
1
|
28
|
0.11 (0.01; 1.89)
|
–
|
–
|
|
|
|
1
|
33
|
0.19 (0.01; 3.78)
|
–
|
–
|
|
|
Stent clogging
|
3
|
219
|
1.20 (0.25; 5.64)
|
0.07
|
63
|
P = 1.00
|
P = 0.28
|
|
3
|
219
|
1.20 (0.25; 5.64)
|
0.07
|
63
|
|
|
|
3
|
219
|
1.20 (0.25; 5.64)
|
0.07
|
63
|
|
|
|
2
|
153
|
0.96 (0.09; 10.10)
|
0.11
|
62
|
|
|
|
1
|
28
|
5.00 (0.26; 95.61)
|
–
|
–
|
|
|
|
1
|
33
|
2.35 (0.49; 11.28)
|
–
|
–
|
|
|
Stent migration
|
3
|
219
|
1.46 (0.45; 4.74)
|
0.59
|
0
|
P = 0.30
|
P = 0.09
|
|
3
|
219
|
1.46 (0.45; 4.74)
|
0.59
|
0
|
|
|
|
3
|
219
|
1.46 (0.45; 4.74)
|
0.59
|
0
|
|
|
|
3
|
219
|
1.60 (0.52; 4.92)
|
0.59
|
0
|
|
|
|
2
|
153
|
2.78 (0.44; 17.71)
|
0.62
|
0
|
|
|
|
1
|
28
|
5.00 (0.26; 95.61)
|
–
|
–
|
|
|
|
1
|
33
|
0.94 (0.50; 4.33)
|
–
|
–
|
|
|
CI, confidence interval; ERCP, endoscopic retrograde cholangiopancreatography; RR,
risk ratio.
1 Includes one double-zero event study.
2 Effect estimate given as weighted mean difference in minutes.
Primary and secondary outcomes
In the primary outcome analysis, EUS-BD was associated with a decreased risk of stent/catheter
dysfunction requiring reintervention (RR, 0.39; 95 %CI 0.27 – 0.57) ([Fig. 2], [Table 2]). Prespecified subgroup analysis by comparator demonstrated a decreased risk of
stent/catheter dysfunction associated with EUS-BD compared to ERCP as primary therapy
(RR, 0.41; 95 %CI 0.23 – 0.74) as well as compared to PTBD as second-line therapy
after failed ERCP (RR, 0.37, 95 %CI 0.22 – 0.61).
Fig. 2 Forest plot of stent dysfunction requiring biliary reintervention. CI, confidence
interval; ERCP, endoscopic retrograde cholangiopancreatography; M-H, Mantel–Haenszel.
EUS-BD was associated with a decreased risk of tumor in/overgrowth overall (RR, 0.18;
95 %CI 0.06 – 0.62) and compared to ERCP (RR, 0.18; 95 %CI 0.05 – 0.69), but no statistically
significant difference was observed compared to PTBD alone in subgroup analysis ([Fig. 3], [Table 2]). Pooled estimates for stent clogging and migration were inconclusive due to wide
confidence intervals. Although no difference was observed overall, compared to ERCP,
EUS-BD was associated with a decreased risk of post-procedure pancreatitis (RR, 0.12;
95 %CI 0.01 – 0.97) ([Fig. 3]). A decreased risk of adverse events was associated with EUS-BD both in the overall
analysis (RR, 0.56; 95 %CI 0.34 – 0.94) and when solely compared to PTBD (RR, 0.59;
95 %CI 0.39 – 0.87); but there was no difference compared to ERCP ([Fig. 4]). There were no differences observed in technical ([Fig. 4]) or clinical success and there was no difference in procedure time compared to ERCP.
Fig. 3 Forest plot: a post-procedure pancreatitis; b tumor in/overgrowth. CI, confidence interval; ERCP, endoscopic retrograde cholangiopancreatography;
M-H, Mantel – Haenszel.
Fig. 4 Forest plot: a technical success; b adverse events. CI, confidence interval; ERCP, endoscopic retrograde cholangiopancreatography;
M-H, Mantel–Haenszel.
