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(1). 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%(2). 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, the study team will
advise patients to start with daily flushing of the PTBD catheter which the investigators
believe will decrease the extent of obstruction and omits re-intervention. The investigators
performed a literature search and the investigators 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(1). The
investigators did find some publications in which an advice with regard to flushing of a PTBD
catheter was mentioned, however without any scientific substantiation(3-7).
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. The investigators hypothesize that daily flushing of an
internal external biliary catheter will increase the time-to-symptom-onset requiring hospital
visits and re-interventions in this patient group.