[Improving the design of an alloplastic epithelialized tracheal prosthesis]

Replacement of the tracheal conduit remains an unresolved problem. The microporous material expanded polytetrafluorethylene (ePTFE) is suitable for tracheal reconstruction. The aim of our study was to improve the limited mechanical properties of this material by incorporating reinforcement elements and to examine the influence of these elements on host incorporation and epithelialization. In so dours ePTFE prostheses were reinforced with lonomer cement and porous high density polyethylene (pHDPE) rings and implanted into the neck muscle of miniature pigs. One of these prostheses was epithelialized by a cell seeding technique and was thus placed into a tracheal defect. Results were examined grossly by endoscopy and than by light and scanning electron microscopy. The shapes of both types of prostheses showed a high stability. The reinforcement elements did not impair bioincorporation or the ability to epithelialize. In vivo interposition of an incorporated and epithelialized prosthesis to a host led to cell differentiation. The improved biomechanical properties of the prostheses waid and the reproducible formation of epitheliums are important advances in the solution of effectively correcting tracheal defects.