Flushing of internalized percutaneous transhepatic biliary drainage catheters

Bile is synthesized and secreted by the liver and transported into the
peripheral bile ducts, to the left or right hepatic duct which join together in
the common hepatic duct and more distally in the common bile duct. Secreted
bile is stored in the gall bladder. During a meal, the bile is secreted into
the duodenum.
Obstruction of the biliary tract will result in cholestasis with symptoms as
jaundice and pruritus and cholangitis in case of infection, usually related to
prior biliary intervention. Causes of biliary obstruction are benign or
malignant.

Percutaneous transhepatic biliary drainage (PTBD) is a drainage method for
biliary obstruction. The procedure starts with percutaneous puncture under
fluoroscopic or ultrasound guidance and cannulation of the peripheral biliary
tree, which is confirmed by contrast injection in the biliary tree. The needle
will be exchanged for a guidewire which can be advanced into the biliary tract.
When the correct position is reached, a drainage catheter with side holes is
placed.

There are two types of PTBD techniques: placement of an external biliary drain
and placement of an internal external biliary drain. The external biliary drain
is positioned in the bile duct above a stenosis and drains the bile externally
into a bag outside the patient. Capping of an external biliary drain will stop
the drainage of bile into the bag and forces the bile to drain towards the
digestive tract. The internal external biliary drain is placed in the bile duct
and the tip of the internal external biliary drain is localised in the duodenum
allowing both bile flow through the drain to the digestive tract (internal) or
into the bag (external). Capping of an internal external biliary drain will
stop the external drainage and results in internal drainage only.

Complications of PTBD are bleeding (usually during or shortly after the
procedure), infection (cholangitis, abscess, peritonitis, cholecystitis,
pancreatitis), catheter obstruction and catheter dislocation. Catheter
obstruction will result in cholestasis resulting in jaundice, drain leakage and
finally cholangitis. The exact prevalence of PTBD catheter obstruction is not
described in literature, however the prevalence of cholangitis in patients with
a PTBD catheter is reported as high as 59%. Subsequently, the PTBD catheter
often needs a revision (re-intervention), i.e. exchanging the catheter for a
new one. If catheter obstruction is assessed during re-intervention, attempts
can be made to remove the obstruction or the obstructed PTBD catheter can be
exchanged for a new PTBD catheter.

After PTBD catheter placement, flushing of the PTBD catheter is not standard
protocol in our center. In clinical practice, when obstruction of PTBD catheter
occurs, we advise patients to start with daily flushing of the PTBD catheter
which we believe will decrease the extent of obstruction and omits
re-intervention. We performed a literature search and we did not find any
clinical trial on the efficacy of flushing of PTBD catheters. Guidelines of the
Society of Interventional Radiology on percutaneous biliary drainage do not
mention flushing of the catheter. We did find some publications in which an
advice with regard to flushing of a PTBD catheter was mentioned, however
without any scientific substantiation.

There is no scientific evidence for or against PTBD catheter flushing. Flushing
is a simple, low-cost and low-risk procedure. Complications or side-effects of
PTBD catheter flushing are not reported in literature. PTBD re-interventions on
the other hand are associated with risks and are invalidating for the patient.
We hypothesize that daily flushing of an internal external biliary catheter
will increase the median time-to-symptom-onset requiring hospital visits and
re-interventions in this patient group.

To compare the median time-to-symptom-onset in patients with an internal
external PTBD catheter without daily flushing compared to median
time-to-symptom-onset in patients with an internal external PTBD catheter who
daily flush the catheter.

Symptoms of catheter obstruction is defined as:
- signs of cholestasis defined as: rising bilirubin level and/or increase in
catheter localized pain and/or leakage of bile along the catheter and/or
resistance while flushing the catheter
- and/or signs of cholangitis defined as: elevation in temperature more than
38.5°C thought to have a biliary cause

Non-blinded randomized controlled trial with 1:1 allocation.

- Intervention group: flushing of internal external PTBD catheter 3 times a day.
- Control group: no flushing of PTBD catheter.

The potential value of this study is that flushing of an internal external PTBD
catheter may result in a longer symptom free period for the patient.

Flushing of the catheter is a low-risk procedure, complications or side-effects
are not reported in literature. Flushing is currently not standard of care.

When obstruction of a PTBD catheter occurs, treating physicians often advise
patients to start with daily flushing of the PTBD catheter.

Participants in this study need to fill in questionnaires on quality of life
and study procedures at baseline, 3 weeks and 6 weeks after randomization. This
study requires no extra site visits.