Keywords
Pancreatobiliary (ERCP/PTCD) - Strictures - PTCD/PTCS - Endoscopic ultrasonography
- Intervention EUS
Endoscopic calibration has become the gold-standard initial approach for management
of benign biliary strictures (BBS) whatever their origin. Transpapillary access is
the preferred one, followed by dilation and placement of plastic stent(s), or in selected
cases with mid-distal common bile duct (CBD) strictures, of fully-covered self-expandable
stent (FC-SEMS), for a period of 1 year corresponding to the usually accepted “calibration
period” [1]. However, endoscopic access to the papilla is not always possible due to the presence
of altered postsurgical anatomy or duodenal obstruction.
Percutaneous transhepatic biliary drainage (PTBD) is still considered the standard
alternative to transpapillary drainage in case of failure, especially when managing
a benign condition. However, PTBD is associated with a significant rate of adverse
events (AEs), reported around 10% for the initial procedure and reaching up to 40%
when considering the events related to percutaneous drainage maintenance [2]. In the case of BBS calibration, PTBD carries the additional discomfort of having
a percutaneous tube (usually equipped with a flat button) fixed to the skin for the
duration of the calibration period. Indeed, deployment of a conventional DeFC-SEMS
in a bile duct that is not endoscopically accessible is obviously contraindicated.
Endoscopic ultrasound-guided biliary drainage (EUS-BD) was described more than 20
years ago [3] as an alternative to PTBD in cases of failure of transpapillary access and is now
well accepted as a less invasive approach for distal or proximal (with preferred left
lobe access) malignant obstruction. In addition, it now has an established role, in
combination with endoscopic retrograde biliary drainage (ERBD) and/or percutaneous
transhepatic cholangiography and drainage, in palliation of more complex malignant
strictures [4].
EUS-BD involves two possible techniques, namely EUS-guided choledochoduodenostomy
(EUS-CDS), which may be proposed in cases of distal malignant obstruction and in the
absence of duodenal obstruction (ie mainly in cases of failure of cannulation), and
EUS-guided hepaticogastrostomy (EUS-HG), which is technically more challenging but
may be offered in cases with altered anatomy or duodenal strictures, which represent
the majority of cases with failed retrograde access for management of benign biliary
stenoses. EUS-HG also allows antegrade access to a distal stricture with placement
of a transpapillary/trans-stenotic stent [5].
In this issue of EIO, Caillol et al report on a series of 36 patients in whom they
used EUS-HG access to calibrate suspected BBS [6]. Thirty-four of their patients had altered postsurgical anatomy and two had chronic
pancreatitis-associated duodenal strictures, a feature that explains their choice
of EUS-HG access because EUS-CDS was either not feasible or obviously not an option
in these cases. The authors report a 100% success rate in creating the hepaticogastrostomy,
but they failed, even in further attempts, to cross the stricture in four cases and
were facing complex bilateral strictures in two more cases. In addition, seven patients
who had previously undergone surgery for malignancy had oncological relapses during
calibration. Altogether, 23 patients underwent “true” calibration for a period of
1 year, which had been completed at the time of publication in 20 of them. Two-thirds
of these patients had the stent removed at 1 year without clinical relapse, while
the others have stents still in place, suggesting mid-long term results (when stents
can be placed through the stricture), similar to those reported with transpapillary
stents placed by ERBD.
The technique the authors use deserves attention and differs from the one the same
pioneering group uses for palliation of malignant jaundice. Creation of the hepaticogastrostomy
is obtained through placement of a long fully (and not partially) covered stent, which
is planned to be removed within 4 weeks and replaced, once the hepaticogastric path
has been secured, by multiple plastic stents (after dilation of both the path and
the stricture). These stents then can be replaced as in usual calibration performed
through ERBD and the technique avoids the discomfort of having a stent fixed to the
skin during the calibration period, as is the case with PTCD. The short duration of
FC-SEMS implantation most probably limits the risk of stent-induced biliary damage.
However, FC-SEMS may block side branches and they are probably responsible for the
majority of early complications, namely iatrogenic cholangitis that occurs shortly
after the initial procedure. This is obviously a limitation to the use of this technique,
which may be solved in the future by development of dedicated devices for creating
an hepaticogastrostomy path without the need to maintain a large expandible stent
in place, or perhaps by mimicking the technique used for PTBD in which, after initial
access to the bile ducts, a percutaneous catheter (Ring’s catheter) is left in place
for a few days to mature the percutaneous path to the biliary tree. A nasobiliary
catheter, maintained for drainage for a few days, might play the same role without
the risk of blocking secondary bile ducts; however, there is a potential risk of complication
if such a catheter were to be accidentally withdrawn.
This highly experienced group obviously chose the optimal indications for such an
approach, and despite maximal technical success, reported an incidence of AEs similar
(or even higher) than has been reported for PTBD. That, of course, has to be balanced
against the gain in comfort for patients during the whole period of calibration and
the fact that most AEs were mild or moderate, associated with initial stent placement,
and apparently easily manageable. Along these lines, it is acceptable to say that
EUS-HG is a viable (although technically more complex) alternative to PTBD for benign
stricture calibration, providing significant advantages in terms of comfort during
calibration, even if its overall superiority has not been demonstrated. As also illustrated
in the authors’ series, both techniques have to be considered in such patients, after
ERBD failure.
These findings, however, do not mean that today, EUS-BD is an acceptable technique
or alternative to PTBD for all benign indications. It is worth noting that a recent
paper published in EIO [7] reported an optimistically low rate of AEs after EUS-BD and an (over) pessimistic
high rate of AEs after PTBD, possibly related to a lack of expertise [8]. In their propensity score matched analysis of a retrospective comparison between
EUS-BD and PTBD, Koutlas et al included 38 patients with benign indications, representing
40% of the cases in their series. These cases also included 15 patients with choledocholithiasis.
This latter indication seems difficult to justify at a time when PTCD can be associated
with percutaneous cholangioscopy and achievement of clearance of CBD stones in almost
all cases over a short period of time, without the need to maintain a percutaneous
stent for months. In addition, the technique the authors describe involves long-term
maintenance of a transgastric FC-SEMS (interestingly associated with much fewer AEs
than those reported by Caillol et al), without a systematic exchange for plastic stents.
FC-SEMS, when placed in small bile ducts (or in pancreatic ducts) may induce secondary
strictures that could not have been identified in during the trial because of the
too-short follow-up and which might compromise long-term clinical outcomes in patients
with benign conditions. Therefore, it is currently not acceptable to recommend such
an approach for all benign indications with failed transpapillary access outside of
dedicated prospective studies. PTBD is still the first alternative technique, especially
when treatment does not imply long calibration periods, and it is not yet time to
“throw the baby away with the bathwater” on the basis of a single retrospective study.
