Cortical Subarachnoid Space Important in Hydrocephalus
Shunt with adjustable valve fails to prevent development of slit-like ventricles
MONDAY, July 7 (HealthDay News) -- In the management of hydrocephalus, the role of the cortical subarachnoid space has been largely ignored and the use of a shunt with an adjustable valve does not prevent the development of slit-like ventricles, according to two studies published in the July issue of the Journal of Neurosurgery: Pediatrics.
In one study, Harold L. Rekate, M.D., of St. Joseph's Hospital and Medical Center in Phoenix, Ariz., and colleagues used the solid geometry of concentric spheres to assess the magnitude of the contribution of the cortical subarachnoid space. They conclude that greater attention to cerebral spinal fluid dynamics will lead to improvements in the understanding of hydrocephalus and the selection criteria for interventions such as endoscopic third ventriculostomy.
In a second study, Martin R. Weinzierl, M.D., of University Hospital RWTH in Aachen, Germany, and colleagues studied 15 infants who underwent initial shunt placement and followed them for 24 months. In a majority of patients, they found that the adjustable differential-pressure valve used in the study was not effective in preventing slit-like ventricles.
"The present study shows rather convincingly that over-drainage cannot be prevented by the active reprogramming of the valve mechanism to higher settings in this specific valve design," Rekate writes in editorial accompanying the Weinzierl article. "The goal of normalizing ventricle size in an attempt to prevent intermittent proximal obstruction or slit ventricle syndrome is a worthwhile effort. I encourage the authors to redo the study with several shunt designs. In this situation, a randomized controlled trial of the multiple shunt designs for adjustable valves would be very valuable, and sooner rather than later."
Rekate is contracted with the Codman Corporation to assist in the development of shunt systems, and also oversees an educational grant for the training of neurosurgeons from outside of North America in CSF dynamics.