Influence of head-over-body and body-over-head posture on craniospinal, vascular, and abdominal pressures in an acute ovine in-vivo model
Abstract
Introduction 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.
Methods 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.
Results 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.
Conclusions 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. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000625123Publication status
publishedExternal links
Journal / series
Fluids and Barriers of the CNSVolume
Pages / Article No.
Publisher
BioMed CentralSubject
Arterial blood pressure; Cerebrospinal fluid; Hydrocephalus; Intracranial pressure; Sheep model; Transfer function; Tilt testingOrganisational unit
09563 - Zeilinger, Melanie / Zeilinger, Melanie
03943 - Meboldt, Mirko / Meboldt, Mirko
Funding
184913 - Quantitative study on the pathophysiology of hydrocephalus (SNF)
Related publications and datasets
Is supplemented by: https://doi.org/10.3929/ethz-b-000623698
More
Show all metadata