Ventriculoperitoneal Shunt Drainage Increases With Gravity and Cerebrospinal Fluid Pressure Pulsations: Benchtop Model.
CSF overdrainage
CSF pulsations
Cerebrospinal fluid (CSF) shunts
Hydrocephalus
Shunt malfunction
Shunt overdrainage
Shunt valve testing
Journal
Neurosurgery
ISSN: 1524-4040
Titre abrégé: Neurosurgery
Pays: United States
ID NLM: 7802914
Informations de publication
Date de publication:
18 11 2021
18 11 2021
Historique:
received:
19
03
2021
accepted:
09
07
2021
pubmed:
17
9
2021
medline:
24
3
2022
entrez:
16
9
2021
Statut:
ppublish
Résumé
There have been few improvements in cerebrospinal fluid (CSF) shunt technology since John Holter introduced the silicon valve, with overdrainage remaining a major source of complications. To better understand why valves are afflicted by supra-normal CSF flow rates. We present in Vitro benchtop analyses of flow through a differential pressure valve under simulated physiological conditions. The pseudo-ventricle benchtop valve testing platform that comprises a rigid pseudo-ventricle, compliance chamber, pulsation generator, and pressure sensors was used to measure flow rates through a differential pressure shunt valve under the following simulated physiological conditions: orientation (horizontal/vertical), compliance (low/medium/high), and pulsation generator force (low/medium/high). Our data show that pulse pressures are faithfully transmitted from the ventricle to the valve, that lower compliance and higher pulse generator forces lead to higher pulse pressures in the pseudo-ventricle, and that both gravity and higher pulse pressure lead to higher flow rates. The presence of a valve mitigates but does not eliminate these higher flow rates. Shunt valves are prone to gravity-dependent overdrainage, which has motivated the development of gravitational valves and antisiphon devices. This study shows that overdrainage is not limited to the vertical position but that pulse pressures that simulate rhythmic (eg, cardiac) and provoked (eg, Valsalva) physiological CSF pulsations increase outflow in both the horizontal and vertical positions and are dependent on compliance. A deeper understanding of the physiological parameters that affect intracranial pressure and flow through shunt systems is prerequisite to the development of novel valves.
Sections du résumé
BACKGROUND
There have been few improvements in cerebrospinal fluid (CSF) shunt technology since John Holter introduced the silicon valve, with overdrainage remaining a major source of complications.
OBJECTIVE
To better understand why valves are afflicted by supra-normal CSF flow rates. We present in Vitro benchtop analyses of flow through a differential pressure valve under simulated physiological conditions.
METHODS
The pseudo-ventricle benchtop valve testing platform that comprises a rigid pseudo-ventricle, compliance chamber, pulsation generator, and pressure sensors was used to measure flow rates through a differential pressure shunt valve under the following simulated physiological conditions: orientation (horizontal/vertical), compliance (low/medium/high), and pulsation generator force (low/medium/high).
RESULTS
Our data show that pulse pressures are faithfully transmitted from the ventricle to the valve, that lower compliance and higher pulse generator forces lead to higher pulse pressures in the pseudo-ventricle, and that both gravity and higher pulse pressure lead to higher flow rates. The presence of a valve mitigates but does not eliminate these higher flow rates.
CONCLUSION
Shunt valves are prone to gravity-dependent overdrainage, which has motivated the development of gravitational valves and antisiphon devices. This study shows that overdrainage is not limited to the vertical position but that pulse pressures that simulate rhythmic (eg, cardiac) and provoked (eg, Valsalva) physiological CSF pulsations increase outflow in both the horizontal and vertical positions and are dependent on compliance. A deeper understanding of the physiological parameters that affect intracranial pressure and flow through shunt systems is prerequisite to the development of novel valves.
Identifiants
pubmed: 34528096
pii: 6370902
doi: 10.1093/neuros/nyab336
pmc: PMC8600163
doi:
Types de publication
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
1141-1147Subventions
Organisme : NCI NIH HHS
ID : P30 CA014520
Pays : United States
Organisme : NCATS NIH HHS
ID : UL1 TR002373
Pays : United States
Informations de copyright
© Congress of Neurological Surgeons 2021.
Références
Pediatr Neurosurg. 1991-1992;17(1):2-9
pubmed: 1811706
J Neurosurg. 2014 Mar;120(3):697-707
pubmed: 24405071
Neurosurg Rev. 2018 Oct;41(4):969-981
pubmed: 28352945
J Am Coll Surg. 2001 Jan;192(1):79-85
pubmed: 11192928
J Neurosurg. 2018 Nov 1;:1-6
pubmed: 30497143
Pediatr Neurol. 2006 Mar;34(3):171-6
pubmed: 16504785
IEEE Trans Biomed Eng. 2014 Sep;61(9):2379-88
pubmed: 25148657
Pediatrics. 1998 Jun;101(6):1031-6
pubmed: 9606231
Neurosurgery. 1998 Aug;43(2):294-303; discussion 303-5
pubmed: 9696082
J Neurosurg Pediatr. 2017 Sep;20(3):216-224
pubmed: 28665241
J Neurosurg Pediatr. 2010 Jan;5(1):4-16
pubmed: 20043731
Acta Neurochir (Wien). 1978;45(1-2):89-101
pubmed: 742440
Childs Nerv Syst. 1995 Apr;11(4):193-202
pubmed: 7621479
J Neurosurg Pediatr. 2019 Sep 6;:1-10
pubmed: 31491755
Fluids Barriers CNS. 2011 Jan 18;8(1):5
pubmed: 21349153
J Neurosurg Pediatr. 2018 Nov 1;22(5):567-577
pubmed: 30117791
Neurosurg Focus. 2007 Apr 15;22(4):E5
pubmed: 17613194
Pediatr Neurol. 2006 Feb;34(2):83-92
pubmed: 16458818
Ann Neurol. 1980 Jun;7(6):508-14
pubmed: 7436357