Related Experiment Videos
Negative-pressure hydrocephalus
M Vassilyadi1, J P Farmer, J L Montes
1Department of Neurosurgery, Montreal Children's Hospital, Quebec, Canada.
Insights
Children with myelodysplasia and shunted hydrocephalus developed complications after spinal arachnoid cystopleural shunting. Revision of shunts resolved craniovertebral symptoms and ventricular dilation by correcting pressure gradients.
Area of Science:
- Neurosurgery
- Pediatric Neurology
- Cerebrospinal Fluid Dynamics
Background:
- Presents two pediatric cases with closed myelodysplasia, Arnold-Chiari malformation, and shunted hydrocephalus.
- Focuses on complications following spinal arachnoid cystopleural shunting.
Observation:
- Postoperative craniovertebral symptoms and ventricular dilation occurred despite functional ventriculoperitoneal (VP) shunts and negative intracranial pressure.
- These symptoms resolved after revising the cystopleural shunts to increase flow resistance.
Findings:
- Hypothesizes communication between the arachnoid cyst and subarachnoid space, leading to preferential transmission of negative pleural pressure.
- Suggests the development of a transmantle pressure gradient causing ventricular dilation and a craniospinal gradient causing craniovertebral symptoms.
- Demonstrates that correcting the iatrogenic transmantle pressure gradient restored VP shunt function.
Implications:
- Highlights the potential for negative pleural pressure to affect intracranial dynamics in specific pediatric neurosurgical cases.
- Underscores the importance of shunt resistance and pressure gradients in managing complex cerebrospinal fluid disorders.
- Suggests careful consideration of shunt mechanics and potential pressure transmission in patients with combined spinal and intracranial abnormalities.
Abstract:
Two cases of children with closed myelodysplasia, Arnold-Chiari malformation, and shunted hydrocephalus who underwent spinal arachnoid cystopleural shunting are presented. Postoperatively, both patients developed craniovertebral symptomatology accompanied by radiologically documented ventricular dilation in spite of negative intracranial pressure and functional ventriculoperitoneal (VP) shunts. Both patients recovered after the cystopleural shunts were revised to increase the resistance to flow within the system. The authors believe that some communication between the arachnoid cyst and the subarachnoid space existed in both cases and that the negative pleural pressure was transmitted preferentially to the spinal and cerebral convexity subarachnoid spaces with relative sparing of the ventricular system. A transmantle pressure gradient was thereby established, leading to ventricular dilation. The authors further suggest that a craniospinal gradient was possibly established as well, leading to craniovertebral symptomatology in the patients. Return of flow in the VP shunts was obtained by correcting this iatrogenic transmantle pressure gradient.