EXPERIMENTAL ACUTE SUBDURAL-HEMATOMA IN INFANT PIGLETS

Traumatic acute subdural hematoma is associated with high mortality in the pediatric population, yet the pathophysiology remains poorly unde rstood. The objective of this study was to develop a pediatric model o f acute subdural hematoma, and to evaluate the resultant histopatholog ical changes in the brain. Ten 3-week-old piglets were studied. A 5-mm craniotomy was made in the right frontal skull. A small silastic tube was inserted through the underlying intact dura into the subdural spa ce. A craniotomy was made posterior to the right coronal suture with u nderlying dura left intact (closed cranial window model). Injection of 5 ml autologous, nonheparinized blood was accomplished through the si lastic tube. Animals were sacrificed after 72 h or 1 week. During the subdural injection, intracranial pressure rose to 62 +/- 8 mm Hg, and returned to baseline within 1 h of surgery. Mean arterial blood pressu re increased transiently. Cresyl violet and hematoxyIin and eosin stai ning demonstrated extensive areas of white matter necrosis under the h ematoma after 72 h survival (n = 7). Zones of necrosis were also noted in cortex, but were less extensive than those seen in white matter. T hese results differ from adult rodent models in which cortex is primar ily affected. This is the first reported pediatric model of traumatic acute subdural hematoma. This model can be used in future studies to i nvestigate pharmacological or other therapies which may improve outcom e after this type of injury.