the most serious complication of endoscopic papillectomy ( ep ) for ampullary adenoma is postprocedure severe pancreatitis .
many studies suggest that the prophylactic placement of a pancreatic duct ( pd ) stent after ep reduces the risk of pancreatitis.1,2 however , proximal migration of the pd stent occurs at a rate of about 5.2%.3 in general , ep is performed for ampullary adenoma not extending into the biliary or pancreatic duct .
therefore , endoscopic retrieval of proximally migrated pd stents after ep is difficult because the pd diameter is within the normal range in most cases .
we describe a case series with proximally migrated pd stents after ep that were retrieved successfully using a wireguided endoscopic snare .
between july 2004 and june 2009 , we attempted endoscopic removal of proximally migrated pd stents after ep for ampullary adenoma in 5 patients .
all patients underwent prophylactic placement of a pd stent after ep to reduce the risk of postprocedure pancreatitis .
wire - guided endoscopic snare retrieval was attempted in four patients and the conventional method using a forceps , snare , or basket without a guidewire in one patient .
the pd is cannulated using an endoscopic retrograde cholangiopancreatography ( ercp ) catheter and then a 0.035-inch guidewire is inserted deeply through the catheter .
after removing the ercp catheter , a snare ( sd-7p-1 or sd-8p-1 ; olympus , tokyo , japan ) is passed over the guidewire .
the migrated stent is captured in the snare and removed via traction on the snare .
if the first attempt of capturing the migrated stent at its distal end was not successful , it was then tried at its proximal end .
after the excision was completed , a 5 fr , 9-cm geenen pd stent ( wilson - cook , winston - salem , nc , usa ) was placed immediately and positioned across the pd orifice ( fig .
after retrieving the resected specimen , the pd stent was not seen in the duodenum .
unfortunately , the stent could not be retrieved because pd cannulation is difficult consequent to the edema and oozing that occurs after ep .
the patient was kept fasting overnight and an attempt to retrieve the pd stent was made the next day .
due to the small diameter of the pd , it was difficult to pass accessories alongside the stent for its retrieval .
after the excision was completed , a 5 fr , 7-cm geenen pd stent was placed immediately . after retrieving the resected specimen ,
we made several attempts to retrieve the stent , although the pd orifice was not seen clearly due to edema .
the next day , we performed wire - guided endoscopic snare retrieval of the pd stent successfully ( fig .
after the excision was completed , a 5 fr , 9-cm geenen pd stent was inserted .
the next day , the plain abdominal radiograph confirmed that the stent had migrated into the proximal pd .
endoscopic retrieval of the stent was not attempted because the patient refused follow - up endoscopy to remove the stent .
then , wire - guided endoscopic snare retrieval of the pd stent was performed successfully .
after the excision was completed , a 5 fr , 5-cm geenen pd stent was inserted .
the next day , the plain abdominal radiograph showed that the stent had migrated proximally .
the migrated stent was removed successfully using the wire - guided endoscopic snare method and no procedure - related complications occurred .
a 34-year - old asymptomatic man was found to have an ampullary adenoma with a normal biliopancreatic duct on ercp .
ep was performed using a reported method.4,5 after the excision was completed , a 5 fr , 9-cm geenen pd stent was placed immediately and the distal end protruded into the duodenum . after taking up the resected specimen , the pd stent was not seen in the duodenum .
several attempts to retrieve the stent via the papillae using a rat - tooth forceps , snare , or basket were unsuccessful . the next day
the migrated stent was removed successfully with a minisnare ( soft acusnare ; wilson - cook ) .
unfortunately , the patient developed severe pancreatitis and required hospitalization for 1 month to recover from the postprocedure pancreatitis .
after the excision was completed , a 5 fr , 9-cm geenen pd stent ( wilson - cook , winston - salem , nc , usa ) was placed immediately and positioned across the pd orifice ( fig .
after retrieving the resected specimen , the pd stent was not seen in the duodenum .
unfortunately , the stent could not be retrieved because pd cannulation is difficult consequent to the edema and oozing that occurs after ep .
the patient was kept fasting overnight and an attempt to retrieve the pd stent was made the next day .
due to the small diameter of the pd , it was difficult to pass accessories alongside the stent for its retrieval .
after the excision was completed , a 5 fr , 7-cm geenen pd stent was placed immediately . after retrieving the resected specimen ,
we made several attempts to retrieve the stent , although the pd orifice was not seen clearly due to edema .
the next day , we performed wire - guided endoscopic snare retrieval of the pd stent successfully ( fig .
a 63-year - old man underwent ep for ampullary adenoma . after the excision was completed ,
the next day , the plain abdominal radiograph confirmed that the stent had migrated into the proximal pd .
endoscopic retrieval of the stent was not attempted because the patient refused follow - up endoscopy to remove the stent .
