Tracheal reconstruction with polytetrafluoroethylene vascular grafts in mongrel dogs

Abstract

Polytetrafluoroethylene (PTFE) vascular grafts were used for reconstruction of the trachea in ten Mongrel dogs and the biocompatibility of the grafts were ex¬amined by light and scanning electron microscopy (SEM). In all dogs, a long tra-cheal segment was resected and replaced with a PTFE reinforced vascular graft. All dogs died of sepsis and respiratory distress within 9 to 48 days. Subcutaneous emphysema was present in all. Necropsy showed purulent collection in the neck, trachea and the graft, and a large amount of granulation tissue at the tracheal anastomosis..The graft was dislodged from the trachea in 3 dogs due to separation of the suture line. Light microscopy revealed inflammatory cells, bacteria -mainly E. Coli- and fibrin accumulation on the luminal surface of the trachea. The lumi-nal surface of the grafts possessed no epithelium but was covered with fibrin and necrotic material which also filled the micropores in the wall of the graft. SEM ex¬amination of one graft revealed accumulation of fibrillar material and bacteria-like structures on the luminal surface of the graft. The results indicate that PTFE vascular grafts cause severe infection and granulation, therefore, are not suitable for tracheal reconstruction.