Enteral stent, migration, complication
Gastric outlet obstruction is a late complication of advanced gastric and pancreatic malignancy. Traditionally, open gastrojejunostomy has been the preferred procedure to relieve obstruction, however, it has been shown to be inferior to palliation using self expanding metal stents (SEMS) in regards to clinical success, morbidity and mortality.1-3 Likewise, Mehta et al demonstrated that duodenal stenting for gastric outlet obstruction was associated with a lower morbidity and mortality and significant cost savings when compared to laparoscopic gastrojejunostomy.4
The indications, techniques, complications, and limitations of SEMS placement are well described in other publications (http://www.vhjoe.org/Volume2Issue4/2-4-3.htm). Since the introduction of SEMS placement for relief of gastroduodenal obstruction in 1993,5,6 numerous studies have shown that stents offer safe and effective palliation in patients with malignant upper gastrointestinal obstruction.7-11 Stent migration distally is a well-known complication that can lead to small bowel obstruction and/or perforation.12-14 This case, we believe, highlights an example of stent migration that is counter-intuitive.
Sixty-five year old man with metastatic pancreatic cancer and gastrojejunostomy for gastric outlet obstruction presented with nausea, vomiting, abdominal distention and large volume nasogastric suction output. Investigation demonstrated outlet obstruction by tumor involvement of the gastrojejunostomy. There was no history of hiatal hernia or surgical alteration of the gastroesophageal junction.
A 22mm x 90mm WallFlex enteral stent (Boston Scientific, Natick, MA, USA) was successfully placed across the obstruction with relief of symptoms (Figure 1). The patient reported intermittent episodes of nausea and vomiting following stent placement that corresponded to administration of chemotherapy. He was asymptomatic in the periods between treatment sessions. Two months later, an abdominal computed tomography was performed to evaluate response to chemotherapy. Abdominal imaging revealed that the stent had migrated into the stomach (Figure 2). The mass that involved the gastrojejunostomy anastomosis was unchanged in size. Endoscopy was performed 13 days later to retrieve the stent; however the stent was found to be firmly embedded in the mid esophagus between 25 cm and 34 cm from the incisors (Figure 3a & 3b). Careful attempts to remove the stent were unsuccessful. No further attempts were made to remove the stent since the patient was asymptomatic and for fear of additional and potentially more serious complications.
Major complications from stent placement occur in 0% - 10% of cases, while minor complications occur in 0% - 30%. 4,8,9 A meta-analysis of 32 evaluable case series involving stents from various manufacturers revealed a migration rate of 5%.9 In a European study of the initial experience with the WallFlex enteral stent, a migration rate of 1.6% was reported within the first 30 days of follow up.8
In most cases, stents will migrate distally in the gastrointestinal tract due to peristalsis. This can lead to the development of small bowel obstruction and/or perforation.12,13 Our case report highlights an interesting and to our knowledge previously unreported example of proximal stent migration, traversing the lower esophageal sphincter and becoming firmly embedded in the mid esophagus.
Although the majority of SEMS currently in use are not designed to be removed once deployed, various techniques have been described to remove or reposition stents.15-18 Our patientís stent migrated initially into the stomach. The need to remove migrated stents is unclear. Several small studies suggest that removal of migrated stents in the stomach is unnecessary, and adopting a wait-and-see approach may be reasonable.19,20 Stents may reside harmlessly in the stomach or pass spontaneously. Given these patientsí limited life expectancy, adopting a conservative approach should be considered, as they are likely to succumb to the underlying malignancy, rather than to a stent-related complication. Little data exist on the importance of removing asymptomatic stent migration in the esophagus.
This case highlights a previously unreported complication of migration of a SEMS used to palliate gastric outlet obstruction proximally into the mid esophagus. Although distal migration has been previously reported, it is important to realize that proximal migration can also occur.
1. Del Piano M, Ballare M, Montino F, et al. Endoscopy or surgery for malignant GI outlet obstruction? Gastrointest Endosc. Mar 2005;61(3):421-426.