then , wire - guided endoscopic snare retrieval of the pd stent was performed successfully .
a 56-year - old woman underwent ep for ampullary adenoma . after the excision was completed ,
the next day , the plain abdominal radiograph showed that the stent had migrated proximally .
the migrated stent was removed successfully using the wire - guided endoscopic snare method and no procedure - related complications occurred .
a 34-year - old asymptomatic man was found to have an ampullary adenoma with a normal biliopancreatic duct on ercp .
ep was performed using a reported method.4,5 after the excision was completed , a 5 fr , 9-cm geenen pd stent was placed immediately and the distal end protruded into the duodenum . after taking up the resected specimen , the pd stent was not seen in the duodenum .
fluoroscopy confirmed that the stent had migrated into the proximal duct . several attempts to retrieve the stent via the papillae using a rat - tooth forceps , snare , or
the migrated stent was removed successfully with a minisnare ( soft acusnare ; wilson - cook ) .
unfortunately , the patient developed severe pancreatitis and required hospitalization for 1 month to recover from the postprocedure pancreatitis .
many studies suggest that placement of a pd stent reduces the risk of pancreatitis after ep.1,2,4,6 - 9 with the increasing use of pd stents , many complications can occur , including migration of the stent .
proximal migration may be more serious because of the technical challenge associated with the attempt at retrieval . in one report , proximal stent migration occurred in 5.2% of patients and the majority of these stents could be retrieved endoscopically.3 lahoti et al.10 reported a successful endoscopic retrieval rate of 80% ( 8 of 10 ) .
of the two patients in whom the stents could not be retrieved , one developed continuous pain and required a distal pancreatectomy for stent removal .
a recent retrospective study of 33 patients involving endoscopic treatment of proximally migrated pancreatic stents reported a successful retrieval rate of 78% for endoscopically placed stents.11 the stents were retrieved using a balloon ( 44% ) , direct forceps grasp ( 28% ) , and guidewire stent cannulation with snare capture ( 11% ) .
four patients underwent surgery and one asymptomatic patient was observed . unfortunately , endoscopic treatment of proximally migrated pd stents after ep is more difficult due to the small diameter of the pd and postprocedure periampullary edema and bleeding . in previous reports ,
the rate of post - ercp pancreatitis was higher when cannulation was difficult and prolonged.12,13 multiple attempts at retrieval of a pd stent may predispose to pancreatitis owing to the added mechanical trauma . therefore
, a safe effective method for retrieving the migrated pd stent is needed to reduce postprocedure pancreatitis .
cannulation of the nondilated main pd can be difficult using the accessories required for migrated stent retrieval .
therefore , we initially cannulate the pd with a catheter and then place a guidewire . after removing the ercp catheter ,
, we attempted to retrieve the proximally migrated pd stent immediately after ep in two patients .
although the migrated stent was retrieved 1 day later , one patient developed severe pancreatitis , which was difficult to treat , and the other developed mild pancreatitis . in the other patients , stent retrieval was attempted between 1 day and 2 weeks after placement .
these three patients did not develop acute pancreatitis . from this perspective , it may be better to delay retrieving a proximally migrated stent because pancreatic duct cannulation immediately after ep is difficult due to edema and bleeding .
if a stent has to be retrieved for a variety of reasons , such as pancreatitis or abdominal pain , further study of the optimal timing of retrieval is needed . in conclusion ,
wire - guided endoscopic snare retrieval of proximally migrated pd stents after ep is safe and effective . in our experience , it is better to delay retrieval of a migrated stent by at least 1 day
. however , further studies are needed to determine effective methods and optimal timing for the retrieval of proximally migrated pd stents after ep .
 with the increasing use of pancreatic duct ( pd ) stents after endoscopic papillectomy ( ep ) , complications such as proximal migration of the stent have become increasingly prevalent . 
 a pd stent that migrates within a nondilated pd may be difficult to remove endoscopically . 
 we performed endoscopic retrieval of proximally migrated pd stents after ep in 5 patients . 
 endoscopic retrieval was performed immediately after ep in one patient , the next day in 3 patients , and 2 weeks later in one patient . 
 wire - guided endoscopic retrieval was attempted in 4 patients , and the migrated stents were removed successfully in these 4 patients . 
 no significant procedure - related complications occurred , other than mild pancreatitis in a single patient . in one patient , 
 endoscopic retrieval performed immediately after ep failed when using the conventional method , and the migrated stent was removed using a minisnare without a guidewire the next day ; this patient developed severe pancreatitis . 
 wire - guided endoscopic snare retrieval seems to be a safe and effective method for removing proximally migrated pd stents after ep . 
INTRODUCTION
CASE REPORT
1. Case 1
2. Case 2
3. Case 3
4. Case 4
5. Case 5
DISCUSSION