Department of Biomedical Engineering, Tel Aviv University, Tel Aviv, Israel.
Department of Neurosurgery, Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Lenox Hill Hospital, 130 77th street, New York, NY, USA.
Neurocrit Care. 2022 Dec;37(3):689-696. doi: 10.1007/s12028-022-01541-z. Epub 2022 Jul 19.
Brain oxygenation improvement is a sought-after goal in neurocritical care patients. Previously, we have shown that cerebral blood flow improvement by cardiac-gated intracranial pressure (ICP) modulation using an intracranial pulsating balloon is feasible in a swine model. We sought to explore specific ICP modulation protocols to assess the feasibility of influencing brain oxygenation.
A previously presented electrocardiogram (ECG)-gated intracranial balloon pump in which volume, timing, and duty cycle of balloon inflation could be altered was used. Different protocols were tested in a swine model of normal and elevated ICP attained by intracranial fluid infusion with continuous monitoring of physiological parameters, and brain tissue oxygen tension (PbtO) was measured at baseline and after device activation.
We studied five swine, subjected to two main protocols differing in their phase relative to the cardiac cycle. In reduced brain perfusion status (ICP > 20 mm Hg, PbtO < 15 mm Hg), the late-diastolic-early-systolic (Inflation/deflation) protocol showed consistent elevation in PbtO (+ 9%, p < 0.01), coupled with ICP reduction (- 12%, p < 0.01), whereas the early-systolic-late-diastolic (inflation/deflation) protocol resulted in PbtO reduction (- 4%, p < 0.01), coupled with ICP increase (+ 5% above baseline, p < 0.01). No significant changes in brain oxygenation or ICP were observed at normal perfusion status (ICP < 20 mm Hg, PbtO > 15 mm Hg).
Intracranial cardiac-gated balloon pump activation can influence cerebral oxygenation and raise PbtO above threshold values. This study supports the concept of late-diastolic pressure rise, coupled with early-systolic pressure drop, as a potential effector of flow augmentation leading to improve brain tissue oxygenation. Further studies are warranted to assess the translational potential of using an intracranial cardiac-gated balloon pump device to improve brain tissue oxygenation.
在神经危重病患者中，脑氧合的改善是一个备受关注的目标。此前，我们已经证明，在猪模型中，通过使用颅内搏动性气球进行心脏门控颅内压（ICP）调节，可以实现脑血流的改善。我们试图探索特定的 ICP 调节方案，以评估影响脑氧合的可行性。
使用之前展示过的心电图（ECG）门控颅内气球泵，该泵可以改变气球充气的体积、时间和占空比。在通过颅内液输注获得正常和升高的 ICP 的猪模型中测试了不同的方案，并在基线和设备激活后连续监测生理参数和脑氧张力（PbtO）。
我们研究了 5 头猪，采用了两种主要的方案，它们在与心动周期的关系上有所不同。在脑灌注状态降低（ICP>20mmHg，PbtO<15mmHg）时，舒张晚期-收缩早期（充气/放气）方案显示 PbtO 持续升高（+9%，p<0.01），同时 ICP 降低（-12%，p<0.01），而收缩早期-舒张晚期（充气/放气）方案导致 PbtO 降低（-4%，p<0.01），同时 ICP 升高（比基线升高 5%，p<0.01）。在正常灌注状态（ICP<20mmHg，PbtO>15mmHg）下，脑氧合或 ICP 没有明显变化。
颅内心脏门控气球泵的激活可以影响脑氧合，并使 PbtO 升高到阈值以上。这项研究支持舒张末期压力升高，同时收缩早期压力下降的概念，作为一种潜在的增加血流的效应器，从而改善脑组织氧合。需要进一步的研究来评估使用颅内心脏门控气球泵装置改善脑组织氧合的转化潜力。
