The role of catheter surface morphology and extractable cytotoxic material in tissue reactions to urethral catheters.

Batches of urethral catheters associated with stricture formation during clinical usage were found to be amongst those causing marked acute and chronic inflammation after subcutaneous implantation in rats. The degree of inflammation did not correlate with the surface roughness of catheters assessed by scanning electron microscopy, but showed an excellent correlation with the cytotoxic effects of soluble extracts from catheters on macrophage monolayers in tissue culture. The findings suggest that stricture formation may be chemically induced and may not relate to surface roughness of catheters.