A polyethylene glycol grafted bi-layered polyurethane scaffold: preliminary study of a new candidate prosthesis for repair of a partial tracheal defect.

The purpose of this study was to develop an artificial prosthesis for use in the reconstruction of a tracheal defect due to trauma, malignancy, stenosis, or other causes. Bi-layered porous-dense film polyurethane (PU) was manufactured for the main framework. Polyethylene glycol (PEG) was grafted onto the inner surface of the PU scaffold to act as a surfactant. The scaffold was transplanted into three beagles. An endoscopic examination was performed for the evaluation of the formation granulation tissue, to evaluate the status of the respiratory mucosa and the amount of crust at 1, 4, 8, and 12 weeks after surgery. A histological examination was also performed at 4, 8, and 12 weeks after surgery. All three beagles studied survived to the expected date. The endoscopic examination showed formation of granulation tissue; the crust was not very severe and the circular tracheal framework was well preserved. The histological examination showed that a large amount of fibrous tissue had grown through the pores of the porous scaffold. Pseudostratified columnar ciliated mucosa was also noted on the surface of scaffold, as visualized by scanning electron microscopy. The use of a bi-layered polyethylene grafted polyurethane scaffold is a good candidate prosthesis for tracheal reconstruction.