endoscopic methods are among the most important and frequently employed means of treating pancreatic pseudocysts .
when possible an endoscopic approach should generally be attempted in all patients with pseudocysts , and for pancreatic fluid collections endoscopic transmural drainage is the treatment of choice .
if the cyst contains more than 2/3 solid material a self - expandable stent should be selected to ensure effective drainage .
an additional advantage of the self - expandable metal stent is that the necrotic tissue contained within the cyst can be actively removed using an endoscope .
this article discusses the unusual case of a stent that became dislodged and migrated into the omental bursa . following this migration some time
was allowed to elapse , and the gastrotomy closed completely . since a simple endoscopic retrieval was no longer possible , a combined laparoscopic - endoscopic technique ( rendezvous technique ) was used instead , and the stent was successfully retrieved .
in 2013 , a 49-year - old male smoker with a history of diabetes mellitus and arterial hypertension developed severe necrotizing pancreatitis .
imaging revealed paralytic ileus along with an expanding cystic formation near the liver hilus and pancreatic head with compression of the duodenum .
a pseudocyst near the left abdominal wall with enormous but stable proportions was also found to be compressing the left colon transversum ( 14 cm ) . due to the extreme thinness of the wall
areas of necrosis in the corpus area developed , necessitating transgastral cystotomy and placement of a wall stent ( niti - s nagi stent - taewoong - medical co , seoul , south korea , 14 mm wide , 22 mm long ) .
twenty - four hours later , however , the stent became dislodged and migrated into the omental bursa .
an attempt at endoscopic removal the following day was unsuccessful , making the insertion of a second stent ( nagi fully covered taewoong,16 mm wide , 22 mm long ) necessary .
endoscopic retrograde cholangiopancreatography ( ercp ) was then performed , along with papilotomy and insertion of an 8.5 fr .
two weeks later , after significant clinical improvement and drainage of necrotic tissue , the second transgastric stent was removed with no complications . for technical reasons ,
retrieval of the migrated stent was not possible . at follow - up gastroscopy 4 weeks later the gastric wall had completely closed and hence that endoscopic localization of the stent was no longer possible . in november 2013
the pseudocysts had regressed significantly , and a computed tomography of the abdomen showed the migrated stent in the omental bursa with no direct contact to the gastric wall . in february 2014
, we decided to attempt a laparoscopic - endoscopic retrieval of the displaced wall stent . in the first step ,
intraoperative endoscopy demonstrated normal gastric mucosa so that a purely macroscopic localization of the stent was not possible [ figure 1 ] .
after localization of the stent via image converter we made a targeted 3 cm incision into the posterior gastric antrum using an endo knife ( erbe , germany ) . due to the location of the stent deep within the omental bursa neither optical nor palpatory contact could be made , and consequently , endoscopic retrieval was not an option . in the next step ,
first , electrocoagulation was used to make three incisions in the anterior wall of the greater gastric curvature ( two in antrum , one in fundus ) . then , 3 ( applied medical kii , usa ) 5 mm trocars were inserted [ figure 1 ] .
dissection within the omental bursa was performed using two dissectors , inserted through an incision that had been made endoscopically .
after localization of the stent and some blunt dissection it was possible to carefully dislodge the stent into the gastric lumen [ figure 2 ] .
after further inspection , the transgastral trocars were removed , and the gastric wall incisions were closed with lahodny stitches ( ethicon , usa ) .
the postoperative clinical course was without complications , and the patient was discharged on the 6 postoperative day . at follow - up 4 weeks later , no complications were found .
the gastric wall has closed , and the stent can not be localized ( a ) .
three applied kii 5 mm trocars in the stomach ( b ) blunt dissection near the omental bursa after incision and retrieval of the stent ( a ) .
currently , endoscopic ultrasound - guided drainage is a safe and effective means of treating pancreatic fluid collections . compared with surgical or percutaneous drainage it is less invasive and results in lower mortality , costs , and hospitalization times .
drainage - related complications either may be related directly to the procedure or can occur in relation to the stents themselves .
the stent should not , however , be removed before complete involution of the pseudocyst or before the passage of at least 2 months . on average ,
15% of stents will become accidentally dislocated , but efforts to develop technically superior stents continue .
tllez - vila et al . , for example , report on fully covered self - expandable metal stents with an innovative anti - migration system .
describe a stent - in - stent combination which employs the mechanical advantages of both plastic stents and fully covered self - expandable metal stents .
although these new solutions will help reduce the rate of migration , they will not eliminate it completely . in most cases of stent migration endoscopic retrieval
can be performed without difficulty . in cases of extraluminal loss , however , a surgical approach is often necessary , and a minimally invasive exploration of the abdominal cavity is the approach of choice .
retrieval from the retroperitoneal space may pose a more significant challenge due to the proximity of the large vessels .
when endoscopic retrieval fails a combined laparoscopic - endoscopic approach offers an alternative to open surgery .
the choice of technique is likely best predicated by individual patient presentation and local expertise . with this endoscopy - laparoscopy combination ( rendezvous technique )
 endoscopic drainage is a widely used treatment for pancreatic pseudocysts . 
 drainage - related complications may be related directly to the procedure or may occur later as stents migrate or erode into adjacent structures . 
 migration of a self - expanding metal stent into peritoneal cavity and incorporation in the omental bursa is rare . when endoscopic retrieval fails a combined laparoscopic - endoscopic ( rendezvous technique ) approach offers an alternative to open surgery . 
 we report a case of successful gastroscopic - transgastric laparoscopic removal of a stent that was dislocated into the omental bursa after a  year observation period . 
INTRODUCTION
CASE REPORT
DISCUSSION