The Stability of Armature Wire to Maintain the Y-Shaped Chest Tube Curvature at Physiologic Temperature

Background: The Y-shaped chest tube with split ends divides within the thoracic cavity, permitting both mediastinal and pleural placement with a single exit port. To maintain the curvature of the pleural tube, we have employed the Jack Richeson 1/16” armature wire. This study tests the migration of the pleural tube due to the expansion of the armature wire at physiologic temperature. The purpose of this study is to provide insight into determining the appropriate biomaterial for the novel Y-shaped chest tube. Methods: This study contains separate experiments for five luminal sizes (20, 24, 28, 32, and 36Fr) of silicone catheter tubes, each wrapped with armature wire. A heated water bath was created with a Cole Parmer Immersion Circulator heater. Tubes were placed in the bath for 24 hours to test the angle changes at the proximal split point and the distal pleural end. Two sets of data were collected for each size, physiologic temperature (n=5) and room temperature (n=5). Results: The tube displacement was measured at proximal and distal sites. Values are compared by ANOVA. Proximal measurements: There is no significant difference in displacement between room and physiologic temperatures (P=0.095). Using the Newman-Keuls method of pairwise multiple comparison, the difference in mean values among the different luminal diameters were noted (within 23.33°C: 32Fr vs. 24 Fr P=0.004; within 37°C: 32Fr vs. 20Fr P=0.012, 32Fr vs. 24Fr P=0.018, 32Fr vs. 28Fr P=0.015, 32Fr vs. 36Fr P=0.028; within both temperatures: 32Fr vs. 20Fr P=0.007, 32Fr vs. 24Fr PDistal measurements: There is no significant difference in displacement between room and physiologic temperatures (P=0.423). There is no significant difference in displacement among the different tube diameters (P=0.073). The effect of different levels of temperature does not depend on which tube luminal diameter is present (P=0.593). Conclusions: These data suggest that change in temperature will not significantly affect the wire to cause tube migration. However, it is noticed that the tube diameter has a significant effect on its migration. Thus, further studies need to be completed to determine the extent of this effect.