IMPROVED DRAINAGE DEVICE FOR CARDIOTHORACIC SURGERY

Purpose: The objectives of this preclinical study are (1) to compare the effectiveness of a novel, Y-shaped, split chest tube vs. conventional, separate tubes to drain pleural and mediastinal effusions following midsternal thoracotomy and thoracic closure; (2) to evaluate the impact of fluid viscosity on the respective abilities of these two tubing configurations to drain the thorax. Methods: A Y-shaped chest tube was developed that allowed for a single incision site while still accommodating separate intrathoracic drainage sites. The split chest drain vs. conventional dual chest drains were compared based on the rate and efficiency of fluid drainage. After sternotomy, pericardiotomy, and left pleurotomy, three domestic pigs (50-60 kg) were fitted sequentially with the Y-shaped tubing and then the separate chest drains to test both configurations in the same animal. The intrathoracic openings of both configurations were positioned in the mediastinum and in the costodiaphragmatic recess, where post-thoracotomy effusions usually accumulate. One liter of 0.58 M sucrose solution, with a viscosity 1.8 times that of pure water and approximating that of plasma, was infused into the thorax and drainage suction was applied at -20 cm H2O for 30 min. Drained volume (mean ± SD) was measured at 1, 5, 10, 20, and 30 minutes to evaluate the efficiency of fluid drainage. Results: Within one minute, the split drain evacuated more fluid (743 ± 556 ml) than the separate drains (630 ± 135 ml). By 30 minutes, the split drain had removed more fluid (1123 ± 71 ml) and left a lower residual volume (22 ± 19 ml) than the separate drains (1120 ± 27 and 43 ± 38 ml, respectively). Results of the current study are being compared with our previous study of low-viscosity D5W in which the Y-shaped tube drained 442 ± 251 ml in the first minute and 1056 ± 60 ml after 30 minute, with a residual volume of 19 ± 24 ml, versus respective values of 194 ± 163, 886 ± 280 and 208 ± 213 ml with separate drains. Conclusions: Initial results of this ongoing study suggest the split chest tube drained the thoracic cavity more effectively than the conventional separate chest tubes, and that the split tube afforded more efficient drainage than the separate tubes when draining fluids of two different viscosities. This new drainage device could potentially reduce postoperative complications of tamponade and residual pleural effusions.