Biocompatibility of latex and silicone T tubes in the porcine common bile duct: an experimental study.

Toxicity of materials used in indwelling drains or catheters has the potential to damage surrounding tissues. The biocompatibility of biliary T-tubes was investigated using in groups of piglets (total 30 animals). In group 1 (n=16) a choledochotomy was performed with insertion of a latex T-tube (n=6) or a silicone T-tube (n=8), or without a T-tube (n=2). In group 2 (n=14) the common bile duct (CBD) was 3/4-transected, and the lesion was sutured over a latex T-tube (n=4) or a silicone T-tube (n=5), or without a T-tube (n=5). The groups were reoperated upon after 2 and 6 weeks respectively, and the CBD was harvested for scanning electron microscopy and light microscopy. The T-tubes were examined for cell culture toxicity with a DNA synthesis inhibition test. According to the cell culture tests, latex T-tubes were toxic and silicone T-tubes nontoxic. T-tubes induced moderate to pronounced fibrosis and epithelial damage in the CBD wall, but did not induce excessive fibrosis or scarring at the site of CBD suture. In the 6-week study period, however, the grade of tissue reactions in the CBD did not correlate with the toxicity of the T-tube materials, but rather reflected a foreign body reaction and mechanical pressure. Although gross anatomical changes did not occur, neither material seemed to be completely harmless for porcine CBD wall.