Ganushchak Y M, Ševerdija E E, Simons A P, van Garsse L, Weerwind P W
Dept. of Cardiothoracic Surgery, Cardiovascular Research Institute Maastricht - CARIM, Maastricht University Medical Center, Maastricht, the Netherlands.
Perfusion. 2012 May;27(3):176-82. doi: 10.1177/0267659112437902. Epub 2012 Feb 15.
Although a growing body of evidence indicates superiority of minimized cardiopulmonary bypass (mCPB) systems over conventional CPB systems, limited venous return can result in severe fluctuations of venous line pressure which can result in gaseous emboli. In this study, we investigated the influence of sub-atmospheric pressures and volume buffer capacity added to the venous line on the generation of gaseous emboli in the mCPB circuit. Two different mCPB systems (MEC - Maquet, n=7 and ECC.O - Sorin, n=8) and a conventional closed cardiopulmonary bypass (cCPB) system (n=12) were clinically evaluated. In the search for a way to increase volume buffer capacity of mCPB systems, we additionally evaluated the 'Better Bladder' (BB) in a mock circulation by simulating, repeatedly, decreased venous return while measuring pressure and gaseous embolic activity. Arterial gaseous emboli activity during clinical perfusion with a cCPB system was the lowest in comparison to the mCPB systems (312±465 versus 311±421 with MEC and 1,966±1,782 with ECC.O, counts per 10 minute time interval, respectively; p=0.03). The average volume per bubble in the arterial line was the highest in cases with cCPB (12.5±8.3 nL versus 8.0±4.2 nL with MEC and 4.6±4.8 nL with ECC.O; p=0.04 for both). Significant cross-correlation was obtained at various time offsets from 0 to +35 s between sub-atmospheric pressure in the venous line and gaseous emboli activity in both the venous and arterial lines. The in vitro data showed that incorporation of the BB dampens fluctuations of venous line pressure by approximately 30% and decreases gaseous emboli by up to 85%. In conclusion, fluctuations of sub-atmospheric venous line pressure during kinetic-assisted drainage are related to gaseous emboli. Volume buffer capacity added to the venous line can effectively dampen pressure fluctuations resulting from abrupt changes in venous return and, therefore, can help to increase the safety of minimized cardiopulmonary bypass by reducing gaseous microemboli formation resulting from degassing.
尽管越来越多的证据表明，与传统体外循环（CPB）系统相比，微创体外循环（mCPB）系统具有优越性，但静脉回流受限可能导致静脉管路压力剧烈波动，进而引发气体栓塞。在本研究中，我们调查了静脉管路中负压及添加的容量缓冲能力对mCPB回路中气体栓塞形成的影响。对两种不同的mCPB系统（MEC - 迈柯唯，n = 7；ECC.O - 索林，n = 8）和一种传统的闭合式体外循环（cCPB）系统（n = 12）进行了临床评估。为寻求增加mCPB系统容量缓冲能力的方法，我们还通过反复模拟静脉回流减少，同时测量压力和气体栓塞活性，在模拟循环中对“改良膀胱”（BB）进行了评估。与mCPB系统相比，cCPB系统在临床灌注期间动脉气体栓塞活性最低（分别为每10分钟时间间隔312±465次、MEC为311±421次、ECC.O为1,966±1,782次；p = 0.03）。cCPB病例中动脉管路中每个气泡的平均体积最大（12.5±8.3 nL，MEC为8.0±4.2 nL，ECC.O为4.6±4.8 nL；两者p = 0.04）。在静脉管路中的负压与静脉和动脉管路中的气体栓塞活性之间，在从0到 +35秒的不同时间偏移处获得了显著的互相关性。体外数据表明，加入BB可使静脉管路压力波动降低约30%，并使气体栓塞减少多达85%。总之，动力辅助引流期间静脉管路负压波动与气体栓塞有关。添加到静脉管路的容量缓冲能力可有效抑制因静脉回流突然变化而导致的压力波动，因此，通过减少脱气产生的气体微栓形成，有助于提高微创体外循环的安全性。