2. van der Schelling GP, van den Bosch RP, Klinkenbij JH, Mulder PG, Jeekel J. Is there a place for gastroenterostomy in patients with advanced cancer of the head of the pancreas? World J Surg. Jan-Feb 1993;17(1):128-132; discussion 132-123.
3. Weaver DW, Wiencek RG, Bouwman DL, Walt AJ. Gastrojejunostomy: is it helpful for patients with pancreatic cancer? Surgery. Oct 1987;102(4):608-613.
4. Mehta S, Hindmarsh A, Cheong E, et al. Prospective randomized trial of laparoscopic gastrojejunostomy versus duodenal stenting for malignant gastric outflow obstruction. Surg Endosc. Feb 2006;20(2):239-242.
5. Keymling M, Wagner HJ, Vakil N, Knyrim K. Relief of malignant duodenal obstruction by percutaneous insertion of a metal stent. Gastrointest Endosc. May-Jun 1993;39(3):439-441.
6. Solt J, Papp Z. Strecker stent implantation in malignant gastric outlet stenosis. Gastrointest Endosc. May-Jun 1993;39(3):442-444.
7. Ely CA, Arregui ME. The use of enteral stents in colonic and gastric outlet obstruction. Surg Endosc. Jan 2003;17(1):89-94.
8. van Hooft J, Mutignani M, Repici A, Messmann H, Neuhaus H, Fockens P. First data on the palliative treatment of patients with malignant gastric outlet obstruction using the WallFlex enteral stent: a retrospective multicenter study. Endoscopy. May 2007;39(5):434-439.
9. Dormann A, Meisner S, Verin N, Wenk Lang A. Self-expanding metal stents for gastroduodenal malignancies: systematic review of their clinical effectiveness. Endoscopy. Jun 2004;36(6):543-550.
10. Kaw M, Singh S, Gagneja H, Azad P. Role of self-expandable metal stents in the palliation of malignant duodenal obstruction. Surg Endosc. Apr 2003;17(4):646-650.
11. Kim TO, Kang DH, Kim GH, et al. Self-expandable metallic stents for palliation of patients with malignant gastric outlet obstruction caused by stomach cancer. World J Gastroenterol. Feb 14 2007;13(6):916-920.
12. Govender P, McAuley G, Murphy C, Torreggiani WC. Small bowel obstruction--an unusual complication of oesophageal stent migration. Br J Radiol. Sep 2007;80(957):767-768.
13. Henne TH, Schaeff B, Paolucci V. Small-bowel obstruction and perforation. A rare complication of an esophageal stent. Surg Endosc. Apr 1997;11(4):383-384.
14. Ho HS, Ong HS. A rare life-threatening complication of migrated nitinol self-expanding metallic stent (Ultraflex). Surg Endosc. Feb 2004;18(2):347.
15. Berg JC. Bird nest deformity of a self-expanding esophageal stent and a technique of removal. Gastrointest Endosc. Jul 1999;50(1):108-110.
16. Bhalerao S, Whiteley GS, Jenkinson LR. Combined laparoscopic and endoscopic retrieval of a migrated self-expanding metal stent. Gastrointest Endosc. Jun 2000;51(6):755-757.
17. Farkas PS, Farkas JD, Koenigs KP. An easier method to remove migrated esophageal Z-stents. Gastrointest Endosc. Aug 1999;50(2):277-279.
18. Noyer CM, Forohar F. A simple technique to remove migrated esophageal stents. Am J Gastroenterol. Sep 1998;93(9):1595.
19. De Palma GD, Iovino P, Catanzano C. Distally migrated esophageal self-expanding metal stents: wait and see or remove? Gastrointest Endosc. Jan 2001;53(1):96-98.
20. Di Fiore F, Lecleire S, Antonietti M, et al. Spontaneous passage of a dislocated esophageal metal stent: report of two cases. Endoscopy. Mar 2003;35(3):223-225; discussion 225.