Covered esophageal stents are used for palliation of dysphagia due to cancer, and for the conservative management of esophageal leaks either post-surgery or after endoscopic esophageal dilatation. Stent migration after placement is a recognized complication and the risk of migration is probably increased with covered stents.
We present a case where stent migration presented as intestinal obstruction. The case was managed conservatively with a satisfactory result - confirming the manufacturer's claim that the stent is indeed "removable"!
A 76-year-old male presented with a short history of dysphagia and weight loss. An endoscopy identified the presence of a stricturing lesion at the lower end of the esophagus, which on biopsy was an adenocarcinoma. Staging investigations confirmed this to be a T3N1 tumor. The patient was deemed a surgical candidate and underwent a total gastrectomy and distal esophagectomy.
Unfortunately, the following day he developed an anastomotic leak. He immediately underwent a thoracotomy and repair of the leak. His post-operative recovery was complicated by breathing difficulties, recurrent chest infections, and a persistently high output of bile from his chest drain.
An omnipaque swallow confirmed the presence of a small leak at the lower end of the esophagus. It was decided to place a covered stent across the anastomosis in an attempt to seal the leak. A new type of stent - the "Niti-S esophageal double stent" (TaeWoong Medical Co Ltd, 610 Ilsan-Technotown, 1141-1 Backsuk-dong, Ilsan-Ku Koyang-Si, Kyunggi-do, Korea) - is one of a number of different stents available to the endoscopist. This stent has the added feature of being removable - achieved by pulling on a metal thread which collapses the stent prior to extraction.
As the aim was to place a stent for a temporary period to allow the leak to settle, we opted for a removable "Niti-S esophageal double stent". The stent was successfully placed endoscopically under x-ray guidance across the anastomotic site. The stent covered the anastomosis completely which was confirmed on fluoroscopy (Fig. 1). Subsequently the chest drain output diminished and he made good progress.
Figure 1 Esophageal stent across the anastomosis.
One week after discharge he presented with sudden onset of upper abdominal pain and sickness. His abdomen was distended and tender but with normal bowel sounds. An abdominal x-ray confirmed small bowel obstruction with the esophageal stent in the small bowel (Fig. 2). He was treated conservatively with intravenous fluids and kept nil by mouth. His symptoms improved over the next 2 days and a repeat abdominal x-ray revealed migration of the stent to the distal small bowel. He was allowed oral fluids and continued to make steady progress. By day 4 of his admission the stent was clearly seen in the sigmoid colon on abdominal x-ray (Fig. 3).
Figure 2 Esophageal stent in the small bowel.
Figure 3 Esophageal stent in the sigmoid colon.
On review in clinic an x-ray showed migration of the stent to the rectum, although a per-rectal examination was unremarkable. A flexible sigmoidoscopy was arranged to try stent extraction but before the sigmoidoscopy he passed the stent spontaneously, without having been aware of doing so.
Stent migration is a recognized complication of self-expanding metal stents (SEMS). Rates quoted vary from 2 to 8% in different series, with two-thirds occurring in the first month after placement . Stents can migrate proximally where they may threaten the airway or distally to the stomach. Often the stent will migrate further than the stomach, but if it does pass through the pylorus it can migrate to the small and large bowel.
However - and somewhat surprisingly - stent migration rarely presents as bowel obstruction. DePalma et al. in their series of 242 patients reported 9 patients with stent migration to the stomach which were left in-situ with no complications and 3 patients were "unaware" of having passed the stent rectally . Williams et al. reported a case with constipation and abdominal pain 2 months after placement of a SEMS for inoperable esophageal cancer . The stent had migrated to the sigmoid colon, which was treated conservatively.
Management of stent migration is challenging with stent extraction associated with significant risk of bleeding and perforation .
In this case, we opted for a conservative approach with a successful outcome, but these cases can pose challenges. In this particular case the stent was placed to try and cover a leak postoperatively. However, these placements can be unstable as the stent may have less to hold it in place than in the case of a tumor. In addition, the cover of the stent gives it less "grip". We can confirm that the manufacturer's claim of the "Niti-S"' stent being removable was correct, albeit from the other end!
This article was first published on GastroHep.com in 2006.
Dr V Goel1
Dr G Clark2
Dr GAO Thomas1
1 Department of Gastroenterology
2 Deparment of Surgery
University Hospital of Wales, Heath Park, Cardiff CF14 4XW, UK.
Dr V Goel
6 Lon-y-Groes, Cardiff CF14 4AB, United Kingdom
- De Palma GD, Iovino P, Catanzano C. Distally migrated esophageal self-expanding metal stents: wait and see or remove? Gastrointest Endosc 2001: 53(1): 96-8.
- Williams GL, Ragunath K, Davies M, et al. Distal migration of a self-expandable metal oesophageal stent, presenting as constipation. Endoscopy 2003; 35(10): 884.
- Ramirez FC , Dennert B, Zierer ST, et al. Esophageal self-expandable metallic stents - indications, practice, techniques, and complications: results of a national survey. Gastrointest Endosc 1997; 45(5): 360-4.
This article was first published on GastroHep in January 2007.