Sensitivity analyses
Results from sensitivity analyses were concordant with the main analysis ([Table 2]). In a post hoc analysis removing Paik et al. [11] from the ERCP-BD comparator subgroup, there was no significant difference found
for risk of stent/catheter dysfunction, tumor in/overgrowth or post-procedure pancreatitis.
Discussion
Although ERCP as primary therapy with PTBD as second line have been the standard of
care for decompression of distal malignant biliary obstruction for several decades,
EUS-BD has emerged as a viable alternative with several potential advantages. Our
meta-analysis is the first, to our knowledge, to compare EUS-BD to ERCP for primary
treatment and the first meta-analysis of RCTs to evaluate the safety and efficacy
of EUS-BD overall. Overall, compared to conventional modalities, EUS-BD was associated
with decreased stent/catheter dysfunction requiring reintervention (RR, 0.39; 95 %CI
0.27 – 0.57), tumor in/overgrowth (RR, 0.18; 95 %CI 0.06 – 0.62), and adverse events
(RR, 0.56; 95 %CI 0.34 – 0.94) with comparable technical (RR, 1.00; 95 %CI 0.95 – 1.06)
and clinical success (RR, 1.02; 95 %CI 0.95 – 1.09). Our subgroup findings are consistent
with previous data [9] demonstrating that EUS-BD outperforms PTBD as a salvage approach after failed ERCP
with decreased risk of stent or catheter dysfunction requiring reintervention (RR,
0.37, 95 %CI 0.22 – 0.61) and adverse events (RR, 0.59; 95 %CI 0.39 – 0.87). Our data
further suggest that EUS-BD is favorable over ERCP as the primary modality for distal
malignant biliary obstruction in terms of risks of stent dysfunction (RR, 0.41; 95 %CI
0.23 – 0.74), tumor in/overgrowth (RR, 0.18; 95 %CI 0.05 – 0.69), and post-procedure
pancreatitis (RR, 0.12; 95 %CI 0.01 – 0.97), while comparable in terms of safety as
represented by adverse events (RR, 0.67; 95 %CI 0.16 – 2.79).
The decreased risk of stent dysfunction requiring reintervention favoring EUS-BD over
ERCP or PTBD is of great clinical significance not only because of the diminished
morbidity in this often-frail patient population, but also because of the potential
impact on oncological outcomes. For patients with metastatic pancreatic cancer with
a good performance status, there is a clear survival benefit to FOLFIRINOX therapy
[26], which would be necessarily delayed by the need for reintervention. Furthermore,
even among resectable patients, in whom a recent trial demonstrated an unprecedented
median survival of 54.4 months after adjuvant FOLFIRINOX [27], there may be a benefit to neoadjuvant chemotherapy administration. It has been
suggested that preoperative chemotherapy may improve surgical outcomes, treat micrometastasis,
and identify those whose disease will inevitably progress, all while patients are
less likely to suffer serious side effects [28]. Indeed, a meta-analysis of 5520 patients with non-metastatic pancreatic adenocarcinoma
demonstrated an impressive 85 % R0 resection rate (no residual tumor) among all patients
who underwent resection after neoadjuvant therapy [29]. Thus, there is currently a push towards neoadjuvant therapy for all resectable
pancreatic cancer and not only for borderline resectable disease needing downstaging.
Optimal biliary drainage is becoming increasingly crucial as limiting the rate of
stent dysfunction may have a significant impact on systemic therapy administration
and, ultimately, oncological outcomes. It should be noted that, in the small cohort
of patients who underwent resection in the study by Bang et al. [10], EUS-guided choledochoduodenostomy did not seem to impact negatively on surgical
outcomes. From a practical efficiency perspective, EUS has the unique ability to achieve
decompression and acquire precise tissue diagnosis at the same setting. As the technique
of EUS-BD continues to improve along with the introduction of dedicated devices, it
may prove to be a preferred drainage modality over ERCP for distal malignant biliary
obstruction.
