Abstract

Background: Self-expandable metal stents (SEMS) are a primary method for palliation of malignant dysphagia. SEMS imbed in tissue and promote granulation tissue preventing removal. Recently removable self-expandable plastic stents (SEPS) have been used for treatment of refractory benign esophageal strictures. SEMS and SEPS each offer unique features. However the ideal stent that does not imbed in tissue, prevents granulation tissue, does not migrate, yet is removable, does not yet exist. Objectives: To evaluate the tissue response in a porcine model induced by a new hybrid esophageal stent designed to offer the advantages of both SEMS and SEPS. The stent is completely coated internally rather than externally which prevents tumor ingrowth and imbedding and may limit tissue hyperplasia. Methods: Study stents (Alveolus ES-STS (TM), 25 mm proximal flange, 23 mm distal flange, 18 mm mid-body diameter, 7 cm long, fully covered internally) and control stents (Ultraflex (TM) stent, Microvasive, 23 mm proximal flange, 18 mm midbody, covered externally) were implanted in the esophagus of 8 Yucatan pigs. Each animal underwent placement of two stents: one study stent and one control stent, placed proximally and distally. The location within the esophagus of the study and control stents was assigned randomly placed in each pig. Follow-up endoscopy was performed 1, 2, 3 and 5 weeks post-implantation, allowing assessment of the extent of granulation tissue formation and esophageal injury caused by the stent. Granulation tissue was estimated as mild, moderate, or severe. Ease of stent removal was assessed at 2 week and 5 week post-placement. Results: The endoscopic tissue hyperplasia response of the new hybrid study stents was graded as mild to moderate. All stents were easily removed from the esophagus without difficulty and atraumatically. In contrast, the control stents produced severe granulation tissue formation with complete embedding of the uncovered stent ends. Removal was possible by resulted trauma to the esophagus and endoscopically visible bleeding. Histopathologic findings are pending. Conclusions: Based upon preliminary findings in the normal porcine esophagus this novel internally covered self-expanding metal stent appears to resist tissue imbedding and tissue hyperplasia and allows removability. Future studies are needed in humans to confirm these findings, which would allow the use of the Alveolus ES-STS (TM) in malignant and benign esophageal strictures. Background: Self-expandable metal stents (SEMS) are a primary method for palliation of malignant dysphagia. SEMS imbed in tissue and promote granulation tissue preventing removal. Recently removable self-expandable plastic stents (SEPS) have been used for treatment of refractory benign esophageal strictures. SEMS and SEPS each offer unique features. However the ideal stent that does not imbed in tissue, prevents granulation tissue, does not migrate, yet is removable, does not yet exist. Objectives: To evaluate the tissue response in a porcine model induced by a new hybrid esophageal stent designed to offer the advantages of both SEMS and SEPS. The stent is completely coated internally rather than externally which prevents tumor ingrowth and imbedding and may limit tissue hyperplasia. Methods: Study stents (Alveolus ES-STS (TM), 25 mm proximal flange, 23 mm distal flange, 18 mm mid-body diameter, 7 cm long, fully covered internally) and control stents (Ultraflex (TM) stent, Microvasive, 23 mm proximal flange, 18 mm midbody, covered externally) were implanted in the esophagus of 8 Yucatan pigs. Each animal underwent placement of two stents: one study stent and one control stent, placed proximally and distally. The location within the esophagus of the study and control stents was assigned randomly placed in each pig. Follow-up endoscopy was performed 1, 2, 3 and 5 weeks post-implantation, allowing assessment of the extent of granulation tissue formation and esophageal injury caused by the stent. Granulation tissue was estimated as mild, moderate, or severe. Ease of stent removal was assessed at 2 week and 5 week post-placement. Results: The endoscopic tissue hyperplasia response of the new hybrid study stents was graded as mild to moderate. All stents were easily removed from the esophagus without difficulty and atraumatically. In contrast, the control stents produced severe granulation tissue formation with complete embedding of the uncovered stent ends. Removal was possible by resulted trauma to the esophagus and endoscopically visible bleeding. Histopathologic findings are pending. Conclusions: Based upon preliminary findings in the normal porcine esophagus this novel internally covered self-expanding metal stent appears to resist tissue imbedding and tissue hyperplasia and allows removability. Future studies are needed in humans to confirm these findings, which would allow the use of the Alveolus ES-STS (TM) in malignant and benign esophageal strictures.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.