Should We Consider Endoscopic Clipping for Prevention of Esophageal Stent Migration?

We read with great interest the paper by Sriram et al. [1] who, following a previous short reference in an abstract [2], gave the first report of the use of endoclips as a method for anchoring an esophageal endoprosthesis.

Since then no further discussion has been published concerning this subject, and we therefore decided to describe our experience, reported for the first time in 1999 [3], with the use of metallic clips to secure in place self-expandable metal stents positioned in malignant strictures of the distal esophagus and gastroesophageal junction.

The main complications related to the placement of self-expanding metal stents for the palliation of malignant dysphagia caused by unresectable esophageal or cardial carcinomas, are stent migration and tumoral or granulation tissue ingrowth [4]. Covered stents are used to prevent tissue ingrowth through the metal mesh but have a higher chance of migration, especially in tumors at the gastroesophageal junction. Migration rates ranging from 0 % to 27 % have been reported [5], with the majority of migrations occurring within the first 4 weeks after placement [6].

The technique of endoscopic clipping was introduced by Hayashi et al. [7] in 1975, and was adopted mainly for hemostasis and marking of gastrointestinal lesions. In the past few years the range of applications has rapidly been expanded, to the treatment of anastomotic leakages after esophagogastric surgery [8], resection of large colorectal polyps [9], placement of enteral feeding tubes [10], and endoscopic closure of small iatrogenic perforations of the gastrointestinal tract [11] [12] [13] [14].

Between May 1998 and May 2001, we used endoclipping in 13 patients with lesions with a high risk for esophageal stent migration. A total of 11 patients with dysphagia, caused by malignancies of the distal esophagus (n = 4) or cardia (n = 5) and by recurrent gastric cancer at the esophagojejunal anastomosis (n = 2), plus two patients with tracheoesophageal fistulae without luminal stenosis, underwent esophageal intubation with self-expanding metal stents. Four patients had received prior chemoradiotherapy (n = 2) or chemotherapy (n = 2). Before stent insertion, through-the-stent balloons or Savary-Gilliard bougies were used to dilate the stenosis to a diameter of 11 - 13 mm.

We used coated self-expanding metal stents (Ultraflex; Microvasive, Boston Scientific Corporation, La Garenne Colombes, France), which are made of a ”memory” metal (nitinol) with a knitted mesh configuration. These stents are covered by a polyurethane layer, except for a 1.5-cm segment at each end. They present an outer diameter of 18 mm or 23 mm, flared at the proximal end to 23 mm or 28 mm, respectively. The presence of radio-opaque markers on the stent delivery catheter permit accurate placement, avoiding the risk of the stent’s being released too distally in the stomach or jejunum.

Immediately after stent deployment, the esophagus was intubated with a standard video endoscope (Olympus GIF 130; Olympus, Hamburg, Germany), and a rotatable clip-fixing device (HX-5QR-1; Olympus) was passed through the working channel. A metallic clip (MD-59; Olympus) with arms measuring 6 mm in length and an exterior jaw angle of 130 ° was used. After protrusion of the clip from the end of the tube sheath, the rotator was slowly turned so that the clip faced in a direction from which it was easier to grasp both the uncovered proximal end of the stent mesh and the esophageal mucosa. The fixing device was then advanced and the clip was applied by controlling the sliding components of the handle, attaching the stent to the esophageal wall.

The position and patency of the stent were routinely checked after 24 hours by means of an esophagogram using water-soluble contrast, before oral feeding was resumed. Patients with stents across the gastroesophageal junction were instructed to elevate the head of the bed and were treated with proton-pump inhibitors, in order to minimize reflux. Follow-up endoscopies were only performed in patients with recurrence of obstructive symptoms.

We do agree with Sriram et al. [1] that the merit of this technique is obvious. However, these authors expressed concerns about the number of clips used and about the permanence of the anchoring. In fact, all the patients in our series received a single clip. Although this was technically more difficult due to the oblique angle of approach, successful clip placement was achieved in all cases. Endoscopic re-intervention with food retrieval was needed in one patient who developed recurrent food bolus obstruction, at 1 and 3 weeks after stent placement; it was confirmed that the clip and stent were in place. A certain grasping depth was probably essential [14] for the clip to keep the stent attached to the esophageal wall long enough to prevent early migration.

We did encounter a case of migration 6 days after stenting, with a smaller diameter (18-23 mm) prosthesis placed across the cardia. There was a severe deterioration in this patient’s condition, and a nasogastric tube was placed for feeding. He died only 20 days after stenting, at 3 months after diagnosis of his tumor of the cardia.

In all the other patients, no evidence of clip detachment or stent migration was noted during a mean follow-up time of 2 months, that is, during the most important period with regard to stent migration.

In conclusion, we wish to note that where there is a higher risk of migration, such as with distal esophageal or cardia tumors, or with esophageal-respiratory fistula without stenosis, the use of endoclipping should be considered as an additional technique, which merits further (controlled) studies to confirm its efficacy in the prevention of esophageal stent migration. Also, whenever possible, large-diameter stents (23 - 28 mm) are currently our first choice for esophageal stenting.

References

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