Department of Mechanical and Process Engineering, ETH Zurich, Zurich, Switzerland.
Center for Surgical Research, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
Fluids Barriers CNS. 2023 Aug 2;20(1):58. doi: 10.1186/s12987-023-00458-9.
Optimal shunt-based hydrocephalus treatments are heavily influenced by dynamic pressure behaviors between proximal and distal ends of shunt catheters. Posture-dependent craniospinal, arterial, venous, and abdominal dynamics thereby play an essential role.
An in-vivo ovine trial (n = 6) was conducted to evaluate communication between craniospinal, arterial, venous, and abdominal dynamics. Tilt-testing was performed between -13° and + 13° at 10-min intervals starting and ending at 0° prone position. Mean pressure, pulse pressure, and Pearson correlation (r) to the respective angle were calculated. Correlations are defined as strong: |r|≥ 0.7, mild: 0.3 <|r|< 0.7, and weak: |r|≤ 0.3. Transfer functions (TFs) between the arterial and adjacent compartments were derived.
Strong correlations were observed between posture and: mean carotid/femoral arterial (r = - 0.97, r = - 0.87), intracranial, intrathecal (r = - 0.98, r = 0.94), jugular (r = - 0.95), abdominal cranial, dorsal, caudal, and intravesical pressure (r = - 0.83, r = 0.84, r = - 0.73, r = 0.99) while mildly positive correlation exists between tilt and central venous pressure (r = 0.65). Only dorsal abdominal pulse pressure yielded a significant correlation to tilt (r = 0.21). TFs followed general lowpass behaviors with resonant peaks at 4.2 ± 0.4 and 11.5 ± 1.5 Hz followed by a mean roll-off of - 15.9 ± 6.0 dB/decade.
Tilt-tests with multi-compartmental recordings help elucidate craniospinal, arterial, venous, and abdominal dynamics, which is essential to optimize shunt-based therapy. Results motivate hydrostatic influences on mean pressure, with all pressures correlating to posture, with little influence on pulse pressure. TF results quantify the craniospinal, arterial, venous, and abdominal compartments as compliant systems and help pave the road for better quantitative models of the interaction between the craniospinal and adjacent spaces.
分流相关脑积水的最佳治疗方案受到分流导管近端和远端之间动态压力行为的严重影响。因此，姿势依赖性的颅脊内、动脉、静脉和腹部动力学发挥着至关重要的作用。
进行了一项体内绵羊试验（n=6），以评估颅脊内、动脉、静脉和腹部动力学之间的沟通。在 0°俯卧位开始和结束时，以 10 分钟为间隔，从-13°倾斜至+13°进行倾斜测试。计算平均压力、脉搏压力和与相应角度的皮尔逊相关系数（r）。相关性定义为强：|r|≥0.7，轻度：0.3<|r|<0.7，弱：|r|≤0.3。推导了动脉与相邻隔室之间的传递函数（TFs）。
观察到姿势与以下参数之间存在强相关性：颈动脉/股动脉平均压（r=-0.97，r=-0.87）、颅内压、鞘内压（r=-0.98，r=0.94）、颈内静脉压（r=-0.95）、腹部颅脊、背侧、尾侧和膀胱内压（r=-0.83，r=0.84，r=-0.73，r=0.99），而倾斜与中心静脉压（r=0.65）之间存在轻度正相关。只有背侧腹部脉搏压力与倾斜具有显著相关性（r=0.21）。TFs 遵循一般的低通行为，具有 4.2±0.4Hz 和 11.5±1.5Hz 的谐振峰，然后平均滚降-15.9±6.0dB/decade。
多隔室记录的倾斜测试有助于阐明颅脊内、动脉、静脉和腹部动力学，这对于优化分流相关治疗至关重要。结果表明，静水压力对平均压力有影响，所有压力都与姿势相关，对脉搏压力的影响较小。TF 结果将颅脊内、动脉、静脉和腹部隔室量化为顺应性系统，为更好地定量模型化颅脊内和相邻空间之间的相互作用铺平了道路。
