Polymeric endoesophageal paving: A biodegradable alternative to stenting

Background: Metallic endoesophageal stents suffer from the limitations of migration, removal difficulty, chronic injury and restenosis. An improvement over current stents would be a method which would provide structural integrity without the liability of a permanent implant. We developed a new technique in which biodegradable polymers could be deployed within a tissue lumen and locally thermoformed to yield an adherent, supporting, custom-contoured endoluminal liner. Aim: In this study we examined the feasibility and acute efficacy of in situ catheter-based thermoforming of biodegradable polymers on the endoluminal surface of freshly explanted porcine esophagi. Methods: Porcine esophagi (n - 6) were mounted in a physiologic organ bath and an endoluminal mucosal tear was induced via passage of a stiff wire. Baseline fiberoptic endoscopy and intraluminal ultrasound was performed. A balloon tipped catheter allowing for controlled mechanical and thermal deformation facilitated polymer application (6 atm, 60° C., 15 sec.). A 55mm × 20mm sheet of polymer covering the catheter balloon was placed in mid-esophagus over the tear, the balloon dilated and heated (4 atm, 63° C.) and the sheet thermoformed on the endoesophageal surface (paving). Repeat endoscopy and ultrasound was performed to examine esophageal integrity and conformity of the polymer layer to the esophageal surface. Results: In all esophagi studied, in situ thermoforming was achieved with esophageal segments being lined with a continuous layer of polymer as a conformal film. In all segments endoluminal polymer was found to readily flow over and seal tears, conforming to surface irregularities. Conclusion: In situ thermoforming of biodegradable structural polymers is feasible yielding an effective endoluminal wall support. Further development of this approach may yield a versatile biodegradable method of providing support.