SAFETY AND EFFICACY STUDY OF A NOVEL HIGH VACUUM CHEST DRAINAGE SYSTEM

Objectives: To assess safety and efficacy of a novel high-vacuum chest drainage system (HVCDS) compared to a conventional chest drainage system (CCDS). Methods: Four anesthetized 40kg pigs underwent a median stemotomy. Three drains were placed in retro-cardiac, retro-sternal and left pleural positions. Two animals received HVCDS (22Fr with 180 2mm-holes; Medela AG, CH), the remaining CCDS (28Fr-Atrium). After chest closure the animals had three 30-min runs of artificial bleeding by infusion of citrate blood (4mL/min) under different aspiration pressures (2,20,40kPa) for both groups, followed by a standardized surgical bleeding (40kPa-HVCDS, 2kPa-CCDS). The output of all drains, as well as the hemodynamic parameters, were registered every 5 minutes. The amount of residual blood was also measured. After euthanasia all drains, the heart and left lung underwent macroscopic and/or histo-pathological examination. Results: The application of the different pressures showed neither hemodynamic changes nor differences in blood drainage with both systems during blood infusion and surgical bleeding. HVCDS had a trend to lower residual post-drainage blood: 10(0-15)mL vs. 16(5-25)mL (p=0.051). However, all HVCDS catheters showed relevant clotting. Application of 20kPa and 40kPa caused macroscopic epicardial and pulmonary lesions (chest tube holes) in both systems. Sub-epicardial or sub-pleural hemorrhage (depth 0.7mm) without myocyte or alveolar damage was found by histology. Conclusions: Both systems showed adequate equal drainage, despite marked chest tube clotting in HVCDS. High-pressure drainage with both systems showed focal sub-epicardial and sub-pleural bleeding. Thus, the long-term assessment of high-pressure chest drainage and potential interaction with fragile structure such as CABG graft should be carried out.