EFFECTS OF GALLSTONE SOLVENTS ON COMMONLY USED CATHETERS

PURPOSE: To determine what interaction and effect different cholestero l gallstone solvents have on catheters used for gallstone chemolysis. MATERIALS AND METHODS: Five types of catheters used for biliary proced ures were chosen: polyethylene, Percuflex, silicone, Silitek, and poly urethane. The solvents chosen were methyl tert-butyl ether, ethyl prop ionate, isopropyl acetate, and N-propyl acetate. After incubation of t he catheters in the solvents for 72 hours, they were air dried. Weight and area changes were determined for each catheter. Additionally, car bon-13 nuclear magnetic resonance (NMR) spectroscopy was performed for analysis of composition changes. RESULTS: Three catheters-silicone, S ilitek, and polyurethane-showed changes in their physical characterist ics that would make them less desirable for stone chemolysis. The sili cone catheter showed changes in elastic texture as well as a marked we ight reduction. The Silitek and polyurethane catheters had similar, bu t less dramatic changes. C-13 NMR analysis of collected solvents showe d that commonly used plasticizers were leached out of some catheters. CONCLUSION: These results suggest that all catheters are not suitable for use with all solvents. The choice of catheter should be made based on the solvent in use. The polyethylene catheter performed best under the conditions and endpoints used in this study.