CRYSTAL ADHERENCE TO URINARY CATHETER MATERIALS IN RATS

Crystal adherence to the surfaces of indwelling urinary catheter mater ials was investigated by scanning electron microscopy and immunofluore scence method. Small sterile disks were inserted into the rat bladder transvesically. Crystals were frequently associated with fibrillar mat erial, some of which was believed to be fibrin. Increases in fibrillar materials were paralleled by increases in crystal adherence. On the o ther hand, a decrease in the amount of fibrin adhering to the surfaces of heparinized material, resulting in a decrease in the quantity of e ncrusting deposits on these materials, was found as compared with othe r catheter materials, including latex, silicone and nonheparinized mat erial. These findings suggest that early adherence of fibrin to the su rfaces of indwelling urinary catheter materials plays an important rol e in the development of crystal adherence and encrustation on catheter materials. It is also suggested that heparin inhibits the adherence o f fibrin, resulting in decreased encrustation on the surfaces of the h eparinized material.