Proximal migration of endoscopically inserted stents has an incidence of approximately
5 % [1]. Endoscopic retrieval may be difficult in cases with distal stent impaction or a
biliary stricture distal to the migrated stent [2]. We describe an unusual case with both migration and perforation.
A 31-year old woman had a lesion of the right hepatic duct after laparoscopic cholecystectomy.
At laparotomy the lesion was sutured over a T tube.
At 3 weeks later, endoscopic retrograde cholangiopancreatography (ERCP) showed a slight
stenosis at the site of the lesion in the right hepatic duct. After sphincterotomy
and removal of the T tube, an endoprosthesis was placed. At control ERCP 3 months
later, the endoprosthesis was found to be proximally displaced. Magnetic resonance
cholangiopancreatography (MRCP) showed that the stent had migrated in such a way that
its distal end had perforated the wall of the common bile duct and passed through
into the pancreatic tissue and the proximal end was in the liver parenchyma (Figure
[1]).
At the following ERCP the stent was grasped with a forceps and successfully removed
(Figure [2]).
The migration of biliary stents is a well known phenomenon. The cause may be a combination
of a large sphincterotomy and a suboptimal function of the flaps. Most straight plastic
stents have one or more short flaps to prevent migration, but sometimes the flaps
are not fully expanded or long enough. Making the flaps longer, however, would make
the stent weaker with increased risk of breakage at the site of the flaps [3]. In the present case the stent was not only migrated, but it had also made a perforation
of the bile-duct wall. The straight plastic stents are rather stiff, and perforation
of the gut has been described earlier [4].
To avoid migration and perforation, the use of pigtail stents of large diameter or
stents with long flaps in the distal end and short flaps in the proximal end might
be better.
Figure 1Magnetic resonance cholangiopancreatography (MRCP) showing a stenosis of the right
main duct and a displaced biliary stent
Figure 2Endoscopic retrograde cholangiopancreatography (ERCP) at removal of displaced biliary
stent
