In vivo biocompatibility of catheter materials

The inflammatory response to four different catheter materials was quantitatively characterized using an in vivo cage implant system over a 21 d implantation period. The greatest differences between materials were observed at day 4, where the total leucocyte concentration in the exudate decreased in the following order: AE-PVC greater than A-PU greater than D-PU1 greater than D-PU2. Similar trends were observed for the polymorphonuclear leucocyte (PMN) and macrophage concentrations at day 4. At day 7, this trend continued, but by day 21 the total leucocyte concentration, PMN concentration and macrophage concentration had decreased to comparable values for all materials. The extracellular alkaline phosphatase activity at day 4 was lowest for the AE-PVC exudate samples. Similar results were observed for the extracellular acid phosphatase activity but after that time point no significant differences were observed. From these results, it appears that AE-PVC is least biocompatible compared with the other three catheter materials, which were polyurethanes.