The fear of adverse events and well-described technical challenges with EUS-BD are
likely major barriers to the implementation of this modality in clinical practice
[30]. Our meta-analysis, however, demonstrates that EUS-BD is comparable to ERCP and
superior to PTBD in terms of minimizing adverse events, at least in the expert hands
of operators participating in the RCTs. Regarding the notorious complication of post-procedure
pancreatitis, we observe an 88 % relative risk reduction compared to ERCP. In terms
of technical feasibility, EUS-BD is indeed labor-intensive and technically difficult
at the present time; however, emerging dedicated biliary stents for EUS such as the
one-step tapered tip stent available in Korea (DEUS, Standard Sci Tech Inc., Seoul,
South Korea) and the electrocautery-enhanced lumen apposing metal stent (LAMS) (Hot
AXIOS, Boston Scientific Corporation, Marlborough, Massachusetts, United States) will
likely facilitate the procedure and increase its implementation outside of expert
centers. In fact, recent retrospective data with EUS-BD using LAMS show excellent
technical success, clinical success, and safety with a low rate of stent dysfunction
[31]. Our group is currently coordinating a multicenter, prospective, randomized trial
to further evaluate EUS-BD with LAMS (clinical trial registration number: NCT03870386).
In terms of the two transmural approaches for EUS-BD, choledochoduodenostomy (CDS)
and hepatogastrostomy (HGS), there is no clearly superior technique. Although two
retrospective studies suggested a possible advantage in stent patency associated with
HGS [32]
[33], and one suggested a decreased risk of late adverse events [33], no significant differences in efficacy or safety outcomes were found in a meta-analysis
of 10 studies [34]. Indeed, in the only randomized trial to compare the two approaches head-to-head,
there were no significant differences found in any outcomes including technical success,
clinical success, adverse events, mortality, and quality of life [35]. In our analysis, only two studies reported on outcomes within the individual techniques.
One found no difference in clinical success and one reported no differences in several
outcomes including reintervention rate, technical success, clinical success, and adverse
events. At this point, the decision on which approach to use should be decided based
on local experience and patient-specific anatomy considerations.
Our study has a few important limitations. The first is the relatively small number
of reported RCTs and included patients. To that end, the more conservative random
effects model was used to estimate effect sizes. The fact that differences in outcomes
were no longer observed with removal of the largest study in a sensitivity analysis
of the ERCP comparison subgroup reflects a lack of robustness and our study should
be repeated once more randomized data are available. The small number of studies also
limits the use of a prediction interval to further ascertain heterogeneity in a random
effects model, given that such statistical methods have been shown to be inaccurate
and potentially misleading in small meta-analyses [36]
[37]. Second, the use of different devices in the individual studies creates clinical
heterogeneity. Again, sensitivity analysis was performed removing the study with a
dedicated device only available in Korea. Third, the per-patient event rate was frequently
not reported in studies; therefore, an overall event rate was used. Finally, the performance
of EUS-BD only within expert centers limits generalizability to other settings.
Some key strengths of this study are the inclusion of only randomized data, the lack
of statistical heterogeneity, and the novelty in that it is the first meta-analysis
to compare EUS-BD to ERCP for the primary treatment of malignant biliary obstruction.
In conclusion, the present systematic review and meta-analysis of RCTs demonstrates
that EUS-BD is effective and safe when compared overall to a combination of standard
therapies for distal malignant biliary obstruction with decreased stent/catheter dysfunction
requiring reintervention, tumor in/overgrowth and adverse events as well as similar
technical and clinical success. As second-line therapy after failed ERCP, it is favorable
to PTBD with regard to stent/catheter dysfunction and adverse events. Compared to
ERCP as primary therapy, EUS-BD is associated with decreased stent dysfunction requiring
reintervention, tumor in/overgrowth, and post-procedure pancreatitis, suggesting a
promising role as an alternative first-line modality for the treatment of distal malignant
biliary obstruction in centers where the expertise is available. Our results should
be validated with the emergence of dedicated EUS therapeutic devices and as more randomized
data become available.