Stents For Benign Esophageal Strictures Research Articles

Utilization of 3D-Printed Polymer Stents for Benign Esophageal Strictures in Patients with Caustic Ingestion

Aim: This study aimed to introduce a 3D printed, flexible esophageal stent, which is useful in personalized treatment of patients with esophageal strictures and also reduce the adverse effects of the existing esophageal stent. Materials & methods: Bio-grade polylactic acid (PLA), bio-grade transparent thermoplastic polyurethane and bio-grade polyvinyl alcohol (PVA) granules were purchased. The dichloromethane (DCM) and dimethylformamide (DMF), and the double distilled water were used as the solvent for PLA, thermoplastic polyurethane and PVA, respectively. The stent was designed by Solidworks software and subsequently printed by a 3D bioprinter (Mobio Tech V1.2). The biocompatibility, self-expansion, anti-inflammation and cytotoxicity of the printed stent were assessed in an in vitro and in vivo normal canine esophagus. An individualized 3D-printed flexible polymer stent was also implemented for a 16-year-old boy who presented with esophageal stricture following ingestion of corrosive chemicals. The patient was followed for 2 months with further endoscopic and pathology evaluations. Results: Several tests were performed before and after the stent placement. Mechanical tests showed that the nature and behavior of the polymeric materials used in the esophagus stent did not change significantly along treatment. Pathology results further indicated that the polymer stent did not have major inflammatory effects and cytotoxicity. Conclusion: The results show that the individualized 3D printed Biocompatible polymeric stent has potential applications in treating esophageal strictures.

Self-Expanding Stents in Benign Esophageal Strictures

Self-expanding metal stents (SEMS) have gained a wide consensus in the treatment of malignant dysphagia. The small diameter of the delivery system has reduced the morbidity related to their placement. These stents could be a reasonable option also in patients with benign refractory esophageal strictures. Two types of stents have been used: self-expandable plastic stent (SEPS; Polyflex ® ) and SEMS. Fluoroscopy is recommended, and predeployment dilation should be performed when a SEPS is placed. SEMS should be completely covered with a silicone layer that opposes the granulomatous ingrowth through the meshes, which prevents imbedding and allows easy retrieval. Migration represents the most frequent complication and is due to the lack of imbedding of these stents. The techniques of stent placement are similar to those when stents are placed for malignant disease. Dilation is not advisable before placing a SEMS, but may be performed after its release. The prolonged and stable dilation of the endoprosthesis is believed to work in some patients by prevention of the scarring process and avoiding the adhesion of damaged areas (such as after extensive endoscopic mucosal resection). Remodeling of scar tissue by the indwelling stent is believed to occur in chronic strictures but is difficult to obtain in patients with refractory hypopharyngeal strictures following radiation therapy. Stents need to be removed, the timing of which is variable but usually more than 4 to 8 weeks after placement. Prolonged placement may lead to complications such as reactive overgrowth and result in a new stricture. This review analyses the risk and benefits of self-expandable stents in the management of dysphagia for benign esophageal strictures.

Expandable metallic stent placement in patients with benign esophageal strictures: results of long-term follow-up.

To evaluate the long-term effectiveness of expandable esophageal metallic stents in benign esophageal strictures. The authors performed long-term follow-up of 14 expandable metallic stents in 12 patients (aged 16-72 years) with benign esophageal strictures. All 12 patients had initially undergone placement of one stent; two patients received an additional stent because of recurrent dysphagia. No procedural complications occurred. Delayed complications occurred in all patients. New strictures formed in six stents (five patients), migration occurred in seven stents (six patients), and both migration and formation of new strictures occurred in one stent (one patient). New stricture formation caused recurrence of dysphagia and necessitated further treatment. Three of four stents that migrated within 2 months after placement but none of the four stents that migrated more than 2 months after placement caused recurrence of dysphagia. Six patients died of unrelated causes 6-20 months after stent placement. The remaining six patients are still alive 24-48 (mean, 35) months after stent placement. The long-term effectiveness of expandable metallic stents in benign esophageal strictures is not encouraging because of the high delayed-complication rate. That the patients with migration showed improvement of dysphagia, however, may warrant further investigation of temporary placement of a retrievable covered stent.