Currently, the three commonly used methods for removal of esophageal stent are surgical resection9, removal under fluoroscopy10, and removal under endoscopy 8,11. Surgical resection is traumatic and can cause complications such as anastomotic stricture and anastomotic leakage; therefore, it is rarely used nowadays. Removal under fluoroscopy is easily performed for esophageal stents with short indwelling time, but it is difficult for stents with prolonged indwelling time, when there may be severe granulation hyperplasia. Endoscopic removal of esophageal stent can be performed through several approaches, including combined cryoablation and SIS technique12, double-step invagination technique13, inversion technique14, and rat-tooth forceps or rat-tooth forceps with a snare technique15. With extended periods of stent placement, the stent tends to get embedded in tissue, and the upper and lower ends of the stent may be severely narrowed. Direct removal of such embedded esophageal stents can cause serious complications such as esophageal mucosal tear, esophageal rupture, and massive hemorrhage. Thus, the endoscopic procedure can be complex and time taking, and so requires the services of an experienced endoscopic surgeon16,17. In addition, endoscopic stent removal is usually carried out under general anesthesia, and so the patient also has to bear the anesthetic risks.
For patients with embedded esophageal stent and hyperplasia-induced stenosis, the SIS technique under endoscopy has been demonstrated to be effective and safe7,16,18. We therefore adapted the SIS method for the interventional radiology approach. Under fluoroscopy, a second esophageal stent with a diameter slightly larger or equivalent to that of the original stent is placed. The radial force exerted by the second stent causes necrosis of the proliferating granulation tissue19, thus facilitating the removal of the original embedded stent.
In contrast to endoscopic esophageal stent removal, interventional radiology procedures are generally carried out under local anesthesia on conscious patients. The process is simple, with the stent being extracted by the guide wire or by a stent retrieval hook applied at the upper or lower end of stent. This minimally invasive method rarely causes serious complications such as esophageal rupture and massive hemorrhage. In our study cohort, no serious complications occurred, and the median time taken for stent removal was only 12.5 minutes.
In the present study, the second stent was placed for a median duration of 26 days before removal; this is consistent with the 2–3 weeks reported in previous studies. None of our patients developed severe granulation hyperplasia, though one patient did have mild granulation hyperplasia at the upper end of the second stent. In our series, one patient developed airway compression after placement of the second stent, necessitating its early removal. Because the indwelling time of the second stent was too short, the original stent remained embedded and was fractured during extraction. Some of the stent wires had to be removed under endoscopy.
Theoretically, the interventional technique under fluoroscopy has several advantages. First, there is no need for general anesthesia; as the procedure is carried out under local anesthesia on conscious patients, it is suitable even for patients with relatively poor general condition. Second, stent placement and removal is quickly and accurately completed under fluoroscopy, thus greatly reducing the patient’s suffering. Third, the first stent is extracted by the inversion technique, a simple technique that minimizes damage to the esophagus. The disadvantages of the SIS method include the inability to directly observe the esophageal cavity and the risk of stent fracture, which may require endoscopy for removal of residual metal wires.
The main limitation of this study is its small sample size. Stronger evidence is needed to determine the optimal indwelling time for the second esophageal stent.
In conclusion, SIS under fluoroscopy appears to be a safe and effective method for the removal of esophageal metallic stent. The advantages and disadvantages of the SIS technique performed under fluoroscopy needs to be studied in greater detail in future research.