Long-term effects of polytetrafluoroethylene injected into the rat bladder submucosa

The use of polytetrafluoroethylene (PTFE) paste in the lower urinary tract for the treatment of vesicoureteral reflux or urinary incontinence is increasing. Its use remains controversial and the long-term consequence of this substance injected into the lower urinary system of humans is largely unknown. When injected into the bladder submucosa, PTFE paste has been shown to elicit a foreign body reaction with chronic inflammation and possibly granuloma formation. Whether these inflammatory changes result in neoplastic changes over the long term has yet to be determined. The purpose of this study was to evaluate histologically the potential for submucosal PTFE paste to induce bladder neoplasia in a rodent model, realizing that others have shown an increased tendency for such alloplastic materials to produce sarcomas in these animals.

Sixteen experimental animals and 4 control animals were sacrificed at various time intervals and evaluated for systemic and local tumor formation following submucosal injection of PTFE paste in the bladder. A time well beyond the equivalent of the latency period believed to be necessary for the induction of tumors in humans (15 months) was evaluated.

On sacrifice, histologic changes consistent with encapsulation and chronic inflammation were evident, but there was no evidence of either epithelial or sarcomatous tumor formation.

A quiescent foreign body reaction occurs when injecting PTFE into the bladder submucosa of rodents. Urologic use of PTFE has never been proven to induce tumors in humans or animals.