Most patients with esophageal cancer have reached the advanced stage when they are diagnosed, and surgical resection is not ideal. The 5-year survival rate is only 15–34% . SEMS insertion provides a substantial advantage in the management of dysphagia in patients with malignant esophageal obstruction. SEMSs can quickly relieve dysphagia and occlude the fistula and has become the main palliative treatment for patients with advanced esophageal cancer. However, complications of stent implantation compromise the patient’s quality of life. Stent migration is one of the major complications associated with esophageal stent implantations . Most migration events occur within one month after stent placement . After stent migration, dysphagia can recur, which seriously affects the quality of life of patients. If the stent migrates into the stomach or enters the intestinal tract, it can also cause serious complications such as perforation and intestinal obstruction. Karagul et al. believe that a stent left in the stomach will not cause related complications . However, in this study, after stent migration, 2 patients suffered from abdominal pain and vomiting that may have been related to stent migration. More importantly, a stent left in the stomach is at an increased risk of migration to the intestinal tract, which is also problematic. According to previous reports [1, 2, 6], the stent type, concurrent chemotherapy or radiotherapy, gastroesophageal junction tumors and sex are important factors for esophageal stent migration. Compared with bare metal self-expandable stents, covered stents are more helpful at preventing tumors from growing inward, but the transverse supporting force of covered stents is weak, and the friction between the covered stent and esophageal wall is small, so they are more likely to shift. Moreover, concerning malignant obstruction of the digestive tract, covered stents and bare metal stents have comparable technical success, clinical success, long-term patency and palliative treatment survival rates . Some newly developed stents, such as partially covered stents, NiTi alloy double-layer stents, and fully covered self-expanding segmented metal stents [8, 9], have great advantages in preventing esophageal stent migration. Simultaneous radiotherapy and chemotherapy will reduce the volume of an esophageal tumor, and the stent will not fit well with the esophageal wall, which will increase the risk of esophageal stent migration. Tumors in the gastroesophageal junction include lower esophageal cancer and cardiac cancer. When a stent is placed here, the distal end of the stent has poor adhesion to the gastric mucosa, and some stents experience radial bending stress after placement; thus, these stents are more prone to migration. Therefore, patients with removable esophageal stents are carefully evaluated and monitored, and selective surgical removal of the migrated metal stents is advocated .
At present, most migrated esophageal stents are removed under endoscopy, which is often performed under general anesthesia or local anesthesia according to a few reports. For a stent that has migrated to the esophagus, the cable sleeve at the proximal end of the stent can be grasped by dental forceps under endoscopy so that the diameter of the proximal end of the stent can shrink and the stent can be pulled back. For stents without cable sleeves at the proximal end, a double-channel endoscope can be used to grasp the two sides of the proximal end of the stent and pull it out. For a stent that has migrated to the stomach, one with a cuff is easy to remove. When there is no proximal cuff, it is challenging and usually requires other devices, such as an inner ring, polypectomy snare, foreign body protection cover, or metal sheath tube [11–14]. When removing a stent in the stomach under endoscopy, there is a risk of insufficient stent contraction and esophageal injury. Some patients experience severe esophageal stenosis, which makes it difficult to remove the unseated stent. On the other hand, the working distance of the endoscope is limited, and a distal migrated stent cannot be removed under endoscopy. The fluoroscopic removal of esophageal stents is rarely reported for distal stent migration.
To solve the difficult problem of removing esophageal stents that have migrated to the stomach under endoscopy, we used fluoroscopy guidance. After esophageal stent placement, a stent withdrawal wire was exchanged from the nasal cavity and fixed. To improve the quality of life in the late stage, some patients will choose to have the stent withdrawal wire removed after the stent is stabilized.
In the absence of a stent removal wire, if a stent migrates to the stomach, the second method is needed; that is, a guide wire is passed through the stomach stent to facilitate the introduction of a sheath tube and a retrieved hook, and the force of the hook is located on the long axis of the stent.
To prevent damage to the tumor and new granulation tissue and prevent bleeding, the distal end of the stent is often hooked. During the removal process, the distal end of the stent will turn over into the stent so that the whole stent can be removed after turning over. When the length of the sheath is not enough or the angle with the stent cannot reach the distal end, the stent can be removed by hooking the proximal end, but the resistance will increase. At the same time, the possibility of tissue damage, bleeding and stent fracture will increase significantly. Sometimes, granulation tissue is wrapped at both ends of the detached stent.
In particular, for patients who have undergone gastrectomy, the stomach cavity is small, the guide wire cannot enter the stent cavity, and the stent cannot be removed by using a stent removal hook.
In these cases, the third method can be used.
When the sheath tube enters the stomach cavity, the guide wire is folded back and then enters the sheath tube so that the guide wire forms an annular catcher at the head end of the sheath tube, the middle position of the stent is captured by the annular catcher, and the guide wire is tightened to make the middle part of the stent smaller and then removed.
The fluoroscopic removal of migrated esophageal stents also has some complications, including esophageal bleeding, perforation, rupture and stent fracture. To avoid bleeding, perforation, etc., when removing a migrated stent, the operation should be performed quickly, and force is needed at the head end of the sheath instead of the esophageal wall when the stent is removed. The main cause of stent fracture is granulation tissue proliferation, which enters the stent lumen through the stent mesh. The removal of a stent 2 weeks after anastomotic leakage or 4 weeks after perforation may significantly reduce the complications related to stent use . An esophageal stent will be endothelialized after 8 weeks, and it is not easy to remove after more than 10 months.